UWorld Neuro Flashcards
What does Nissl stain and where?
Stains the RER in neurons. Shows up in Dendrites and cell body. NOT in axon
How does Kinesin move?
ATP hydrolysis
Man treated for depression has severe confusion, hallucination, hypotension, mouth is dry, face is flushed. QRS prolongation and frequent preventricular beats. What is this and what do you do?
TCA can have quinidine like affects on cardiac TCA tox - Cardio, confusion, coma, biCARB. Effect is due to inhibition of Na channels.
MS is autoimmune. What are the gross and micro histological findings
scattered periventricular plaque like lesions - within plaques you see loss of myelin sheath and depletion of oligodendrocytes. May also see lipid laden M! containing products of myelin breakdownOligoclonal bands of IgG may be detected in CSF.Optic Neuritis - central scotoma, painful eye movementsInternuclear opthalmoplegia - demyelination of MLFCerebellar dysfunction (ataia, nystagmus)Sensory/motor sx - bowel/bladder dysfunction
Where do you see oligodendrocytes depletion? (2)
MS and Progressive Multifocal Leukoencephalopathy
Signs of parasagittal mengiomas?
Leg weakness and splasticity
Beta endorphins are derived from? What else is drived from this?
POMC (pro-opio-melano-cortin) Minus the dashes. POMC makes opiods, malanin, ACTH
Noxious stimuli results in what biochemical/cellular release?
opioid system. Narcotics bind to mu receptor and modulate pain.
Other name for Insulin Like Growth Factor?
Somatomedin C
Fragile X - where do you see the cytologic problem?
gap near the tip of the LONG ARM of X.
Fragile X gene mutation? Also Fragile X presentation?
FMR1 (familial mental retardation1). Large jaw, ears, testicles. Becomes evident within 1 year of life.
Short stature broad chest ammenorrhea - female. Name and cytology
Turners - 45 XO
Tall, gynecomastia, infertile male. Name and cytology
Klinefelters 47 XXY.
Short broad hands. Transverse palmar crease
Down syndrome
Sudden onset weakness and numbness. HTN.
HTN usu from intraparencyhmal hemorrhage. This is usu from charcot bouchard pseudoaneurysm (basal ganglia and thalamus small arterioles)
Charcot Bouchard Pseudoaneurysm presentation vs Saccular Aneurism rupture?
Charcot Bouchard - sudden onset of focal deficitsSaccular Aneurism rupture - sudden onset of headache (subarachnoid hemorrhage!) and altered level of consciousness are more prominent than focal neuro deficit.
Presentation of hemorrhagic stroke vs ischemic stroke?
Hemorrhagic is acute onset w/ focal neuro deficits whereas ischemic develops over hours and is boarder in scope
What is the most common cause of intraparenchymal (Brain) hemorrhage? What is the underlying pathology?
HTN. Leads to hyaline arteriolosclerosis (often in basal ganglia) Walls become weak and dilated.
3 year immigrant kid - MR, seizures, autopsy - abnormal pallor of catecholaminergic brain suggests? What is def here?
PKU. DEF of phenylalanine hydroxylase. Light pigment is due to inhibitory effect of excessive phenylalanine on melanin synth. Can classically have musty body odor.
Locus ceruleus - site for synth of what?
NE
Where do you see Dihydropteridine reductase and dopamine hydroxylase?
Phenylalanine converted to Tyrosine by phenylalanine hydroxylase and BH4. BH4 becomes BH2, and is regenerated to BH4 by Dihydropteridine reductase. Tyrosine then converted to Dopa, then Dopamine, then Dopamine hydroylase turns Dopamine into NE.
Alkaptouria. Inheritance? What is the problem? What is the s/sx.
AR in tyrosine degredation from def in homogentisic acid oxidase. Results in high levels of homogentisic acid -> connective tissue hyperpigmentation, and degenerative joint disease
What is the biochemical cause of albinism? Albinism inheritance?
AR. Dopa cannot be converted to Melanin in melanocytes due to lack of Tyrosinase enzyme
Describe embryological creation of neural tube
Dorsal surface of embryo -> neural plate. This deepens in center fo form neural groove (which is bound on both sides by neural folds. These folds fuse to form neural tube.
