Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
123 Cards in this Set
- Front
- Back
|
Cranial nerves with PNS inputs
|
CN III
CN VII CN IX CN X |
|
|
PNS, SNS, Adrenal and Somatic synaptic junctions
|
PNS - Ach nicotinic between neuron; Ach muscarinic on organ
SNS - Ach nicotinic between neurons; norepinephrine on organ (except Ach on sweat glands) Adrenal - Ach on nicotinic from SNS system Somatic - Ach on Nicotinic on organ |
|
|
Adrenergic and cholingergic receptors
|
a1 - Smooth muscle (vessels, sphincters, radial muscle), Gq - constriction
a2 - GI tract, postganglionic nerve terminals, platelets, Gi, inhibition/relaxation/dilation b1 - heart, Gs, contractility, HR, up b2 - smooth muscle (skeletal, bronchial, walls of GI and bladder), Gs, relaxation N1 - Skeletal muscle - opens Na+/K+ channel N2 - Autonomic ganglia - opens Na/K channel M1 - CNS, Gq M2 - Heart, Gi M3 - glands, smooth muscle, Gq |
|
|
Hexamethonium
|
Blocks nicotinic but not muscarinic cholinergic receptors
|
|
|
Alpha 1 agonists and antagonists
|
Agonists - Norepi, phenylephrine (RAISE BP)
Antagonist - Phenoxybenzamine, Phentolamine, Prazosin (LOWER BLOOD PRESSURE) |
|
|
Alpha 2 agonists and antagonists
|
Agonist - clonidine
Antagonist - Yohimbine |
|
|
Beta 1 agonists and antagonists
|
Agonist - Norepinephrine, Isoproteerenol, Dobutamine
Antagonist - Propanolol, Metoprolol (SELECTIVE); (Lower HR, contractility) |
|
|
Beta 2 agonists and antagonists
|
Agonist - Isoproterenol, Albuterol (treat asthma)
Antagonist - Propanolol, Butoxamine (NO in asthma) |
|
|
Sensory receptor transduction general
|
Stimulus causes ion channel opening and current flow, usually depolarizing inward EXCEPT photoreceptor where light reduces inward flow to hyperpolarize
|
|
|
Fastest and slowest nerve fibers
|
Fastest - Alpha motor neurons, 1a muscle spindle or IIb golgi tendon organs
Touch and pressure on Type II next, also gamma motor neurons to muscle spindles Slowest - C fibers (slow pain); pain and temp |
|
|
Fast pain and temp
|
Carried by delta fibers and III afferents
Faster than C fibers |
|
|
Slowly adapting vs rapid adapting
|
Slowly adapting - respond repeatedly to prolonged stimuli (muscle spindle, pressure, slow pain)
Fast adapting - onset and offset of stimulus is detected (Pacinian [vibration], light touch) |
|
|
Substance P
|
NT for nociception, inhibited release via opioids
|
|
|
Correction
a) Hypertropia b) Myopia c) Astigmatism d) Presbyopia |
a) Hypertropia - light focused behind retina, convex lens
b) Myopia - light focused in front of retina, biconcave lens c) Astigmatism - lens not uniform, cylindric lens d) Presbyopia - loss of accommodation, near point is farther, convex lens |
|
|
Vision pathway
|
Light strikes epithelial cells, Cis retinal to all trans retinal; metarhodopsin II formed, activates transducin, which activates phosphodiesterase, cGMP drops, hyperpolarization due to Na+ channel closure, DECREASED NT release
Feeds into optic nerve, superior colliculis, lateral geniculate, occipital lobe/calcarine sulcus Nasal fields cross, temporal fields ipsilateral at chiasm |
|
|
Rods vs cones
|
Rods - high sensitivity, low acuity, slow to adapt to dark, not in fovea
Cones - low sensitivity, high acuity, fast to adapt to dark, rich in fovea (and with 1:1 bipolar cell connections) |
|
|
Cutting optic pathway at
a) Optic nerve b) Optic chiasm c) Optic tract d) Geniculocalcarine tract e) Temporal lesion, MCA f) Parietal lesion, MCA g) Macular degeneration |
Temporal fields stay ipsilateral, Nasal fields cross at optic chiasm
a) Optic nerve - one eye lost b) Optic chiasm - Bitemporal hemaniospia c) Optic tract - Homonymous hemaniopsia d) Geniculocalcarine tract - Homonymous hemaniopsia with macular sparing e) Temporal lesion, MCA - Contralateral upper quadrant anopia f) Parietal lesion, MCA - Contralateral lower quadrant anopia g) central scotoma |
