Neuro Flashcards
What CNS abnormality is associated with Shh mutation?
Holoprosencephaly (failure of L-R separation)
What is Chiari 1 Malformation?
Chiari 2?
Chiari 1 = cerebellar tonsil herniation + syringomyelia
Chiari 2 = lumbosacral myelomeningocele + cerebellar vermis herniation + hydrocephalus
What is a Dandy Walker malformation?
Agenesis of cerebellar vermis
Fried egg cells (3)
Oligodendrocytes, HPV koilocytosis, testicular seminomas
“Oligo my eggo”
Which CNS cell type is directly infected by HIV?
Microglial - form multinucleate giant cells
What 3 pathologies decrease 5HT levels?
Parkinson disease, anxiety, and depression
Where is ACh made in the brain?
Basal nucleus of Meynert
What effect does ACh have one movement?
Inhibits movement (indirect extrapyramidal pathway)
What NT is made in the Locus ceruleus?
Raphe nucleus?
Nucleus accumbens?
NE
5HT
GABA
What is damaged in transcortical motor aphasia?
How does this affect speech?
Pre-Broca’s input
Non-fluent spontaneous speech with intact repetition (Broca’s aphasia has non-fluent speech with impaired repetition)
What is damaged in transcortical sensory aphasia?
How does this affect speech?
Pre-Wernicke’s input
Poor comprehension with intact repetition (Wenicke’s aphasia has poor comprehension with impaired repetition)
How does mixed transcortical aphasia present?
Confluent speech + impaired comprehension + normal repetition
What is dysprosody?
A lesion in what area of the brain affects it?
Musical quality/inflections of speech
Lesion of Broca’s/Wernicke’s on the non-dominant hemisphere (Brocas = monotone speech, Wernickes = don’t understand sarcasm)
Agraphia + acalculia + R-L disorientation + finger agnosia (cannot distinguish fingers)
Gerstmann syndrome - lesion the dominant (left) angular gyrus (parietal lobe = synthesizes information)
Hemispatial neglect results from a lesion in what location of the brain?
Non-dominant (right) parietal lobe
Return of primitive reflexes could indicate a lesion in what lobe?
Frontal lobe
Lesion to left frontal eye field would cause gaze in which direction?
Left - FEF are constitutively active (lesion L FEF = unopposed R FEF = L-ward gaze)
Lesion to left PPRF would cause gaze in which direction?
Right - PPRF are downstream from contralateral FEFs and transmit message for ipsilateral gaze (lesion L PPRF = impaired transmission from R FEF = unopposed L FEF = R-ward gaze)
Impaired upward gaze
Parinaud syndrome - lesion of superior colliculus
Wernicke-Korsakoff syndrome
Nystagmus/opthalmoplegia + ataxia + amnesia/confabulation
Lesion to the mammillary bodies (thiamin B1 deficiency)
Kluver-Bucy syndrome
Hyper-orality + hypersexuality + disinhibited behavior
Lesion to the amygdala
What is hemiballismus?
What lesion causes it?
Flailing of one arm
Subthalamic nucleus
How will compression of CN3 present?
Ischemia?
Compression - lesion outer fiber = parasympathetics (blown pupil
Ischemia - lesion inner fiber = motor neurons (ptosis + down and out)
What is the most common cause of Bell’s Palsy?
HSV/VZV
R vagus nerve lesion will cause uvula to deviate in which direction?
Left (L palate elevates = uvula points L)
What CN originates from the nucleus ambiguous?
What 2 functions are mediated there?
CNX
Speech and swallow
Are motor CN nuclei found medially or laterally in the brainstem?
Motor medial, sensory lateral
Horseness/dysphagia + vertigo/nystagmus + uvula deviates R + L ptosis/miosis/anhydrosis + R pain/temp loss in legs + L pain/temp loss in face
Wallenberg syndrome - L lateral medulla infarct = L PICA
CN 5 is huge and extends down into the medullar
L spastic paralysis + L proprioceptive loss + tongue deviates R
R Medial medullary syndrome - ASA
L facial droop + L pain/temp loss in face + R pain/temp loss in legs
Lateral inferior pontine syndrome - L AICA
CN7 is in the inferior pons, superior pons would be CN5 presenting with jaw weakness
Left gaze causes L eye nystagmus + no R eye abduction + L spastic paralysis + L proprioceptive loss +/- preferential gaze to L
R Medial pontine syndrome - Basilar a
R PPRF damage would cause preferential gaze to contralateral side
If L gaze causes L eye nystagmus, which side is the MLF lesioned?