What is smoking during oregnancy assoc w/?
Fetal hypoxai - intrauterine growth retardiation, low birth weight and premature delivery. NOT assoc w/ neural tube defects
Insomnia headache periodic agitation and dysphagia, 30-50 days ago after cave exploration. How does this progress? WHat is the treatment composed of?
Rabes . progresses as flaccd paralysis and coma following the acute neurological phase. Death after 2 weeks of being comatose. Killed vaccine. Killed by beta propiolactone.
Synaptophysin - where is it found?
Presynaptic vesciles of neurons, neuroectodermla and neuroendocrine cells. Indicates neuronal origin (usu used for tumor analysis).
What cells stain for GFAP?
Gliomas - Astrocytes, oligodendrocytes, ependymal cells.
DSM criteria for generalized anxiety disorder?
Excssive uncrontrollable worry about multiple issues - can be accompaneid by irratability, distrurbed sleep, poor concentration, muscle tension, fatigability, restlessness. Need 3 or more NONWORRY symptoms for diagnosis and must be present for at elast 6 months. This differes from MDD in that you are less likely to have anhedonia and depressed mood. Tx for GAD is antidepressants, benzodiazepines, Buspirone
Delirium vs dementia
Delirium - acute onset - global memory impairment, fluctuations in consciousness - reversible.Dementia - gradual conset - can be antregrade/retrograde - no changes in conscousness . Usu not reversible.
How long odes brief psychotic disorder last?
Few hours to months
Vascular dementia (other name for this ) and presentation?
Mutli-infarct dementia - occurs over time - FOCAL! neurological signs
60 y.o. Behavioral abnormalitie, speech language decline, socially inappropriate behavior. Urinary incontience
Picks disease - cytoplasmic inclusions of microtubule assoc Tau.
Broke off engagement. How has random severe weakness in leg. Think?
Conversion disorder. Symptoms are not produced intentionally. Often in young women after emotional stress. 75% have spontaneous recovery.
Conversion disroder vs somatization
Conversion - occurs in young women after life stres - unconscous manifestation. Somatization requires 4 pain symptoms, 2 GI symptoms, 1 sexual symptom, 1 pseudoneurologic symptoms - relatively rare. Numerous physical complaints over years.
Damage to radial head presents as?
Wrist etensor weakness - Radial head subluxation “nursemaids elbow” - can be caused whe adult attempts to pull child upwards by arm. Can lead to weakeness of extensors. “Wrist drop” usu results from radal nerve injury. Deep branhc of radial nerve does not carry any sensory innervation
2 mechanisms that lead to diabetic neuropathy/
NEG of proteins -> hyalinization and narrowing of walls of arteries -> diabetic miroangiopathy of endoneural arterioles -> ischemic damageIntracellular hyperglycemia -> glucose -> sorbital by aldose reductase. Dmg to Axon and schwann cells.
3 Types of botulism? Where does botulism bind?
Food borne, wound, infant. Food borne type - botulinum neurotoxin - prevents the release of ACh rom nerve terminals in NMJ. CONDUCTION IS FINE. Just synapse problem.
16 Y.o w/ progressive gait instability and dysarthria.
Friedreich ataxia - . Can be mimicked by Vit E DEF.
Tabes dorsalis presentation?
Loss of position and vibration sense and severe lancinating pains. Peripheral reflexes may be absent. Argyll Robertson pupil due to damage to midbrain TECTUM. Wide based gain and + Romberg sign.
How is alanine converted to glucose?
Amino group transfered to a-KG. Alanine becomes pyruvate when a-KG receives the NH3 and is transformed into glutamate. Glutamine then literated back to AKG by glutamate dehydrogenase, and ammonia enters urea cycle to form urea. In essense, alanine is major AA responsible for transferring nitrogen to lvier for disposal.
How d calculate COnfidence interval? (95% confident of…)
Mean + 1.96SD/square root of nn = sample size.
Most common meningitis in adults?
