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215 Cards in this Set
- Front
- Back
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Astrocyte functions
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Support/repair
K+ metabolism BBB Marker: GFAP |
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Astrocyte marker
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GFAP
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Ependymal cells
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Inner lining of ventricle
Make CSF |
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Microglia
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Macrophages of the brain
Mesodermal (like macrophages) Multinucleated giant formation (HIV) Small nuclei Little cytoplasm --> Ameboid with injury Not very visible on Nissl stain |
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Oligodendrocytes
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Myelinates up to 30 axons
Destroyed in MS Small nuclei w/little cytoplasm Fried eggs on H&E stain Visible on Nissl stain |
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Schwann Cells
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Neural crest origin
PNS myelin: 1 axon per Schwann cell Source of acoustic neuromas (internal acoustic meatus) |
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Peripheral nerve wrappings
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Endoneurium = Single axon
Perineurium = Bundle of axons *PERMEABILITY BARRIER *Rejoin during surgery Epineurium = Vessels and bundles |
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Site of NE synthesis
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Locus ceruleus
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Site of DA synthesis
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Ventral tegmentum
Substantia nigra pars compacta (SNc) |
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Site of Serotonin synthesis
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Raphe nucleus
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Site of Ach synthesis
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Nucleus basalis of mynert
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Blood brain barrier layers (3)
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1. Endothelial cells (tight junctions)
*Damage/destruction = vasogenic edema 2. Basement membrane 3. Astrocyte processes |
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Areas w/o blood brain barrier (2)
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Area postrema (informational blood sampling)
Neurohypophysis/PP: Excretion of oxytocin, ADH |
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Sites of other blood:organ barriers beside BBB
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Blood:Testes barrier
Blood:Placenta barrier |
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Hypothalamic functions
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The hypothalamus wears TAN HATS:
Thirst --> Supraoptic nucleus Adenohypophysis Neurohypophysis + median eminance Hunger and satiety *Ventromedial = Satiety *Hunger = Lateral Autonomic regulation, circadian rhythm *pArasympathetic = Anterior *Sympathetic = Posterior *Circadian = Suprachiasmatic Temperature regulation *Cooling = Anterior (A/C) *Heating = Posterior (pH) Sexual urges and emotions *Septal nucleus = Control |
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Posterior pituitary hormone sources
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Oxytocin: Paraventricular
Vasopressin/ADH: Supraoptic *Area controlling thirst |
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Thalamus functions
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LGN --> "Light" (visual relay)
MGN --> "Music" (audio relay) VA/VL --> Motor VPL --> Body sensation *From dorsal columns + spinothalamic tract VPM --> Face sensation *From CN V *"Makeup on your face" |
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Thalamus supplying arteries
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1. Posterior communicating arteries
2. Posterior cerebral 3. Anterior choroidal |
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Limbic system
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CHFM
Cingulate gyrus Hippocampus Fornix Mammillary bodies The 5 F's: Fight, Flight Feeding, feeling... |
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Cerebellar nerve types
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Climbing, mossy = Input
Purkinje = Output |
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Basal ganglia: Excitatory pathway
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D1 receptor binding = Excitement of excitatory pathway
1. Striatum (caudate, putamen) inhibits GPi 2. GPi stops inhibiting thalamus 3. Thalamus can stimulate cortex Striatum (-) --> GPi (-) ---> Thalamus |
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Basal ganglia: Inhibitory pathway
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D2 receptor binding = Inhibition of inhibitory pathway
1. Striatum is inhibited from inhibiting GPe 2. GPe is free to inhibit STN 3. STN stops stimulating GPi 4. GPi stops inhibiting Thalamus 5. Thalamus can stimulate cortex Striatum(-) --> GPe (-) --> STN (+) --> GPi (-) --> Thalamus |
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Primary auditory cortex location
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Heschl's gyrus
Just under posterior Sylvian fissure |
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Wernike's area is...
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Associative auditory cortex
Superior temporal gyrus |
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"Arteries of stroke"
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Lateral striate arteries
Supply striatum (caudate, putamen), globus pallidus, internal capsule |
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Most common sites of aneurysm
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Anterior communicating artery
*Most common circle of Willis aneurysm site *May cause visual field defects Posterior communicating artery *May cause CNIII palsy |
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Anterior cerebral artery stroke
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Leg-foot area sensory and motor deficits
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Middle cerebral artery stroke
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Trunk-arm-face sensory and motor deficits
Wernike's area Broca's area |
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Anterior circle stroke
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Sensory and motor dysfunction
Aphasia |
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Posterior circle stroke
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Cranial nerve deficits
Cerebellar deficits Coma |
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Hydrocephalus
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Accumulation of excess CSF in the VENTRICULAR system
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CSF path through ventricles
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Lateral ventricles --> 3rd ventricle
*Via foramen of Monro 3rd ventricle --> 4th ventricle *Via cerebral aqueduct 4th ventricle --> Subarachnoid space *Lateral = Luschka *Medial = Magendie Monro vs. Magendie: Shorter name for smaller ventricle # (ventricle 3 vs. 4) |
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CSF path through ventricles
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Lateral ventricles --> 3rd ventricle
*Via foramen of Monro 3rd ventricle --> 4th ventricle *Via cerebral aqueduct 4th ventricle --> Subarachnoid space *Lateral = Luschka *Medial = Magendie Monro vs. Magendie: Shorter name for smaller ventricle # (ventricle 3 vs. 4) |
