General neuro 0426Q Flashcards by ashley bui

effect of GLUCOSE LOADING in acute intermittent porphyria

decreases porphyrin synthesis by repressing ALA synthase activity - alleviates abd pain and neuropsych manifestations

*also treat with heme, which also decreases ALA synthetase activity to decrease ALA (thus porphobilinogen) levels

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AIP

Painful abdomen
Port wine colored urine - darkens upon standing
Polyneuropathy
Psychologlic disturbances
Precipitated by drugs

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drugs that cause AIP

phenobarbital
griseofulvin
phenytoin
ALCOHOL

decrease hepatic conc of heme by inducing P450

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simple seizure

no impairment of consciousness during or after event

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complex seizure

loss of memory during event.

post ictal state.

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progressive weakening diaphragmatic contractions during max voluntary ventilation with intact phrenic nerve stimulation indicates?

NMJ problem (myasthenia gravis)

2. abnormal rapid diaphragm fatigue (restrictive lung or chest wall dz)

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diaphragmatic contraction

responsible for intrapleural pressure FALL during inspiration

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cryptococcus dx

latex agglutination: thick polysacc capsule Ag

India ink staining: round or oval budding yeast

culture (sabouraud agar)

methenamine (GMS) or mucicarmine stains of tissue

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viral esophagitis + pneumocystic pneumonia

= HIV infection

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pineal tumor

most common location of BRAIN GERMINOMA (similar to testicular seminoma).

sx: 
precocious puberty (beta hCG).
Parinaud syndrome (paralysis of upward gaze). 
obstructive hydrocephalus (aqueduct compression).

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radial n. injury

deep branch arises near lateral epicondyle of humerus - radial head subluxation (nursemaid’s elbow) can damage deep branch - cause weakness of forearm and hand extensors with NO SENSORY deficits.

*superficial branch is purely sensory (radial half of dorsal hand NOT including distal 1st-3rd digits [median n])

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arnold-chiari malformations

congenital impaired development of posterior fossa - small size causes parts of cerebellum and medulla to herniate through foramen magnum

type I: benign, may manifest in adulthood
type II: severe, evident in newborn

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multiple ring-enhancing lesions

in HIV pt - toxoplasmosis (with oral thrush, lymphadenopathy). seizures result from lesion and surrounding edema

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CNS glioblastoma

solitary ring-enhancing butterfly lesion

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absence + tonic clonic seizures

sodium valproate

*ethosuximide only effective against absence seizures, valproic acid effective against both

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most common cause of excessive daytime sleepiness in US

obstructive sleep apnea - due to poor oropharyngeal tone (transient upper airway obstruction); results in sleepiness, morning HA, depression.

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fragile X signs

mild to mod MR, speech and language delay, autistic / ADHD behavior.

long face, prominent jaw, large ears, cleft palate.

macroorchidism.

mitral valve prolapse.

short height, joint laxity, scoliosis, pes cavus, double jointed thumbs, single palmar crease.

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acute stress disorder vs. PTSD

same sx: recurrent nightmares/flashbacks, potential memory loss, exaggerated startle response.

ACUTE: < 4 wks
PTSD: > 4 wks

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neonatal tetanus

usu. results from C.tetani colonization of umbilical stump

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huntington gene product

increased CAG repeats on gene coding for huntingtin - decreases expression of other genes by inhibiting their transcription (transcriptional repression or silencing) via hypermethylation of histone fragments.

acetylation vs. methylation

acetylation enhances gene transcription.

methylation decreases it.

low frequency sound

best detected at apex of cochlea near helicotrema

high frequency sound

detected at BASE of cochlea near oval and round windows

synaptophysin

protein in presynaptic vesicles of neurons, neuroendocrine, and neuroectodermal cells.

CNS tumors of neuronal origin stain positive for synaptophysin

GFAP

glial origin - astrocytes, ependymal cells, oligodendrocytes

caudate atrophy in Huntington

typical dilation of frontal horns of lateral ventricles (gliosis, neuronal loss on histo)

thiamine - cofactor

1. pyruvate dehydrogenase (pyruvate of glycolysis to acetyl CoA of TCA) 2. alpha ketoglutarate dehydrogenase in TCA 3. transketolase in hexose monophosphate pathway - converts pentoses from glucose to G3P for glycolysis * thiamine deficiency results in decreased glucose utilization

dx of thiamine deficiency

increased erythrocyte transketolase levels after thiamine infusion

meningiomas

PSAMMOMA BODIES. arise from cells of arachnoid villi. slow growing. sx: new onset seizures in adult.

psammoma bodies

round eosinophilic laminar structures. | core of dense calcification with surrounding collagen fiber bundles.

interferons alpha and beta

produced by euk cells in response to viral infx. stimulate neighbors to synthesize antiviral proteins that IMPAIR VIRAL PROT SYNTH. no impact on cellular mRNA of host.

interferon gamma

only produced by T cells and NK cells

location of intracranial schwannoma

cerebellopontine angle - between cerebellum and lateral pons. arise from CN VIII.

bilateral acoustic neuromas

NF type 2. aka schwannomas of CN VIII.

food-borne botulism

neurotoxin prevents release of ACh from nerve terminals at NMJ, thus preventing muscular contraction. toxin produced by vegetative bact. remains intracellular until autolysis releases toxin into food.

sx of botulinum neurotoxin consumption

Diplopia Dysphagia Dysphonia

Waterhouse-Friderichsen syndrome

DIC + hemorrhagic destruction of bilateral adrenal glands + shock. complication of meningococcemia (N.meningitidis bacteremia). *N.meningitidis bacteremia often occurs without meningeal involvement. present with signs of sepsis, purpuric lesions, hypotension.

adverse effect - nonselective beta blocker

dose-dependent bronchoconstriction, wheezing (beta2). esp concerning with asthma, COPD.

pituitary adenoma

prolactin-secreting: bitemporal hemianopia, amenorrhea. anterior pituitary (lactotrophs) - derived from surface ectoderm.

main ectoderm derivatives

surface ectoderm. | neural plate: neural tube, neural crest cells.

rapid correction of HYPERnatremia

cerebral edema

rapid correction of HYPOnatremia

central pontine myelinosis | osmotic demyelination of axons in central part of pons

autonomic signal pathways

cAMP IP3 ion channels

nicotinic receptors

ligand-gated ion channels that open after binding ACh - results in immediate influx of Na and Ca into cell, efflux of K out of cell

cell membrane receptors

1. ionotropic: ion channels that open directly upon ligand binding (immediate response) 2. metabotropic: utilize 2nd messengers to indirectly influence their respective ion channels

naloxone

pure opioid receptor ANTagonist. treat opioid intox or OD. antagonizes all receptor types but has highest affinity for mu receptors. displaces narcotics from receptor. reverses analgesia, sedation, hypotension, resp depression. must be given IV (completely inactivated by liver when given orally).

buspirone

first line for generalized anxiety disorder. clinical response may delayed up to 2 wks w/regular use.

prok DNA pol proof reading activity

ALL 3 pols remove mismatched nucleotides via 3'-5' exonuclease activity. DNA pol I also has 5'-3' exonuclease activity to excise and replace RNA primers and damaged DNA sequences