Strep pneumo
Narcolepsy vs Cataplexy
Narcolepsy - excessive daytime sleepiness and REM skeep reated phenomena (including cataplexy, sleep paralysis, hypnagogic/hyponopompic hallucinations)Cataplexy -sudden loss of muscle tone w/o loss of consciousness - often provoked by strong emotions or surprises. Seen in 70% of narcoleptics.
Person who has recurrent Neisseria infection
Def in C5-C9 - results in recurrent neisseria infections. - Inability to form membrane attack complex.
Pure T cell Dysfunction?Ineffective intracellular Killing?Insufficient IgA prodcution?Inability to form MAC?
Pure T cell - DiGeorge/thymic hypoplasiaDEF Intracellular Killing - Chronic granulomatous disease - inability to synth NADPH oxidase. suffer from recurrent catalase postiive (staph etc)Various things. But on the flip side, TOO much IgA production binds bacteria and prevents from attaching to mucosal surfaces but BLOCKS IgM and IgG. IgA does not trigger complement cascade. IgM and IgG are more bacteriocidal.Inability to form MAC complex - C5-9 def. Neisseria infection
Dysarthria vs apraxia
Dysarthria - motor related. Apraxia - conscious speech planning and more
Which major arteries can affect the 3rd Cranial nerve?
Aneurysms of either the Poster Cerebral or Superior Cerebellar artery.
Ptosis w/ ipsilateral, dilated pupil, eye down and out. Aslo may have unilateral heardache, eye pain, diploplia
3rd nerve. Nonpupil sparing third nerve palsy. Can be from aneurysm of PCerebral or Superior Cerebellar
Anisocoria definition
Different pupil sizes
Japanese Food - Pufferfish poison - Name and activity
Tetrodotoxin - neurotoxin that binds VOltage gated sodium channels in nerve and cardiac tissue -> prevents sodium depolarization
4 types of exotic toxins -
Tetrodotoxin (puffer fish) - inhibits Na depol by binding to channels. Saxitoxin (dinoflagellates in red tide) - inhibits na depol by binding to channels. Ciguatoxin (exotic fish, Moray eel) - binds Na channel, keeps it persistently depolarizedBatrachotoxin (South American frogs) - bins to Na channel, keeps it open and causes persistent depolarizationSO Tetrodotoxin and Saxitoxin prevent depolCiquatoxin, Batrachotoxin block by causing persistent depol
Double stranded break repair failure - disease and constellation
Ataxia Telangiectasia - 4 year old kid - frequent respiratory infections (difficulty w/ class switching), ocular telangiectasias and CEREBELLAR ATROPHY. Rate of CA is greater due to inefficient DNA repair. This is from RADIATION induced mutations, Not single stranded problems.
Fanoni Anemia mechanisms
Hypersensitivity of DNA to cross-linking agents
Bloom syndrome mechanism
Chromosomal instability, INC susceptibility to neoplasms
White-yellow chrioretinal lesions in both eyes, INC head circumference/enlarged ventricles, scattered inracranial calcification. What is the problem and how did it happen?
In utero infection by Toxo.
What is the elassic triad of in utero toxo
hydrocephalus, inracranial calcifications, chorioretinitis
/Astrocytosis/Gliosis/Glial scar pathogenesis. How does this appear histologically
All the samet hing. Proliferation of astroytes in area of neuron degerneration. Scar compensates for volume loss.Histo - large nuclei w/ glial fibrils, GFAP, intense cytoplasmic EOSINOPHILIA
Intense cytoplasmic eosinophilia in the contex of neuronal shrinkage
Glial hyperplasia, reactive astrocytosis, gliosis, glial scar
Brief Psychotic Disorder vs Schizophreniform vs Schizophrenia
Brief Psychotic Disorder - less than 1 monthSchizophreniform - 1-6 monthsSchizophrenia - more than 6 monthsActive pychosis w/ progressive functional capacity decline. Can include hallucinations, delusions, negative and positive symptoms
Complication of anti-psychotic therapy?
Akathisia - movement disorder w/ restlessness and inability to stand still. Difficult to diagnose, as some physicians may wrongly thinnk the pt has WORSENING psychotic behavior and INC the dose, which is exactly the problem.
