Flashcards in Neuro Deck (304)
GPe vs. GPi/SNr
GPi/SNr tonically inhibits the VA/VL. GPe tonically inhibits the sub-thalamic nucleus (which activates the GPi/SNr). Globus = globally tonically active in inhibiting. Internal segment INHIBITS movt. External = EXTRA and inhibits STN, which normally inhibits GPi)
Chorea vs. athetosis?
Sudden jerky movts vs. slow writhing movts (esp. fingers). Both seen in basal ganglia lesions (HD).
Essential vs. resting vs. intention tremor?
Action tremor exacerbated by holding posture/limb vs. alleviation by movt (Parkinson's) vs. poor finger2nose (cerebellar)
Medial to lateral = Toes to hand to face to tongue and swallowing
B/l - Kluver-Bucy = hyperorality, hypersexuality, disinhibied behavior. Associated with HSV-1
Mammillary body lesion?
B/l lesions in Wernicke-Korsakoff syndrome (confusion, opthalmoplegia, ataxia, memory, confab, personality)
STN activates GPi to inhibit movt. So lesion = contralateral hemiballismus.
B/l lesions lead to anterograde amnesia.
Central pontine myelinolysis
Massive axonal demyelination in pontine white matter 2/2 osmotic forces and edema (Na+ from low to high correction). Acute paralysis, dyarthria, dysphagia, dipolopia, LOC. (Pseudobulbar symptoms)
Where do the ICA's come from?
Right one from the brachiocephalic artery. Left one straight from the aortic arch.
Basilar artery into Circle of Willis anatomy?
Superior cerebellar arteries come off 1st, THEN the posterior cerebral arteries!
Where do the vertebral arteries come from?
Right one from braciocephalic artery (after R ICA). Left one from the subclavian artery.
AICA vs. PICA?
PICA's off the vertebral arteries. AICA's at junction with basilar artery.
A1 vs. A2 ACA?
A1 between MCA and ACom. A2 after Acom.
P1 vs. P2 PCA?
P2 after PCom. P1 between Pom and Basilar before Superior cerebellar arteries.
Two numbers to know for cerebral blood flow.
PO2 < 50 mmHg ---> increased cerebral perfusion pressure. PCO2 > 90 mmHg is LIMIT to increasing cerebral blood flow (via vasodilation) in proportion to PCO2.
By decreasing PCo2, we decreased cerebral blood flow and therefore intracranial pressure. Used for stroke, trauma.
Contralateral paralysis of upper limb and face. Contralateral loss of sensation in upper and lower limbs, and face. Aphasia if dominant or hemineglect if non-dominant.
Contralateral paralysis and loss of sensation in the LOWER limb. (B/c ACA perfuses in the middle-inside portion of brain.
Common location of lacunar stroke?
Internal capsule of the striatum supplied by lenticulotriate artery.
ASA (anterior spinal artery) stroke
Complete motor paralysis. Loss of pain and temp b/l. Retained propioception.
Lateral Medullary syndrome - dec. pain and temp from ipsilateral face and contralateral body, dysphagia, hoarseness, dec. gag, ipsilateral Horner, ataxia
Lateral pontine syndrome - vertigo, vomiting, nystagmus, falling over to side, ipsi facial paralysis and loss of sensation
Contralateral hemianopia w/ macular sparing
Basilar artery stroke
Most commonly from aneurysm. Visual field deficits.
Saccular aneurysm. CN III palsy.
Occurs at bifurcations in Circle of Willis. e.g. Acom and ACA. Rupture to SAH. Associated with ADPKD, Ehlers-Danlos, Marfan. Age, HTN, smoking.
Associated with chronic HTN, affecting small vessels