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# of spinal nerves
# of vertebrae |
31 spinal nerves
Cervical: 8 nerves, 7 vertebrae Thoracic: 12 nerves, 12 vertebrae Lumbar: 5 nerves, 5 vertebrae Sacral: 5 nerves, fused vertebrae Coccygeal: 1 nerve |
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Most common site of vertebral disk herniation
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L5-S1
Why don't you balance a circle on a triangle! |
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Lumbar puncture
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L3-5 keeps the spinal cord alive
SC extends to lower border of L1-L2 CSF extends to lower border of S2 Ligaments pierced in the following order: Supraspinous, interspinous, ligamentum flavum |
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Arachnoid granulations
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Allow CSF to travel through arachnoid + meningeal layer of dura (periosteal layer not crossed)
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Fasciculus gracilis
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Your ass is grass(ilis)
Legs and lower body Dorsal, Medial placement |
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Fasciculus cuneatus
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Arms, upper body
Dorsal, lateral placement |
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Path of a dorsal column signal
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Sensory nerve (CB @ dorsal root):
*1 end connects to sensory site *Other end ascends ipsilateral cord and synapses in ipsilateral medulla *Synapse site: Nucleus cuneatus or gracilis 2nd neuron decussates travels from nucleus cuneatus/gracilis to VPL of thalamus 3rd neuron travels from VPL to cortex |
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Path of a spinothalamic tract signal
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Sensory nerve (CB @ dorsal root):
*1 end connects to sensory site *Other end stops in ipsilateral gray matter 2nd neuron travels from ipsilateral gray matter across anterior white commissure and up cord to VPL 3rd nerve travels from VPL to thalamus |
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Path of a corticospinal signal
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UMN leaves cortex and descends ipsilaterally through brain
Decussation at the caudal medulla and continuation to the anterior horn 2nd cell starts at anterior horn (LMN) and continues to NMJ |
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Cervical dermatome landmarks
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C2: Posterior 1/2 of a "skull cap"
*Includes most of ear and underneath chin C3: Neck of a turtleneck shirt C4: Turleneck - Boat neck shirt |
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Thoracic dermatome landmarks
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T4: "teat pore" (nipple)
T7: Xiphoid process T10: Umbilicus *Early appendicitis |
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Lumbar/Sacral dermatome landmarks
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L1: Inguinal ligament
L4: Includes the kneecaps S2,3,4: Erection and sensation of genitals, anal zone *"S2-4 keeps the penis off the floor" |
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Gall bladder pain referral
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Right shoulder
Via phrenic nerve (C3-5) |
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Golgi tendon organ
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Found at muscle insertion points
Monitors tension --> if too high, sends inhibitory feedback to alpha motor neurons **Drop the suitcase that is going to tear the muscle** |
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Muscle spindle
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Found in parallel with regular muscle fibers
Spindles = Intrafusal Regular muscle fibers = Extrafusal Stretch causes 1a sensory transmission to cord --> returns an alpha motor neuron signal to contract Intrinsic tension is guided by gamma motor neurons *Increases sensitivity of reflex arc |
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Biceps reflex: Involved spinal levels
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C5 --> C6
Think about musculocutaneous nerve damage: trouble flexing elbow (problem w/biceps) |
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Triceps reflex: Involved spinal levels
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C7 --> C8
Think about radial nerve: damage causes problems w/arm extensors (wrist drop, elbow extension) |
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Patellar reflex: Involved spinal levels
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L4 --> L3
L4: L is 4 for Leg |
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Achilles reflex: Involved spinal levels
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S1 --> S2
Achilles: "All the way down" |
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1st year reflexes
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**May re-emerge following frontal lobe lesion**
Moro reflex: Extension of limbs when startled Rooting reflex: Nipple seeking Palmar reflex: Grasps objects in palm Babinski reflex: Large toe dorsiflexes w/plantar stimulation |
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Cranial nerve placement
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Most medial: All motor
3 (x2) 6 (x2) 12 Midbrain: 3-4-5 *Just anterior to cerebellum Pons: 6-7-8 *Just behind cerebellum Medulla: 9-10-11-12 *Down sides brainstem |
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Pineal gland function
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Melatonin secretion (circadian rhythm)
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Superior colliculus function
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Conjugate vertical gaze center
Lesion (such as pinealoma) --> Vertical conjugate gaze palsy Conjugate gaze palsy: Inability to move both eyes in a particular direction |
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Only CN without a thalamic relay to cortex
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CN 1
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Cranial nerves: Sensory and Motor
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1: Some --> Smell
2: Say --> Sight 3: Marry --> Eye 4: Money --> Eye 5: But --> Mastication, facial and anterior 2/3 tongue sensation 6: My --> Eye movement 7: Bro --> Facial movement, taste (anterior 2/3), etc 8: Says --> Hearing, vestibular 9: Big --> Pharynx movement, taste (posterior 1/3), etc. 10: Brains --> Pharynx, taste (pharynx), etc. 11: Matter --> Head turn, shrug 12: Most --> Tongue |
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Cranial nerve 1
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Olfactory nerve
Entirely sensory NO thalamic relay to cortex |
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Cranial nerve 2
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Optic nerve
Entirely sensory Enters brain between anterior communicating artery and middle cerebral artery |
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Cranial nerve 3
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Oculomotor nerve
Entirely motor Enters brain behind PCA 1. All oculomotor muscles EXCEPT: *Lateral rectus (CN VI) *Superior oblique (CN IV) 2. Pupil constriction (Sphincter Pupillae) 3. Accomodation (Ciliary muscle) 4. Eyelid opening (Levator Palpebrae) Loss: Eye appears "down and out" *Pupil dilation *Poor accomodation *Drooping eyelid |
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Cranial nerve 4
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Trochlear nerve
Entirely motor Superior oblique muscle: AIDs the eye *Abducts *Intorts *Depresses Loss: *DEFECTIVE downward gaze *Diplopia |
