Fa: Neurology - Anatomy & Physiology

Front 1

What are the characteristics of neuron regeneration?

Back 1

Neurons are permanent cells - do not divide in adulthood and have no progenitor stem cells

Front 2

What are the structural components of a neuron?

Back 2

- Dendrites: receive input
- Cell bodies
- Axons: send output

Front 3

How can you stain neurons?

Back 3

Stain the Nissl substance (stains RER which is found in cell bodies and dendrites, but not in axons)

Front 4

What happens if an axon is injured?

Back 4

Undergoes Wallerian Degeneration:
- Degeneration distal to injury and axonal retraction proximally
- Allows for potential regeneration of axon (if in PNS)

Front 5

What are the functions of astrocytes?

Back 5

- Physical support
- Repair
- K+ metabolism
- Removal of excess NT
- Blood-brain barrier
- Glycogen fuel reserve buffer
- Reactive gliosis in response to neural injury

Front 6

What is the marker of astrocytes?

Back 6

GFAP

Front 7

What are astrocytes derived from?

Back 7

Neuroectoderm

Front 8

What are the phagocytes in the CNS? Origin?

Back 8

Microglia - originate from mesoderm

Front 9

What is the appearance of a microglia? Stain?

Back 9

- Not readily discernible in Nissl stains
- Have small irregular nuclei and relatively little cytoplasm

Front 10

What are the functions of microglia?

Back 10

- Phagocytosis in CNS
- Scavenger cells
- Respond to tissue damage by differentiating into large phagocytic cells
- Part of the mononuclear phagocyte system

Front 11

Which type of glial cell can be infected with HIV? Implications?

Back 11

HIV infected microglia fuse to form multi-nucleated giant cells in the CNS

Front 12

What kinds of cells increase the conduction velocity of signals transmitted down axons?

Back 12

Myelin:
- Oligodendrocytes (CNS)
- Schwann cells (PNS)

Front 13

What is the function of myelin?

Back 13

- ↑ conduction velocity of signals transmitted down axons
- Results in saltatory conduction of AP between nodes of Ranvier

Front 14

What are the findings of the Nodes of Ranvier?

Back 14

High concentrations of Na+ channels

Front 15

What kind of cell myelinates the axons of neurons in the CNS? Characteristics?

Back 15

Oligodendroglia
- Each one can myelinate many axons (~30)

Front 16

What are oligodendroglia derived from?

Back 16

Neuroectoderm

Front 17

What is the appearance of oligodendroglia histologically?

Back 17

Fried egg appearance on H&E stain

Front 18

What diseases are associated with injury to oligodendroglia?

Back 18

- Multiple Sclerosis
- Progressive Multifocal Leukoencephalopathy (PML)
- Leukodystrophies

Front 19

What kind of cell myelinates the axons of neurons in the PNS? Characteristics?

Back 19

Schwann Cells
- Each one can myelinate only axon

Front 20

What is the function of Schwann cells?

Back 20

- Myelinates 1 PNS axon
- Promotes axonal regeneration
- ↑ Conduction velocity via saltatory conduction between nodes of Ranvier, where there are high concentrations of Na+ channels

Front 21

What are Schwann cells derived from?

Back 21

Neural crest

Front 22

What diseases are associated with injury to Schwann cells?

Back 22

- Guillain-Barré syndrome
- Acoustic Neuroma (type of Schwannoma)

Front 23

What are the characteristics of an Acoustic Neuroma? What is it associated with?

Back 23

- Type of Schwannoma
- Typically located in internal acoustic meatus (CN VIII)
- If bilateral, strongly associated with neurofibromatosis type 2

Front 24

What are the types of sensory corpuscles?

Back 24

- Free nerve endings
- Meissner corpuscles
- Pacinian corpuscles
- Merkel discs

Front 25

What sensory corpuscles are responsible for sensing pain and temperature?

Back 25

Free Nerve Endings
- C - slow, unmyelinated fibers
- Aδ - fast, myelinated fibers

Front 26

What sensory corpuscles are responsible for sensing dynamic, fine/light touch and position sense?

Back 26

Meissner Corpuscle
- Large, myelinated fibers, adapt quickly

Front 27

What sensory corpuscles are responsible for sensing vibration and pressure?

Back 27

Pacinian Corpuscle
- Large, myelinated fibers, adapt quickly

Front 28

What sensory corpuscles are responsible for sensing pressure, deep static touch (eg, shapes, edges), and position sense?

Back 28

Merkel Discs
- Large, myelinated fibers, adapt slowly

Front 29

What kind of fibers have free nerve endings? Characteristics?

Back 29

- C: slow, unmyelinated fibers
- Aδ: fast, myelinated fibers

Front 30

What kind of fibers connect to Meissner Corpuscles? Characteristics?

Back 30

Large, myelinated fibers that adapt quickly
(same as Pacinian Corpuscle)

Front 31

What kind of fibers connect to Pacinian Corpuscles? Characteristics?

Back 31

Large, myelinated fibers that adapt quickly
(same as Meissner Corpuscle)

Front 32

What kind of fibers connect to Merkel Discs? Characteristics?

Back 32

Large, myelinated fibers that adapt slowly

Front 33

What do free nerve endings sense? Location?

Back 33

- Sense: pain and temperature
- Location: all skin, epidermis, some viscera

Front 34

What do Meissner Corpuscles sense? Location?

Back 34

- Sense: dynamic, fine/light touch and position sense
- Location: glabrous (hairless) skin

Front 35

What do Pacinian Corpuscles sense? Location?

Back 35

- Sense: vibration and pressure
- Location: deep skin layers, ligaments, and joints

Front 36

What do Merkel Discs sense? Location?

Back 36

- Sense: pressure, deep static touch (eg, shapes and edges), and position sense
- Location: basal epidermal layer and hair follicles

Front 37

What layer of tissue surrounds single nerve fibers?

Back 37

Endoneurium

Front 38

What layer of tissue surrounds a fascicle of nerve fibers?

Back 38

Perineurium

Front 39

What layer of tissue surrounds the entire nerve?

Back 39

Epineurium (dense CT) - surrounds fascicles and blood vessels)

Front 40

Where does inflammatory infiltrate get in Guillain-Barré Syndrome?

Back 40

Gets into endoneurium (that surrounds single nerve fiber layers)

Front 41

What layer of tissue surrounding nerve fibers must be rejoined in microsurgery for limb reattachemnt?

Back 41

Perineurium (surrounds a fascicle of nerve fibers)

Front 42

Does the endoneurium, perineurium, or epineurium form the permeability barrier?

Back 42

Perineurium

Front 43

What are the types of NTs?

Back 43

- Norepinephrine
- Dopamine
- 5-HT
- ACh
- GABA

Front 44

What diseases affect the level of norepinephrine? How is it changed? Location of synthesis?

Back 44

Norepinephrine:
- ↑ in anxiety
- ↓ in depression

Synthesized in locus ceruleus (pons)

Front 45

What diseases affect the level of dopamine? How is it changed? Location of synthesis?

Back 45

Dopamine:
- ↑ in Huntington disease
- ↓ in Parkinson disease
- ↓ in Depression

Synthesized in ventral tegmentum and SNc (substantia nigra) in midbrain

Front 46

What diseases affect the level of 5-HT? How is it changed? Location of synthesis?

Back 46

5-HT (serotonin)
- ↑ in Parkinson Disease
- ↓ in anxiety
- ↓ in depression

Synthesized in raphe nucleus (pons, medulla, midbrain)

Front 47

What diseases affect the level of acetylcholine? How is it changed? Location of synthesis?

Back 47

Acetylcholine:
- ↑ in Parkinson Disease
- ↓ in Alzheimer Disease
- ↓ in Huntington Disease

Synthesized in basal nucleus of Meynert

Front 48

What diseases affect the level of GABA? How is it changed? Location of synthesis?

Back 48

GABA:
- ↓ in anxiety
- ↓ in Huntington disease

Synthesized in nucleus accumbens

Front 49

What NTs are altered in anxiety? Location of synthesis?

Back 49

- ↑ NE (locus ceruleus, pons)
- ↓ 5-HT (raphe nucleus - pons, medulla, midbrain)
- ↓ GABA (nucleus accumbens)

Front 50

What NTs are altered in depression? Location of synthesis?

Back 50

- ↓ NE (locus ceruleus, pons)
- ↓ Dopamine (ventral tegmentum and SNc - midbrain)
- ↓ 5-HT (raphe nucleus - pons, medulla, midbrain)

Front 51

What NTs are altered in Huntington Disease? Location of synthesis?

Back 51

- ↑ Dopamine (ventral tegmentum and SNc - midbrain)
- ↓ ACh (basal nucleus of Meynert)
- ↓ GABA (nucleus accumbens)

Front 52

What NTs are altered in Parkinson Disease? Location of synthesis?

Back 52

- ↓ Dopamine (ventral tegmentum and SNc - midbrain)
- ↑ 5-HT (raphe nucleus - pons, medulla, midbrain)
- ↑ ACh (basal nucleus of Meynert)

Front 53

What NTs are altered in Alzheimer Disease? Location of synthesis?

Back 53

↓ ACh (basal nucleus of Meynert)

Front 54

What functions does the locus ceruleus mediate? What NT does it synthesize?

Back 54

Stress and panic - mediated via NE

Front 55

What functions does the nucleus accumbens and septal nucleus mediate? What NT does it synthesize?

Back 55

- Reward enter, pleasure, addiction, fear
- Mediated via GABA

Front 56

What structures mediate the blood brain barrier?

Back 56

- Tight junctions between non-fenestrated capillary endothelial cells
- Basement membrane
- Astrocyte foot processes

Front 57

What is the function of the blood brain barrier?

Back 57

- Prevents circulating blood substances from reaching the CSF / CNS
- Helps prevent bacterial infection from spreading into the CNS
- Also restricts drug delivery to brain

Front 58

What crosses the blood brain barrier slowly?

Back 58

Glucose and amino acids cross slowly via carrier-mediated transport mechanism

Front 59

What crosses the blood brain barrier quickly?

Back 59

Non-polar / lipid-soluble substances cross rapidly via diffusion

Front 60

What specialized brain regions have fenestrated capillaries and no blood-brain barrier? Effect?

Back 60

Allows molecules in the blood to affect brain function:
- Area postrema → vomiting after chemo
- OVLT → osmotic sensing

Allows neurosecretory products to enter the circulation:
- Neurohypophysis → ADH release

Front 61

Besides the blood brain barrier, what are the other notable barriers?

Back 61

- Blood-testis barrier
- Maternal-fetal blood barrier of placenta

Front 62

What can cause vasogenic edema in the brain?

Back 62

Infarction and/or neoplasm that destroys the endothelial cell tight junctions

Front 63

What inputs and outputs permeate the blood brain barrier?

Back 63

Hypothalamic inputs and outputs

Front 64

What does the hypothalamus control?

Back 64

TAN HATS:
- Thirst and water balance
- Adenohypophysis control (regulates anterior pituitary)
- Neurohypophysis releases hormones produced by hypothalamus
- Hunger
- Autonomic regulation
- Temperature regulation
- Sexual urges

Front 65

What inputs to the hypothalamus are not protected by the blood brain barrier?

Back 65

- OVLT (organum vasculosum of the lamina terminalis) - senses changes in osmolarity
- Area Postrema - responds to emetics

Front 66

Where is ADH made?

Back 66

Supraoptic nucleus of the hypothalamus

Front 67

Where is oxytocin made?

Back 67

Paraventricular nucleus of the hypothalamus

Front 68

Where are ADH and oxytocin stored and released from?

Back 68

Posterior pituitary

Front 69

What are the areas of the hypothalamus with specific functions?

Back 69

- Lateral area
- Ventromedial area
- Anterior hypothalamus
- Posterior hypothalamus
- Suprachiasmatic nucleus

Front 70

Which part of the brain is responsible for telling you you're hungry?

Back 70

Lateral area of hypothalamus

Front 71

Which part of the brain is responsible for telling you you're full (satiated)?

Back 71

Ventromedial area of hypothalamus

Front 72

Which part of the brain is responsible for cooling you down?

Back 72

Anterior hypothalamus

Front 73

Which part of the brain is responsible for warming you up?

