Test #33 (BsPN Week 3N Block 3: Neuro)

Question 1

(1) Dx: 8 mo girl irritability and regression of motor skills, birth unremarkable, appeared to develop normally, but can no longer sit or roll over, startles easily with loud noises. Reveals macrocephaly. Ophthalmological exam reveals loss of peripheral vision and abnormal red circular area of choroid at fovea centralis surrounded by contrasting white macula. Ab exam normal. (2) Explain how to differentiate from other ddx

Answer 1

(1) Tay-Sachs: autosomal recessive disorder caused by def. in Beta-hexosaminidase A, which results in accumulation of GM2 ganglioside. Characterized by progressive neurodegeneration and a cherry-red macular spot. (2) In contrast to Niemann-Pick disease, no hepatosplenomegaly

Question 2

Embryologic origin of pituitary adenoma

Answer 2

Surface ectoderm

Question 3

(1) Dx: 62 yo female comes to ER complaining of difficulty walking started 3 hours ago, also says she cannot feel her right side, PE shows loss of sensation affecting right upper and lower extremities and right side of face. muscle strength 5/5 in all extremities. (2) Explain

Answer 3

(1) Thalamic syndrome (2) Characterized by total sensory loss on the contralateral side of the body. Although there are no motor deficits, proprioception is often profoundly affected and may lead to difficulty ambulating and falls.

Question 4

(1) Dx: neurodegenerative disorder with cystic degeneration of putamen (2) Location of putamen on coronal sections

Answer 4

(1) Wilson’s disease (also damages other basal ganglia structures) (2) Putamen is located medial to insula and lateral to globus pallidus on coronal sections

Question 5

Highly suggest imaging finding for Alzheimer disease (i.e., area of brain most affected & the effect)

Answer 5

Hippocampal atrophy

Question 6

Dx/Explain: 60 yo develops left-side weakness and numbness during lecture, BP 190/100 mm Hg, HR 78/min. PE reveals diminished power on left side (1/5) and an upgoing plantar reflex. Brain CT without contrast shows intraparenchymal hemorrhage

Answer 6

Hypertension is most common overall cause of intraparenchymal hemorrhage, usually through formation of small Charcot-Bouchard pseudoaneurysms in small arterioles that penetrate basal ganglia and thalami. Note: Contrast to rupture of saccular aneurysm, which typically presents with subarachnoid hemorrhage

Question 7

(1) Type of drug that Phenelzine is (2) Clinical use for this type of drug

Answer 7

(1) Monoamine oxidase inhibitors (2) Particularly useful in patients with atypical depression and treatment-resistant depression

Question 8

(1) Common first sx of alcohol withdrawal (2) Other sx (3) Most severe manifestation & its time of onset

Answer 8

(1) Tremulousness (2) GI distress, agitation, anxiety, and autonomic disturbance (3) Delerium tremens, typically begins between 48-72 hrs after last drink

Question 9

(1) Dx: symmetrical enlargement of lateral ventriculi on gross brain section of 54 yo male who suffered from severe tuberculosis meningitis (2) Usual cause/Explain dx

Answer 9

(1) Communicating hydrocephalus: (2) Symmetrical enlargement of ventriculi characteristic. Usually secondary to dysfunction or obliteration of subarachnoid villi. Dysfunction usually sequelae of meningeal infection (including tuberculosis meningitis) or subarachnoid/intraventricular hemorrhage

Question 10

Explain this light microscopy finding in brain tissue: neurons with shrunken nuclei, no detectable Nissl substance, and intensely eosinophilic cytoplasm

Answer 10

“Red neurons” = neuron responding to irreversible injury; Changes become evident 12-24 hours after injury: shrinkage of cell body, eosinophilia of cytoplasm, pyknosis of nucleus, & loss of Nissl substance

Question 11

Methods for assessing patient’s concentration

Answer 11

Counting down from 100 by 7 or 3, reciting months of year in reverse order, and spelling “world” backwards = quick clinical tests to assess attention and concentration. Tested as part of MMSE (cognitive impairment tool, which measures orientation to time and place, short-term memory, calculation, language, & constructional praxis).

Question 12

Components of an old infarct

Answer 12

Old infarct (months or years since onset of ischemia) consists of cystic cavity surrounded by dense wall. Wall of cyst formed by astrocyte processes.

Question 13

Dx/Explain: 32 yo Caucasian female, complaining of left eye pain accentuated by ocular movements, periodic dimming of vision in her left eye, several such episodes over last month, mostly after a hot shower or intense workout, a year ago she had an episode of numbness and intense tingling in her left arm that resolved spontaneously

Answer 13

Multiple sclerosis: manifests with various self-limiting neurologic symptoms, usually in patients 20-30 years old. Most common initial symptoms are optic neuritis, internuclear ophthalmoplegia, and sensory deficits. Sx usually worsen with heat exposure.

Question 14

(1) Uniform lab finding for Temporal arteritis (2) What’s necessary for confirming dx? (3) Tx approach & reason

Answer 14

(1) ESR uniformly elevated (2) Temporal artery bx (3) Corticosteroid tx should be started ASAP to prevent possible vision loss

Question 15

Pufferfish poisoning mechanism

Answer 15

Caused by tetrodotoxin, a neurotoxin produced by microorganisms assoc. with the fish. Binds voltage-gated sodium channels in nerve and cardiac tissue, preventing sodium influx and depolarization

Question 16

(1) What kind of drug is primidone? (2) To what does it metabolize?

Answer 16

Primodone (antiepileptic) metabolized to phenobarbital and phenylethylmanlonamide (PEMA). All 3 compounds are active anticonvulsants.

Question 17

Point of action potential at which K+ ion permeance is highest

Answer 17

Repolarization phase