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Cranial nerve 5
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Trigeminal nerve
Sensory and motor Sensory: Facial sensation Palate/teeth/gums Parts of meninges Motor: Muscles of mastication (pterygoids, temporalis, masseter) Tensor tympani TENSOR VELI PALATINI |
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Cranial nerve 6
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Abducens nerve
Purely motor Enters brain behind pons Lateral rectus muscle Loss: Eye looks medially |
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Cranial nerve 7
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Facial nerve
Sensory and motor Sensory: Taste from anterior 2/3 of tongue Motor: Facial muscles Lacrimation Salivation (submandibular, sublingual) Eyelid closure (orbicularis ori) Stapedius muscle |
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Cranial nerve 8
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Vestibulococchlear
Sensory Hearing Vestibular |
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Cranial nerve 9
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Glossopharyngeal
Sensory and motor Sensory: Pharynx Posterior 1/3 of tongue (taste + somatic) Carotid body and sinus Motor: Stylopharyngeus Parotid |
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Cranial nerve 10
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Vagus nerve
Sensory and motor Sensory: Taste from epiglottis region Thorax/abdomen (visceral) Aortic arch chemo/baroreceptors Motor: Swallowing and palate elevation Talking Coughing PALATOGLOSSUS |
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Cranial nerve 11
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Spinal accessory nerve
Purely motor SCM Trapezius |
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Cranial nerve 12
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Hypoglossal
Purely motor Tongue movement |
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Clinical reflexes: Cranial nerves
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Corneal: 5(1) --> 7 (Orb oris)
Lacrimation: 5(1) --> 7 Pupillary: 2 --> 3 (sphincter pupillae) Jaw jerk: 5(3) --> 5(3) Gag: 9 --> 9, 10 |
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Vagal nuclei
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Nucleus Solitarius: 7, 9, 10
*Taste *Baroreceptors *Visceral sensory (gut distention) Nucleus ambiguus: 9, 10, 11 *Motor innervation of pharynx, larynx, upper esophagus Dorsal motor nucleus: 10 only *The CRANIO of craniosacral *Parasympathetic fibers *Heart, lungs, upper GI |
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Optic canal contents
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CN II
Opthalmic artery Central retinal vein |
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Superior orbital fissure contents
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CN 3, CN 4, CN 5-1, CN 6
Opthalmic vein |
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Foramen rotundum contents
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CN 5-2
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Foramen ovale contents
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CN 5-3
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Foramen spinosum contents
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Meningeal artery
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Internal auditory meatus contents
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CN 7, CN 8
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Jugular foramen contents
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CN 9
CN 10 CN 11 Internal jugular vein |
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Foramen magnum contents
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Brainstem
Spinal roots of CN 11 Vertebral arteries |
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Hypoglossal canal contents
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CN 12
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Cavernous sinus contents
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CN 3, 4, 5-1, 5-2, 6
Internal carotid artery *CN VI is sort of banded to it (only free floating CN in sinus) Cavernous sinus syndrome =Compression *CN 3, 4, 6: Opthalmoplegia *CN V-1, V-2: Opthalmic, maxillary sensory loss |
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KLM sounds
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Kuh = Palate elevation = CN X
La = Tongue = CN 12 Mi = Lips = CN 7 |
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Mastication muscles
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All trigeminal nerve 5-3
M's munch Medial pterygoid TeMporalis Masseter Lateral lowers: Lateral pterygoid |
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Glossus rule
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All muscles w/GLOSSUS in the name are innervated by CN 12
Exception: PALATOGLOSSUS *Fight between palat and glossus rules--CN X wins |
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Palat rule
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All muscles w/PALAT in the name are innervated by CN 10
Exception: TENSOR VELI PALATINI (too "tense" to go to vagus) *CN V-3 |
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Sensory corpuscles (4)
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1. Free nerve endings (A-delta, C)
*Pain, temp *All skin 2. MeiSSner's corpuscles (40% fingertip) *SMOOTH SKIN (glabrous) *Dynamic fine touch (impeded by hair?) 3. Pacinian corpuscles (15% fingertip) *Feels powerful forces (vibration) *Deep skin layers, ligaments, joints 4. Merkel's disks (25% fingertip) *Static touch *Cup-shaped --> hair follicle |
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Inner ear components
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Outer shell = Bony labyrinth *3 compartments: cochlea, vestibule, semicircular canals
*Filled with perilymph (ECF, Na+) Membranous labyrinth = cochlear duct, utricle, saccule, semicircular canals *Filled w/endolymph (ICF, K+) STRIA VASCULARIS makes endolymph Utricle/Saccule: Otolith organs *Maculae --> Thickened platforms *Detect LINEAR acceleration Semicircular canals *Ampullae: Cupula sitting over hair cells *Detect angular acceleration Organ of corti: Contains hair cells Cochlear membrane: Scuba flipper *High frequency = base |
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Hearing loss: Conductive vs. Sensorineural
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CONDUCTIVE LOSS: Sounds louder when it's touching
Weber *Conductive: louder on affected side *Sensorineural: softer on affected side Rinnie: Conductive: bone > air Sensorineural: air > bone |
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Canal of Schlemm
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Collects aqueous humor from front chamber of eye and delivers to blood
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Iris
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Source of eye color
Iris is colored, like the flower |
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Ciliary body
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Contains ciliary muscle
Influences lens shape (accomodation) |
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Choroid (eye)
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Vascular layer between retina and sclera
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What enters eye w/the optic nerve?
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Central retinal artery and vein
Optic nerve, opthalmic artery and central retinal vein go through the optic canal *Central retinal artery is a branch of the opthalmic artery |
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What vein enters the superior orbital fissure?