Back 73

Posterior hypothalamus

Front 74

Which part of the brain is responsible for the Circadian rhythm?

Back 74

Suprachiasmatic nucleus of hypothalamus

Front 75

What happens if you destroy the lateral area of the hypothalamus?

Back 75

Anorexia, failure to thrive (infants)

"If you zap your lateral nucleus, you shrink laterally"

Front 76

What happens if you destroy the ventromedial area of the hypothalamus?

Back 76

Hyperphagia (can be destroyed by craniopharyngioma)

"If you zap your ventromedial nucleus, you grow ventrally and medially"

Front 77

What are the actions of leptin?

Back 77

- Leptin inhibits the lateral nucleus of the hypothalamus (prevents you from feeling hungry)
- Leptin stimulates the ventromedial nucleus of the hypothalamus (makes you feel satiated)

Front 78

A craniopharyngioma can destroy what part of the hypothalamus? Implications?

Back 78

Can destroy the ventromedial nucleus of the hypothalamus → hyperphagia (gain weight)

Front 79

What controls the anterior hypothalamus and posterior hypothalamus?

Back 79

- Anterior: parasympathetic (cools you down)
- Posterior: sympathetic (heats you up)

Front 80

What happens if you damage your posterior hypothalamus?

Back 80

Become a "Poikilotherm" = cold-blooded, like a snake

Front 81

What hormones are controlled by the Circadian rhythm?

Back 81

Nocturnal release of:
- ACTH
- Prolactin
- Melatonin
- Norepinephrine

Suprachiasmatic Nucleus → NE release → pineal gland → melatonin

Front 82

What regulates the Suprachiasmatic Nucleus (SCN)?

Back 82

Environment (eg, light)

Front 83

What are the stages of sleep?

Back 83

- Rapid Eye Movement (REM)
- Non-REM

Front 84

What controls the movement of eyes during REM sleep?

Back 84

Extraocular movements due to activity of PPRF (paramedian pontine reticular formation / conjugate gaze center)

Front 85

How often does REM sleep occur? How long is it relatively during the night?

Back 85

- REM occurs every 90 minutes
- Duration ↑ throughout night

Front 86

What drugs decrease REM sleep and delta wave sleep?

Back 86

- Alcohol
- Benzodiazepines
- Barbiturates
- Norepinephrine

Front 87

What drugs can be used to treat bed-wetting?

Back 87

- Oral desmopressin acetate (DDAVP) - mimics ADH
- Imipramine (less optimal due to adverse effects)

Front 88

What drugs can be used to treat night terrors and sleepwalking?

Back 88

Benzodiazepines

Front 89

What EEG waveform is characteristic of being awake with eyes open?

Back 89

Beta (highest frequency, lowest amplitude)

Front 90

What EEG waveform is characteristic of being awake with eyes closed?

Back 90

Alpha waves

Front 91

What EEG waveform is characteristic of stage N1 (light sleep)?

Back 91

Theta waves

Front 92

What EEG waveform is characteristic of stage N2 (deeper sleep)?

Back 92

Sleep spindles and K complexes

Front 93

What EEG waveform is characteristic of the stage N3 (deepest non-REM sleep)?

Back 93

Delta (lowest frequency, highest amplitude)

Front 94

What EEG waveform is characteristic of REM sleep?

Back 94

Beta waves (like in awake with eyes open stage)

Front 95

How much of your sleep is spent in each stage of sleep?

Back 95

- Stage 1: 5%
- Stage 2: 45%
- Stage 3: 25%
- REM sleep: 25%

Front 96

During which stage of sleep does bruxism (teeth grinding) occur?

Back 96

Stage N2

Front 97

During which stage of sleep does sleepwalking occur?

Back 97

Stage N3

Front 98

During which stage of sleep do night terrors occur?

Back 98

Stage N3

Front 99

During which stage of sleep does bedwetting occur?

Back 99

Stage N3

Front 100

During which stage of sleep does dreaming occur?

Back 100

REM sleep

Front 101

During which stage of sleep does penile and clitoral tumescence occur?

Back 101

REM sleep

Front 102

What happens to your brain and body during REM sleep?

Back 102

- Loss of motor tone
- ↑ brain O2 use
- ↑ and variable HR and BP
- May serve a memory processing function

Front 103

What does the posterior pituitary (neurohypophysis) receive inputs from?

Back 103

Receives hypothalamic axonal projections from supraoptic (ADH) and paraventricular (oxytocin) nuclei

Front 104

What is the function of the thalamus?

Back 104

Major relay for all ascending sensory information (except olfaction)

Front 105

What are the nuclei of the thalamus?

Back 105

- VPL
- VPM
- LGN
- MGN
- VL

Front 106

What information is relayed through the VPL nucleus of the thalamus?

Back 106

- Pain and temperature
- Pressure, touch, vibration, and proprioception

Front 107

What information is relayed through the VPM nucleus of the thalamus?

Back 107

Face sensation and taste

Front 108

What information is relayed through the LGN nucleus of the thalamus?

Back 108

Vision

Front 109

What information is relayed through the MGN nucleus of the thalamus?

Back 109

Hearing

Front 110

What information is relayed through the VL nucleus of the thalamus?

Back 110

Motor

Front 111

Pain and temperature information travels on what tracts? Through what nucleus of the thalamus? Destination?

Back 111

- Spinothalamic tract →
- VPL nucleus →
- 1° Somatosensory Cortex

Front 112

Pressure, touch, vibration, and proprioception information travels on what tracts? Through what nucleus of the thalamus? Destination?

Back 112

- Dorsal columns / Medial lemniscus →
- VPL nucleus →
- 1° Somatosensory Cortex

Front 113

Face sensation information travels on what tracts? Through what nucleus of the thalamus? Destination?

Back 113

- Trigeminal nerve →
- VPM nucleus →
- 1° Somatosensory Cortex

Front 114

Taste information travels on what tracts? Through what nucleus of the thalamus? Destination?

Back 114

- Gustatory pathway →
- VPM nucleus →
- 1° Somatosensory Cortex

Front 115

Visual information travels on what tracts? Through what nucleus of the thalamus? Destination?

Back 115

- CN II →
- LGN nucleus
- Calcarine sulcus

Front 116

Auditory information travels on what tracts? Through what nucleus of the thalamus? Destination?

Back 116

- Superior olive and inferior colliculus of tectum →
- MGN nucleus →
- Auditory cortex of temporal lobe

Front 117

Motor information travels on what tracts? Through what nucleus of the thalamus? Destination?

Back 117

- Basal ganglia and cerebellum →
- VL nucleus →
- Motor cortex

Front 118

What does the limbic system control?

Back 118

- Emotion
- Long-term memory
- Olfaction
- Behavior modulation
- Autonomic nervous system function

Front 119

What structures are apart of the limbic system?

Back 119

- Hippocampus
- Amygdala
- Fornix
- Mammillary bodies
- Cingulate gyrus

Front 120

What are the functions of the limbic system?

Back 120

5 F's:
- Feeding
- Fleeing
- Fighting
- Feeling
- Fornication (sex)

Front 121

What does the cerebellum control?

Back 121

- Modulates movement
- Aids in coordination and balance

Front 122

What are the inputs to the cerebellum?

Back 122

- Contralateral cortex via middle cerebellar peduncle
- Ipsilateral proprioceptive information via inferior cerebellar peduncle from the spinal cord (input nerves = climbing and mossy fibers)

Front 123

What are the outputs from the cerebellum?

Back 123

- Sends information to contralateral cortex to modulate movement
- Output nerves = Purkinje cells → deep nuclei of cerebellum → contralateral cortex via superior cerebellar peduncle
- Deep nuclei (lateral → medial): Dentate, Emboliform, Globose, Fastigial

Front 124

What is the path along which information from the cerebellum is sent to the contralateral cortex to modulate movement?

Back 124

Purkinje cells → deep nuclei of cerebellum → contralateral cortex via the superior cerebellar peduncle

Front 125

What are the deep nuclei of the cerebellum (from lateral to medial)?

Back 125

From lateral → medial:
"Don't Eat Greasty Foods"
- Dentate
- Emboliform
- Globose
- Fastigial

Front 126

What are the implications of lateral lesions to the cerebellum?

Back 126

Propensity to fall toward injured (ipsilateral side) - problem with voluntary movement of extremities

Front 127

What are the implications of medial lesions to the cerebellum?

Back 127

Generally bilateral motor deficits affecting axial and proximal limb musculature:
- Truncal ataxia
- Nystagmus
- Head tilting
- Wide-based gait
- Deficits in truncal coordination

Front 128

Lesions to what structures can lead towards a propensity to fall to one side?

Back 128

Injury to lateral structures in cerebellum on same side as they are falling towards

Front 129

Lesions to what structures can lead to truncal ataxia, nystagmus, and head tilting?

Back 129

Lesions to midline structures of the cerebellum (vermal cortex, fastigial nuclei) and/or the flocconodular lobe

Front 130

The basal ganglia is important for what functions?

Back 130

Voluntary movements and making postural adjustments

Front 131

What does the basal ganglia receive input from? How does it respond?

Back 131

Receives cortical input and provides negative feedback to cortex to modulate movement

Front 132

What are the components of the striatum in the basal ganglia?

Back 132

Putamen (motor) + Caudate (cognitive)

Front 133

What are the components of the lentiform nucleus in the basal ganglia?

Back 133

Putamen + Globus Pallidus

Front 134

What are the areas of the Basal Ganglia?

Back 134

- SNc: Substantia Nigra pars Compacta
- GPe: Globus Pallidus externus
- GPi: Globus Pallidus internus
- STN: Subthalamic Nucleus
- Putamen
- Caudate

Front 135

What pathways pass through the substantia nigra? Functions?

Back 135

Dopamine can bind to:
- Direct pathway: D1 receptor → stimulates excitatory pathway
- Indirect pathway: D2 receptor → inhibits inhibitory pathway

Both lead to ↑ motion

Front 136

What happens on the excitatory pathway through the basal ganglia? Effect?

Back 136

- Cortical inputs stimulate the striatum
- Stimulates release of GABA
- Disinhibits thalamus vis the GPi/SNr
- ↑ Motion

Front 137

What happens on the inhibitory pathway through the basal ganglia? Effect?

Back 137

- Cortical inputs stimulate the striatum
- Disinhibits STN via GPe
- STN stimulates GPi/SNr
- Inhibits thalamus
- ↓ Motion

Front 138

What kind of disorder is Parkinson Disease? What accumulates to mediate the pathology?

Back 138

- Degenerative disorder of CNS
- Accumulation of Lewy bodies and loss of dopaminergic neurons in SNc

Front 139

What are Lewy bodies?

Back 139

Composed of α-synuclein - intracellular eosinophilic inclusions

Associated with Parkinson disease

Front 140

What happens to the substantia nigra pars compacta (SNc) in Parkinson disease?

Back 140

Loss of dopaminergic neurons in this area → depigmentation

Front 141

What are the signs/symptoms of Parkinson disease?

Back 141

Parkinson TRAPS your body:
- Tremor (at rest - eg, pill-rolling tremor)
- Rigidity (cogwheel)
- Akinesia (or bradykinesia)
- Postural instability
- Shuffling gait

Front 142

What is the cause of Huntington disease?

Back 142

- Autosomal dominant
- Trinucleotide repeat disorder on chromosome 4: CAG repeats
- Caudate loses ACh and GABA (CAG)

Front 143

When and how does Huntington disease present?

Back 143

- Between ages 20-50 (appears earlier in successive generations)
- Symptoms: choreiform movements, aggression, depression, dementia

Front 144

What can Huntington disease sometimes be mistaken for initially?

Back 144

Substance abuse (aggression, depression, dementia)

Front 145

What NT changes occur in Huntington disease?

Back 145

↓ levels of GABA and ACh in the Caudate

Front 146

What happens to neurons in Huntington disease? Mechanism?

Back 146

- Neuronal death via NMDA-R binding and glutamate toxicity
- Atrophy of caudate nuclei can be seen on imaging

Front 147

What are the types of movement disorders?