|
|
Sound mechanism
|
Sound into ear, passes to tympanic membrane and carried into malleus, incus, stapes. Stapes causes oval window vibration and displacement of fluid in membranous ducts
Perilymph (high Na) on outside, endolymph (high K) on inside Organ of corti - Basilar membrane has hair cells with cilia that embed on tectorial membrane. High frequency at rigid base, low frequency at compliant apex (near helicotrema); bending causes change in K+ conductance, transmited to spiral ganglion of Auditory nerve |
|
|
Sound auditory pathway
|
Lateral lemniscus to inferior colliculus to medial geniculate of thalamus to auditory cortex
Cross quickly so only a lesion of cochlea produces unilateral deafness |
|
|
Olfactory mechanism
|
Receptor cells are true neurons, and only continuous turnover ones. Odor binds receptors, activate G proteins, cAMP, and depolarization for APs to carry (most other senses are graded not APs)
Unmyelinated C fibers carry smell, Trigeminal (V) carries noxious stimuli (ammonia) Olfactory neurons synapse on mitral cells which project to prepiriform cortex |
|
|
Taste pathway, anterior vs posterior tongue
|
Anterior 2/3 - chorda tympani (VII), fungiform papillae, sweet, salty and umami
Posterior 1/3 - Glossopharyngeal, (some Vagus at throat and epiglottis), circumvallate adn foliate papillae, sour and bitter NOT neurons, depolarizing potential transmitted to solitary nucleus then to ipsilateral ventral posteromedial nucleus of thalamus then taste cortex |
|
|
Small vs Large motoneurons
|
Small - few fibers, lowest threshold, fire fast but small force
Large - many fibers, high threshold, fire last, most force |
|
|
Muscle spindle function
|
Nuglear bag (dynamic change in length, goup Ia afferent) and Nuclear chain (static change in length, group II afferent)
Detect change in length, INTRAFUSAL fibers, activate alpha motorneuron to contract homonymous muscle; gamma motoneurons modulate sensitivity by changes length of muscle spindle |
|
|
Golgi tendon reflex
|
Golgi tendon organs EXTRAFUSAL (near tendons), detect muscle tension, 1b afferents. Disynaptic and activate inhibitory interneurons to relax syngergistic and activate antagonist muscle (activated in decerebrate rigidity)
|
|
|
Flexor withdrawal reflex
|
Polysynaptic, pain on II, III and IV afferents leads to many synapses for ipsilateral flexion and contralateral extension
i.e withdraw hand from hot stove |
|
|
Renshaw cells
|
Inhibitory cells of ventral horn of spinal cord
Get input from collateral axons of motorneurons and can negatively feed back on the motoneurons |
|
|
Spinal shock, Brown-Sequard syndrome
|
Transection of cord, permanent loss of conscious sensation below and motor movements BUT
Spinal shook is loss of excitatory influence after cut, limbs flaccid, reflexes are absent. With time they can return and may even by hyperreflexive C1 - death C3 - loss of breathing C7 - loss of SNS to heart, HR and BP drop T1 and up - Horner's syndrome due to damage to SNS ganglion Brown Seyquard - cutting cord leads to Ipsilateral UMN signs below lesion (corticospinal loss), ipsilateral tactile, vibration, proprioception loss (dorsal column), contralateral pain and temp a few levels below (spinothalamic), Ipsilateral LMN signs at level of lesion |
|
|
Lesion above lateral vestibular nucleus
|
Tract controls stimulation of extensors and inhibition of flexors
Loss gets decerebrate rigidity because removal of inhibition, cut dorsal roots to get rid of reflex |
|
|
lesion above the red nucleus
|
Decorticate posturing
|
|
|
Cerebellum parts and role
|
Vestibulocerebellum - balance and eye movement
