Neurology Flashcards
What would you see in an ACA infarct?
Contralateral motor and sensory loss of lower limbs
Where is glioblastoma tumor located?
Cerebral cortex (frontal, temporal etc)
Where is meningioma tumor located?
It is from arachnoid cells, external, and benign
What can cause parinaud syndrome?
Germinomas of the pineal gland (also in gonads and mediastinum)
What presents with parinaud syndrome, precocious puberty, and obstructive hydrocephalus?
Germinomas of pineal gland (histologicall similar to seminomas)
What is parinaud?
No conjugate vertical gaze due to lesion in superior colliculi
What presents with unilateral headache and associated with rhinorrhea and periorbital pain?
Cluster headache; MC in men
What levels do you see lateral horn in?
T1 - L2
What do lower spinal cord segments look like?
Bigger ventral horn (more gray less white)
What do upper spinal cord segments look like?
More white less gray
What happens in age related macular degeneration wet?
Bleeding due to choroidal neovascularization
What is the diagnosis? Grayish green subretinal membrane and hemorrhaging.
Wet age related macular degeneration
Where is meyer’s loop?
Temporal lobe
Where is upper optic radiation?
Parietal lobe
What does the huntington mutation cause?
GOF mutation that causes histone deacetylation
What chromosome is mutated with VHL?
Chromosome 3 (remember 3 letters in VHL)
What gets damaged in noise induced hearing loss?
Stereocilia of organ of corti
What does succinylcholine cause?
Life threatening hyperkalemia
What happens to CN III function in diabetic neuropathy?
Ocular motion lost but accommodation intact because only central part is affected and the parasympathetic fibers are on the outside
What is located in the internal capsule?
Corticospinal tract
What is a 5mm cavity in the brain?
Small lacunar infarct from lipohyalnois and microemboli
What do use for bradycardia in inferior wall MI?
Atropine
What do you see ring enhancing lesions?
Toxoplasma, brain abscesses (complication of bacterial endocarditis from S. aureus usually), CNS lymphoma
Why do Friedreich ataxia people get ataxic symptoms?
Mutation in frataxin (binds iron) that impairs mitochondrial functioning and causes degeneration of myelinated axons
What does friedreich ataxia affect?
Dorsal root ganglia, spinocerebellar tract, corticospinal tract, dorsal column –> spinal cord atrophy
What is a key presentation of Friedreich ataxia?
Wide-based gait with difficulty maintaining balance in 5-15 yo
How do you tell myasthenia gravis and lambert eaton apart?
Myasthenia has diplopia, dysarthria etc whereas lambert eaton is more likely to present with proximal muscle weakness and autonomic symptoms (dry mouth, impotence etc) and minimal change with AchE inhibitors
What causes halos around light, vision worse after dark room (eye dilation)?
Closed angle glaucoma
What are two key findings for Wallenburg?
Dysphagia and dysarthria; nucleus ambiguus lesions are specific for it
How do you tell CN III palsy from INO?
Convergence is normal in INO
What is a calcified cystic mass with thick brownish fluid high in choelsterol?
Craniopharyngioma
How old is a child who can use utensils and copy a circle?
About 3 years old
What is a bilateral wedge shaped necrosis parallel to longitudinal fissures in hypoxic ischemic encephalopathy?
Watershed infarct
What is the MCC of aseptic meningitis?
Enteroviruses
What is the MCC of lobar hemorrhage in adults >60yo?
Cerebral amyloid angiopathy particularly in parietal and occipital lobes
Where is area postrema located?
Dorsal surface of medulla near caudal end of 4th ventricle
When do microglia move to area of infarct/ischemia?
3-5 days after injury and then astrocytes form scars
Which tracts does Vitamin b12 affect?
Lateral corticospinal and dorsal columns
What do you do if someone is above 40degree celsius?
This is hyperpyrexia. Lower temperature with cold blankets and then give anti-pyretics
What is a major side effect of halothane?
Hepatic necrosis (inc AST, ALT, prolonged PT, shrunken liver)
What part of Wernicke Korsakoff is irreversible?
Memory loss
What causes IVH in neonates?
Fragile germinal matrix bleeding
Where is broca’s area located?
Lower frontal lobe
What happens if you get pure internal capsule stroke?
Pure motor weakness in arms, leg, face
What innervates the posterior part of external auditory meatus?
Vagus
What innervates the inner part of tympanic membrane?
Glossopharyneal
What type of tremor happens with certain actions and improves with alcohol?
Essential tremor
How do you treat an essential tremor?