Back 147

- Hemiballismus
- Chorea
- Athetosis
- Myoclonus
- Dystonia
- Essential tremor (postural tremor)
- Resting tremor
- Intention tremor

Front 148

What would you call sudden, wild flailing of one arm +/- the ipsilateral leg? Characteristic lesion?

Back 148

Hemiballismus
- Lesion to contralateral subthalamic nucleus (eg, lacunar stroke)

Front 149

What would you call sudden, jerky, purposeless movements? Characteristic lesion?

Back 149

Chorea
- Lesion to basal ganglia (eg, Huntington disease)

Front 150

What would you call slow, writhing movements, especially seen in fingers? Characteristic lesion?

Back 150

Athetosis
- lesion to basal ganglia (eg, Huntington disease)

Front 151

What would you call sudden, brief, uncontrolled muscle contraction? Specific examples? Characteristic cause?

Back 151

Myoclonus
- Jerks or hiccups
- Common in metabolic abnormalities such as renal and liver failure

Front 152

What would you call sustained, involuntary muscle contractions? Specific examples?

Back 152

Dystonia
- Writer's cramp
- Blepharospasm (sustained eyelid twitch)

Front 153

What would you call a tremor that is exacerbated by holding a posture or limb position? Cause?

Back 153

Essential Tremor (Postural Tremor)
- Occurs while moving
- Genetic predisposition
- Patients often self-medicated with EtOH, which ↓ tremor amplitude

Front 154

How can you treat/prevent tremors that are exacerbated by holding a posture of limb position?

Back 154

Essential Tremor (Postural Tremor)
- Treatment: β-blockers and Primidone
- Patients often self-medicated with EtOH, which ↓ tremor amplitude

Front 155

What would you call an uncontrolled movement of distal appendages (most noticeable in hands) that is relieved by intentional movement? Specific example? Cause?

Back 155

Resting Tremor
- Occurs at rest, "pill-rolling tremor"
- Seen in Parkinson Disease

Front 156

What would you call a slow, zigzag motion when pointing / extending toward a target? Characteristic lesion?

Back 156

Intention Tremor
- Cerebellar dysfunction

Front 157

What are the three types of tremors? How do they differ?

Back 157

Essential Tremor (Postural Tremor)
- Action tremor, exacerbated by holding a posture / limb position

Resting Tremor
- Uncontrolled movement when at rest, eg, pill-rolling tremor

Intention Tremor
- Slow, zigzag motion when pointing/extending toward a target

Front 158

What important areas are in the frontal component of the cerebral cortex?

Back 158

- Principal motor area
- Premotor area (part of extrapyramidal circuit)
- Frontal eye fields
- Motor speech: Broca's area
- Frontal association areas

Front 159

What important areas are in the parietal component of the cerebral cortex?

Back 159

- Principal sensory area
- Arcuate fasciculus

Front 160

What important areas are in the temporal component of the cerebral cortex?

Back 160

- Primary auditory cortex
- Associative auditory cortex: Wernicke area

Front 161

What important areas are in the occipital component of the cerebral cortex?

Back 161

Principal visual cortex

Front 162

Describe the layout of the homunculus?

Back 162

- Leg is most medial along longitudinal fissure
- Arm is most superior
- Face is most lateral

Distorted appearance is due to certain body regions that are more richly innervated and thus have ↑ cortical representation

Front 163

What syndrome is associated with hyperorality, hypersexuality, and disinhibited behavior? What lesion is it associated with?

Back 163

Klüver-Bucy Syndrome
- Lesion in amygdala (bilateral) - associated with HSV-1

Front 164

What lesion is associated with disinhibition and deficits in concentration, orientation, and judgment?

Back 164

Lesion to frontal lobe

Front 165

What lesion is associated with reemergence of primitive reflexes?

Back 165

Lesion to frontal lobe

Front 166

What lesion is associated with spatial neglect syndrome (ignoring the contralateral side of the world)?

Back 166

Lesion to right parietal-temporal cortex

Front 167

What lesion is associated with agraphia, acalculia, finger agnosia, and left-right disorientation?

Back 167

Gerstmann Syndrome
- Lesion to left parietal-temporal cortex

Front 168

What lesion is associated with reduced levels of arousal and wakefulness (eg, coma)?

Back 168

Lesion to reticular activating system in midbrain

Front 169

What syndrome and lesion is associated with confusion, opthalmoplegia, ataxia, memory loss (anterograde and retrograde amnseia), confabulation, and personality changes?

Back 169

Wernicke-Korsakoff syndrome
- Lesion to mammillary bodies (bilateral) due to thiamine (B1) deficiency and excessive EtOH use
- Can be precipitated by giving glucose without B1 to a B1-deficient patient

Front 170

What lesion is associated with tremor at rest, chorea, or athetosis?

Back 170

Lesions to basal ganglia
- Eg, Parkinson disease

Front 171

What lesion is associated with intention tremor, limb ataxia, and loss of balance?

Back 171

Lesion to ipsilateral cerebellar hemisphere (lateral)
- Fall towards side of lesion

Front 172

What lesion is associated with truncal ataxia and dysarthria (difficult or unclear articulation of speech)?

Back 172

Lesion to cerebellar vermis (centrally located)

Front 173

What lesion is associated with hemiballismus (flailing limb(s) on one side of body)?

Back 173

Lesion to contralateral subthalamic nucleus

Front 174

What lesion is associated with anterograde amnesia (inability to make new memories)?

Back 174

Lesion to hippocampus (bilateral)

Front 175

What lesion is associated with eyes that look away from the side of the lesion?

Back 175

Lesion of paramedian pontine reticular formation (looking away from the side injured)

Front 176

What lesion is associated with eyes that look towards the side of the lesion?

Back 176

Lesion of frontal eye fields (looking at side injured)

Front 177

What injury is associated with "locked in syndrome" that causes acute paralysis, dysarthria, dysphagia, diplopia, and loss of consciousness?

Back 177

Central Pontine Myelinolysis
- Due to massive axonal demyelination in pontine white matter tracts
- Can be due to osmotic forces and edema
- Commonly iatrogenic due to overly rapid correction of hyponatremia

Front 178

What can happen if you correct a low serum Na+ too quickly?

Back 178

From low to high, your pons will die (central pontine myelinolyis = locked in syndrome)

Front 179

What can happen if you correct a high serum Na+ too quickly?

Back 179

From high to low, your brain will blow (cerebral edema / herniation)

Front 180

What are the symptoms of Central Pontine Myelinolysis?

Back 180

- Acute paralysis
- Dysarthria
- Dysphagia
- Diplopia
- Loss of consciousness

Can caused locked in syndrome

Front 181

What is the term for a higher order inability to speak (language defecit)?

Back 181

Aphasia

Front 182

What is term for a motor inability to speak (movement deficit)?

Back 182

Dysathria

Front 183

What are the types of aphasia (language deficit)?

Back 183

- Broca
- Wernicke
- Global
- Conduction
- Transcortical motor
- Transcortical sensory
- Mixed transcortical

Front 184

What is the name for the deficit that causes non-fluent aphasia with intact comprehension?

Back 184

Broca Aphasia
- Deficit in inferior frontal gyrus of frontal lobe

Front 185

What is the name for the deficit that causes fluent aphasia with impaired comprehension and repetition?

Back 185

Wernicke Aphasia (Wernicke is wordy but makes no sense)
- Deficit in superior temporal gyrus of temporal lobe

Front 186

What is the name for the deficit that causes non-fluent aphasia with impaired comprehension?

Back 186

Global Aphasia
- Both Broca and Wernicke areas are affected

Front 187

What is the name for the deficit that causes poor repetition but fluent speech with intact comprehension?

Back 187

Conduction Aphasia
- Can be due to damage to left superior temporal lobe and/or left supramarginal gyrus

(Can't repeat phrases such as "no ifs, ands, or buts")

Front 188

What is the name for the deficit that causes non-fluent aphasia with good comprehension and repetition?

Back 188

Transcortical Motor Aphasia

Front 189

What is the name for the deficit that causes poor comprehension with fluent speech and repetition?

Back 189

Transcortical Sensory Aphasia

Front 190

What is the name for the deficit that causes non-fluent speech, poor comprehension, but good repetition?

Back 190

Mixed Transcortical Aphasia

Front 191

What deficit occurs with Broca Aphasia? What language capabilities are intact?

Back 191

- Non-fluent speech

- Intact comprehension

Front 192

What deficit occurs with Wernicke Aphasia? What language capabilities are intact?

Back 192

- Impaired comprehension
- Impaired repetition

- Fluent speech

Front 193

What deficit occurs with Global Aphasia? What language capabilities are intact?

Back 193

- Non-fluent speech
- Impaired comprehension

Front 194

What deficit occurs with Conduction Aphasia? What language capabilities are intact?

Back 194

- Poor repetition

- Fluent speech
- Intact comprehension

Front 195

What deficit occurs with Transcortical Motor Aphasia? What language capabilities are intact?

Back 195

- Non-fluent speech

- Intact comprehension
- Intact repetition

Front 196

What deficit occurs with Transcortical Sensory Aphasia? What language capabilities are intact?

Back 196

- Poor comprehension

- Fluent speech
- Intact repetition

Front 197

What deficit occurs with Mixed Transcortical Aphasia? What language capabilities are intact?

Back 197

- Non-fluent speech
- Poor comprehension

- Intact repetition

Front 198

What are the components of the Circle of Willis?

Back 198

- Internal Carotid Arteries
- Anterior Cerebral Arteries (connected by Anterior Communicating Artery)
- Posterior Cerebral Arteries (connected to ICA by Posterior Communicating Arteries)

Front 199

What are the branches of the Vertebral Arteries?

Back 199

Inferior to Superior:
- Posterior Inferior Cerebellar Arteries (PICA)
- Anterior Spinal Artery (ASA)
- Anterior Inferior Cerebellar Arteries (AICA)

Combine to form Basilar Artery

Front 200

What are the branches of the Basilar Artery?

Back 200

Inferior to Superior:
- Pontine Arteries
- Superior Cerebellar Arteries (SCA)
- Posterior Cerebral Arteries (PCA)

Front 201

What is the system of anastomoses between the anterior and posterior blood supplies to the brain?

Back 201

Circle of Willis

Front 202

What part of the brain is supplied by the Anterior Cerebral Arteries?

Back 202

Anteromedial surface of brain

Front 203

What part of the brain is supplied by the Middle Cerebral Arteries?

Back 203

Lateral surfaces of brain

Front 204

What part of the brain is supplied by the Posterior Cerebral Arteries?

Back 204

Posterior and Inferior surfaces of brain

Front 205

What are the Watershed Zones? What are they susceptible to?

Back 205

- Between anterior cerebral / middle cerebral and middle cerebral / posterior cerebral arteries
- Damage caused by severe hypotension → upper leg/upper arm weakness, defects in higher order visual processing

Front 206

What regulates brain perfusion?

Back 206

Tight auto-regulation
- Primarily driven by PCO2
- PO2 also modulates perfusion in severe hypoxia

Front 207

What can cause increased intracranial pressure? How can you decrease this by using the principles of cerebral perfusion regulation?

Back 207

Caused by acute cerebral edema (stroke, trauma)

Therapeutic Hyperventilation → ↓ PCO2 → vasoconstriction → ↓ cerebral perfusion

Front 208

How does PO2 affect cerebral perfusion?

Back 208

Hypoxemia only increases cerebral perfusion when PO2 <50 mmHg

(Normal: ~100 mmHg)

Front 209

How does PCO2 affect cerebral perfusion?

Back 209

Hypercapnia stimulates cerebral perfusion when PCO2 > 90 mmHg

(Normal: ~40 mmHg)

Front 210

What are the effects of a stroke in the MCA?

Back 210

- Contralateral paralysis - upper limb and face (motor cortex deficit)
- Contralateral loss of sensation - upper and lower limbs and face (sensory cortex deficit)
- Aphasia if in dominant (usually left) hemisphere
- Hemineglect if in non-dominant (usually right) hemisphere

Front 211

What are the effects of a stroke in the ACA?

Back 211

- Contralateral paralysis - lower limb (motor cortex deficit)
- Contralateral loss of sensation - lower limb (sensory cortex deficit)

Front 212

What are the effects of a stroke in the Lenticulostriate Artery?

