Neuro Flashcards
Sturge-Weber Syndrome
Somatic activating mutation in the GNAQ gene that causes developmental anomaly of neural crest derivatives.
Port Wine stain (bv derangement) V1/V2 distribution–>Ipsilateral leptomeningial angioma–> seizures/epilepsy, intellectual disability
Episclearl hemangioma –>Increase IOP –> early onset glaucoma
STURGE (Sporadic; Tram track calcifications; Unilateral port wine stain; Retardation; Glaucoma/GNAQ gene; Epilepsy)
Tuberous sclerosis
HAMARTOMAS: Hamartomas in the CNS and skin Angiofibromas Mitral regurg Ash leaf spots Cardiac Rhabdomyomas Tubserous sclerosis Autosomal dOminant Mental retardation renal Angiomyolipoma Seizsures/Shagreen patches
- Increased risk of subependymal astrocytomas
- ungual fibroms (nail growth)
Neurofibromatosis type 1 (von Recklinghausen disease)
Cafe au lait spots
Lisch nodules
Cutaneous neurofibromas (derived from neural crest cells)
Optic gliomas
Pheochromacytomas
NF1 mutation, chromasome 17, neurofibrim (negative regulator of Ras)
Von Hippel Lindau disease
Chromosome 3, VHL gene,
Hyperchromatic nuclei
Hemangioblastomas of cerebellum, spinal cord, brainstem and retina
Angiomatosis (cavernous hemangiomas of the skin, mucosa and organs)
Pheochromacytomas
Bilateral renal cell carcinoma
Charcot Marie Tooth Disease
Hereditary motor and sensory neuropathy
AD
Defect in production of proteins involve in the structure of peripheral nerves and the myelin sheath
Associated with scoliosis and foot deformities
Metachromatic leukodystrophy
AR Lysosomal storage disease
Arylsulfatase A deficiency that inhibits ability to degrade myelin and thus turn over myelin
Sulfatides build up
Central and peripheral demyelination with ataxia and dementia
Krabbe disease
AR lysosomal storage disease
Deficiency is galatocerebrosidase
Build up of galatocerebroside and psychosine destroys myelin sheath
Peripheral neuropathy, developmental delay, optic atrophy, and globoid cells
Adrenoleukodystrophy
X linked
Impaired addition of coenzyme A to long chain fatty acids and thus disruption of metabolism
Long chain fatty acids build up in the nervous system, the adrenal glands, and the testes
Long term coma and death, adrenal crisis
Aphasia
inability to speak (cortical)
Dysarthria
loss of motor function to speak
Where is Broca’s area?
Inferior front gyrus of the frontal lobe
Where is Weirnke’s area?
Superior temporal gyrus of the temporal lobe
Conduction aphasia
Damage to arcuate fasiculus, can’t repeate
“no ifs, ands or buts”
What is the difference between Broca’s and transcortical motor aphasia?
Broca’s has impaired repetitive with nonfluent speach and intact repitition whereas transcortical motor has nonfluent speach with preserved repitition and comprehension (same pattern for Wernicke’s)
Kluver Busy syndrome:
Damage to the amygdala associated with HSV1 producing inhibited behavior like hyperphagia, hyperorality, hypersexuality
Gerstman syndrome
Damaged to the dominant parietal-temporal cortex (angular gyrus near the parietal-temporal lobe junction) resulting in dysgraphia, dyscalcula, finger agnosia, left right disorientation
Ramsay hunt syndrome
VZV in the geniculate gyrus of the facial nerve (facial nerve paralysis, pain in the ear, loss of taste to the anterior 2/3 of the tongue and a rash on the ear canal, tongue, and hard palate
Ddx for a facial nerve palsy/Bells
Lyme disease HSV1 VZV / Ramsay Hunt syndrome Sarcoidosis Diabetes Tumors Hermes eats Lymes at the Zoo and Stares Directly at the Teradactyls
What levels does the Artery of Adamkewitz help perfuse?