Strep pneumo leading cuase of
community acquired pneumonia, otitis media, meningitis in adults. Gram stain as lancet shaped gram + cocci in pairs
Friedreich ataxia presentation - 4 major s/sx. Cytogenetic problem? Inheritance
Usus presents in kids 5-15 y.o as gait ataxia. Wide based gait may be charateristic. Progresses to all 4 limbs due to CEREBELLAR DYSFUNCTION - also degen of dorsal columns lead to position and vibration sensation loss. Possible iron mitochondria problem w/ demyelinationKyphoscoliosis, hypertrophic Cardiomyopathy, diabetes mellitus, foot deformities. AR Chr 9 trinucleotide repeats
Location of vomiting center
Chemoreceptor trigger zone - area postrema of dorsal medulla near fourth ventricle
What does V3 do? Cranial nerve Where does it exit.
Sensation AS WELL AS invervates muscle of mastication (masseter, medial/alatera pterygoids, temporalis) Exist through Foramen Ovale.
Foramen rotundum, spinosum, lacernum, jugular foramen
Rotundum - V2Ovale - V3Spinosum - Middle meningeal artery//vein and recurrent meningeal branch of V3Lacerum - ascending pharyngeal artery and artery/nerve of pteryoid canal. Otherwise occluded by cartilage.Jugular foramen - CN 9, 10, 11, posterior meningeal artery. Inferior petrosal and sigmoid sinuses.
Elderly person w/ scalp tenderness or headache, blurred vision and claudication of jaw? Diagnosis S/Sx?
Temporal arteritis. VERY high ESR - often in the setting of polymyalgia rheumatica. Radic steroid treatment to prevent blindness
Cluster headache resentation?
Sudden unilateral periorbital pain - ispilateral rhinorrhea, watering of eye.
3 risk factors for Obstructive Sleep Apnea
Obesity, tonsillar hypertrophy, hypothyroidism.
Obstructive Sleep Apnea vs Obesity hypoventilation Syndrome (Pickwickian)
Difference is that Obstructive Sleep Apnea has normal blood gas - wake u when you have the osbtruction.Obesity hypoventilation syndrome leads to chronically elevated PaCO2 and reduced PO2. Also may eventually get polycythemia, pulmonary HTN, righ ventricular failure. Often have concomitant obstructive sleep apnea
What is first step of urea cycle?
CO2 + NH4 + 2ATP. PLUS N-acetylglutamate and Carbamoyl phosphate synthetase 1 -> carbamoyl phosphate.
Explain Lesch Nyhan pathway. What builds up?
Knock out of HGPRT. This is a failure in purine salvage and hypoxanthine and guanine degraded to URIC acid at higher rates. THUS you need to INC purine de novo synthesis. Because HGRPT and PRPP are required to push the cycle through (Guanine -> GMP and Hypoxanthine -> IMP), if HGRPT is not working, PRPP INC as well. This is good beause it’s needed for de novo purine synth.
WIlsons disease on histological section of brain
Cystic degenreation of putamen - damage to other basal ganglia structures.
Leg numbness, lifts leg higher up, foot slaps to ground. Nerve damage?
Common peroneal - MOST commonly injurged nerve in leg. Can be due to blunt trauma to lateral leg. Splits into deep peroneal and superficial peroneal
Kinesins and dynein - travel on intermediate filaments or microtubules
Microtubules
Decreate muscular stresnght in bilatereal lower extremities w/ absent deep tendon reflexes
Diarrhea 2 weeks ago w/ campylobacter - - guillain barre
Common pica?
pica can include eating ice due to anemia
Anorexia def?
Wegith loss of 25% of body weight or weight that is 15% below normal weight for age and height
Huntington disease underlying mechanism?
Hypermethylation of histones - prevents transcriptions - disrupts synthesis of neurotrophic proteins
Nicotinic cholinergic channel receptors vs Muscarinin cholinergic channel receptors - mechanism
Nicotinic -ligand gated ion channelsl that open after binding Ach - influx of Na/Ca, Efflux of K. Muscarin - M1, M3 - use IP3 pathway. activate kinase c.