Back 212

- Contralateral hemiparesis / hemiplegia (deficit in striatum or internal capsule)
- Common location of lacunar infarcts, 2° to unmanaged hypertension

Front 213

What are the effects of a stroke in the ASA?

Back 213

- Contralateral hemiparesis - upper and lower limbs (deficit in lateral corticospinal tract)
- ↓ Contralateral proprioception (deficit in medial lemniscus)
- Ipsilateral hypoglossal dysfunction - tongue deviates ipsilaterally (deficit in caudal medulla / hypoglossal nerve)

Front 214

What are the effects of a stroke in the PICA?

Back 214

Deficit in lateral medulla:
- Vomiting, vertigo, nystagmus
- ↓ Pain and temperature sensation from ipsilateral face and contralateral body
- Dysphagia, hoarseness, ↓ gag reflex
- Ipsilateral Horner syndrome
- Ataxia and dysmetria (lack of coordination)

Front 215

What are the effects of a stroke in the AICA?

Back 215

Deficit in Lateral Pons:
- Vomiting, vertigo, nystagmus
- Paralysis of face
- ↓ Lacrimation, salivation
- ↓ Taste from anterior 2/3 of tongue
- ↓ Corneal reflex
- Face: ↓ pain and temperature sensation
- Ipsilateral ↓ hearing
- Ipsilateral Horner syndrome

Deficit in Middle and Inferior Cerebellar Peduncles
- Ataxia and dysmetria (lack of coordination)

Front 216

What are the effects of a stroke in the PCA?

Back 216

Deficit in occipital cortex and visual cortex
- Contralateral hemianopia with macular sparing

Front 217

What are the effects of a stroke in the Basilar Artery?

Back 217

Deficits to Pons, Medulla, Lower Midbrain, Corticospinal and Corticobulbar Tracts, Ocular CN nuclei, Paramedian Pontine Reticular Formation:
- Preserved consciousness and blinking
- Quadriplegia
- Loss of voluntary facial, mouth, and tongue movements

Front 218

What are the effects of a stroke in the Anterior Communicating Artery?

Back 218

- Visual field defects

- Commonly due to aneurysm

Front 219

What are the effects of a stroke in the Posterior Communicating Artery?

Back 219

- CN III palsy - eye is "down and out" with ptosis and pupil dilation

- Lesion is commonly due to saccular aneurysm

Front 220

What areas are lesioned in an MCA stroke?

Back 220

- Motor cortex: upper limb and face
- Sensory cortex: upper limb and face
- Temporal lobe (Wernicke area possibly)
- Frontal lobe (Broca area possibly)

Front 221

What areas are lesioned in an ACA stroke?

Back 221

- Motor cortex: lower limb
- Sensory cortex: lower limb

Front 222

What areas are lesioned in a Lenticulostriate artery stroke? Common cause?

Back 222

- Striatum
- Internal Capsule

Common location of lacunar infarct, 2° to unmanaged hypertension

Front 223

What areas are lesioned in an ASA stroke?

Back 223

- Lateral corticospinal tract
- Medial lemniscus
- Caudal medulla / hypoglossal nerve

Front 224

What areas are lesioned in a PICA stroke?

Back 224

Lateral Medulla:
- Vestibular nuclei
- Lateral spinothalamic tract
- Spinal trigeminal nucleus
- Nucleus ambiguus
- Sympathetic fibers
- Inferior cerebellar peduncle

Front 225

What areas are lesioned in an AICA stroke?

Back 225

Lateral Pons:
- Cranial nerve nuclei
- Vestibular nuclei
- Facial nucleus
- Spinal trigeminal nucleus
- Cochlear nuclei
- Sympathetic fibers

Middle and inferior cerebellar peduncles

Front 226

What areas are lesioned in a PCA stroke?

Back 226

- Occipital cortex
- Visual cortex

Front 227

What areas are lesioned in a Basilar Artery stroke?

Back 227

- Pons, medulla, lower midbrain
- Corticospinal and corticobulbar tracts
- Ocular cranial nerve nuclei
- Paramedian pontine reticular formation

Front 228

What is a common location of a lacunar infarct? Effect?

Back 228

Lenticulostriate artery
- Lesions striatum and internal capsule
- Causes contralateral hemiparesis and hemiplegia

Front 229

What causes Medial Medullary Syndrome? Effects?

Back 229

- Caused by infarct of paramedian branches of ASA and vertebral arteries (commonly bilaterally)
- Lesions lateral corticospinal tract → contralateral hemiparesis (upper and lower limbs)
- Lesions medial lemniscus → ↓ contralateral proprioception
- Lesions caudal medulla and hypoglossal nerve → ipsilateral hypoglossal dysfunction (tongue deviates ipsilaterally)

Front 230

What causes Lateral Medullary (Wallenberg) Syndrome? Effects?

Back 230

Stroke in PICA
* Nucleus ambiguus effects are specific for PICA lesion
* Dysphagia and hoarseness
- Vomiting, vertigo, nystagmus
- ↓ Pain and temperature sensation from ipsilateral face and contralateral body
- ↓ Gag reflex
- Ipsilateral Horner syndrome
- Ataxia and dysmetria

"Don't pick a (PICA) horse (hoaraseness) that can't eat (dysphagia)"

Front 231

What causes Lateral Pontine Syndrome? Effects?

Back 231

Stroke in AICA
* Facial nucleus effects are specific to AICA lesions
* Paralysis of face

"Facial droops means AICA's pooped"

Front 232

A stroke in what artery will caused "locked in syndrome"?

Back 232

Basilar Artery

Front 233

Where does a Berry Aneurysm occur?

Back 233

Bifurcations in the Circle of Willis
- Most common site: Anterior Communicating Artery and Anterior Cerebral Artery

Front 234

What are the most common complications of a Berry Aneurysm?

Back 234

- Rupture → subarachnoid hemorrhage → worse headache of life
- Hemorrhagic stroke
- Bitemporal hemianopia via compression of optic chiasm

Front 235

What is a Berry aneurysm associated with?

Back 235

- ADPKD
- Ehlers Danlos Syndrome
- Marfan Syndrome

- Advanced age
- Hypertension
- Smoking
- Race (↑ in blacks)

Front 236

What is a Charcot-Bouchard Microaneurysm associated with? What does it affect?

Back 236

- Chronic hypertension
- Affects small vessels (eg, in basal ganglia and thalamus)

Front 237

What sensations can occur post-stroke?

Back 237

Central Post-Stroke Pain Syndrome
- Neuropathic pain due to thalamic lesions
- Initial sensation of numbness and tingling following in weeks to months by allodynia (ordinarily painless stimuli cause pain)
- Dysaesthesia

Front 238

What is the syndrome that causes neuropathic pain after a stroke? How common?

Back 238

Central Post-Stroke Pain Syndrome - occurs in 10%o f stroke patients

Front 239

What are the types of intracranial hemorrhages?

Back 239

- Epidural hematoma
- Subdural hematoma
- Subarachnoic hemorrhage
- Intraparenchymal (hypertensive) hemorrhage

Front 240

What kind of injury can occur if the temporal bone is fractured?

Back 240

Rupture of middle meningeal artery (branch of maxillary artery) → Epidural Hematoma

Front 241

What are the characteristics of a middle meningeal artery bleed?

Back 241

Epidural Hematoma
- Lucid interval
- Rapid expansion under systemic arterial pressure
- Can cause transtentorial herniation, CN III palsy
- CT shows biconvex (lentiform), hyperdense blood collection
- Can NOT cross suture lines
- Can cross falx and tentorium

Front 242

What kind of injury can occur if the bridging veins are ruptured? Characteristics of bleed?

Back 242

- Slow venous bleeding (less pressure → hematoma develops over time)
- Crescent-shaped hemorrhage
- Can cause midline shift
- Can cross suture lines
- Can NOT cross falk or tentorium

Front 243

What is more likely to get a subdural hematoma? Predisposing factors?

Back 243

- Elderly
- Alcoholics
- Blunt trauma
- Shaken baby

Predisposing factors:
- Brain atrophy
- Shaking
- Whiplash

Front 244

Which type of hematoma can cross suture lines?

Back 244

Subdural Hematoma

Front 245

Which type of hematoma can cross the falx and tentorium?

Back 245

Epidural Hematoma

Front 246

Which type of brain bleed can be caused by the rupture of an aneurysm? What is this associated with?

Back 246

Subarachnoid Hemorrhage
- Berry aneurysm associated with Marfan, Ehlers-Danlos, and ADPKD

Front 247

What can cause a Subarachnoid Hemorrhage?

Back 247

- Berry aneurysm: associated with Marfan, Ehlers-Danlos, and ADPKD
- Atrioventricular malformation (AVM)

Front 248

What are the symptoms of a Subarachnoid Hemorrhage?

Back 248

- Rapid time course
- "Worst headache of my life"

Front 249

On what type of brain bleed would you expect to see a bloody or yellow (xanthochromic) spinal tap?

Back 249

Subarachnoid Hemorrhage

Front 250

What are the potential complications of Subarachnoid Hemorrhage? Appearance on CT? Treatment?

Back 250

- 2-3 days afterword risk of vasospasm due to blood breakdown (not visible on CT, treat with nimodipine)
- Rebleed possible (visible on CT)

Front 251

What type of brain bleed is commonly caused by systemic hypertension?

Back 251

Intraparenchymal Hemorrhage

Front 252

What can cause an Intraparenchymal Hemorrhage?

Back 252

- Systemic hypertension
- Amyloid angiopathy
- Vasculitis
- Neoplasm

Front 253

Where do Intraparenchymal Hemorrhages usually occur?

Back 253

- Typically occurs in basal ganglia and internal capsule (Charcot-Bouchard aneurysm of lenticulostriate vessels)
- Can be lobar

Front 254

How long does hypoxia have to occur to cause irreversible damage? Implications?

Back 254

>5 minutes → irreversible neuronal injury

Front 255

What areas of the brain are most vulnerable to hypoxia?

Back 255

- Hippocampus
- Neocortex
- Cerebellum
- Watershed areas

Front 256

What is the appearance of an ischemic brain stroke on imaging?

Back 256

- Diffusion weighted MRI: bright
- Non-contrast CT: dark (hemorrhage appears bright)

Front 257

How can you detect an ischemic stroke early on?

Back 257

Bright on diffusion-weighted MRI from 3-30 minutes after stroke (highest sensitivity for early ischemia)

Front 258

How can you detect an ischemic stroke later on?

Back 258

Dark abnormality on non-contrast CT from 12-24 hours after stroke

Front 259

Why do you need to do a CT for a patient you suspect of having a stroke if it doesn't show ischemia for 12-24 hours?

Back 259

Non-contrast CT will show bright area if there is a hemorrhage; if there is a hemorrhage you can't give tPA for ischemia

Front 260

What are the histologic signs of an ischemic stroke 12-48 hours after it occurs?

Back 260

Red neurons

Front 261

What are the histologic signs of an ischemic stroke 24-72 hours after it occurs?

Back 261

Necrosis and neutrophils

Front 262

What are the histologic signs of an ischemic stroke 3-5 days after it occurs?

Back 262

Macrophages

Front 263

What are the histologic signs of an ischemic stroke 1-2 weeks after it occurs?

Back 263

Reactive gliosis + Vascular proliferation

Front 264

What are the histologic signs of an ischemic stroke >2 weeks after it occurs?

Back 264

Glial scar

Front 265

What are the types of strokes?

Back 265

- Hemorrhagic stroke
- Ischemic stroke: thrombotic, embolic, and hypoxic
- Transient ischemic attack

Front 266

What can cause a hemorrhagic stroke?

Back 266

- Hypertension
- Anticoagulation
- Cancer (abnormal vessels can bleed)
- 2° to ischemic stroke followed by reperfusion (↑ vessel fragility)

Front 267

What is the most common site of hemorrhagic strokes (intracerebral hemorrhages)?

Back 267

Basal ganglia

Front 268

What is the consequence of an ischemic stroke?

Back 268

Liquefactive necrosis

Front 269

What are the types of ischemic strokes?

Back 269

- Thrombotic
- Embolic
- Hypoxic

Front 270

What causes a thrombotic ischemic stroke?