T8-L4 (collateral circulation)
Makes mid thoracics T4-T8 ish suceptible to infarct
Meninere’s disease
idiopathic disorder affecting people 30-60 years old; presents with the triad of sensorineural hearing loss, vertigo lasting hrs with nystagmus, and tinitus. Hearing loss often progresses to low frequency permanent loss in both ears. Results of an increase in the volume of endolymph possibly due to malfunction of the endolymphatic sac (responsible for the filtration and excretion of endolymph)
Guillian Barre syndrome/Acute inflamatory demyelinating polyradiculopathy
Autoimmune destruction of Schwann cells resulting in symmetric ascending muscles weakness and paralysis with facial paralysis in 50% of the cases. Can see concomitant sensory and autonomic (hypo/hypertension, cardiac issues). Most resolve spontaneously in weeks to months. Labs will show CSF with a normal cell count but elevated protein (albuminocytologic dissociation) which may cause papilledema. Assciated with Campy, HSV, and Orthomixovirus infections. Possible molecular mimcry pathway. Treat with respiratory support and plasmapheresis/IVIG
How to amino acids cross the BBB?
carrier facilitated transport
How do small molecules like CO2 and O2 cross the BBB?
simple diffusion
How does glucose cross the BBB?
carrier mediated transport
How do non polar/lipid soluble molecules cross the BBB?
diffusion
What areas in the brain have fenestrated capillaries?
Area postrema: toxin vomiting
Vascular organ of lamina terminalis: OVLT (third ventricle, sense osmolarity and transmits to pituitary for ADH release)
Neurohypothesis
Neurons
Permanent (don’t divide in adulthood)
Nissle stain –> RER , can see cell bodies and dendrites, but not axons
Wallerian degeneration
Trauma to axon
Distal degeneration
Proximal retraction
PNS axons can regenerate
Astrocytes function
Physical support K metabolism Removal of excess neurotransmitter BBB Glycogen fuel reserve Reactive gliosis in response to nerve injury (main component of glial scar)
What is the histological appearance of HIV encephalitis?
HIV infected microglia fuse to form multinucleated giant cells
What electrical changes does myelin make to the axon?
increase length constant along the axon
Decrease capacitance and increases the resistance across the membrane
In what disease process do you see injury of Schwann cells?
Guillain Barre (inflammatory infiltrate in the endoneurium - fascia that invests a single nerve fiber)
In what disease process do you see damage to oligodendrocytes?
MS, PML, leukodystrophies
Free nerve endings
C fibers: small, unmyelinated, conduct pain and temp
Adelta: fast myelinated, conduct pain and temp
Found in all of the epidermis and some viscera
Meissners corpusle
Large, myelinated axons, dynamic. glaborous surfaces (non hairy, like hands and feet); fine touch, position
Paccinian corpusle
Large myelinated, dynamic, deeper dermis, ligaments, joints, vibration and pressure
Merkels discs
Large, myelinated, adapt slowly, finger tips, sharp edges pressure, position
Ruffian corpusles
dendritic endings, adapt slowly, finger tips, joints; joint angle change, slippage on a flat surface
What do oligodendrocytes look like on histology?
fried eggs
Where in NE synthesized and what else does this area mediate?
Locus ceruleus in the pons
Mediates stress and panic
Where is 5-HT synthesized?
raphe nucleus
Where is Ach synthesized?
basal nucleus of Meynert
Where is GABA synthesized? What else does this area mediate?
