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Step 1 12.6.12
Neuro IV
| Question | Answer |
|---|---|
| what does the inner part of CN III fiber carry? What are the sx of its injury? | output to ocular muscles. sx: ptosis, down and out gaze, nonreactive pupils |
| What types of diseases injure the inner part of CNIII, why? | vascular disease(diabetes glucose-->sorbitol) due to decr diffusion to the interior |
| What does the outer part of CNIII fiber carry? What are the sx of its injury? | PSNS output, use pupillary light reflex to asess. "blown pupil" |
| What is the mech of retinal detatchement? What might cause it? | separation of neurosensory layer of retina from pigment epithelium=degeneration of photoreceptors=vision loss. often secondary to trauma or DM |
| What is the mech of age related macular degeneration (ARMD)? | degeneration of macula causing loss of central vision. due to fat deposits so visual loss is gradual. |
| What is rapid ARMD? | rapid loss of vision due to neovascularization |
| What happens in a complete lesion of the optic nerve on the right side prior to the optic chiasm? | right anopia |
| What happens in a lesion of the optic nerve at the crossing over of the optic chiasm? | bitemproal heminopia ( nasal side of retina crosses over) |
| What happens in a lesion of the optic tract on the right side just after the optic chiasm? | left homonymous hemianopia (left half of both eye visions lost) |
| What happens in a lesion of the optic nerve in Meyers loop on the right side (temproal lobe)? What artery could be invovled? | left upper quadrantic anopia (right temporal lesion MCA). |
| What happens in a lesion of the dorsal optic radiation (parietal lobe) on the right side? What artery might be invovled? | left lower quadrantic anopia (both left lowers knocked out). MCA |
| What happens in a lesion of the optic nerve in the visual cortex (occipital lobe). What artery might be invovled? | left hemianopia, with macular sparing. macular sparing has bilateral projection to occiput. PCA |
| What happens in a lesion of only the macular part of the optic nerve? | central scotoma (macular degeneration) loss of central vision |
| What is Meyer's loop? | inferior retina; loops around inferior horn of lateral ventricle |
| What is the dorsal optic radiation? | superior retina; takes shortest path via internal capsule |
| What is internuclear opthalmoplegia (MLF syndrome)? What do you see on PE? | lesion in medial longitudinal fasciculus= medial rectus palsy on attempted lateral gaze. nystagmus in abducting eye. convergence is normal |
| What is a common associated disease with internuclear opthalmoplegia (MLF syndrome)? | multiple sclerosis |
| What is the normal function and mech of the medial longitudinal fasciculus in an attempt to gaze left? | when looking left, the left nucleus of CN VI fires, contracting the left lateral rectus and stimulates contralateral of CNII via right MLF to contract right medial rectus |
| What is dementia? | decr in cognitive ability, memory or function with intact consciousness |
| What genes are associated with early onset Alzheimers disease? | APP(@!), presenili,-1 (14), presenilin-2(1) |
| What genes are associtated with late onset Alzheimers? What gene is protective? | late: ApoE4(19), protective:ApoE2(19) |
| Who tends to gets Alzheimer's? | Old people and Down syndrome |
| What are 4 general histologic and gross findings in alzheimer's disease? | decr ACH, senile plaques, neurofibrillary tangles, widespread cortical atrophy |
| What are senile plaques? | extracellular beta amyloid core can cause amyloid angiopathy-->intracranial hemorrhage. The A beta amyloid is synthsized by cleaving an amyloid precursor |
| What are neurfibrillary tangles? | intracellular abnormmaly phosphorylated tau protein=insoluble cytoskeletal elements; tangels correlate with degree of dementia |
| What are the Sx of Pick's disease? What parts of the brain are spared? | dementia, aphasia, parkinsonian aspects, change in personality. Spares parietal lobe and posterior 2/3 of superior temoparal gyrus |
| What histologica and gross findings are seen in Pick's disease? | pick bodies ( intracellular aggregated tau), frontotemporal atrophy |
| What are the sx of Lewy body dementia? | Parkinsonism with dementia and hallucinations |
| What are the histologic and gross findings of Lewy body dementia? | alpha synuclein defect |
| What is the time course and presentation of Creutzfeld-Jakob disease? | rapidly progressive (weeks to months) demential with myoclonus |
| What are the histiologic or gross findings in Creutzfeld-Jakob disease? | spongiform cortex, Prions ( PfPc-->PrPSC sheet which is resistant to proteases |
| what are some common causes of dementia besides the named diseases? | multi infarct, syphilis, HIV, vit B12 deficiency, Wilson's disease |