R MLF - impaired R eye adduction
Dysphagia + L spastic hemiparesis + R ptosis/mydriasis/down and out
Weber syndrome (midbrain peduncle infarct) - paramedian branches of the R PCA (corticobulbar tract - dysphagia, corticospinal tract - paralysis, strabismus - CN3 travels thru peduncles)
Paraventricular hypothalamic nucleus
Secretes oxytocin
“Causes milk let down, need it for your para tits”
Lateral hypothalamic nucleus
Ventromedial hypothalamic nucleus
Lateral - hunger “Grow laterally”
Ventromedial - satiety “V points down, decreases hunger)
Anterior hypothalamic nucleus
Posterior hypothalamic nucleus
Anterior - cooling (Anterior = AC), pArasympathetic
Posterior - warming, sympathetic
Supraoptic hypothalamic nucleus
Preoptic hypothalamic nucleus
Suprachiasmatic hypothalamic nucleus
Supraoptic - ADH “Osmolarity above all”
Preoptic - GnRH “Must ovulate before conception”
Suprachiasmatic - Circadian rhythm “Charisma requires sleep”
Urinary incontinence + ataxia + cognitive dysfunction (dementia)
Normal pressure hydrocephalus - normal ICP with ventricle expansion that distorts the corona radiata
“Wet, wacky, and wobbly”
Young obese woman + daily pulsatile headaches + papeilledema
Pseudotumor cerebri (idiopathic intracranial HTN) - increased ICP without hydrocephalus (i.e. normal CSF volume)
What is one cause of Pseudotumor cerebri?
What drug can be sued to treat it?
Vitamin A toxicity (isotretinoin)
Acetazolamide (decreases CSF production)
Patient with worst headache of life is stabilized, days later present with hemiparesis. CT scan shows no changes.
What happened?
How would you treat?
Vasospasm following subarachnoid hemorrhage
Treat with nimodipine (CCB)
What conditions are associated with berry aneurysms?
ADPKD and Ehlers Danlos
What microscopic changes are seen following an ischemic stroke over time?
Red neurons | PMN, M0 | granulation | scar
1 day 1 wk 1 mo
What 3 tissues are most vulnerable to ischemia during hypo perfusion?
Cerebellum, cortical layers (esp in watershed areas), and the hippocampus
What is associated with a partial seizure?
Where do they typically occur?
Aura (burning rubber smell)
Temporal lobe
What’s the difference between a simple and complex partial seizure?
Simple - no loss of consciousness
Complex - loss of consciousness
Seizures + angiofibromas + intellectual disability
Tuberous sclerosis
Seizures + CNV1 port-wine stain + intellectual disability
Sturge-Weber syndrome
(Seizures/intellectual disability due to leptomeningeal angioma - damages underlying gyri causing seizures and tram-track calcifications)
Treatment for Trigeminal neuralgia
Carbamazepine
What is the mechanism of Ethosuxamide?
T-type Ca channel blocker, used for absence seizures
“When a girl has an absence seizure she is vulnerable to getting sux’d, milk will come out which contains Ca” (this is the worst)
What is the mechanism of Valproic acid?
Na channel blocker and GABA agonist (same as topiramate)
“Val is salty, she just GABs and GABs”
What seizure drugs block Na channels?
Phenytoin, carbamazepine, valproic acid/topiramate, lamotrigine
What seizure drugs are GABA agonists?
BDZ/barbiturates, valproic acid/topiramate, GABApentin
What is first line treatment for absence seizures?
Second line?
Ethosuximide
Valproic acid
Treatment for Status epilepticus
Benzodiazepine (terminate) + phenytoin (prophylaxis)
Treatment for seizures due to eclampsia
Magnesium sulfate
Phenytoin side effects
“Phenytoin Status-epilepticus Seizure Prohylaxis May Get Horrible Feedback”
Peripheral neuropathy, SLE-like syndrome, SJS, P450 inducer, Megaloblastic anemia, Gingival hyperplasia, Hirsutism, and Fetal hydantoin syndrome (cleft lip/palate + congenital heart disease)
Which 3 seizure drugs are teratogenic?