Pontocerebellum - planning and initiation of movement Spinocerebellum - synergy for rate, force, range and direction of movement Granular layer - innermost, Granule, Golgi Type II and glomeruli, mossy fibers in (all over brain, simple spikes Purkinje cell layer - ALWAYs inhibitory output (GABA), ONLY cerebellar cortex output Molecular layer - outer, stellate and basket cells, dendrites from Purkinje and Golgi cells; parallel fibers on all three |
|
|
Climbing fibers vs mossy fibers
|
Climbing fibers - from ION, synapse on Purkinje cells and have complex spike bursts to condition Purkinje cells (motor learning)
Mossy fibers - many centers in brain, simple spikes on Purkinje cells, synapse on granule cells too, help coordinate |
|
|
Globus pallidus lesion
|
Loss of postural support
|
|
|
STN lesion
|
Hemiballismus, release of inhibition on contralateral side
|
|
|
Striatum lesion
|
Loss of inhibition, quick continuous uncontrollable movements (Huntington's disease)
|
|
|
Substantia nigra lesions
|
Loss of dopaminergic neurons
Direct path - D1 - excitatory; Indirect path - D2 - inhibitory Overall loss of dopamine leads to inhibitory activity and lead pipe rigidity, tremor, reduced voluntary movement |
|
|
Language in brain
|
Right hemisphere - facial expresion, tone, body language
Left hemisphere - language; Wernicke's for sensory understanding; Broca's for motor aphasia |
|
|
CSF vs blood components
|
CSF is similar to blood in Most small ions and lipophilic small things. LESS protein, glucose, cholesterol, K+, Ca++; More creatinine and Mg2++
|
|
|
Embryology development of brain and regions in development
|
Notochord induces neuroectoderm and neural plate formation
Gives rise to neural tube and neural crest cells; notochord becomes nucleus pulposus of IV discs Alar plate (dorsal) sensory; Basal (ventral) motor Prosencephalon becomes Telencephalon (Cerebrum and lateral ventricles) and Diencephalon (thalamus and 3rd ventricle) Mesencephalon becomes midbrain and Aqueduct Rhombencephalon becomes Metencephalon (Pons, Cerebellum, 4th ventricle upper) and Myelencephalon (Medulla, lower part 4th ventricle) |
|
|
Neural tube defects
|
Elevated AFP and AChE in amniotic fluid
Spina bifida (bony, no structures, hair tuft or dimple); Meningocele (no cord just meninges) and Meningomyelocele at caudal |
|
|
Anencephaly vs Holoprosencephaly
|
Anencephaly - anterior neural tube malforms, no forebrain, open calvarium, high AFP, polyhydramnios (no swallowing), DM I association, folate reduce
Holoprosencephaly - failure of hemisphere separation, multifactorial, Shh related. Cleft lip/palate in mild, cyclopia in severe |
|
|
Chiari II and Dandy Walker
|
Chiari II - cerebellar tonsillar and vermian herniation thru foramen magnum; acqueductal stenosis and closed hydrocephalus. Usually has myelomeningocele and paralysis
Dandy-Walker - Agenesis of cerebellar vermis, enlarged 4th ventricle, hydrocephalis and spina bifida |
|
|
Syringomyelia
|
Cyst in central part of cord. Loss of Spinothalamic tract first (BIL pain and temp); sensation in upper extrimities is preserved
|
|
|
Astrocyte role and marker
|
Physical support, repair (reactive gliosis), K+ metabolism, removal of NT, BBB barrier maintenance
GFAP marker |
|
|
Meissner's corpuscles
|
Large, myelinated, fast adapt for fine touch, position sense, dynamic
|
|
|
Pacinian corpuscles
|
Deep, large myelinated fibers for vibration and pressure
|
|
|
Merkel's discs
|
Large, myelinated slow adapting fibers near hair follicles for pressure, deep static touch (shapes, edges), position
|
|
|
NT Location and Change in disease: NE
|
Locus ceruleus (pons)
High in anxiety, low in depression |
|
|
NT Location and Change in disease: dopamine
|
Substantia nigra and ventral tegmentum
High in schizophrenia, low in parkinson's and depression |
|
|
NT Location and Change in disease: Serotonin
|
Raphe nuclei
low in anxiety, low in depression |
|
|
NT Location and Change in disease: ACh
|
Nucleus basalis of meynert
low in Alzheimers, Huntington's, high in REM |
|
|