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Opthalmic vein
Made from superior and inferior opthalmic veins |
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Pupillary light reflex
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CN II sends a signal to pretectal (before Sup Colliculus) nuclei in midbrain
Pre-tecal nuclei activate Edinger-Westphal nuclei Pupils contract bilaterally via CN III *Ciliary ganglion, sphincter pupillae muscle |
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Visual field defects
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Optic nerve: 1 entire eye
Optic chiasm: Bitemporal hemanopsia Optic tract (past chiasm): L/R field from EACH eye Dorsal optic radiations (parietal lobe): Lower L/R quadrant of EACH eye *Dorsal down Meyer's loop (temporal lobe): Upper L/R quadrant of EACH eye *Temoral up: Mrs. Meyers bought TUPperware Late Meyer's loop (Calcarine fissure): L/R field from each eye, EXCEPT for macula |
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Internuclear opthalmoplegia
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When looking left, the left eye lateral rectus muscle fires
Signal is sent to MLF of the right eye; tells Medial Rectus Subnucleus of CN III to contract the right medial rectus |
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Visual field testing: Superior oblique
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Adduct eye (to minimize contribution of inferior rectus)
Depress eye while still in adducted position |
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Visual field testing: Inferior oblique
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Adduct eye (to minimize contribution of superior rectus)
Elevate eye while still in adducted position |
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Visual field testing: Superior rectus
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Abduct eye (to minimize contribution of inferior oblique)
Elevate eye while still in abducted position |
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Visual field testing: Inferior rectus
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Abduct eye (to minimize contribution of superior oblique)
Depress eye while still in abducted position |
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Spina bifida occulta
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Failure of bony spinal canal to close, but not structural herniation
Dura is INTACT Elevated alpha-fetoprotein |
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Meningocele
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Form of spina bifida
Failure of bony spinal canal to close + Meninges herniate through defect Dura is not completely intact Elevated alpha-fetoprotein |
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Meningomyelocele
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Form of spina bifida
Failure of bony spinal canal to close + Meninges herniate through defect + Spinal cord herniates through defect Dura is not completely intact Elevated alpha-fetoprotein |
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Telencephalon derivatives
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Cerebral hemispheres
Lateral ventricles |
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Diencephalon
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Thalamus, hypothalamus
3rd ventricle |
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Mesencephalon
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Midbrain
Cerebral aqueduct (along w/pons) |
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Metencephalon
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Pons, cerebellum
Pons --> Cerebral aqueduct (along w/midbrain) Cerebellum --> 4th ventricle |
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Myencephalon
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Medulla
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Anencephaly
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No brain/calvarium
Elevated AFP Polyhydramnios *No swallowing center in brain |
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Holoprosencephaly
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Failure of hemispheres to separate
May cause cyclopia Causes: Fetal alcohol syndrome Trisomy 13 (Patau's syndrome) |
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UMN lesion signs
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Weakness (the only thing UMN and LMN lesions have in common)
Everything goes UP: Tone DTRs Toes (Babinski) |
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LMN lesion signs
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Weakness (the only thing UMN and LMN lesions have in common)
Everything goes DOWN: Muscle mass (w/fasciculations) Tone DTRs Toes (no Babinski) |
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Multiple Sclerosis: Spinal cord lesions
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Random damage
Usually in the cervical cord Motor: UMNs and LMNs can be affected Sensory: Dorsal columns and spinothalamic |
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ALS: Spinal cord lesions
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Motor only
UMNs and LMNs |
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Poliomyelitis
Werdnig-Hoffmann disease |
Anterior horn destruction: LMNs
Wednig-Hoffmann disease is a genetic (AR) disease (a.k.a. Infantile Spinal Muscular Atrophy, or SMA Type 1) *SMN gene *Floppy baby w/tongue fasciculations *Median age of death = 7 months |
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Anterior spinal artery occlusion
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Atrophy of all neurons in cord EXCEPT:
*Dorsal columns |
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Tract of Lissauer
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Incoming P/T info
Ascends 1-2 spinal levels before synapsing 2nd order neuron decussates at anterior white commissure and ascends |
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Tabes dorsalis: Spinal cord lesions
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Tertiary syphilis
Dorsal roots and dorsal columns destroyed Diminished sensation: *Proprioception/touch below highest lesion point --> locomotor ataxia *P/T information at every level of dorsal root destruction |
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Syringomyelia: Features
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Enlargement of the central canal of the spinal cord
*Associated w/Arnold-Chiari formation *Most common in C8-T1 Damages anterior white commissure *Local (extremities) bilateral loss of pain and temperature sensation |
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Vitamin B12 deficiency and Friedreich's ataxia: Cord lesions
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Demyelination of the:
*Dorsal columns *Spinocerebellar tracts *Corticospinal tract *Impaired proprioception/touch *Ataxic gait *Weakness w/hyperreflexia |
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Syphilus symptoms
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GoT CRABS?