Carbamazepine, valproic acid - spina bifida
Phenytoin - fetal hydantoin syndrome
What 4 drugs cause SJS?
Seizure drugs (Phenytoin, phenobarbital, carbamazepine, ethosuximide, lamotrigine) Sulfonamides, penicillins, allopurinol
What 4 drugs cause agranulocytosis?
Carbamazepine - anti-seizure
Clozipine - antipsychotic
Colchicine - gout
PTU/methimazole - antithyroid
What anti seizure drugs cause hepatotoxicity?
Carbamazepine and valproic acid
What drugs induce P450s?
“Coronas, Guiness, and PBRS induce Chronic alcoholism”
Carbamazepine, griseofulvin, phenytoin, barbiturates, rifampin, St Johns wort, and chronic alcoholism
Treatment for tonic-clonic seizures (3)
Phenytoin, valproic acid, or carbamazepine
Treatment for cluster headaches (2)
Sumpatriptan or 100% O2
What is the mechanism of sumatriptan?
What are side effects?
5HT 1B/1D agonist (vasoconstriction and reduces activity in CN5)
Vasospasm - contraindicated in CAD/prinzmental angina and pregnancy
Treatment for migraines (3)
Sumatriptan (abortive)
Prophylaxis - propranolol, CCBs
What dietary intake exacerbates migraines?
Tyramine
GFAP + brain tumor
Adult - glioblastoma
Kids - astrocytoma
Brain tumor with psammoma bodies
Meningioma
S100+ primary brain tumor
Schwannoma (originate from neural crest cells)
Rosenthal fibers in brain tumor (dark pink, thick, corkscrew fibers)
Astrocytoma
Differential for brain tumor in 4th ventricle
Medulloblastoma or ependymoma
Homer-wright rosettes (rosette around central fibril tangles)
Medulloblastoma
Perivascular rosettes
Ependymoma
Bitemporal hemianopsia + cyst filled with brown fluid + calcifications
Craniopharyngioma (originates from Rathke’s pouch)
L eye strabismus + R eye homonymous hemianopsia + L spastic paralysis
L uncal herniation (ipsi CN3, ipsi PCA = conta visual field, contra corticospinal tract = ipsi weakness)
Brain tumor + polycythemia
Medulloblastoma
Medilloblastoma + retina angiomas
Von Hippel Lindau
What EEG waveforms correspond to the sleep stages?
NREM1 - theta
NREM2 - sleep spindle/K complexes
NREM3 - delta
REM - beta
Inhaled anesthetics - what correlates with:
Lipid solubility
Blood solubility
Lipid solubility (MAC) = potency (gets into brain easier) Blood solubility = onset of action (low solubility = fast)
What side effect is common to the inhaled anesthetics?
Hepatotoxicity
Patient in ICU on ventilator for a week and develops acute pancreatitis - why?
Propofol (a sedation agent) has high TG content that can predisposed to acute pancreatitis if given for more than a few days
Dissociative anesthetic (conscious/aware but disconnected)
Ketamine (PCP analog)
What IV anesthetic is preferred for brain surgeries?
Barbiturates (thiopental) - decreases cerebral blood flow
Kid starts having hallucinations post-op - why?
Ketamine used as anesthetic (since PCP analog can cause this, especially in kids)
Conscious sedation (relaxation and amnesia, but still awake)
Benzodiazepines (given with opioid for analgesia)
Antidote for BDZ OD?
Flumazenil
What is fentanyl?
How is it superior to morphine?
An opioid
Does not cause histamine release like morphine does
What is the mechanism of -curine/curonium drugs?
Non-depolarizing neuromuscular blocking agents
When can a AChEI (Neostigmine) be used to antagonize succinylcholine?
At high doses - phase 2 blockade (AChRs have repolarized but succinylcholine is still bound competitively)
PostOp hyperthermia + rigidity = what pathology?
What drugs caused this?
What mutation is associated with this?