NT Location and Change in disease: GABA
|
nucleus accumbens
Low in anxiety and Huntingtons |
|
|
Hypothalamus role and regions
|
TAN HATS (Thirst and water, Adenohypophysis control, Neurohypophysis release, Hunger, Autonomic regulation, Temperature, Sexual urges)
Lateral - Hunger, destruction = anorexia, inh. by leptin Vertical - Satiety, destruction = hyperphagia, stimulated by leptin Anterior - Cooling, PNS, determines set point (modulated by IL-1, aspirin (COX inh.), etc) Posterior - Heating, SNS Suprachiasmatic - sleep wake |
|
|
Limbic system
|
5 F's: Feeding, Fleeing, Fighting, Feeling, Sex
Emotion, LT memory, olfaction, behavior modulation, ANS Hippocampus, Amygdala, Fornix, Mamillary bodies, cingulate gyrus |
|
|
Cerebellum inputs and outputs
|
Inputs:
a) Contralateral cortex via middle cerebellar peduncle b) Ipsilateral proprioception via inferior cerebellar peduncle (climbing and mossy fibers) Output a) Contralateral cortex via Purkinje fibers (INHIBITION) to deep nuclei of cerebellum to cortex via superior cerebellar peduncle Deep nuclei (dentate, emboliform, globose, fastigial) Lateral parts for voluntary movement, fall towards injured side Medial parts for balance, truncal coordination |
|
|
Parkinson's Disease pathology
|
Lewy bodies with alpha synuclein and loss of dopaminergic neurons of SN pars compacta
Tremor, cogwheel rigidity, Akinesia, Postural instability |
|
|
Hungtington's Disease pathology
|
CAG repeat, Caudate loses ACh and GABA
Chorea, aggression, depression, dementia, Neuronal death via NMDA-R binding and glutamate tox Atrophy of striatal nuclei |
|
|
Moving disorder and lesion
a) Hemiballismus b) Chorea c) Athetosis d) Myoclonus e) Dystonia |
a) Hemiballismus - contralateral STN, sudden wild flinging
b) Chorea - Basal ganglia such as in huntington's c) Athetosis - slow writhing, ex Huntingtons, basal ganglia d) Myoclonus - Sudden BRIEF muscle contract, Jerks, hiccups, metabolic abnormalities (renal and liver fail) e) Dystonia - SUSTAINED muscle contract, Writer's cramp, blepharospasm |
|
|
Tremor types
|
Essential tremor (postural) - action tremor, exacerbated by holding position; pts often self medicate with alcohol to reduce
Resting tremor - uncontrolled, alleviated by intention, ex. Parkinson's Intention tremor - during intentional action, cerebellar dysfunction |
|
|
Lesion: Amygdala
|
BIL causes Kluver-Bucy (hyperorality, hypersexual, disinhibited)
HSV-1 assoc. |
|
|
Lesion: Frontal lobe
|
Disinhibition and deficits in concentration, orientation, judgement
|
|
|
Lesion: Right parietal lobe
|
Spatial neglect syndrome
|
|
|
Lesion: Reticular activating system
|
Reduced arousal and wakefullness
|
|
|
Lesion: Mammillary bodies
|
Wernicke-Korsakoff syndrome, B1 def, alcohol
Precipitated by giving glucose without B1 |
|
|
Lesion: Basal ganglia
|
Tremor at rest, chorea or athetosis
Parkinson's and Huntington's |
|
|
Lesion: Cerebellar hemisphere
|
Intention tremor, limb ataxia, loss of balance, IPSILATERAL deficits. Fall towards lesion
|
|
|
Lesion: Cerebellar vermis
|
Truncal ataxia, dysarthria
|
|
|
Lesion: Hippocampus
|
Anterograde amnesia
|
|
|
Lesion: PPRF
|
Eyes look away from lesion
|
|
|
Lesion: Frontal eye fields
|
Eye looks toward lesion
|
|
|
Central pontine myelinosis
|
Acute paralysis, dysarthria, dysphagia, diplopia, loss of consciousness
May be "Locked-in"; Due to massive axonal demyelination in pontine white matter tracts Usually due to overly rapid correction of Na+ levels in hyponatremia |
|
|
Aphasia types
a) Broca's b) Wernicke's c) Global d) Conduction |
a) Broca's - Nonfluent aphasia, intact comprehension, Broca's area in inferior frontal gyrus of frontal lobe
b) Wernicke's - Fluent aphasia with impaired comprehension; superior temporal gyrus of temporal lobe c) Global - Nonfluent aphasia with impaired comprehension. BOTH areas d) Conduction - poor repetition but fluent speech, intact comphrehension. Can't repeat phrases. Damage to arcuate fasciculus |