nucleus accumbens
reward, pleasure, addiction, fear
BATS Drink Blood
Awake: beta (high f, low amp)
Awake eyes closed: alpha
N1 (5%): Theta, light sleep
N2(45%): spindle wave, K complex, deeper sleep, bruxism
N3 (25%) : Delta, deep, bed wetting (desmopressin) and night terrors, sleep walking (benzos), high amp, low f
REM (25%): 90 mins, increases as night goes on, increases O2 use in cerebrum, variable pulse and BP, REM cause via PPRF, penile and clitoral tumescence, dream, maybe memory fn
VPL pathway
DCML/spinothalamic –> VPL –> primary somatosensory
VPM pathway
Trigeminal/gustatory –> VPM –> primary somatosensory
LGN pathway
Optic nerve/CN II –> LGN –> calacrine fissure
MGN pathway
Sup. olive + inferior colliculus tectum –> MGN –> temporal auditory contex
VL pathway
Basal ganglia –> VL–> motor cortex
What substantia nigra is destroyed in Parkinsons?
pars compacta
“Compact cars make you go!”
What are the interposed nuclei?
Embuliform and Globose in the cerebellum
What is the lentiform structure?
Putamen and GP
Athetosis
“writhing, snake like movements “ esp in fingers
Huntingtons
Chorea
“Sudden jerky purposeless movements”
Huntingtons
Dystonia
Sustained, involuntary, muscle contractions
Writers cramp
blepharospam (sustained, eyelid twitch)
Essential tremor
High frequency tremor with sustained posture (like outstreatched hands) that is worse with movement or when anxious
Familial, self medicate with EtOH
Tx: beta blockers, primidone
Hemiballisumus
sudden wild flailing of arm +- ipsilateral leg
Contralateral STN lacunar stroke
Intention tremor
Slow, zigzagging motion pointing to a large target
MS , cerebellar
Resting tremor
uncontrolled movement of distal appendages improved with movement
Parkinsons
“pill rolling tremor”
Myoclonus
sudden, brief, uncontrolled, muscle contraction
hiccups, jerk, renal and liver failure causing metabolic abnormalities
A lesion to what area will give you return of primitive reflexes?
frontal lobe
What should you not give a patient was suspected Weirnke’s encephalopathy?
glucose without B1
B1 is a cofactor for some of the glucose metabolism reaction so giving glucose without B1 can make the symptoms of WK worse
What does a bilateral hippocampal lesion cause?
Anterograde amnesia
When are watershed areas at risk and what do strokes to them cause?
severe hypotension
higher order visual processing, upper leg and arm weakness
What are the symptoms of an Acomm aneurysm?
Visual field defects
Central post stroke pain syndrome
Neuropathic pain after a thalamic lesion
Presents with parethesias followed by allodynia and dysesthesia weeks to months later
What are risk factors for developing pseudotumor cerebrei?
danazol
Vit A
woman of childbearing age
Parinaud’s syndrome
hydro with dilation of suprapineal recess (3rd vent, pineal tumor)
Get problems with lataeral eye movements, esp upgaze
eyelid abnormalities
large irregular pupils
convergence and retraction nystagmus
At what vertebral level does the spinal cord end? Subarachnoid space?
L1/L2
Subarachnoid space ends around S2
Spinal muscle atrophy/Werdnig Hoffman
AR destruction of anterior horn cells
Flaccid paralysis “floppy baby” and tongue facilculations
Death by 7 months
Friedrich’s ataxia
AR GAA trinucleotide repeat that codes for frataxin on chromosome 9
Frataxin binds Fe, loss of frataxin leads to mitochondrial tox and impairment of function
Presents in childhood as kyphosis; leads to muscle weakness, loss of DTRs, staggarding gait, frequent falling, pes cavus (high arch), hammer toes, diabetes, HOCM (cause of death)
Cholesteatoma
Overgrowth of desquamated kertin debris within the middle ear that can erode the ossicles or mastoid air cells and lead to conductive hearing loss
Acute disseminated encephalomyelitis
multifocal periventricular inflammation and demyelination after an infection (usually measeales or VZV) or certain vaccines (rabies, smallpox)
Subacute sclerosing panencephalitis
progressive debilitating encephalitis caused by measles virus
Develops yrs after infancy infection with measles when virus invades neurons and oligodendrocytes, can lead to death