Back 270

Clot forms directly at the site of infarction (commonly the MCA), usually over an atherosclerotic plaque

Front 271

What causes an embolic ischemic stroke?

Back 271

Embolus from another part of the body obstructs a vessel, can affect multiple vascular territories; often cardioembolic

Front 272

What causes a hypoxic ischemic stroke?

Back 272

Due to hyperperfusion or hypoxemia
- Common during cardiovascular surgeries, tends to affect watershed areas

Front 273

How do you treat an ischemic stroke?

Back 273

tPA (if within 3-4.5 hours of onset and no hemorrhage/risk of hemorrhage)

Front 274

How do you reduce the risk of an ischemic stroke?

Back 274

- Medical therapy: aspirin, clopidogrel
- Optimum control of BP, blood sugars, and lipids
- Treat conditions that increase the risk (eg, atrial fibrillation)

Front 275

What is a transient ischemic attack (TIA)?

Back 275

- Brief, reversible episode of focal neurologic dysfunction lasting <24 hours without acute infarction (- MRI)
- Majority of resolve in <15 minutes
- Deficits are due to focal ischemia

Front 276

What are the large venous channels that run through the dura? Purpose?

Back 276

Dural venous sinuses - drains blood from cerebral veins and receives CSF from arachnoic granulations

Front 277

What do the dural venous sinuses drain into?

Back 277

Internal Jugular Vein

Front 278

What are the ventricles of the brain?

Back 278

- Lateral ventricle
- 3rd ventricle
- 4th ventricle

Front 279

What is the path through the ventricular system of the brain?

Back 279

- Lateral ventricle → R & L interventricular foramina of Monro → 3rd ventricle
- 3rd ventricle → Cerebral Aqueduct (of Sylvius) → 4th ventricle
- 4th ventricle → Foramina of Luschka and Foramen of Magendie → Subarachnoid Space

Front 280

What connects the lateral ventricles and 3rd ventricle?

Back 280

R and L Interventricular Foramina of Monro

Front 281

What connects the 3rd and 4th ventricles?

Back 281

Cerebral Aqueduct of Sylvius

Front 282

What connects the 4th ventricle to the subarachnoid space?

Back 282

- Foramina of Luschka (lateral)
- Foramen of Magendie (medial)

Front 283

What is the origin of CSF?

Back 283

Ependymal cells of choroid plexus

Front 284

How is CSF reabsorbed?

Back 284

Arachnoid granulations absorb CSF and drain it into the dural venous sinuses

Front 285

What are the types of hydrocephalus?

Back 285

Communicating (non-obstructive)
- Communicating hydrocephalus
- Normal pressure hydrocephalus
- Hydrocephalus ex vacuo

Non-Communicating (obstructive)
- Non-communicating hydrocephalus

Front 286

What is the cause of communicating hydrocephalus? What does it lead to?

Back 286

- ↓ CSF absorption by arachnoid granulations (eg, arachnoid scarring post-meningitis)
- Causes ↑ intracranial pressure, papilledema, and herniation

Front 287

What is the cause of normal pressure hydrocephalus? What does it lead to?

Back 287

- Does not result in increased subarachnoid space volume
- Expansion of ventricles distorts the fibers of the corona radiata and leads to the clinical triad of urinary incontinence, ataxia, and cognitive dysfunction (sometimes reversible)
- "Wet, wobbly, and wacky"

Front 288

What is the cause of hydrocephalus ex vacuo? What does it lead to?

Back 288

- Appearance of ↑ CSF in atrophy (eg, Alzheimer disease, advanced HIV, Pick disease)
- Intracranial pressure is normal - triad is not seen
- Apparent increase in CSF observed on imaging is actually the result of ↓ neural tissue due to neuronal atrophy

Front 289

What is the cause of non-communicating hydrocephalus? What does it lead to?

Back 289

Caused by a structural blockage of CSF circulation within the ventricular system (eg, stenosis of the aqueduct of Sylvius)

Front 290

How many spinal nerves are there? Types?

Back 290

31 total spinal nerves:
- 8 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 1 coccygeal

Front 291

How do the spinal nerves exit relative to the vertebrae?

Back 291

- Nerves C1-C7 exit ABOVE the corresponding vertebra
- All other nerves exit BELOW the corresponding vertebra

Front 292

What happens in a vertebral disc herniation? What direction?

Back 292

- Nucleus pulposus (soft central disc) herniates through annulus fibrosis (outer ring)
- Usually occurs in posterolateral direction

Front 293

What is the most common location for a vertebral disc herniation?

Back 293

- L4-L5
- L5-S1

Front 294

How far down does the spinal cord extend?

Back 294

Extends to lower border of L1-L2 vertebrae

Front 295

How low does the subarachnoid space (which contains CSF) extend?

Back 295

Extends to lower border of S2 vertebra

Front 296

Where do you do a lumbar puncture? Why?

Back 296

Between L3-L4 or L4-L5 (level of cauda equina)
- Goal is to obtain sample of CSF without damaging the spinal cord
- To keep the cord alive, keep the spinal needle between L3 and L5

Front 297

What are the tracts in the dorsal column? Function?

Back 297

Ascending tracts of dorsal column:
- Fasciculus gracilis: pressure, vibration, touch proprioception sensation from lower body and legs
- Fasciculus cuneatus: same sensation from upper body and arms

Front 298

What is the orientation of spinal nerves in the dorsal column?

Back 298

From medial to lateral:

Fasciculus gracilis:
- Sacral
- Lumbar

Fasciculus cuneatus:
- Thoracic
- Cervical

Front 299

What tracts carry sensory information about pressure, vibration, touch, and proprioception? Location?

Back 299

Fasciculus gracilis and cuneatus
- Found in dorsal column

Front 300

What tracts carry sensory information about pain and temperature? Orientation?

Back 300

Lateral Spinothalamic Tract
- Lateral: sacral
- Medial: cervical

Front 301

What tracts carry sensory information about crude touch and pressure?

Back 301

Anterior Spinothalamic Tract

Front 302

What tracts carry voluntary motor information? Orientation?

Back 302

Lateral Corticospinal Tract
- Lateral: sacral
- Medial: cervical

Anterior Corticospinal Tract

Front 303

What is the function of the dorsal column in the spinal cord?

Back 303

Ascending sensory information: pressure, vibration, fine touch, and proprioception

Front 304

What is the path of the first order neuron of the dorsal column?

Back 304

- Sensory nerve ending → cell body in dorsal root ganglion → enters spinal cord, ascends ipsilaterally in the dorsal column
- Synapses on the ipsilateral nucleus cutaneous or gracilis (in medulla)

Front 305

What is the path of the second order neuron of the dorsal column?

Back 305

- Originates from the ipsilateral nucleus cutaneous or gracilis (in medulla)
- Decussates in medulla → ascends contralaterally in medial lemniscus
- Synapses on VPL (thalamus)

Front 306

What is the path of the third order neuron of the dorsal column?

Back 306

- Originates in VPL (in thalamus)
- Travels to sensory cortex

Front 307

What is the function of the spinothalamic tract in the spinal cord?

Back 307

Ascending sensory information:
- Lateral: pain and temperature
- Anterior: crude touch and pressure

Front 308

What is the path of the first order neuron of the spinothalamic tract?

Back 308

- Sensory nerve ending (Aδ and C fibers) (cell body in dorsal root ganglion) → enters spinal cord
- Synapses on ipsilateral gray matter (spinal cord)

Front 309

What is the path of the second order neuron of the dorsal column?

Back 309

- Originates at ipsilateral gray matter (in spinal cord)
- Decussates at anterior white commissure and ascends contralaterally
- Synapses on VPL (thalamus)

Front 310

What is the path of the third order neuron of the dorsal column?

Back 310

- Originates on VPL (thalamus)
- Travels to sensory cortex

Front 311

What is the function of the lateral corticospinal tract in the spinal cord?

Back 311

Descending:
- Voluntary movement of contralateral limbs

Front 312

What is the path of the first order neuron of the lateral corticospinal tract?

Back 312

- UMN: cell body in 1° motor cortex → descends ipsilaterally (through internal capsule), most fibers decussate at caudal medulla (pyramidal decussation) → descends contralaterally
- Synapses on cell body of anterior horn (in spinal cord)

Front 313

What is the path of the second order neuron of the spinothalamic tract?

Back 313

- LMN originates in cell body of anterior horn of spinal cord
- LMN leaves spinal cord and synapses at neuromuscular junction

Front 314

What are the signs of an upper motor neuron lesion?

Back 314

Everything UP (tone, reflexes, toes):
- Weakness
- ↑ Reflexes
- ↑ Tone
- Babinski sign
- Spastic paralysis
- Clasp knife spasticity

Front 315

What are the signs of a lower motor neuron lesion?

Back 315

Everything LOWERED (less muscle mass, ↓ muscle tone, ↓ reflexes, downgoing toes):
- Weakness
- Atrophy
- Fasciculations
- ↓ Reflexes
- ↓ Tone
- Flaccid paralysis

Front 316

What are fasciculations?

Back 316

Muscle twitching

Front 317

What is a positive Babinski sign indicative of?

Back 317

- Normal in infants
- Positive in UMN lesions

Front 318

What kind of disease causes this area to be injured? Characteristics of lesion?

Back 318

- Caused by poliomyelitis and spinal muscular atrophy (Werdnig-Hoffman disease)
- LMN lesions only, due to destruction of anterior horns
- Causes flaccid paralysis

Front 319

What kind of disease causes this area to be injured? Characteristics of lesion?

Back 319

Multiple Sclerosis
- Due to demyelination of random regions (often asymettric)
- Mostly white matter of cervical region
- Scanning speech, intention tremor, and nystagmus

Front 320

What kind of disease causes this area to be injured? Characteristics of lesion?

Back 320

Amyotrophic Lateral Scerlosis / Lou Gehrig disease:
- Can be caused by defect in superoxide dismutase 1
- Combined UMN and LMN deficits with no sensory, cognitive, or oculomotor deficits (both UMN and LMN signs)
- Commonly presents as fasciculations with eventual atrophy and weakness of hands
- No cognitive defect
- Fatal

Front 321

What drug can be used to treat this condition?

Back 321

Amyotrophic Lateral Scerlosis / Lou Gehrig disease:
- Riluzole treatment modestly ↑ survival by ↓ presynaptic glutamate release

Front 322

What kind of disease causes this area to be injured? Characteristics of lesion?

Back 322

Complete Occlusion of Anterior Spinal Artery
- Spares dorsal columns and Lissauer tract
- Upper thoracic ASA territory is a watershed area, as artery of Adamkiewicz supplies ASA below T8

Front 323

What kind of disease causes this area to be injured? Characteristics of lesion?

Back 323

Tabes Dorsalis (caused by 3° syphilis)
- Results from degeneration / demyelination of dorsal columns and roots → impaired sensation and proprioception and progressive sensory ataxia (inability to sense or feel legs → poor coordination)
- Absence of reflexes and positive Romberg

Front 324

What is Tabes Dorsalis associated with?

Back 324

- Charcot joints
- Shooting pain
- Argyll Robertson pupils (small bilateral pupils that further constrict to accommodation and convergence, but not to light)
- Exam will demonstrate absence of reflexes and positive Romberg

Front 325

What is the term for pupils that are small bilaterally that constrict to accommodation and convergence, but not to light?

Back 325

Tabes Dorsalis

Front 326

What kind of disease causes this area to be injured? Characteristics of lesion?

Back 326

Syringomyelia
- Syrinx expands and damages anterior white commissure of spinothalamic tract (2nd order neurons)
- Bilateral loss of pain and temperature sensation (usually C8-T1)
- Seen with Chiari I malformation
- Can expand and affect other tracts

Front 327

What kind of disease causes this area to be injured? Characteristics of lesion?

Back 327

Vitamin B12 or Vitamin E deficiency:
- Subacute combined degeneration
- Demyelination of dorsal columns, lateral corticospinal tracts, and spinocerebellar tracts
- Ataxic gait, paresthesia, impaired position and vibration sense

Front 328

What causes Poliomyelitis?

Back 328

Poliovirus (fecal-oral transmission)

Front 329

How does poliovirus infect someone?