Gummas/Penicillin G tx Tabes dorsalis Charcot joints Robertson (Argyll) pupil Aortitis Broad-based gait Stroke without HTN Charcot: progressive degeneration of weight bearing joints A-R pupil: Accomodates, doesn't react (to light) |
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Brown-Sequard syndrome
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Motor:
Ipsilateral LMN signs at lesion level UMN signs below lesion Sensory: 1. Ipsilateral loss of ALL sensation at level of lesion (dorsal root) 2. Ipsilateral touch/proprio loss below lesion 3. Contralateral P/T loss below lesion |
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Horner's syndrome
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Occurs w/CERVICAL lesions
(lesions above T1) 1. Descending sympthatic input from hypothalamus synapses in lateral horn of T1 2. 2nd neuron enters cervical chain (adjacent to cord) and synapses in superior cervical ganglion (at level of T2) 3. 3rd neuron goes to: *Eyelid --> Ptosis if lost *Facial sweat glands --> Anhidrosis if lost *Pupil --> Constriction if lost "PAM is horny" Pancoast's tumor (superior lung) Brown sequard Sever syringomyelia |
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Causes of Horner's syndrome
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Brown sequard
Severe syringomyelia Pancoast's tumor (superior lung) |
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Symptoms of arcuate fasciculus lesion
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Arcuate fasciculus connects Broca's and Wernike's area
Conduction aphasia = Poor repetition Good comprehension Fluent speech |
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Symptoms of bilateral amygdala lesion
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Kluver-Bucy syndrome
Hyperorality Hypersexuality Disinhibited behavior |
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Frontal lobe lesions
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Personality changes
Judgement Concentration Orientation Possible re-emergence of PRIMITIVE REFLEXES |
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Right parietal lobe lesions
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Left spatial neglect
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Mammillary body lesions
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Wernike-Korsakoff syndrome
Periventricular hemorrhage/necrosis (surrounding mamillary bodies) is also seen Wernike: *Confusion, coma, death *Eyes: OPTHALMOPLEGIA, aniscoria, nystagmus, sluggish pupillary reflexes Korsakoff: *Retrograde and anterograde AMNESIA *CONFABULATION *Hallucinations |
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Basal ganglia lesions
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Possibilities include:
Resting tremor Chorea Athetosis (slow writhing) |
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Cerebellar hemisphere lesions
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IPSILATERAL limb effects
Intention tremor |
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Cerebellar vermis lesions
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Truncal effects
Dysarthria (speech) |
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Subthalamic nucleus lesions
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Contralateral hemiballismus (violent thrashing movements)
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Hippocampal lesions
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Anterograde amnesia
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Paramedian pontine reticular formation (PPRF) lesions
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PPRF
Eyes look AWAY from lesion ("blemish")...only wants to see PPRFect things |
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FEF lesions
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Eyes look TOWARD lesion
Saccades, eye movements |
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Broca's area is...
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Inferior frontal gyrus
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Alzheimer's Disease: Cellular evidence
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Diffuse CORTICAL atrophy
Decreased Ach (give AchE Inhibitors) B-amyloid plaques *Extracellular Neurofibillary tangles *Abnormally phosphorylated Tau protein *Intracellular *CORRELATES w/degree of dementia |
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Alzheimer's Disease: Risk factors
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Down syndrome
Familial (10% of cases) *APO-E: Chromosomes 1, 14, 19 *p-App: Chromosme 21 |
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Pick's disease features
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Frontotemporal lobe atrophy
*Pick bodies (aggregated TAU) Dementia Parkinsonism APHASIA |
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Multi-infarct dementia features
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2nd most common cause of dementia in the elderly
Amyloid may be deposited in vessels --> ICH |
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Creutzfelt-Jakob disease features
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Prions --> Spongiform cortex
Progresses in weeks-months MYOCLONUS |
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Lewy body dementia
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Dementia
Parkinsonism HALLUCINATIONS Lewy bodies are made of Alpha synuclein |
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Huntington's features
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Chromosome 4 (Hunting 4 food)
Autosomal dominant CAG triplet repeat: *Caudate atrophy *Anticipation *GABAergic neurons lost *Decreased Ach |
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Parkinson's Features
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Lewy bodies (Alpha synuclein)
Depigmentation of the substantia nigra TRAP: Tremor at Rest Rigidity (cogwheel) Akinesia (impaired movement) Postural instability |
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Fredereich's Ataxia: Lesion
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Olivopontocerebellar atrophy
Autosomal recessive mutation of the Frataxin gene |
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Poliomyelitis
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Replication in oropharynx and small intestine --> Blood --> CNS
*Throat: Sore throat *SI: Nausea, abdominal pain *Blood/CSF: Malaise/headache/fever Fecal-oral transmission CSF features lymphocytes w/pleocytosis and slightly elevated protein LMN breakdown |
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Multiple Sclerosis: Risk factors
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Increasing prevalence w/distance from the equator
Women in 20-30s Most common in whites |
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Multiple Sclerosis: Features
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PERIVENTRICULR plaques: Oligodendrocyte loss and reactive gliosis