Latent period vs Lead Time bias
Latent period - pathogenesis/exposure may occur years before clinical manifestations.Lead time Bias - Time between initial detection and specific outcome or measured endpoint. This is usually seen when tehre are 2 diff test for same disease but one test can detect disease at earlier stage. Comparing survival times may erroneous
Early facial, pubichair growth - enlarged genitalia, IMPAIRED upward gaze in 4 year old
Brain germinoma - most common spot is pineal region. Germinomas are similar to testicular seminomas - precocious puberty, obstructive hydrocephalus. This is NOT GnRH related
IMpaired upward gaze suggests?
Parinaud syndrome - Paralysis of upward aze and convergence - suggest compression of tectal area of mdibrain.
Alzherims has diffus brain atrophy - where is atrophy pronounced tho?
Temporoparietal lobes and HIPPOCAMPUS. Hippocampal atrophy evident in early stages and can be detected by brain MRI.
weakness an INC tone in arm. Initial resitance w/ passive extensino followed by sudden release when maxium extenisno is released. What is this and what is the problem?
Clasp knife spasticity - intial jerking resistance to passive extension followed by sudden release of resistance. Usu seen in UMN damage- corticospianl tracts, medulla, pons, midbrain, Internal capsul, precentrla gyrus. Usu just one of these. Can see other upper motor signs.This is all due to spasticity and lack of UMN inhibitory cotrol of stretch reflex arc.
Where is the first page w/ ischemic damage during global cerebral ischemia? AKA after MI etc.
Hippocampus (pyramidal cells), and Purkinje cells of cerebellum.
What is related to temporal arteritis?
Polymyalgia rheumatic (more than 50% of pt) - stiffness/pain in neck, torso, shoulder, pelvic girdle and morning stiffness. May also see fatigue, fever, weight loss.
Thiopental?
short acting barbituate general anesthetic. analogue of thiobarbital - AKA affects GABA receptor - inhibitory. Highly lipid soluble. Equilibrtes in brian tissue w/in 1 min and cuases L.o.C. Rapidly restributes to skeletal muscles and adipose. Highest CONC restributed to skeletal muscle/adipose.
Sertraline most common side effect
Sertraline (SSRI) - sexual dysfunction is relatively common side effect
Liquefactive necrosis in brain. When do you see hemorrhagic infarctions in CNS?
From reperfusion in injury.
Hperpyrexia (over 40C)- Emergent treatment
body cooling (cold blanket), and antipyretics). Do body cooling first( immediate) vs antipyretics)
INC GABA receptor chloride channel opening and are anxiolytic, anticonvuslant, and muscle relaxant w/ sedative-hyponotic effects
Benzodiazepine
Brain hitology - gray matter changes w/ unfiform vacuoles between neuron cell bodies and perikaryon of neurons. NO INFLAM present.
SPongiform encephalopathy - eventually translates to cysts. Prions are not pro-inflam.
JC polyoma virus in ICH - hist of brain?
Patches of demyelination due to preferential infection of oligodendrocytes
Mechanism drug induced parkinsonism (usu antipsychotics, neuroleptics). Treament?
Mech - D2 receptor blockade - Tx - Benztropine/amantadine (centrla acting antimuscarinc). Levodopa cant be used as it precipitates psychosis and bromocriptine can exacerbate underlying psychosis. You give benztropine because you need to maintain anti-dopamine effects while mellowing out their parkinsonism
What is the mechanism of opioid tolerance?How would you go about blocking morphine tolerance?
Not totally understood, but involves phosphorylation of opioid receptor by protein kinase. Chronic tolerance may INC adenylyl cyclase activity or NO levels.W/ morphine, GLUTAMATE thought to play a major role. Glutamate activates NMDA receptors, which can INC phosphorylation of opioid receptors and -> tolerance. If you use an NMDA receptor ANTAGONIST (Ketamine), you can prevent glutamate and its downhill morphile tolerance.
Ketamine mech?