|
|
Therapeutic hyperventilation
|
Reduce CO2 to help ICP in cases of acute cerebral edema (stroke, trauma); decreases cerebral perfusion
|
|
|
Stroke effect: MCA
|
Motor and sensory loss in contralateral upper limb and face
Aphasia if in left (dominant) hemisphere, Hemineglect if in nondominant (right) |
|
|
Stroke effect: ACA
|
Sensory and motor loss in contralateral lower limb
|
|
|
Stroke effect: Lateral striate artery
|
Striatum, internal capsule
Contralateral hemiparesis/hemiplegia; common location of lacunar infarcts for HTN |
|
|
Medial medullary syndrome
|
Infarct of paramedian branches of ASA and vertebral bodies leads to contralateral hemiparesis of lower limbs, reduced proprioception
Ipsilateral hypoglossal dysfunction Supplies lateral corticospinal tract, medial lemniscus, caudal medulla |
|
|
Stroke effect: PICA
|
Lateral medulla
Have vomiting, vertigo, nystagmus, pain and temp from face/limbs lost Lateral medullary syndrome (Wallenberg's) - Dysphagia and Hoarseness, gag, reflex, ipsilateral Horner's syndrome; Nucleus AMBIGUUS |
|
|
Stroke effect: AICA
|
Vomiting, vertigo, nystagmus,
FACIAL PARALYSIS, loss of lacrimation, salivation, taste from ant 2/3 tongue, corneal reflex, loss of pain and temp and ipsilateral hearing due to lateral pontine syndrome Ataxia and dysmetria due to middle and inferior cerebellar peduncles |
|
|
Stroke effect: PCA
|
Occipital cortex, visual cortex leads to contralateral hemaniopia with macular sparing
|
|
|
Stroke effect: AComm & PComm
|
Berry aneurysm sites
AComm - impinges on CN, visual field PComm - CN III palsy (down and out, ptosis and pupil dilation) |
|
|
Things associated with berry aneurysms
|
ADPKD, Ehlers-Danlos, Marfan's
RFs - Age, HTN, smoking, African american |
|
|
Charcot-Bouchard aneurysm
|
Usually due to HTN, affects small vessels of basal ganglia, thalamus
|
|
|
Intracranial hemorrhage differentiation
a) Epidural b) Subdural c) Subarachnoid d) Intraparenchymal |
a) Epidural - rupture of middle meningeal a (maxillary a tributary), fractured temporal bone, rapid expansion, transtentorial herniation CN III palsy. DOESN"T cross suture lines
b) Subdural - Rupture of bridging veins, chronic (elderly, alcoholics, shaken baby, whiplash), CRESCENT hemorrhage, crosses sutures, cannot cross falx, tentorium c) Subarachnoid - Ruptured aneurysm ususally, yellow spinal tap, worst headake of life, vasospasm due to blood breakdown d) Intraparenchymal - HTN, or amyloid, vasculitis, neoplasm. Typically basal ganglia or internal capsule |
|
|
Ventricular system
|
CSF made by ependymal cells in choroid plexus, Lateral ventricles through foramen of monroe to third ventricle through cerebral aqueduct of sylvius to fourth venticle with foramen of Luschka (lateral) and Magendie (medial); reabsorbed by arachnoid granulations, drains to dural venous sinuses
|
|
|
Hydrocephalus types
|
Communicating hydrocephalus - reduced CSF absorption, elevated IOP, (arachnoid scarring usually causes)
Normal pressure hydrocephalus - increased subarachnoid space volume, but no pressure, distorts fibers of corona radiata; urinary incontinence, ataxia, cognitive dysfunction Hydrocephalus ex vacuo - CSF leads to atrophy, Alzheimer's disease, HIV, Pick's disease is normal, triad not seen; decreased neural tissue Noncommunicating hydrocephalus - blockage at stenosis of aqueduct of sylvius |
|
|
Normal pressure hydrocephalus triad
|
urinary incontinence, ataxia, cognitive dysfunction
|
|
|
Spinal nerve sets
|
8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal
C1-C7 exit ABOVE vertebra; All others exit below |
|
|
Spinal cord tracts and locations and neuron bodies
|