| What is the pathophys of multiple sclerosis? | autoimmune inflammation and demyelination of CNS (brain and spinal cord) |
| How might a multiple sclerosis patient present and what is the time course? | optic neuritis (sudden loss of vision), MLF syndrome (internucler opthalmoplagia), hemiparesis, hemisensory sx, or bladder/bowel incontinence. relapsing or remitting course |
| Who is most likely to get MS? | women in 20s and 30s,v more common in whites |
| What are the major findings in MS? | incr protein (IgG) in CSF, oligoclonal bands, MRI is gold standard. see periventricular plaques (oligodendrocyte loss) with axon preservation |
| What is Charcot's classic triad of MS? Mnemonic? | SIN: scanning speech, intention tremor, Incontinence, internuclear opthalmoplegia, mystagmus |
| How is MS tx? | Beta interferon, immunosurpression, natalizumab. symptomatic treatment for bladder, spasticity, pain |
| What is Guillain-Barre syndrome( acute inflammatory demylinating polyradiculopathy)? What does it cause? | inflammation an demyelination of periphepheral nerves and motor fibers of ventral roots. causes symmetric ascending muscle weakness beggining in distal lower extremities. also facial paralysis |
| What can happen in Guillain-Barre syndrome besides muscle weakness? | sever effect on autonomic function sometimes ( cardiac irregularities, hyper or hypotension) |
| What are the typical findings in Guillain-Barre syndrome? | incr CSF protein with normal cell count (albuminocytoloic dissociation), incr protein leading to papilledema |
| What is Guillain-Barre syndrome associated with? | infection leading to Auto immune attack on peripheral myelin (campylobacter jejuni or herpes), inoculations, stress |
| What is the tx for Guillain-Barre syndrome? | respiratory support is critical until recovery. also plasma phoresis, IV Ig |
| What is progressive multifocal leukoencephalopathy? What is it associted with and what is its outcome? | demyelination of CNS due to destruction of oligodendrocytes. associated with JC virus and seen in 2-4% of AIDS pt (reactivation of latent viral infection). rapidly progressive and usually fatal |
| What is acute disseminated (post infectious) encephalomyelitis? | multifocal perivenular inflammation and demyelination after infection (chickenpox, measels) or vaccinations (rabies, smallpox) |
| What is metachromatic leukodystophy? | autosomal recessive lysosomal storage disease most commonly due to arylsulfatase A deficiency. get build up of sulfatides leading to imparied production of the myelin sheath |
| What is Charcot-Marie-Tooth disease? | a.k.a. HMSN. group of progressive hereditary nerve disorders related to defective production of proteins invovled in the structure and function of peripheral nerves or the myelin sheath |
| What are the general characterisitcs of a partial seizure? | 1 area of brain, most commonly originates in the medial temporal lobe, often preceded by aura |
| What is a simple partial vs complex partial seizure? | simple: motor, sensory, autonomic, psychic affected but consciousness is intact. A complex partial seizure has impaired consciousness |
| What is an absence seizure? | petit mal, 3 Hz, postictal confusion-blank stare |
| What is a myoclonic seizure? | quick repetitive jerks |
| What is a tonic-clonic seizure? | grand mal, alternating stiffening and movement |
| What is a tonic seizure? | stiffening |
| What is an atonic seizure? | drop seizures(falls to floor) commonly mistaken for fainting |
| What is epilepsy? | disorder of recurrent seizures (febrile dont counmt) |
| What are the most common causes of seizures in children? | genetic, infection, trauma, congenital, metabolic |
| What are the most common causes of seizures in adults? | tumors, trauma, stroke, infection |
| What are the most common causes of seizures in the elderly? | stroke, tumor, trauma, metabolic, infection |
| What is a headache? | pain due to irritation of structures like dura, CN, extracranial structures, not the brain parenchyma |
| What is a migraine? | unilateral 4-72hrs of pulsing pain with nausea, photophobia, phonopohobia. and or aura including visual, sensory, speech disturbances |
| What causes migraines? | irritation of CN V and release of substance P, CGRP, vasoactive peptides |
| What is the tx for migraines? | propanolol, NSAIDS, sumatriptan for acute migraines |
| What is a tension HA? | bilateral > 30 mins of steady pain. no aggrivated by light or noise, no aura. |
| What is a cluster HA? | unilateral, repetitive brief Ha characterized by periorbital pain associated with lacrimation, rhinorrhea, Horner's syndrome. much more common in males |
| What is the tx for cluster HA? | oxygen or sumatriptan |
| What might be the cause of "the worst HA of my life"? | subarachnoid hemorrhage |