Classic symptoms: GOSHIN *IgG in CSF *Optic neuritis *Scanning speech *Hemiparesis/sensory *Intention tremor *Incontinence *Internuclear opthalmoplegia *Nystagmus Treatment: Beta interferon or immunosuppressants |
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Demyelinating/Dysmyelinating diseases (5)
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MS: GOSHIN
*IgG *Optic neuritis *Scanning speech *Hemiparesis/sensory *Intention tremor, incontinence, internuclear opthalmoplegia *Nystagmus Progressive multifocal leukoencephalitis *JC virus *2-4% of AIDs patients (latent reactivation) Acute disseminated encephalomyelitis (postinfectious) Metachromatic leukodystrophy *AR lysosomal storage disease *Arylsulfatase A deficiency *Demyelination --> ataxia *Dementia Guillain-Barre syndrome |
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Guillian-Barre Syndrome
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Guillian ~ Goin campin (campylobacter)
Barre ~ Picked up HSV at a BAR Autoimmune attack of peripheral myelin following infection (esp. campylobacter and herpes), inoculation, stress Inflammation and demyelination of peripheral sensory nerves + alpha motor neurons + autonomics *Sensory effect < motor *Cardiac irregularities, HTN, hypotension Progressive weakness beginning in distal lower extremities *50% have facial paralysis Treatment: Plasmapheresis IV immune globins |
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Guillian Barre Syndrome: Findings
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CSF: Albuminocytologic dissociation
*High Protein *Normal WBCs (no "pleocytosis") *Papilledema |
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Partial Seizures
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Involve 1 region of the brain
Can secondarily generalize Simple = Consciousness intact *Motor, sensory *Autonomic *Psychic Complex: Impaired consciousness |
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Generalized seizures
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Diffuse involvement
*Tonic ~ stiffening *Clonic ~ movement 1. Absence (petit mal) = blank stare 2. Myoclonic = Quick, repetitive jerks 3. Tonic-clonic (grand mal) = Alternating stiffening and movement 4. Tonic = Stiffening 5. Atonic = Drop seizures *Commonly mistaken for fainting |
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Causes of seizures by age
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Children: GENETICS, infection, trauma, congenital, metabolic
Adults: TUMORS, trauma, stroke, infection Elderly: STROKE, tumor, trauma, metabolic, infection |
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Epidural Hematoma
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Middle meningeal artery
Often after fracture of temporal bone Biconvex disk DOES NOT cross suture lines |
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Subdural Hematoma
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Bridging veins
Less pressure than epidural hematoma --> Delayed onset of symptoms Crescent-shaped hemorrhage that crosses suture lines Risk factors: Brain atrophy, shaking, whiplash |
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Subarachnoid Hemorrhage
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Aneurysm or AVM rupture
"Worst headache of life" Spinal tap: Bloody or yellow (Xanthochromic--broken down RBCs) |
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Parenchymal hematoma
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Vessel issues:
*HTN *Amyloid angiography *DM Tumor |
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Charcot-Bouchard Microaneurysms
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Associated with chronic HTN
Affects small vessels |
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Berry Aneurysms
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Occur at bifurcations in the Circle of Willis
*Most commonly ACA Rupture --> SAH Risk factors: 1. HTN + smoking 2. Advanced age Populations: 1. More common in blacks 2. Diseases: *Adult PCKD --> Generalized collagen and ECM abnormality *Ehlers-Danlos --> Collagen 3 *Marfan --> Fibrillin |
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Normal pressure hydrocephalus
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No obstruction = communicating
*Arachnoid GRANULATION prob NORMAL opening pressure Enlarged ventricles Symptoms: "Weird GAIT, can't WAIT, and a little CRAZED" *Gait problems *Urinary incontinence *Dementia |
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Obstructive hydrocephalus
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Hydrocephalus caused by an obstruction of the ventricular system
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Neurocutaneous (4)
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Sturge-Weber
Tuberous Sclerosis Neurofibromatosis Von Hippel Landau |
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Sturge-Weber Disease
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Sturge = Sturgeon = Port
Weber = Web in brain = AVM Congenital small vessel disease *Capillaries Port-wine stain on face Leptomeningeal angiomatosis (intracerebral AVM) *Seizures *Hemiparesis *Mental retardation *Glaucoma (Increased IOP) |
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Tuberous Sclerosis
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Face --> "Ash to Green"
*Facial angiofibroma *Ash leaf spots *Shagreen patch (orange peel texture) CAR Cardiac rhabdomyoma Astrocytoma (seizures, MR) Renal angiomyolipoma |
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Neurofibromatosis Type 1
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NF 1 gene
Chromosome 17 *Von Recklinghausen SCALDING COFFEE: *Cafe au lait spots *SColiosis Tumors: LMNOP Lisch nodules (iris hamartomas) Many tumors (overall risk inc.) Neural tumors Optic gliomas Pheos |
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Von Hippel Landau Disease
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Chromosome 3
Autosomal dominant HEMANGIO, HALF: Hemangioblastomas: Retina, brainstem, cerebellum Cavernous hemangiomas: Everywhere 50% get bilateral renal cell carcinomas |
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Adult brain tumors: Supra or infratentorial?
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Supratentorial
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Childhood brain tumors: Supra or infratentorial?
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Infratentorial
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Most common site for adult brain mets
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Gray-white junction
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Adult primary brain tumors (5)
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GOP MS
