Neurology Flashcards
thymoma + EOM weakness =?
MOA?
Myasthenia gravis
Antibodies against a neurotransmitter NICOTINIC receptor (Ach)
The receptor is a PLASMA MEMBRANE protein.
Note: overdose of neostigmine can cause desensitization of the nicotinic receptors
HIV patient, irregularly shaped pupils that dont react to light is called what? Assoc with what disease and features?
Argyll robertson pupils
Tertiary Syphillis, tabes dorsalis
Posterior inferior cerebellar artery occlusion causes what syndrome?
Symptoms?
PICA can occur with cervical spine trauma with dissection of what artery?
Lateral medullary syndrome (wallenberg)
vertigo/nystagmus, ipsilateral cerebellar signs, loss of pain/temp on ipsilateral face, contralateral body, bulbar weakness, ipsilateral horner syndrome
Vertebral artery
What type of necrosis occurs in the brain?
How is it characterized?
Liquefactive
complete digestion and removal of necrotic tissue with formation of cystic cavity - assoc with large amounts of lipids and lysosomal enzymes
Occlusion of what artery causes contralateral hemiplegia of the face and upper limb with preservation of lower limb? L facial weakness spares the forehead
MCA
also supplies Broca and Wernicke’s area
Obstructive hydrocephalus (papilledema, headache, vomiting) and dorsal midbrain syndrome is due to what? Describe reaction to light and gaze
Pineal gland mass
Light - pupils react to accomodation but not light
Gaze - upward limited, downward preference.
progressive forgetfulness, learning difficulty and poor recall due to problem with what structure?
hippocampal formation
Neuro deficits that cannot be explained by a single lesion indicates what disease?
What is it characterized by?
Multiple sclerosis
Demyelination of axons in white matter (loss of OLIGODENDROCYTES). White matter plaques. Optic neuritis, intention tremor.
CSF has inc IgG, oligoclonal band on protein electrophoresis (autoimmune process).
Note: sx worse with HEAT because dec axonal transmission assoc with inc heat.
Ipsilateral shoulder pain, upper limb paresthesias and areflexic arm weakness can be a sign of what?
pancoast tumor near superior sulcus involving the brachial plexus. Can also involve cervical symp ganglia
NT found in raphe nuclei of brainstem?
Serotonin
NT found in caudate nucleus and putamen?
GABA
NT found in locus ceruleus? Located in posterior rostral pons near the lateral floor of the 4th ventricle
NE
NT found in nucleus basalis of Meynert?
Acetylcholine
NT found in red nucleus?
None. Involved in motor coordination
NT found in the substantia nigra?
Dopamine
Chronic sx of headaches, dec libido, meningeal irritation, bitemporal hemianopsia, cardiovascular collapse is a sign of what?
Pituitary apoplexy (acute hemorrhage into the pituitary gland)
Synaptophysin stain what?
CNS tumors of NEURONAL origin (neurons, neuroectodermal, neuroendocrine cells)
Glial fibrilllary acidic protein (GFAP) stain what?
neoplasms of GLIAL origin (astrocytomas, ependymomas, oligodendrogliomas)
MCC of spontaneous deep intracerebral hemorrhage?
Hypertensive vasculopathy of small penetrating branches of the major cerebral arteries (lenticulostriate arteries - branch of MCA that supplies basal ganglia)
Why doesnt axonal regeneration occur in the CNS?
Persistence of myelin debris suppress axonal growth via myelin-assoc inhib factors
Glial scar= barrier
Hydrocephalus in infants (Eg in lateral ventricles) if left untreated can lead to what?
Muscle hypertonicity due to stretching of periventricular pyramidal tracts, developmental delays, and seizures
Which skull foramen does CN I olfactory bundles go through?
Cribiform plate
Which skull foramen does CN II, ophthalmic aa, central retinal vein go through?
Optic canal
Which skull foramen does CN III, IV, V1, VI, ophthalmic v, sympathetic fibers go through?
Superior orbital fissure
Which skull foramen does CN V2 (maxillary) go through?
Foramen rotundum
Which skull foramen does CN V3 (mandibular) go through?
Foramen ovale
Which skull foramen does Middle meningeal aa and vv go through?
Foramen spinosum
Which skull foramen does CN VII, VIII go through?
Internal acoustic meatus
Which skull foramen does CN IX, X, XI, jugular v go through?
Jugular foramen
Which skull foramen does CN XII go through?
Hypoglossal canal
Which skull foramen does spinal roots of CN XI, brainstem, vertebral aa go through?
Foramen magnum
Acute nausea after systemic chemo is from stimulation of the chemoreceptor trigger zone (CTZ) in the area postrema of what part of the brain?
dorsal medulla near the 4th ventricle
What is the key neuro-anatomic landmark for locating the trigeminal nerve on CT?
Middle cerebellar peduncles. Trigeminal n exits the brainstem at the lateral aspect of the midpons at this level.
What channels are important for generation and propagation of AP?
What channels are essential for fusion and release of NT vesicles into the synaptic cleft?
- Voltage-gated Na channels
2. Voltage-gated Ca channels
Multiple vacuoles seen in gray matter of the brain on microscopic exam
Creutzfeldt-Jakob disease (spongiform encephalopathy)
Loss of neurons of the anterior horns of the spinal cord; demyelination of lateral corticospinal tract
ALS
LMN and UMN lesions respectively
Damage to motor neurons of the anterior horn
polio - flacid paralysis, atrophy, areflexia
LMN damage
Degeneration of dorsal (posterior) and lateral spinal columns
Vit B12 def
Brain tumor gross exam showing areas of necrosis and hemorrhage
Micro: pseudopalisading tumor cells around area of necrosis
glioblastoma multiform (MC primary brain tumor in adults)
Myasthenia gravis is due to antibodies to which protein?
Nicotinic acetylcholine receptor
Seizure type? consciousness unaffected; affects only 1 area of the brain
Simple partial
Seizure type? consciousness impaired; affects only 1 area of the brain
Complex partial
Increased ICP does what to bp and HR? What is the Cushing reflex?
Increase BP, decrease HR
Cushing reflex = resp depression in setting of inc ICP in addition to the above