Malignant hyperthermia
Succinylcholine + inhaled anesthetic
RYR1 gene mutation
Why don’t local anesthetics work in infected tissue?
Low pH = ionized drug = cannot passively diffuse through PM to bind their ion channels from the inside
What is blocked at lower doses of local anesthetics:
Small or large?
Myelin or unmyellin?
Small
Myelinated
What synapses at the thalamic nuclei:
VPL, VPM
LGN, MGN
VPL - spinothalamic, DCML (“Very Painful Legs”)
VPM - trigeminal and taste (“Very Painful Mouth”)
LGN - vision (CN2 to calcarine sulcus)
MGN - hearing (inf colliculus to temporal lobe)
What does the Romberg test evaluate?
Posterior column function (proprioceptive part of balance)
Rapid/fine tremor of hands, head, voice with family history. Improves with alcohol
Essential tremor (present at rest and with movement)
Treatment for essential tremor
B blockers, primidone (anti-seizure drug)
What is the mechanism of Bromocriptine?
Why is it not first line?
Ergot DA agonist used in Parkinson Disease
Has peripheral action which increases BP
What is the mechanism for pramipexole and ropinirole?
What are 2 indications?
Non-ergot DA agonists
Parkinson disease and restless leg syndrome
What is the mechanism for Amantadine in the treatment of Parkinson disease?
Increases DA release and decreases repute = increases DA in the synapse
What is the mechanism of Selegiline?
MAO type B inhibitor
What is the mechanism of entocapone/tolcapone?
Peripheral COMT inhibitors - used with L-dopa/carbidopa to increase CNS delivery and decrease PNS side effects
“Alcapone evaded taxes, tolcapone evades peripheral L-dopa loss”
Treatment for MPTP exposure
Selegiline
What symptoms can benztropine improve? What does it not improve?
Tremor and rigidity can be reduced, bradykinesia has little improvement
What is the genetic defect in Huntington disease?
What grossly changes are seen in the brain?
What 3 NTs are affected?
CAG trinucleotide repeat on chr 4
Caudate atrophy
Increase DA, decrease GABA and ACh
What 3 drugs are used to treat Huntingtons?
Tetrabenazine, reserpine - VMAT inhibitor (decreases DA in vesicles)
Haloperidol (D2R antagonist)
What is Werdnig-Hoffmann disease?
Spinal muscular atrophy - congenital LMN death due to destruction of the anterior horns in the spinal cord
Floppy baby + tongue fasciculations
What two infectious agents attack the anterior horns in the spinal cord?
Poliovirus and west nile virus
What is Charcot’s triad associated with neurology?
What is Charcot’s triad associated with GI?
Scanning speech + intention tremor + nystagmus = MS
Jaundice + fever + RUQ pain (+ HoTN + altered mental status) = cholangitis (biliary tree infection)
What mutation is associated with ALS?
Superoxide dismutase 1 mutation
What is Subacute combined myelopathy?
Dorsal column/corticospinal tract demyelination due to vitamin B12 deficiency
What are 2 causes of bilateral Bell’s Palsy?
Guillan Barre and lyme disease
JC virus destroys what cell type?
Oligodendrocyte (demyelinating disease seen in AIDS pts)
Arylsulfatase A deficiency, sulfatide accumulation
Metachromatic leukodystrophy (lysosomal storage disease) = ataxia and dementia
What is Charcot-Marie Tooth disease?
What is the inheritance pattern?
Defect in myelin proteins = PNS dysmyelination (progressive loss of muscle tissue and touch sensation)
Autosomal dominant
What does CSF look like in Guillan Barre?
Increased protein with normal cell count
Galactocerebrosidase deficiency, galactocerebroside/psychosine accumulation
Krabbe disease = peripheral neuropathy, developmental delay, optic atrophy, globoid cells
Defect in very long chain FA metabolism
What is the inheritance pattern?
Adrenoleukodystrophy = neuropathies and adrenal gland crisis
X-linked
What 2 drugs can be used in glaucoma to decrease aqueous humor production?
B blockers and acetazolamide
What 3 drugs can be used in glaucoma to increase outflow?
PGs, apraclonidine (a agonist), and pilocarpine (cholinergic agonist)