Back 329

- Replicates in the oropharynx and small intestine
- Spreads to the CNS via the bloodstream
- Infection causes destruction of cells in the anterior horn of the spinal cord (LMN death)

Front 330

What are the symptoms of Poliomyelitis?

Back 330

LMN lesions signs:
- Weakness
- Hypotonia
- Flaccid paralysis
- Fasciculations
- Hyporeflexia
- Muscle atrophy

Front 331

What are the signs of a poliovirus infection?

Back 331

- Malaise
- Headache
- Fever
- Nausea

Front 332

What are the lab findings associated with poliomyelitis?

Back 332

- CSF: ↑ WBCs and slight ↑ of protein (no change in CSF glucose)
- Virus recovered from stool or throat

Front 333

What causes "floppy baby" syndrome?

Back 333

Spinal Muscular Atrophy (Werdnig-Hoffmann Disease)
- Congenital degeneration of anterior horns of spinal cord → LMN lesion
- Autosomal recessive inheritance

Front 334

What are the symptoms of the congenital degeneration of the anterior horns of the spinal cord?

Back 334

Floppy Baby: Spinal Muscular Atrophy (Werdnig-Hoffmann Disease)
- Marked hypotonia and tongue fasciculations
- Median age of death is 7 months

Front 335

What causes degeneration of multiple spinal cord tracts leading to muscle weakness and loss of deep reflexes, vibratory sense, and proprioception?

Back 335

Friedreich Ataxia
- Autosomal recessive trinucleotide repeat disorder (GAA) on chromosome 9 (encodes Frataxin - iron binding protein)
- Impairs mitochondrial functioning
- Leads to degeneration of multiple spinal cord tracts

Front 336

What is the cause of Friedreich Ataxia?

Back 336

- Autosomal recessive trinucleotide repeat disorder (GAA) on chromosome 9 (encodes Frataxin - iron binding protein)
- Impairs mitochondrial functioning
- Leads to degeneration of multiple spinal cord tracts

Front 337

What are the problems caused by Friedreich Ataxia?

Back 337

- Muscle weakness
- Loss of deep reflexes
- Loss of vibratory sense
- Loss of proprioception

Front 338

What are the symptoms caused by Friedreich Ataxia?

Back 338

- Staggering gait
- Frequent falling
- Nystagmus
- Dysarthria
- Pes cavus
- Hammer toes
- Hypertrophic cardiomyopathy (cause of death)
- Presents in childhood with kyphoscoliosis

Front 339

What disease presents in childhood with kyphoscoliosis? Cause of death?

Back 339

Friedreich Ataxia
- Cause of death is hypertrophic cardiomyopathy

Front 340

What is the mnemonic to remember the characteristics of Friedreich Ataxia?

Back 340

"Friedreich is FRATAstic (Frataxin gene): He's your favorite FRAT brother, always stumbling, staggering, and falling, but he has a big heart (hypertrophic cardiomyopathy)"

Front 341

What is the cause of Brown-Séquard Syndrome?

Back 341

Hemisection of Spinal Cord

Front 342

What is the name for the syndrome caused by a hemisection of the spinal cord? What are the neurologic findings?

Back 342

Brown-Séquard Syndrome
- Ipsilateral UMN signs BELOW the lesion (corticospinal tract damage)
- Ipsilateral loss of tactile, vibration, proprioceptio sense 1-2 levels BELOW the lesion (dorsal column damage)
- Contralateral pain and temperature loss BELOW level of lesion (spinothalamic tract damage)
- Ipsilateral loss of all sensation AT level of lesion
- Ipsilateral LMN signs (eg, flaccid paralysis) AT level of lesion

Front 343

What are the additional problems that can be associated with a patient with Brown-Séquard Syndrome if the lesion occurs above T1?

Back 343

Patient may present with Horner Syndrome due to damage of the oculosympathetic pathway

Front 344

What are the ipsilateral findings associated with a hemisection of the spinal cord?

Back 344

- UMN signs below lesion
- Loss of tactile, vibration, proprioception 1-2 levels below lesion
- Loss of all sensation at level of lesion
- LMN signs at level of lesion (eg, flaccid paralysis)

Front 345

What are the contralateral findings associated with a hemisection of the spinal cord?

Back 345

Loss of pain and temperature sensation below level of lesion

Front 346

What are the symptoms of Horner syndrome?

Back 346

- Ptosis (slight drooping of the eyelid)
- Anhidrosis (absence of sweating) and flushing (rubor)
- Miosis (pupil constriction)

Front 347

What happens to the eyelid in Horner Syndrome? Why?

Back 347

Ptosis: slight drooping of eyelid - no input to superior tarsal muscle

Front 348

What happens to the face in Horner Syndrome? Why?

Back 348

- Anhidrosis: absence of sweating
- Rubor: flushing

Front 349

What happens to the pupil in Horner Syndrome? Why?

Back 349

Miosis: pupil constriction

Front 350

What lesion is Horner Syndrome associated with?

Back 350

Lesion of spinal cord above T1 (eg, Pancoast tumor, Brown-Séquard syndrome [cord hemisection], late-stage syringomyelia)

Front 351

What pathway is damaged leading to ptosis, anhidrosis, and miosis?

Back 351

Interruption of the 3-neuron oculosympathetic pathway projects from the hypothalamus to the intermediolateral column of the spinal cord → superior cervical (sympathetic) ganglion → pupil, smooth muscle of eyelids, and the sweat glands of the forehead and face

Front 352

What is the dermatome associated with the posterior half of the skull "cap"?

Back 352

C2

Front 353

What is the dermatome associated with the high turtleneck shift?

Back 353

C3

Front 354

What is the dermatome associated with a low-collar shirt?

Back 354

C4

Front 355

What is the dermatome associated with the nipples?

Back 355

T4

Front 356

What is the dermatome associated with the xiphoid process?

Back 356

T7

Front 357

What is the dermatome associated with the umbilicus?

Back 357

T10 (at the belly butTEN)

Front 358

What is the dermatome associated with the inguinal ligament?

Back 358

L1

Front 359

What is the dermatome associated with the kneecaps?

Back 359

L4 (down on ALL 4's)

Front 360

What is the dermatome associated with the erection and sensation of the penile and anal zones?

Back 360

S2, S3, and S4
(S2, 3, 4 keep the penis off the floor)

Front 361

What nerve root is tested by the biceps reflex?

Back 361

C5 nerve root

Front 362

What nerve root is tested by the triceps reflex?

Back 362

C7 nerve root

Front 363

What nerve root is tested by the patellar reflex?

Back 363

L4 nerve root

Front 364

What nerve root is tested by the achilles reflex?

Back 364

S1 nerve root

Front 365

What nerve root is tested by the cremaster reflex (movement of testicles)?

Back 365

L1 and L2

Front 366

What nerve root is tested by the anal wink reflex?

Back 366

S3 and S4

Front 367

What is the mnemonic to remember the nerve roots associated with the clinical reflexes?

Back 367

S1, 2 - buckle my shoe (Achilles reflex)
L3, 4 - kick the door (patellar reflex)
C5, 6 - pick up sticks (biceps reflex)
C7, 8 - lay them straight (patellar reflex)

L1, L2 - testicles move (cremaster reflex)
S3, S4 - winks galore (anal wink reflex)

Front 368

What are primitive reflexes? Types?

Back 368

CNS reflexes that are present in a healthy infant, but are absent in a neurologically intact adult; normally disappear within 1st year of life
- Moro reflex
- Rooting reflex
- Sucking reflex
- Palmar reflex
- Plantar reflex
- Galant reflex

Front 369

What happens to the primitive reflexes present in healthy infants?

Back 369

- Normally disappear in the first year of life
- These primitive reflexes are inhibited by a mature / developing frontal lobe
- They reemerge in adults following frontal lobe lesions → loss of inhibition of these reflexes

Front 370

What reflex causes babies to abduct / extend their limbs when they are startled and then draw them together?

Back 370

Moro Reflex: "Hang on for life" reflex

Front 371

What reflex causes babies to move their head to one side if the cheek is stroked? Function?

Back 371

Rooting Reflex - nipple seeking

Front 372

What reflex occurs when the roof of the mouth in a baby is touched?

Back 372

Sucking Reflex

Front 373

What reflex occurs when the palm of a baby's hand is stroked?

Back 373

Palmar Reflex - causes them to curl their fingers

Front 374

What reflex occurs when the plantar surface of a baby's foot is stimulated?

Back 374

Plantar Reflex - causes dorsiflexion of large toe and fanning of other toes

Called the Babinski sign when it occurs in adults (UMN lesion)

Front 375

What reflex occurs when the side of the spine in a baby is stroked when they are in the ventral suspension (face down)?

Back 375

Galant Reflex - lateral flexion of the lower body toward the stimulated side

Front 376

What CNs lie medially in the brain stem?

Back 376

III, VI, XII
Motor = Medial

Front 377

What is the function of the pineal gland?

Back 377

- Melatonin secretion
- Circadian rhythm

Front 378

What is the function of the superior colliculi?

Back 378

Conjugate vertical gaze center

Front 379

What is the function of the inferior colliculi?

Back 379

Auditory function

Front 380

What is the term for the syndrome caused by a lesion of the superior colliculi? What are the symptoms? What can cause this?

Back 380

Parinaud Syndrome
- Paralysis of conjugate vertical gaze
- Cause: Pinealoma

Front 381

What is the name and function of CN I? Type?

Back 381

Olfactory (I)
- Smell: only CN without thalamic relay to cortex
- Sensory only

Front 382

What is the name and function of CN II? Type?

Back 382

Optic (II)
- Sight
- Sensory only

Front 383

What is the name and function of CN III? Type?

Back 383

Oculomotor (III)
- Eye movement (SR, IR, MR, IO)
- Pupillary constriction (sphincter pupillae: Edinger-Westphal nucleus w/ muscarinic receptors)
- Accommodation
- Eyelid opening (levator palpebrae)
- Motor only

Front 384

What is the name and function of CN IV? Type?

Back 384

Trochlear (IV)
- Eye movement (SO)
- Motor only

Front 385

What is the name and function of CN V? Type?

Back 385

Trigeminal (V)
- Mastication, facial sensation (ophthalmic, maxillary, mandibular divisions)
- Somatosensation from anterior 2/3 of tongue
- Sensory and motor function

Front 386

What is the name and function of CN VI? Type?

Back 386

Abducens (VI)
- Eye movement (LR)
- Motor only

Front 387

What is the name and function of CN VII? Type?

Back 387

Facial (VII)
- Facial movement
- Taste from anterior 2/3 of tongue
- Lacrimation
- Salivation (submandibular and sublingual glands)
- Eyelid closing (orbicularis oculi)
- Stapedius muscle in ear
- Note: nerve courses through parotid gland, but does not innervate it
- Both sensory and motor function

Front 388

What is the name and function of CN VIII? Type?

Back 388

Vestibulocochlear (VIII)
- Hearing and balance
- Sensory only

Front 389

What is the name and function of CN IX? Type?

Back 389

Glossopharyngeal (IX)
- Taste and somatosensation from posterior 1/3 of tongue
- Swallowing
- Salivation (parotid gland)
- Monitoring carotid body and sinus chemo- and baroreceptors
- Stylopharyngeus (elevates pharynx and larynx)
- Sensory and motor function

Front 390

What is the name and function of CN X? Type?

Back 390

Vagus (X)
- Taste from epiglottic region
- Swallowing
- Soft palate elevation
- Midline uvula
- Talking
- Coughing
- Thoracoabdominal viscera
- Monitoring aortic arch chemo- and baroreceptors
- Both sensory and motor function

Front 391

What is the name and function of CN XI? Type?

Back 391

Accessory (XI)
- Head turning (SCM) and shoulder shrugging (trapezius)
- Motor only

Front 392

What is the name and function of CN XII? Type?

Back 392

Hypoglossal (XII)
- Tongue movement
- Motor only

Front 393

What is the mnemonic for remembering which CNs have motor and sensory function?

Back 393

Some Say Marry Money But My Brother Says Big Boobs Matter More

Front 394

Where are the cranial nerve nuclei located?

Back 394

Tegmentum portion of the brain stem (between the dorsal and ventral portions)

Front 395

What CN nuclei are in the midbrain?