| What is vertigo in general? | illusion of movement, not confusion with light headedness or dizziness |
| What is peripheral verigo? What is the etiology? | more common, inner ear etiology ( canal debris, infection, mensiere disease) |
| What postional testing is used to dx peripheral vertigo? | delayed horizontal nystagmus |
| What is central vertigo? | brainstemm or cerebellar lesion (vestibular nuclei, posterior fossa tumor) |
| What postional testing is seen in central vertigo? | immediate nystagmus in any direction. may change directions |
| What is Sturge-Weber syndrome? | congenital disorder with port-wine stains (nevus flammeus), typically in V1 distrobution. get ipsilaterl leptomeningeal angiomas, pheochromocytomas |
| What can Sturge-Weber syndrome cause? | glaucoma, seizures, hemiparesis, mental retardation. |
| What is a Mneomonic for the presentation of tuberous sclerosis? | HAMARTOMAS: hamartomas in CNS and skin, Adenoma sebaceum, mitral regurgitation, Ash-leaf spots, cardiac Rhabdomyoa, Tubuerous sclerosis, autOsomal D, Mental retardation, renal Angiomyolipoma, seizures |
| What is seen in neurofibromatosis type I ( von Recklinhausen's disease)? | cafe au lait spots. Lisch nodules (pigmented iris hematomas, neurofibromas on skin, optic gliomas, pheochromocytomas |
| What is the inheritance and gene associated with neurofibromatosis type I ( von Recklinhausen's disease)? | autoD, variable expression with mutated NF-1 gene on chr 17 |
| What is seen in von-Hippel-Lindau disease? | cavernous hemangiomas on skin, mucosa, organs; bilateral renal cell carcinoma, hemangioblastoma in retina, brain stem, cerebellum. pheochromocytomas. |
| What is the gene and inheritance of von Hippel-Lindau syndrome? | autoD with mutated tumor surpressor VHL on Chr 3 |
| where are the majority of adult primary brain tumors located? | supratentorial |
| Where are the majority of childhood primary brain tumors located? | infratentorial |
| Where do metastases to the brain normall look like? Where do they go? | well circumscribed, present at the gray-white junction |
| What is the prognosis, location and what do you stain for in glioblastoma multiforme (grade IV astrocytoma)? | most common primary brain tumor. prognosis is <1 year. found in cerebral hemispheres, can cross corpus callosum. stain astrocytes for GFAP |
| Pseudopallisading pleomorphic tumor cells bordering central areas of necrosis and hemmorrhage describes? | glioblastoma multiforme (grave IV astrocytoma) |
| What is the location, prognosis and origin of meningioma? | most often occurs at convexities of hemispheres and parasaggital region. arises from arachnloid cell external to brain, resectable. |
| Spindle cells concentrically arranged in a whorled pattern with psammoma bodies (laminated calcifications) describes what tumor? | meningioma |
| What is a the origin of, prognosis and where are scwannomas found? | scwann cell origin often localized to CNVIII-->acoustic schwannona. resectable and usually found at the cerebellopontine angle |
| What is a useful tumor marker for Schwannomas? | S-100 positive |
| What type of tumor is associated with neurofibromatosis type 2? | bilateral scwannoma |
| What is the orign and histology of the oligodendroglioma? | relatively rare, slow growing. most often in frontal lobes. chicken wire capillary pattern. oligodendrocytes= fired egg cells, round nuclei with clear cytoplasm. often found calcifed |
| Where doe a pituitary adenoma occur and what are some common presenting sx? | most common prolactinoma. bitemporal hemianopia anmd hyper-or hypo pituitarianism are sequelae |
| What is the prognosis, appearance and location of pilocytic (low grade) astrocytoma? | well circumscribed in kids, found in posterior fossa but can be supratentorial. good prognosis |
| What is a marker for pilocytic astrocytoma? | GFA positive |
| What are rosenthal fibers? What tumor are they associated with? | eosinophilic, corkscrefibers associated with pilocytic astrocytoma |
| What is the prognosis and origin of medulloblastoma? What can it compress? | highly malignant cerebellar tumor. form of primitive neuroectodermal tumor. can compress 4th ventricl causing hydrocephalus |
| What is seen in histology of medulloblastoma? | rosettes or perivascular pseudorosette pattern of cells. small blue cells |
| What is an ependymoma? | ependymal cell tumor cmost commonly found in 4th ventricle. can cause hydrocephalus with poor prognosis |
| What is seen in histology and patholgoy of ependymom? | characteristic perivascular pseudorossettes. Rod shaped blepharoplasts (cbasal ciliary bodies), found near nucleus |
| What is a hemangioblastoma? What is it associated with? What can it cause? | most often cerebellar, associated with von Hippel Lindau when found with retinal angiomas. Can produce EPO causing a secondary polycythemia |