G > M > S > O 1. Glioblastoma multiforme: *Grade IV Astrocytoma (stains GFAP) *CEREBRAL HEMISPHERES *PSEUDOPALISADING cells border areas of necrosis, hemorrhage 2. Oligodendroglioma *Rare, slow growing *FRONTAL LOBES *Chicken-wire capillary pattern 3. Pituitary adenoma (Rathke's pouch) *Usually prolactinoma *Bitemporal hemanopsia *Hyper or hypoactive 4. Meningioma (Arachnoid origin) *Found on surface of brain *Concentric, whorled spindle cells *Psammoma bodies (concentric calcifications) 5. Schwannoma (Schwann cells) *Often CN VIII *NF2: Bilateral schwannomas |
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Childhood primary brain tumors
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CHEMP
1st and last are supratent, benign Hydrocephalis ~ Rosettes 1. Craniopharyngioma (benign) *Most common childhood supratentorial *Origin: Rathke's pouch remnants *Tooth enamel-like calcification *Confused w/pituitary tumor 2. Hemangioblastoma *Cerebellar *Foamy cells w/high vascularity *EPO SECRETION --> Polycythemia *VON-HIPPEL-LANDAU 3. Ependymoma (Poor prog) *Usually in 4th ventricle --> hydroceph *Perivascular pseudorosettes 4. Medulloblastoma (Poor prog) *Cerebellar: can compress 4th ventricle *Considered a PNET tumor *Rosettes or perivascular pseudorosettes 5. Pilocytic astrocytoma (benign) *Posterior fossa *Rosenthal fibers (pink, corkscrew) |
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Posterior fossa malformations
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Arnold chiari malformations:
Small posterior fossa --> Cerebellar displacement, medulla deformity Chiari 1: Often asymptomatic *Tonsils descend *Medulla compressed (CSF flow) Chiari 2: Fatal *Tonsils and VERMIS descend *MEDULLA descends Dandy walker: *Large posterior fossa *Cerebellum replaced by cyst |
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Physical signs and cranial nerve lesions
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Ipsilateral (4):
CN 12: Tongue deviates TOWARD lesion *"Lick your wounds" CN 11: Shoulder droops on SAME side *Trouble turning head toward contralateral side CN V: Jaw deviates toward SAME side Cerebellum: Patients fall TOWARD lesion Contralateral signs (1) CN X: Uvula deviates AWAY from lesion |
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Facial nerve: UMN lesion
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Lost movement on contralateral side, lower face only
*Includes ability to close eye |
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Facial nerve: LMN lesion
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Lost movement on ipsilateral side
Upper AND lower face Facial motor nucleus has bilateral input for upper face (ipsilateral intact) Contralateral input for lower face (lost) |
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Causes of Bell's palsy
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ALexander Bell has an STD:
AIDS Lyme Sarcoidosis Tumors Diabetes |
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Cingulate herniation
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A.k.a. subfalcine herniation
Herniation through falx cerebri May compress anterior cerebral artery |
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Uncal herniation
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A form of transtentorial herniation
Medial temporal lobe/hippocampus Duret hemorrhages *Paramedian artery rupture *Caudal displacement of brainstem Signs: TRUST THE EYES Ipsilateral dilated pupil/ptosis *Stretching of CNIII Contralateral homonymous hemanopia *Compression of ipsilateral PCA Ipsilateral paresis *FALSE localizing sign *Contralateral crus cerebri are compressed *Kernohan's notch (indentation in peduncle) is formed |
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Kernohan's Notch
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Indentation made in peduncle (crus cerebri) during uncal herniation
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Opiod receptors
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Mu = Morphine
Delta = Enkephalin Kappa = Dynorphin |
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Opiod analgesics
|
Methodone - addiction maintenance
DEXTROmethORPHAN - cough *Sick right-handed orphan Loperamide - diarrhea DIPHENOXYLATE - diarrhea Morphine FENTANYL Codeine Heroin MEPERIDINE General uses: 1. Pain 2. Acute pulmonary edema (respiratory depression) Toxicity: Miosis (PINPOINT) Constipation Respiratory depression CNS depression Addiction Antidote: Naloxone, naltrexone |
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Opiod antidote
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Naloxone
Naltrexone |
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Benzodiazepine
|
Increases GABA action
*Phenobarbitol, Topirimate (2 mechs) have same general action Alters GABA by FREQUENCY of Cl- channel opening (unique) 1. 1st line to treat acute status epilepticus (phenytoin = prophylaxis) 2. Used (but not 1st line) for eclampsia siezure prevention 3. Anesthesia (Midazolam) SE: STD *Sedation *Tolerance *Dependence |
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Phenobarbitol
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Increases GABA action
*Benzodiazepines, Topirimate (2 mechs) have same action Alters GABA by DURATION of Cl- channel opening (unique) Uses: 1. Partial and tonic-clonic seizures *1st line in pregnant women, babies 2. Anxiety, Insomnia 3. Anesthesia (thiopental) SE: STD (like benzos) + P450 *More likely to lead to FATAL respiratory depression |
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Topiramide
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Increases GABA action (like benzodiazepines, phenobarbitol)
Blocks Na+ channels (like Lamotrigine) Uses: Partial and tonic-clonic seizures SE: Part of GTP Sedation Kidney stones (toppling stones) Weight loss (good if you top scales) |
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Lamotrigine
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Blocks Na+ channels (like Topiramide)
Uses: Partial and tonic-clonic seizures SE: Stevens-Johnson |
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Gabapentin
|
Increases GABA release (unique)
Uses: 1. Partial and tonic-clonic seizures 2. Peripheral neuropathy (pain) SE: Gab that AS Ataxia Sedation (part of GTP) |
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Valproic acid
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Increases GABA concentration (unique)
Inactivates Na+ channels (like carbamazepine, phenytoin) Uses: *Partial and tonic-clonic seizures *Myoclonic seizures *Absence seizures (2nd line) SE: *Hepatotoxicity (like carbamazepine) *Not for use in pregnancy (like carbamazepine, phenytoin)--NTD defects *Weight gain (gain VALume), despite GI effects *Tremor |
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Carbamazepine
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Inactivate Na+ channels (like phenytoin, valproic acid)
Uses: 1. Partial and tonic-clonic seizures 2. Trigeminal neuralgia SE: *DAP: Diplopia, Ataxia, P-450 *Hepatotoxicity (like valproic) *Teratogen (valproic, phenytoin) *Blood changes (like phenytoin), including aplastic anemia, agranulo |
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Phenytoin
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Inactivates Na+ channels (like carbamazepine, valproic acid)