Back 395

Nuclei of CN III, IV
>4

Front 396

What CN nuclei are in the pons?

Back 396

Nuclei of CN V, VI, VII, VIII
5-8

Front 397

What CN nuclei are in the medulla?

Back 397

Nuclei of CN IX, X, XII
(>9, except 11)

Front 398

What CN nuclei are in the spinal cord?

Back 398

Nucleus of CN XI

Front 399

Which CN nuclei are located laterally?

Back 399

Lateral nuclei = Sensory (aLar plate)

Front 400

Which CN nuclei are located medially?

Back 400

Medial nuclei = Motor (basal plate)

Front 401

What separates the sensory nuclei from the motor nuclei?

Back 401

Sulcus Limitans separates Alar plate (sensory/lateral) from the Basal plate (motor/medial)

Front 402

What makes up the afferent and efferent branches of the corneal reflex?

Back 402

- Afferent: V1 ophthalmic (nasociliary branch)
- Efferent: VII (temporal branch: orbicularis oculi)

Front 403

What makes up the afferent and efferent branches of the lacrimation reflex?

Back 403

- Afferent: V1 (loss of reflex does not preclude emotional tears)
- Efferent: VII

Front 404

What makes up the afferent and efferent branches of the jaw jerk reflex?

Back 404

- Afferent: V3 (sensory - muscle spindle from masseter)
- Efferent: V3 (motor - masseter)

Front 405

What makes up the afferent and efferent branches of the pupillary reflex?

Back 405

- Afferent: II
- Efferent: III

Front 406

What makes up the afferent and efferent branches of the gag reflex?

Back 406

- Afferent: IX
- Efferent: X

Front 407

What are the nuclei of the vagus nerve?

Back 407

- Nucleus Solitarius
- Nucleus Ambiguus
- Dorsal Motor Nucleus

Front 408

What kind of information comes through the nucleus solitarius? What CNs have their nuclei here?

Back 408

Visceral sensory information (eg, taste, baroreceptors, gut distention): CN VII, IX, and X

Front 409

What kind of information comes through the nucleus ambiguus? What CNs have their nuclei here?

Back 409

Motor innervation of pharynx, larynx, and upper esophagus (eg, swallowing, palate elevation): CN IX, X, and XI (cranial portion)

Front 410

What kind of information comes through the dorsal motor nucleus? What CNs have their nuclei here?

Back 410

Sends autonomic (parasympathetic) fibers to the heart, lungs, and upper GI: CN X

Front 411

Which CNs pass through the Cribriform Plate?

Back 411

CN I (Olfactory)

Front 412

Which CNs pass through the middle cranial fossa of the sphenoid bone?

Back 412

2-6
- CN II (Optic)
- CN III (Oculomotor)
- CN IV (Trochlear)
- CN V (Trigeminal)
- CN VI (Abducens)

Front 413

Which structures pass through the optic canal?

Back 413

- CN II
- Ophthalmic artery
- Central retinal vein

Front 414

Which structures pass through the superior orbital fissure?

Back 414

- CN III, IV, V1, VI
- Ophthalmic vein
- Sympathetic fibers

Front 415

Which structures pass through the Foramen Rotundum?

Back 415

CN V2

Front 416

Which structures pass through the Foramen Ovale?

Back 416

CN V3

Front 417

Which structures pass through the Foramen Spinosum?

Back 417

Middle Meningeal Artery

Front 418

Which CNs pass through the posterior cranial fossa of the temporal and occipital bone?

Back 418

7-12
- CN VII: Facial
- CN VIII: Vestibulocochlear
- CN IX: Glossopharyngeal
- CN X: Vagus
- CN XI: Accessory
- CN XII: Hypoglossal

Front 419

Which structures pass through the internal auditory meatus?

Back 419

- CN VII
- CN VIII

Front 420

Which structures pass through the jugular foramen?

Back 420

- CNs IX, X, XI
- Jugular vein

Front 421

Which structures pass through the hypoglossal canal?

Back 421

CN XII

Front 422

Which structures pass through the Foramen Magnum?

Back 422

- Spinal roots of CN XI
- Brain stem
- Vertebral arteries

Front 423

Through what structures do the divisions of CN V exit the skull?

Back 423

Middle cranial fossa in sphenoid bone
- V1: Superior orbital fissure
- V2: Foramen rotundum
- V3: Foramen ovale

Front 424

What is the cavernous sinus?

Back 424

Collection of venous sinuses on either side of the pituitary

Front 425

What blood drains into the cavernous sinus? Where does it drain next?

Back 425

- Drains from eye and superficial cortex → cavernous sinus
- Cavernous sinus drains → internal jugular vein

Front 426

What structures are found within the cavernous sinus?

Back 426

- CN III, IV, V1, V2, and VI and post-ganglionic sympathetic fibers (nerves that control extra-ocular muscles (plus V1 and V2))
- Internal carotid artery

Front 427

What causes cavernous sinus syndrome?

Back 427

- Mass effect
- Fistula
- Thrombosis

Front 428

What are the symptoms of cavernous sinus syndrome?

Back 428

- Ophthalmoplegia (paralysis of the muscles within or surrounding the eye)
- ↓ Corneal and maxillary sensation with normal visual acuity
- CN VI commonly affected

Front 429

What are the common cranial nerve lesions?

Back 429

- CN V motor lesion
- CN X lesion
- CN XI lesion
- CN XII lesion (LMN)

Front 430

What nerve lesion could cause the jaw to deviate to one side? How?

Back 430

CN V motor lesion: jaw deviates TOWARD the side of the lesion due to unopposed force from the opposite pterygoid muscle

Front 431

What nerve lesion could cause the uvula to deviate to one side? How?

Back 431

CN X lesion: uvula deviates AWAY from side of lesion, weak side collapses and uvula points away

Front 432

What nerve lesion could cause weakness of turning the head and shoulder droop? How?

Back 432

CN XI lesion: weakness turning the head toward the CONTRALATERAL side of the lesion (SCM), shoulder droop on side of lesion (trapezius); the left SCM contracts to help turn the head to the right

Front 433

What nerve lesion could cause the tongue to deviate to one side? How?

Back 433

CN XII lesion (LMN): tongue deviates TOWARD side of lesion ("lick your wounds") due to weakened tongue muscles on the affected side

Front 434

What are the components and function of the outer ear?

Back 434

- Consists of the visible portion of the ear (pinna), including the auditory canal and eardrum
- Transfers sound waves via vibration of eardrum

Front 435

What are the components and function of the middle ear?

Back 435

- Air filled space with three bones called the ossicles (malleus, incus, stapes)
- Ossicles conduct and amplify sound from the eardrum to the inner ear

Front 436

What are the components and function of the inner ear?

Back 436

- Snail-shaped, fluid-filled cochlea
- Contains basilar membrane that vibrates 2° to sound waves
- Vibration transduced via specialized hair cells→ auditory nerve signaling → brainstem

Front 437

How does the frequency of sound waves relate to the basilar membrane?

Back 437

Tonotopy:
- Low frequency heard at apex hear helicotrema (wide and flexible)
- High frequency heard best at base of cochlea (thin and rigid)

Front 438

Where are low frequency sounds heard best?

Back 438

Apex of basilar membrane (wide and flexible)

Front 439

Where are high frequency sounds heard best?

Back 439

Base of cochlea / basilar membrane (thin and rigid)

Front 440

What are the types of hearing loss?

Back 440

- Conductive
- Sensorineural
- Noise-induced

Front 441

What type of hearing loss causes an abnormal Rinne test (bone > air) and a Weber test that localizes to the affected ear?

Back 441

Conductive Hearing Loss

Front 442

What type of hearing loss causes a normal Rinne test (air > bone) and a Weber test that localizes to the unaffected ear?

Back 442

Sensorineural Hearing Loss

Front 443

What causes noise-induced hearing loss?

Back 443

Damage to sterociliated cells in organ of Corti
- Loss of high frequency hearing first
- Sudden extremely loud noises can produce hearing loss due to tympanic membrane rupture

Front 444

What is a normal Rinne test result?

Back 444

Air conducts sound/vibration better than bone

Front 445

How does the Weber test help you determine the type of hearing loss?

Back 445

- Localizes to AFFECTED ear: CONDUCTIVE hearing loss
- Localizes to UNAFFECTED ear: SENSORINEURAL hearing loss

Front 446

How does the Rinne test help you determine the type of hearing loss?

Back 446

- Abnormal (bone > air): Conductive
- Normal (air > bone): Sensorineural

Front 447

What type of hearing loss is characterized by loss of high frequency hearing first?

Back 447

Noise-induced hearing loss

Front 448

How can sudden extremely loud noises produce hearing loss?

Back 448

Due to tympanic membrane rupture

Front 449

What are the types of facial lesions?

Back 449

- UMN lesion
- LMN lesion
- Facial nerve palsy

Front 450

What kind of lesion causes paralysis of the lower face with the forehead spared?

Back 450

- UMN lesion of facial nerve (contralateral to lower face paralysis)
- Forehead spared because of bilateral UMN innervation

Front 451

What kind of lesion causes paralysis of the upper and lower face?

Back 451

- LMN lesion of facial nerve (ipsilateral to face paralysis)
- Forehead affected unlike in an UMN lesion

Front 452

What causes facial nerve palsy?

Back 452

Complete destruction of the facial nucleus itself or its branchial efferent fibers (facial nerve proper)

Front 453

What are the symptoms of facial nerve palsy?

Back 453

Peripheral ipsilateral facial paralysis (drooping smile) with inability to close eye on involved side

Front 454

What can cause a facial nerve palsy (destruction of facial nucleus or its branchial efferent fibers)?

Back 454

- Idiopathically (Bell palsy)
- Lyme disease
- Herpes simplex
- Less common: Herpes Zoster, Sarcoidosis, tumors, and diabetes

Front 455

How do you treat facial nerve palsy?

Back 455

Corticosteroids

Front 456

What muscles are involved in mastication?

Back 456

- Masseter
- Temporalis
- Medial Pterygoid
- Lateral Pterygoid

Front 457

Which muscles close the jaw?

Back 457

M's Munch:
- Masseter
- Temporalis
- Medial pterygoid

"It takes more muscle to keep your mouth shut" (opening uses gravity)

Front 458

Which muscles open the jaw?

Back 458

Lateral Pterygoid (lateral lowers)

"It takes more muscle to keep your mouth shut" (opening uses gravity)

Front 459

What innervates the muscles of mastication?

Back 459

Trigeminal nerve (V3)

Front 460

What kind of eye conditions improve with glasses?

Back 460

Refractive Errors

Front 461

What eye condition causes light to focus behind the retina? What is wrong with the eye?

Back 461

Hyperopia: eye is too short for refractive power of cornea and lens

Front 462

What eye condition causes light to focus in front of the retina? What is wrong with the eye?

Back 462

Myopia: eye is too long for refractive power of cornea and lens

Front 463

What eye condition causes an abnormal curvature of the cornea? Effect on vision?

Back 463

Astigmatism
- Results in different refractive power at different axes

Front 464

What eye condition causes a decrease in focusing ability during accommodation? Why?

Back 464

Presbyopia - due to sclerosis and ↓ elasticity

Front 465

What causes sterile pus (hypopyon) and conjunctival redness?

Back 465

Uveitis - inflammation of anterior uvea and iris

Front 466

What is uveitis associated with?

Back 466

Systemic inflammatory disorders
- Sarcoid
- Rheumatoid arthritis
- Juvenile idiopathic arthritis
- TB
- HLA-B27-associated conditions

Front 467

What eye condition is associated with retinal edema and necrosis leading to a scar?

Back 467

Retinitis
- Often viral (CMV, HSV, HZV)
- Associated with immunosuppression

Front 468

What happens to an eye with retinitis?

Back 468

- Retinal edema
- Necrosis leading to scar

Front 469

What causes acute, painless monocular vision loss? What is the appearance of the retina in this condition?

Back 469

Central Retinal Artery Occlusion:
- Retina appears cloudy with attenuated vessels
- Cherry-red spot at fovea

Front 470

What happens if there is central retinal artery occlusion?

Back 470

Acute, painless monocular vision loss

Front 471

What causes retinal hemorrhage and edema in the affected area?