Dorsal columns - proprioception, vibration, touch - 1st order in dorsal root ganglion, enter and ascend in dorsal columns, synapse in nucleus cuneatus (arms) or gracilis (legs) in medulla, decussate and go to VPL
Spinothalamic - Lateral has pain and temp and is beside fasiculus cuneatus; anterior is in middle of gray matter and has crude touch, pressure. 1st order neuron in dorsal root ganglion, enters cord to synaspe in ipsilateral gray matter, decussates 1-3 levels up in anterior white commisure and ascends contralaterally to VPL Corticospinal - Lateral most in anterior horn (legs farther than arms), motor cortex, ipsilaterally in internal capsule, decussates in caudal medulla, descends contralaterally. Cell body is in anterior horn, then axon in lateral part anterior horn to go to NMJ |
|
|
UMN vs LMN lesions
|
UMN - Hyperreflexia, hypertonia, Babinski, spastic paralysis, clasp knife spasticity
LMN - Atrophy, fasciculations, hypotonia, hyporeflexia, flaccid paralysis BOTH have weakness |
|
|
Spinal cord lesion: Poliomyelitis and Werdnig Hoffmann disease
|
LMN lesion, destroys anterior horns in gray matter, flaccid paralysis
Polio - virus fecal oral, replicates before going to bloodstream and CNS. Destroys anterior horn neurons. CSF has elevated WBCs and protein Werdnig-Hoffman - congenital degeneration of anterior horns, "floppy baby" with hypotonia and tongue fasciculations. AR, death at 7 months |
|
|
Spinal cord lesion: MS
|
White matter in cervical region, random and asymmetric
Scanning speech, intention tremor, nystagmus |
|
|
Spinal cord lesion: ALS
|
Combined UMN and LMN lesion, NO SENSORY LOSS or COGNITIVE loss
Can be due to superoxide dismutase 1 Fasiculations leading to atrophy Damage in anterior horn and corticospinal tracts |
|
|
Spinal cord lesion: Anterior spinal artery occlusion
|
Spares dorsal column and Lissauer's tract
Below upper thoracic ok due to artery of Adamkiewiz |
|
|
Spinal cord lesion: B12 or Vit E def
|
Subacute degeneration of dorsal column, lateral corticospinal tracts and spinocerebellar tracts via demyelination
Ataxia, paresthesia, impaired position and vibration |
|
|
Friedreichs ataxia
|
GAA repeat (Frataxin gene)
Impaired mitochondria, staggering gait, frequent falls, nystagmus, dysarthria, pes cavus, hammer toes, kyphoscoliosis Death by hypertrophic cardiomyopathy |
|
|
Landmark dermatomes
|
C2 - back of skull
C3 - high turtleneck C4 - low collar shirt T4 - nipple level T7 - Xiphoid process level T10 - umbilicus (early appendicitis) L1 - inguinal lig L4 - kneecaps S2, S3, S4 - erection and sensation of penile and anal zones |
|
|
Important reflexes
|
Count up
S1 (S2) - Achilles (L3) L4 - patella C5 (C6) - Biceps C7 (C8) - Triceps |
|
|
Primitive reflexes
|
Inhibited as frontal lobe develops
Moro - abduct/extend limbs when startled Rooting - stroke cheek or mouth and turn Sucking - suck if touch roof of mouth Palmar - curl fingers Plantar - Babinski like Galant - stroke spine of face down and laterally flexes body towards |
|
|
Perinaud syndrome
|
Paralysis of conjugate vertical gaze due to lesion in superior colliculi or compression due to pinealoma
|
|
|
Cranial Nerve, Role
|
I - Olfactory - Smell (only one without thalamic relay)
II - Optic - Sight III - Oculomotor - eye movement (SR, IR, MR, IO), pupillary constriction, Edinger-Westphal nucleus, accomodation, eyelid close IV - Trochlear - Eye movement (SO) V - Trigeminal - Mastication, facial sensation (opthalmic, maxillary , mandibular, divisions); somatosensation from anterior 2/3 tongue VI - Abducens - eye movement (LR) VII - Facial - Facial movement, taste from anterior 2/3 tongue, lacrimation, salivation (exc. parotid), eyelid closing (orbicularis oculi), stapedius muscle in ear VIII - vestibulocochlear - hearing, balance IX - Glossopharyngeal - taste and somatosensation from posterior 1/3 tongue, swallowing, parotid, monitor carotid body and sinus, stylopharyngeus X - Vagus - Taste from epiglottic region, swallowing, palate elevation, midline uvula, coughing, thoracoabdominal viscera, monitoring aortic arch XI - Accessory - Head turn, shoulder shrug XII - Hypoglossal - tongue movement Some Say Money Matters But My Brother Says Big Brains Matter Most |