Primidone, Propranolol
What is the treatment for status epilepticus?
1st line is benzodiazepines then give phenytoin. Phenobarbital if they are seizing still.
What do you see cortical atrophy as well as caudate and putamen atrophy?
Huntington
What does PCA stroke cause?
Homonymous hemianopia with macular sparing (MCA doesn’t spare macula)
What is the time constant?
Time it takes for a change in membrane potential
What is the length constant?
How far conduction travels before it dissipates
What does myelination do time and length constant?
Decreases time constant and increases elngth constant
What do you see anti-yo, hu, P/Q antibodies in?
Paraneopalstic cerebellar degeneration
What is paraneoplastic cerebellar degeneration?
Immune response against tumor cells that cross react with purkinje neuron antigens. Associated with lung cancers. Causes dysarthria, visual problems, ataxia
What is the diagnosis? Muscle rigidity, fever after surgery under inhaled anesthetics?
Malignant hyperthermia
Who gets malignant hyperthermia?
Those who inherit a defect in ryanodine receptor that causes large amounts of Ca to be released from SR
What does malignant hyperthermia present with?
Muscle rigidity, tachycardia, HTN, hyperkalemia, myoglobinuria, fever
What type of meningits? Elevated protein, normal glucose, lymphocytes
Viral meningitis
What is associated with polyhadamnios?
Anencephaly and GI obstruction
How does entacapone work?
Prevents L-dopa degradation and increases quantity entering the brain
What is the diagnosis? Ipsilateral pain/weakness of shoulder, miosis, ptsosis.
Pancoast tumor
What does hepatic encephalopathy deplete?
Glutamate and alpha-ketoglutrate (because it is used in neurons to detoxify accumulated glutamine; use alpha KG to convert it to glutamate)
How do mu receptors work?
Increase potassium efflux and close Ca channels
What ciliary epithelium do?
Produce aqueous humor
What targets ciliary epithelium?
Timolol (targets beta receptor)
What are the short acting benzos?
Triazolam, Alprazolam, Oxazepam
What side effects do you see with short acting benzos?
Less sedation but more withdrawal
How do you opioid analgesics affect the gallbladder?
Cause sphincter of oddi smooth muscle contraction causing biliary colic
What happens to albumin in hepatic necrosis?
Remains the same since it has a long half life; only changed with end stage liver disease
What ion contributes to resting membrane potential?
Mostly K and some Na
Which way does chloride flow?
Into the cell despite negative potential
What is Naloxone?
Mu antagonist
What presents with transient numbness and tingling that onsets suddenly and disappears in 20 minutes?
TIA
Where do the cerebral hemishperes and lateral ventricles come from?
Telencephalon (which comes from the prosencephalon)
Where do the third ventricle and thalamus come from?
Diencephalon (which comes from the prosencephalon)
Where do the aqueduct and mdibrain come from?
Mesencephalon (which also comes from the mesencephalon aka midbrain)
Where do the upper part of the fourth ventricle, pons, cerebellum come from?
Metencephalon (which comes from rhombencephalon)
Where do the lower part of fourth ventricle and medulla come from?
Myelencephalon (which comes from rhombencephalon)
Where do PNS neurons and Schwann cells come from?
Neural crest
What is the confirmatory test for neural tube defects?
AchE
What is anencephaly associated with?
Polyhydramnios and maternal diabetes type I
What is Dandy Walker malformation associated?
Hydrocephalus and Spina bifida
What is wallerian degeneration?
Degeneration distal to injury and proximal axon retraction
What is the gene associated with holoprosencephaly?
SHH
What fuses to form mutlinucleated giant cells in the CNS in HIV patients?
Microglia
Which nerve fibers are unmyelinated?
Autonomic postganglionic and C fibers
What are the sensory corpuscles?
Merkel: deep static touch, position, slow
Meissner’s: fine/light touch, position, fast
Ruffini: stretch of skin, slow
Pacinian: vibration, pressure, fast
What nucleus is involved with stress and panic?
Locus cereleus because NE increases in anxiety
What neurotransmitters are implicated in huntington’s?
Decreased GABA and Ach
In what disease did Ach increase?
Parkinson’s
How does NE promote sleep?
SCN makes NE which stimulates pineal gland to make melatonin
What causes rapid eye movement in REM?
PPRF
What is Papez’s circuit?
Cingulate –> hippocampus –> fornix –> mamillary body –> thalamus
What are the inputs to the cerebellum?
Middle cerebellar peduncle: contralateral cortex
Inferior cerebellar peduncle: ipsilateral proprioception