Back 471

Retinal Vein Occlusion
- Blockage of central or branch retinal vein due to compression from nearby arterial atherosclerosis

Front 472

What happens due to retinal vein occlusion?

Back 472

- Retinal hemorrhage
- Retinal edema

Front 473

What happens to the eye in patients with diabetes?

Back 473

Diabetic Retinopathy:
- Non-proliferative type
- Proliferative type

Front 474

What causes the non-proliferative type of diabetic retinopathy? How do you treat it?

Back 474

- Damaged capillaries leak blood → lipids and fluid seep into retina → hemorrhages and macular edema

- Treat with blood sugar control and a macular laser

Front 475

What causes the proliferative type of diabetic retinopathy? How do you treat it?

Back 475

- Chronic hypoxia results in new blood vessel formation with resultant traction on retina

- Treat with peripheral retinal photo-coagulation and anti-VEGF injections

Front 476

What happens to the eye with glaucoma?

Back 476

- Optic disc atrophies
- Characteristic cupping of optic disc
- Usually ↑ intra-ocular pressure (IOP)
- Progressive peripheral visual field loss

Front 477

In whom is there greater incidence of open angle glaucoma?

Back 477

- ↑ Age
- African-American race
- Family history
- More common in US

Front 478

What is the cause of primary open angle glaucoma?

Back 478

Causes is unclear

Front 479

What is the cause of secondary open angle glaucoma?

Back 479

Blocked trabecular meshwork from WBCs (eg, uveitis), RBCs (eg, vitreous hemorrhage), retinal elements (eg, retinal detachment)

Front 480

What is the cause of primary closed/narrow angle glaucoma?

Back 480

- Enlargement or forward movement of lens against central iris (pupil margin)
- Leads to obstruction of normal aqueous flow through pupil
- Fluid builds up behind iris, pushing peripheral iris against cornea and impeding flow through the trabecular meshwork

Front 481

What is the cause of secondary closed/narrow angle glaucoma?

Back 481

Hypoxia from retinal disease (eg, diabetes or vein occlusion) induces vasoproliferation in iris that contracts angle

Front 482

How does the time course over which closed/narrow angle glaucoma occurs affect the prognosis?

Back 482

- Chronic closure: often asymptomatic with damage to optic nerve and peripheral vision
- Acute closure: ophthalmologic emergency, very painful, sudden vision loss, halos around lights, rock-hard eye, frontal headache

Front 483

What are the symptoms of an acute closed/narrow angle glaucoma?

Back 483

- Very painful
- Sudden vision loss
- Halos around lights
- Rock-hard eye
- Frontal headache

Front 484

What should you not give a patient with acute closed/narrow angle glaucoma?

Back 484

Don't give epinephrine because of its mydriatic effect

Front 485

What happens in cataracts?

Back 485

Painless, often bilateral, opacification of the lens → ↓ in vision

Front 486

What are the risk factors for cataracts?

Back 486

- ↑ Age
- Smoking
- EtOH
- Excessive sunlight
- Prolonged corticosteroid use
- Classic galactosemia
- Galctokinase deficiency
- Diabetes (sorbitol)
- Trauma
- Infection

Front 487

What is the term for optic disc swelling?

Back 487

Papilledema

Front 488

What is Papilledema? Cause?

Back 488

- Optic disc swelling (usually bilateral)
- Due to ↑ intracranial pressure (2° to mass effect)

Front 489

What is the appearance of Papilledema on physical exam?

Back 489

Enlarged blind spot and elevated optic disc with blurred margins on fundoscopic exam

Front 490

What nerves innervate the extraocular muscles?

Back 490

(LR6 SO4)3
- CN VI innervates Lateral Rectus
- CN IV innervates Superior Oblique
- CN III innervates Superior Rectus, Medial Rectus, Inferior Rectus, and Inferior Oblique

Front 491

What is the function of the superior oblique? Innervation?

Back 491

- Abducts, intorts, and depresses while abducted
- Innervated by CN IV

Front 492

What lesion causes the eye to look down and out?

Back 492

CN III damage
- Superior Rectus
- Medial Rectus
- Inferior Rectus
- Inferior Oblique

Front 493

What are the effects of CN III damage?

Back 493

- Eyes look down and out
- Ptosis
- Pupillary dilation
- Loss of accommodation

Front 494

What lesion causes the eye to move upward, particularly with contralateral gaze and head tilt toward the side of the lesion?

Back 494

CN IV damage
- Superior Oblique

Front 495

What are the effects of CN IV damage?

Back 495

- Eye moves upward
- Particularly moves upward with contralateral gaze and head tilt toward the side of the lesion
- Problems going downstairs, may present with compensatory head tilt in the opposite direction

Front 496

What lesion causes the eye to look medially and cannot abduct?

Back 496

CN VI damage
- Lateral Rectus

Front 497

What are the effects of CN VI damage?

Back 497

- Medially directed eye
- Eye cannot abduct

Front 498

How does the action of the superior and inferior obliques compare to the rectuses?

Back 498

- S & I Obliques: medial
- S & I Rectuses: lateral

(Obliques move the eye in the Opposite direction)

Front 499

How do you test the superior oblique?

Back 499

Have patient depress eye from adducted position (medial)

Front 500

How do you test the inferior oblique?

Back 500

Have patient elevate eye from adducted position (medial)

Front 501

How do you test the superior rectus?

Back 501

Have patient elevate eye from abducted position (lateral)

Front 502

How do you test the inferior rectus?

Back 502

Have patient depress eye from abducted position (lateral)

Front 503

What is the term for constriction of the pupil? How is this mediated?

Back 503

Miosis (parasympathetic)
- 1st neuron: Edinger-Westphal nucleus → ciliary ganglion via CN III
- 2nd neuron: short ciliary nerves → pupillary sphincter muscles

Front 504

What is the term for dilation of the pupil? How is this mediated?

Back 504

Mydriasis (sympathetic)
- 1st neuron: hypothalamus → ciliospinal center of Budge (C8-T2)
- 2nd neuron: exits at T1 to superior cervical ganglion (travels along cervical sympathetic chain near lung apex and subclavian vessels)
- 3rd neuron: plexus along internal carotid → cavernous sinus → enters orbit as long ciliary nerve to pupillary dilator muscles

Front 505

What is the function of the short vs long ciliary nerves?

Back 505

- Short ciliary nerves → pupillary sphincter muscle (miosis / constriction)
- Long ciliary nerves → pupillary dilator muscles (mydriasis / dilation)

Front 506

What happens when light hits the retina?

Back 506

- Sends a signal via CN II → pretectal nuclei in midbrain → activates bilateral Edinger-Westphal nuclei
- Pupils contract bilaterally

Front 507

What does the swinging flashlight test check?

Back 507

Checks for "Marcus Gunn Pupil"
- Afferent pupillary defect
- Optic nerve damage or severe retinal injury → ↓ bilateral pupillary constriction when light is shone in affected eye relative to unaffected eye

Front 508

If there is an afferent pupillary defect, what would you expect to happen when you shine the line in the affected eye vs the unaffected eye?

Back 508

When you shine in the affected eye there is less of a pupillary constriction bilaterally

Front 509

What kind of fibers are in CN III?

Back 509

- Motor output: interior of nerve (white)
- Parasympathetic output: peripheral part of nerve (red)

Front 510

What can affect the motor output from CN III? Signs?

Back 510

- Vascular disease (eg, diabetes: glucose → sorbitol) due to ↓ diffusion of O2 and nutrients to interior fibers from compromised vasculature that resides on outside of nerve
- Signs: ptosis, "down and out" gaze

Front 511

What can affect the parasympathetic output from CN III? Signs?

Back 511

- Fibers on periphery are first affected by compression (eg, posterior communicating artery aneurysm or uncal herniation)
- Signs: diminished or absent pupillary light reflex, "blown pupil", often with "down-and-out" gaze

Front 512

What happens in a Retinal Detachment?

Back 512

Separation of neurosensory layer of retina (photoreceptor layer with rods and cones) from outermost pigmented epithelium (normally shields excess light, supports retina) → degeneration of photoreceptors → vision loss

Front 513

What can cause retinal detachment?

Back 513

May be secondary to:
- Retinal breaks
- Diabetic traction
- Inflammatory effusions

Front 514

In what patients is retinal detachment more common? Clinical course?

Back 514

- Breaks more common in patients with high myopia (nearsightedness)
- Often preceded by posterior vitreous detachment (flashes and floaters)
- Eventual monocular loss of vision like a "curtain drawn down"
- Surgical emergency

Front 515

What are the complications of macular degeneration?

Back 515

Causes distortion (metamorphopsia) and eventual loss of central vision (scotomas)

Front 516

What are the types of macular degeneration? Which is more common?

Back 516

- Dry (non-exudative, >80%)
- Wet (exudative, 10-15%)

Front 517

What happens in dry, non-exudative macular degeneration?

Back 517

- Deposition of yellowish extracellular material in and beneath Bruch membrane and retinal pigment epithelium ("drusen")
- Gradual ↓ in vision

Front 518

How can you prevent progression of dry, non-exudative macular degeneration?

Back 518

Prevent progression with multivitamin and anti-oxidant supplements

Front 519

What happens in wet, exudative macular degeneration?

Back 519

Rapid loss of vision due to bleeding secondary to choroidal neovascularization

Front 520

How do you treat wet, exudative macular degeneration?

Back 520

Anti-vascular endothelial growth factor injections (anti-VEGF) or laser

Front 521

What causes this visual defect?

Back 521

1. Right Anopia - lesion to R optic nerve

Front 522

What causes this visual defect?

Back 522

2. Bitemporal Hemianopia - pituitary lesion, lesion at chiasm

Front 523

What causes this visual defect?

Back 523

3. Left Homonymous Hemianopia - lesion to Optic Tract (after chiasm)

Front 524

What causes this visual defect?

Back 524

4. Left Upper Quadrantic Anopia - R temporal lesion (Meyer loop), MCA

Front 525

What causes this visual defect?

Back 525

Left Lower Quadrantic Anopia
- Right parietal lesion (dorsal optic radiation), MCA

Front 526

What causes this visual defect?

Back 526

6. Left Hemianopia with Macular Sparing (PCA infarct)

Front 527

What causes this visual defect?

Back 527

Central Scotoma
- Macular degeneration

Front 528

What is the path of Meyer's loop? What information does it carry? Lesion?

Back 528

- Loops around inferior horn of lateral ventricle
- Contains visual images of inferior retina (so lesion to it causes loss of upper quadrant)

Front 529

What is the path of dorsal optic radiation? What information does it carry? Lesion?

Back 529

- Takes shortest path via internal capsule
- Contains visual images of superior retina (so lesion to it causes loss of lower quadrant)

Front 530

What are the characteristics of an image as it hits the primary visual cortex?

Back 530

It is upside down and left-right reversed

Front 531

What structure allows for crosstalk between CN VI and CN III nuclei?

Back 531

Medial Longitudinal Fasciculus (MLF)

Front 532

What is the function of the Medial Longitudinal Fasciculus (MLF)?

Back 532

- Pair of tracts that allows for crosstalk between CN VI and CN III nuclei
- Coordinates both eyes to move in same horizontal direction
- Highly myelinated (must communicate quickly so eyes move at same time)

Front 533

What disease causes injury to Medial Longitudinal Fasciculus (MLF)? Implications?

Back 533

- Can be demyelinated in multiple sclerosis
- Causes Internuclear Ophthalmoplegia (INO)

Front 534

What is wrong in Internuclear Ophthalmoplegia (INO)?

Back 534

Lesion of Medial Longitudinal Fasciculus (MLF)
- Lack of communication, such that when CN VI nucleus activates ipsilateral lateral rectus, contralateral CN III nucleus does not stimulate medial rectus to fire
- Abducting eye gets nystagmus (CN VI overfires to stimulate CN III)
- Convergence is normal

Front 535

What happens when you look left?

Back 535

- Left nucleus of CN VI fires, which contracts the Left Lateral Rectus
- Stimulates the contralateral (right) nucleus of CN III via the Right MLF to contract the right medial rectus

Front 536

What does the "right" or "left" refer to in Right INO or Left INO?

Back 536

Directional term - refers to which eye is paralyzed