| What is seen in histology of hemangioblastoma? | foamy cells and high vascularity |
| What is a craniopharyngioma? | benign childhood tumor confused with pituitary adenoma *can also cause bitemporal hemianopia). most common childhood supratentorial tumor |
| Where does craniopharyngioma come from? What is often seen in histology? | derived from remnants of Rathke's puch. calcification is a common finding |
| What is a cingulate (subfalcine) herniation? What structure can be compressed? | herniation under flax cerebri. can compress ACA |
| What is a cerebellar tonsillar herniation? | herniation into the formen magnum |
| What might cause ipsilateral dilated pupil/ptosis in an uncal herniation? | stretching of CNIII (innervates levator palpebrae) |
| What might cause contralateral homonymous hemianopia in an uncal herniation? | compression of ipsilateral PCA |
| What might cause ipsilateral paresis in an uncal herniation? | compression of the contralateral crus cerebri (Kernohan's notch) |
| What might cuase duret hemorrages or paramedian artery rupture in an uncal herniation? | caudal displacement of the brainstem |
| What is the DDX for a ring enhancing lesion in the brain? | metastases (lung>breast>melanoma>kidney>GI), absesses, toxoplasmosis, primary CNS lymphoma(AIDS, EBV) |
| What is the DDX for a unifromaly enhancing lesion in brain imaging? | metastatic lymphoma (often B Cell NHL), menangioma, metastases |
| What is the DDX for a heterogenously enhancing lesion on brain imaging? | glioblastoma multiforme |
| What is the mech of epinephrine for glaucoma? | alpha agonist which decr aqueous humor synthesis due to vasoconstriction |
| What is the SE of epinephrine for glaucoma? | mydriasis, stinging, DONT USE in closed angle |
| What is the mech of brimonidine in glaucoma? | decr aqueous humor synth |
| What are the eye SE for brimonidine? | none |
| What is the action of timolol, betaxolol, cartelol in glaucoma? SE? | decr aqueous humor secretion, no pupillary SE |
| What is the mech of acetazolamide for glaucoma? SE? | decr aqueous humor secretion due to decr HCO3 (inhbits carbonic anhydrase). no pupillary SE |
| What is the class of pilocarpine and carbachol for glaucoma? | direct cholinomimetics |
| What is the class of physostigmine, echothiophate for glaucoma? | indirect cholinomimetics |
| What is the mech of pilocarpine, carbachol, physostigmine, echothiphate for glaucoma? | incr outflow of aqueous humoe, contract ciliary muscle and open trabecular meshwork; use pilocarpine in memergencies since its very effective at openign trabecular network |
| What are the SE of pilocarpine, carbachol, physostigmine, echothiphate for glaucoma? | miosis, cyclospasm |
| What is the mech and SE of latanoprost for glaucoma? | incr outflow of aqueous humor. Can turn iris brown |
| What is the class of morphine , fetanyl, codeine, heroin, methadone, merperidine, dextromethorphan, diphenoxylate? | opioid analgesics |
| what is the mech of morphine , fetanyl, codeine, heroin, methadone, merperidine, dextromethorphan, diphenoxylate? | all are opioid receptor agonisis which open K+ channels, close Ca++ and inhibit the release of ACH, NE< 5-HT, glutamate, substance P |
| What receptor does morphine work on? | mu |
| What receptor does enkephalin work on? | delta |
| What opioid receptor does dynorphin work on? | kappa |
| What are the clinical uses of morphine , fetanyl, codeine, heroin, methadone, merperidine, dextromethorphan, diphenoxylate? | pain, acute pulmonary edema |
| What opioid could be used to surpress cough? | dextromethorphan |
| What opioid could be used for diarrhea? | loperimide or diphenoylate |
| What opioid could be used for maintenance programs for addicts? | methadone |
| What are the major SE of morphine , fetanyl, codeine, heroin, methadone, merperidine, dextromethorphan, diphenoxylate? | addiction, respiratory depression, constipation, miosis (pinpoint pupils), additive CNS depression with other drugs |
| What 2 SE does tolerance not develop to for opioids? How is an OD tx? | no tolerance for miosis or constipation. toxicity is treated with naloxone or naltrexone (opioid receptor antagonists) |
| What is the mech of butorphanol? | partial agonist at opioid mu receptors, agonist at kappa receptors |
| What is the clinical use of butorphanol? | pain, causes less respiratory depression than full agonists |
| What are the major SE of butorphanol? | causes withdrawl if on full opioid agonist |
| What is the mech of tramadol? | very weak opioid agonist, also inhibits serotonin and NE reuptake |
| What is the clinical use of tramadol? | chronic pain |
| What is the major SE of butorphanol? | similar to opioids. decreases seizure threshold |
Created by:
tjs2123
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