*Use-dependent Uses: 1. Partial and tonic-clonic seizures 2. Class IB anti-arrhythmic 3. Prevention of status epilepticus SE: *DAPS: Diplopia, ataxia, P-450, sedation *Teratogen (like carba, valproic)-Fetal Hydantoin *Blood changes (like carba): MB anemia *Phenny looking: Nystagmus, SLE-like, Hirsutism, Gingival hyperplasia |
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Ethosuximide
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Blocks T-type Ca2+ channels
*Thalamus Uses: 1st line for absence seizures SE: EFGHIJ Fatigue GI distress Headaches Itching (urticaria) J: Stevens-Johnson |
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Anesthetics: Low blood solubility
|
Rapid induction and recovery
Ex. N20 |
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Anesthetics: High blood solubility
|
Slow induction and recovery
Ex. Halothane |
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Anesthetics: High lipid solubility
|
High potency
Corresponds to 1/MAC (Minimum alveolar concentration) Ex. Halothane |
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Low lipid solubility
|
Low potency
Corresponds to 1/MAC (Minimum alveolar concentration) Ex. N2O |
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Inhaled anesthetics
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Halothane, Nitrous oxide (N2O) + FLURANES
UNKNOWN mechanism SE: Depression of all organs *Myocardial, respiratory *GI --> nausea, emesis *Brain --> Decreased cerebral flow Halothane --> Hepatotoxicity Methoxyflurane --> Nephrotox *M-N: closest Enflurane --> Convulsant *"ENter a seizure state" |
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IV Anesthetics
|
B.B. King on OPIATES PROPOses FOOLishly
Barbiturate: Thiopental *Induction: high potency, short acting Benzo: Midazolam *Most common drug for ENDOSCOPY: "Midazolam to look at your MIDDLE" *Used in conjunction w/gaseous anesthetics and narcotics Ketamine/Arylcyclohexylamines *PCP analog --> dissociative *Disorentation, hallucination *Bad dreams *Cardiovascular stimulant --> INCREASES cerebral blood flow Opiates: Used during general anesthesia Propofol: *Short acting *Less nausea than thiopental |
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Thiopental
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High potency (lipid soluble) barbiturate
Short acting: Short processes or INDUCTION of anesthesia |
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Midazolam
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Benzodiazepine
Most common drug for ENDOSCOPY *"Midazolam to look at your MIDDLE" *Used in conjunction w/gaseous anesthetics and narcotics SE: Severe respiratory depression Amnesia If BP drops too low, treat w/FLUMENAZIL (true of all benzos) |
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Arylcyclohexylamines
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a.k.a. Ketamine
PCP analog --> dissociative anesthesia *Disorentation, hallucination *Bad dreams Cardiovascular stimulant --> INCREASES cerebral blood flow |
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Local anesthetics
|
Block Na+ channels from the INSIDE
Work prefentially on ACTIVATED channels (shares property with phenytoin) ALL cause CNS excitation and vascular effects (HTN or hypotension) Esters: CAINES *May be allergic; if so, give amides Procaine Cocaine -- Arrythmia Tetracaine Amides: 2 I's *Enter uncharged but bind as ions Lidocaine Mepivacaine Bupivacaine--Cardiotoxicity |
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Local anesthetics: Efficacy factors
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1. Wounds are acidic: Cause compounds to become charged, unable to enter cells
*More must be given 2. Small size, myelination aid in efficacy *Numbness order: Pain --> Temp --> Touch --> Pressure (PTTP) *Sm myelinated > Sm unmyelinated > Lg unmyelinated > Lg myelinated 3. Given with vasoconstrictors: *Reduce systemic leakage *Decrease bleeding Minor surgical procedures |
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Neuromuscular blocking drugs
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Uses:
*Paralysis during surgery *Mechanical ventilation Depolarizing: Succinylcholine *Rhabdomyolysis --> High Ca2+, K+ *Phase 1: Excessive Ach stimulation does not allow muscle time to "reset" (AchE-I helps block) *Phase 2: Receptors have desensitized/closed; AchE-I weakens block Nondepolarizing: Tubocurarine + CURIUMs *Competitive inhibitor of Ach receptor *Reversal of blockade: AchE-I |
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Acetylcholinesterase Inhibitors
|
Neostigmine, Edrophonium
Succinylcholine (depolarizing NMJ blocker): *Strengthens phase 1 block *Weakens phase 2 block Nondepolarizing NMJ blockers (Curiums + Tubocurarine): *Weakens block |
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Dantrolene
|
Inhibits release of Ca2+ from sarcoplasmic reticulum
Uses: Inhibit uncontrolled skeletal muscle oxidative metabolism 1. MALIGNANT HYPERTHERMIA *Inhalation anaesthetics (not N2O) + succinylcholine *Circulatory collapse if not treated quickly 2. NEUROLEPTIC MALIGNANT SYNDROME (antipsychotic drug tox) |
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Malignant hyperthermia
|
Usually triggered by inhaled anesthetics
Uncontrolled increase in skeletal muscle oxidative metabolism Circulatory collapse if not treated quickly --> DANTROLENE |
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Neuroleptic Malignant Syndrome
|
Neuroleptic toxicity
Muscle rigidity Fever Autonomic instability Delirium Increased CREATININE |
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Parkinsons drugs
|
BALSA
1. Bromocriptine, pramipexole, ropinirole --> DA agonists 2. Amantadine --> Increase DA release *Influenza A and rubellA (90% resistance) *Ataxia (cerebellA) 3. Levodopa--> Converted to DA in CNS *Carbidopa = peripheral decarboxylase inhibitor (increases CNS availability) *Peripheral conversion ~ arrhythmia 4. Selegiline (MAO-B inhibitor) Entacapone, tolcapone (COMT inhibitor) --> Prevent DA breakdown *Both may increase L-dopa SE 5. Antimuscarinics (Benztropine) *BenzTROPine: calm your TREMOR before you PARK your BENZ *Calms excess Ach activity in CNS *Parkinson's disease--tremor, rigidity *Has little effect on bradykinesia |
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Essential/Familial tremor treatment
|
B blocker
Not...alcohol! |
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Sumatripan
|
5HT-1D agonists
Short-term vasoconstrictor *T1/2 = < 2 hours SSS: Sumatripan --> Like serotonin --> Makes vessels SMALL Uses: 1. Acute migraine 2. Cluster headache attacks SE: *Vasospasm (not for CAD/Prinzmetal) *Mild tingling *Hypertensive emergencies |
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Freidrich's Ataxia
|
AR mutation of chromosome 9
*Increased trinucleotide repeats Seen in children 5-15 years old 1. Posterior column and spinocerebellar degeneration *Gait ataxia (seen early) *Kyphoscoliosis, PES CAVUS (fixed plantar flexion), hammer toes 2. >50% develop hypertrophic cardiomyopathy *Arrhythmias *CHF 3. ~10% develop DM |