|
|
CN nuclei in
a) Midbrain b) Pons c) Medulla d) Spinal cord |
a) Midbrain - III, IV
b) Pons - V, VI, VII, VIII c) Medulla - IX, X, XII d) Spinal cord - XI |
|
|
Reflex arc's
a) Corneal b) Lacrimation c) Jaw jerk d) Pupillary e) Gag |
a) Corneal - V1 (opthalmic) senses, VII (orbicularis oculi) efferent
b) Lacrimation - V1 efferent, VII c) Jaw jerk - V3 sense, V3 motor all via masseter d) Pupillary - II senses, III acts e) Gag - IX senses, X acts |
|
|
Vagal nuclei
|
Nucleus solitarius - Visceral sensory sensation (VII, IX, X)
Nucleus ambiguus - motor innervation of pharynx, larynx and upper esophagus (IX, X); swallowing, elevate palate Dorsal motor nucleus - Sends ANS fibers to heart, lungs, GI - X |
|
|
Cranial nerve exits
a) Optic Canal b) Superior Orbital fissure c) Foramen Rotundum d) Foramen Ovale e) Foramen Spinosum f) Internal auditory meatus g) Jugular foramen h) Hypoglossal canal i) Foramen magnum |
a) Optic Canal - II, ophthalmic artery, central retinal vein
b) Superior Orbital fissure - CN III, IV, V1, VI, ophthalmic vein, SNS fibers c) Foramen Rotundum - V2 d) Foramen Ovale - V3 e) Foramen Spinosum - middle meningeal artery f) Internal auditory meatus - VII, VIII g) Jugular foramen - IX, X, XI, jugular vein h) Hypoglossal canal - XII i) Foramen magnum - XI, brain stem, vertebral arteries |
|
|
Cavernous sinus syndrome
|
due to mass effect, thrombosis, fistula
Opthalmoplegia and decreased corneal and maxillary sensation with normal vision CN III, IV, V1, V2, and IV and PNS fibers; Also some part of internal carotid artery |
|
|
Cranial nerve lesions
a) CN V motor lesion b) CN X lesion c) CN XI lesion d) CN XII lesion |
a) CN V motor lesion - Jaw towards lesion due to unopposed opposite pterygoid
b) CN X lesion - Uvula deviates away from lesion c) CN XI lesion - Weakness turning to contralateral side, shoulder drop in ipsilateral side d) CN XII lesion - Tongue deviates toward side of lesion |
|
|
Differentiating facial lesions
|
UMN - motor cortex or connection between motor cortex and facial nucleus. Contralateral paralysis of lower face sparing forehead (BIL UMN innervate)
LMN - ipsilateral paralysis of upper and lower face Facial nerve palsy - Loss of nucleus or facial nerve, peripheral ipsilateral facial paralysis with inability to close eye on involved side; complications of AIDS, Lyme disease, herpes simplex, less common herpes zoster, sarcoidosis, tumors, diabetes |
|
|
Jaw close vs jaw open muscles
|
Jaw close - Masseter, temporalis, medial pterygoid
Open - lateral pterygoid |
|
|
Central retinal artery occlusion
|
Acute, painless, monocular vision loss
Retina whitening with cherry-red spot |
|
|
Age-related macular degeneration
|
Degeneration of macula (central area of retina), causes distortion and eventual central vision loss
Dry - mostly, yellowish material beneath, retinal pigment, gradual loss Wet - rapid loss due to bleeding b/c of choroidal neovascularization, anti-VEGF to treat |
|
|
MLF syndrome
|
MLF allows cross talk between Edinger Westphal nucleus and CN VI nucleus
VERY myelinated and lost in MS Abducting eye gets nystagmus as CN VI overfires to stimulate CN III. NORMAL convergence. |
|
|
Alzheimer's dementia findings, early onset genes, late onset
|
Widespread cortical atrophy, low ACh, senile plaques of B-amyloid, neurofibrillary tangles (tau protein abn. phosphorylated = degree)
Early onset - APP, presenilin1 and 2 Late onset - Apo E4 Apo E2 is protective |
|
|
Differentiating dementias
a) Pick's disease b) Lewy body dementia c) Creutzfeldt-Jakob |
