Neuro UWorld Flashcards
Supplementation of which vitamin reduces risk of neural tube defects and is recommended for all women of childbearing age?
Folate (vitamin B9)
Folate (vitamin B9) should be give to women of childbearing age during what part of their pregnancy to prevent neural tube defects?
before they conceive
Which medication for bipolar disorder and epilepsy is associated with 10-20 fold increased risk of neural tube defects if taken during the first trimester of pregnancy?
Valproate/valproic acid
Anterograde axonal transport (moves organelles/viruses etc via microtubules, away from nucleus, down axon, toward nerve terminal) is mediated by which motor protein?
kinesin
Retrograde axonal transport (moves organelles/viruses etc via microtubules, toward the nucleus) is mediated by which motor protein?
dynein
A patient has had a subarachnoid hemorrhage. In order to prevent cerebral vasospasm with subsequent ischemia, which medication should the patient be given ?
Calcium channel blocker.
Delayed cerebral ischemia due to vasospasm usually presents 3-12 days after the initial SAH with acute mental status and/or new focal neurological deficits. Nimodipine, a selective calcium channel blocker, improves patient outcomes with SAH by preventing or reducing the extent of ischemic neurological deficits caused by cerebral vasospasm. This neuroprotective effect is likely due to a combination of increased cerebral vasodilation and decreased calcium dependent excitotoxicity.
What neuronal property is most likely to decrease as a direct result of demyelination?
length (space) constant would decrease.
time constant would increase.
The speed of conduction down an axon depends on 2 constantsL the length constant and the time constant (ie, velocity=length/time). Myelination increases th elength constant and decreases the time constant, both of which improve axonal conduciton speed. Demyelination thus impairs stimulus transmission.
moving rostrally in the spinal cord, spinal levels have increasing amounts of ______, and decreasing amounts of _______.
white matter, gray matter
Moving rostrally in the spinal cord, the what shape does the spinal cord become?
oval
Spinal cord sections in the lower cervical and lumbosacral regions have large _____ horns
ventral horns.
these areas innervate the muscles of the arms (cervical) and legs (lumbosacral)
What distiguishes spinal cord section in the thoracic and early lumbar area from the other areas in the spinal cord?
lateral gray matter horns (interomediolateral cell columns), which are made up of sympathetic preganglionic neurons
Above which spinal level are both the gracile and cuneate fasciculi present?
T7
Which fasciculus is present below the leve of T7?
gracile/gracilis
what are the side effects of Phenytoin?
PHENYTOIN
P450 INDUCER
Hirsituism
ENLARGED GUMS
Nystagmus
Yellow-brown skin
Teratogenicity (fetal hydantoin syndrome)
Osteopenia
Inhibited folate absorption
Neuropathy
Phenytoin is a known P450 inducer. What types of medications are affected by this and need to be checked in patients?
Inducers of CYP450 will increase metabolism of oral contraceptives, anticoagulants, antivirals, and HIV drugs. When the P450 oxidase system is induced, the serum concentration of such medications will decrease, thereby reducing efficacy.
Phenytoin is metabolized by CYP 450. How is it influenced by CYP450 inducers? Name some examples
- Giving phenytoin with CYP450 inducers decreases its concentration and renders it ineffective.
- Examples of CYP450 inducers include:
- barbiturates
- rifampin
- carbamazepine
- griseofulvin
- chronic alcohol consumption