NMDA receptor Antagonist
3 groups within Ectoderm and their products
Surface ectoderm - ANT. PIT. lens, cornea, inner ear, epidermis, salivary, sweat, mammary glandsNeural Tube - Brain and spinal cord, POST PIT. pineal gland, retinaNeural Crest - Autonomic, sensory, celiac ganglia. Schwanna cells, pia, arachnoid. Skull bones, melanocytes, adrenal medulla. Aorticopulmonary stepum and endocardial cushions
Molecular mechanism of Narcolepsy (w/ cataplexy)
Hypocretin 1 (orexinA) and Hypocretin 2 (orexin B) - are neuropeptides produced by Lateral hypothalamus that promote wakefulness and inhibit REM sleep. Most pt w/ narcolepsy w/ cataplexy have VERY LOW levels of these 2 in their CSF.
Elevated 14-3-3 in CSF suggests?
CJD
Homovanillic - what is it? Levels linked to what?
Homovanillic acid is a primary dopamine metabolite. Linked to many psychiatric conditions - substance use disorders, psychosis, mood disorders.LOW CSF levels are seen in Parkinson Disease
DEC Melatonin in CSF suggests?
Progression of Alzheimer
Common problems w/ deletions in genes?
Di Goerge, Cri du Chat, CF
Describe red neuron?
Shrinkage of cell body, pyknosis, Loss of Nissl, EOSINOPHILIC CYTOPLASM - ACUTE IRREVERSIBLE DAMAGE. Can be from ischemia, hypoxia, toxicity, or hypoglycemia. Aswtrocytes will proliferate and cause glial scar later.See 12-24 hours after injurious eventRed neurons are NOT seen w/ normal aging, although atrophy is.
What neurotransmitters are used in inhibitory interneurons (of reflex loops etc)
GABA and Glycine (BOTH are inhibitory)
Mech of C. tetani toxin
Binds to receptors at PRESYNAPTIC MEMBRANE . Migrates reetrograde to axonally to cell body. Inhibits GABA and Glycine in interneurons.
Two spherical lesions in both cerebral hemispheres in HIV pt
Toxo. Dont necessarily have to say ring enchancing
2 most common brain focal lesions in HIV pt
Toxo and CNS lymphoma
EBV in HIV pt CSF w/ ring lesion. Concern for? What type of inflam cells would you see?
CNS lymphomna. See B lymphocytes w/ CNS lymphjoma. EBV strongly related to AIDS related primary CNS lymphoma
Timolol? Mech? Role in Glaucoma?
Nonselective B blocker. DEC acqueous humor production by CAPILLARY EPITHELIUM
2 pharm drugs to DEC aqueous humor production?2 pharm that INC OUTFLOW of aqueous humor
DEC production - Nonselective B blockers (Timolol), also Acetazolamide (Carbonic Anhydrase inhibitor) INC outflow - Prostaglandin F2a (latanoprost, unoprostone, travoprost), and Cholinomimetics (Pilocarpine, carbachol - both promote miosis by contracting sphincter of iris)
5 y.o w/ bilateral lens subluxation(dislocated lens, ectopia lentis). Lots of thrombosis, stroke, renal infarcts. Disease? How could it have been ameliorated?
Cystathionine Synthetase? B6 supplMimics Marfans in many ways + many have devo delay. Higher riks of thromboembolism. 50% respiond well to B6.
Maternal inheritance?
Means FROM MITOCHONDRIA. Can see Heteroplasmy - multiple types of mitochondria (normal and mutated). MANY mitochondria in ovum
Name 3 mito disease and presentation
Mitochondrial Encephalopathy w/ Lactic Acidosis and Stroke Like Episodes (MELAS) - can also have seizuresLeber Hereditary Optic Neuropathy - bilateral vision lossMyoclonic Epilepsy w/ Ragged Red Fibers - Myoclonic seizures and myopathy w/ exercise. Ragged figers on biopsy.
NF1 - neurofibromas - what are cell origins from?
Neural crest - Neurofibroms are tumors of Schwann cells - which are from neural crest.
If pt is unresponsive, has no written documents, and is in need of resuscitation. What happens?
Decision of Closest kin (spouse, adult children, parents, adult siblings)
Wernicke encephalopathy - Triad? what can make it worse?
Triad - confusion, ataxia, opthalmoplegiaDmg to mamillary bodies - chronic THiamine def - ALWAYS GIVE thiamine before glucose. GLucose infusion can precipitate ENCEPHALOPATHY
Prophylaxis for Neisseria meningitidis?
Rifampin