a) Pick's disease - Dementia, aphasia, parkinsonism, change in personality, FRONTOTEMPORAL, pick bodies (tau aggregates)
b) Lewy body dementia - Parkinsonism with dementia and hallucinations. Alpha synuclein defect c) Creutzfeldt-Jakob - Rapidly progressive with myoclonus, spongiform cortex, Prions |
|
|
External dementia causes
|
syphilis, HIV, HSV (temporal lobe)
Vitamin B1, B3, B12 def Wilson's diseae NPH |
|
|
MS traid, diagnostic
|
Demyelination and inflamamtion of CNS (oligodendrocytes)
Scanning speech, intention tremor/incontinence/internuclear opthalmoplegia, nystagmus High IgG in CSF, Oligoclonal bands |
|
|
Demyelinating diseases
a) PML b) acute disseminated encephalomyelitis c) Metachromatic leukodystrophy d) Charcot-marie-tooth e) Krabbe's disease |
a) PML - JC virus in AIDS pts, rapid CNS demyelination and oligodendrocyte destruction
b) acute disseminated encephalomyelitis - Multifocal perivenular inflammation and demyelination after infection (measles, VZV) or vaccine (rabies, smallpox) c) Metachromatic leukodystrophy - Lysosomal storage disease of Arylsufatase A def d) Charcot-marie-tooth - hereditary nerve disorder of defective proteins in peripheral nerve or myelin sheath e) Krabbe's disease - lysosomal storage disease due to galactocerebrosidase def, destroys myelin sheath |
|
|
Sturge-Weber syndrome
|
Port-wine stains, V1 distribution usually; ipsilateral leptomeningeal angiomas, pheochromocytomas.
Glaucoma, seizures, hemiparesis and MR associated |
|
|
Tuberous sclerosis findings
|
HAMARTOMAS
Hamartomas in CNS and skin Adenoma sebaceum (angiofibromas) Mitral regurg Ash-leaf spots cardiac Rhabdomyoma Tuberous sclerosis autosomal Dominant Mental retardation renal Angiomyolipoma Seizures |
|
|
Main adult brain tumors
|
Glioblastoma multiforme - most common, blurred borders, most aggressive
Meningoma - near surfaces of brain, from arachnoid cells, resectable and benign, cause seizures or focal signs. Psammoma bodies Schwannoma - Localized to CN VIII (acoustic), S-100 positive, In NFM 2 have BIL Oligodendroglioma - rare, slow growing, round nuclei with clear cytoplasm in frontal lobes, often calcified |
|
|
Main childhood brain tumors
|
Pilocytic astrocytoma - well circumscribed, posterior fossa (cerebellum); Rosenthal fibers (eosinophilic, corkscrew), benign and good prognosis. GFAP +
Medulloblastoma - highly malignant, can cause hydrocephalus from 4th ventricle compressoin, and mets to cord. Small blue cells Ependymoma - found in 4 ventricle, hydrocephalus, poor prognosis, Rod shaped blepharoplasts (basal ciliary bodies), Hemangioblastoma - associated with VHL, can produce EPO, foamy cells with high vascularity Craniopharyngioma - benign tumor of rathke's pouch origin, often has tooth like structures, mistaken for pituitary adenoma because also causes bitemp hemaniopia. Most common supratentorial tumor |
|
|
Herniation types
|
a) Cingulate (subfalcine) herniation under falx cerebri - can compress ACA (lower limbs)
b) Downward transtentorial (central) herniation c) Uncal herniation (medial temporal lobe, CN III palsy d) Cerebellar tonsillar herniation into foramen magnum - coma and death if compresses brain stem |
|
|
Neurofibromatosis
|
Cafe-au-lait spots
Lisch nodules (iris hamartomas) Neurofibromas and Schwannomas in skin Optic gliomas Pheochromocytomas AD, variable expression, 100% penetrant |
|
|
Aqueous humor pathway
|
Ciliary epithelium (B) makes, moves from posterior chamber over lens, around and over iris (dilated by a1, constricted by M3) to anterior chamber and reabsorbed at trabecular meshwork to Canal of Schlemm
Open Glaucoma - trabecular meshwork doesn't reabsorb as well. Painless, slow Closed Glaucoma - Lens foward doesn't allow passage into anterior chamber, builds behind iris, painful, sudden vision loss possible or optic nerve damage. Do not give Epi due to mydriatic effect |
