Neuro Flashcards
Middle Cerebral Artery Stroke: Signs / Sx etc.
contralateral hemiparesis + hemisensory loss of the FACE and UPPER LIMB
other features = anosognosia (insight lack), contralateral spatial neglect (if in non-dominant parietal lobe), conjugate gaze deviation TOWARD lesion side, contralateral homonymous hemianopsia (optic radiation damage in subcortical temporoparietal)
Anterior Cerebral Artery Stroke: Signs / Sx etc.
contralateral hemiparesis of LOWER limb
if bilateral ACA occlusion, may have ABULIA (lack of initiative/will), primitive reflexes (Moro, grasp), urinary incontinence (prefrontal cortex damage)
Posterior Cerebral Artery Stroke: Signs/ Sx etc.
contralateral hemianopia with macular sparing (due to collateral circ. from MCA) via visual cortex infarction
Basilar Artery Occlusion: Signs/ Sx etc.
damages corticospinal / -bulbar tracts
quadriplegia; bulbar dysfunction (facial weakness, dysarthria) and oculomotor issues (horizontal gaze palsy)
Anterior Inferior Cerebellar Artery occlusion: Signs / sx etc.
LATERAL PONTINE SYNDROME
ipsilateral pain/temp loss (trigeminal nucleus)
ipsi facial weakness (facial nucleus)
ipsi hearing loss (cochlear nucleus)
contra pain/temp trunk/limbs (lateral spinothalamic)
cerebellar dysfunction (ataxia, dysmetria)
Anterior Communicating Artery aneurysm: signs sx etc
compresses central optic chiasm
bitemporal hemianopia
Posterior Communicating Artery aneurysm: signs sx etc.
compresses CN III
ipsilateral mydriasis, ptosis + “down n out” deviation
Histopathology of brain biopsy shows:
amyloid deposits in cortical vessels
what’s the condition?
cerebral amyloid angiopathy
beta amyloid; usually asymptomatic, can be assoc. with hemorrhage or Alzheimer’s dementia
Histopatho of brain shows:
Congo red staining plaques in hippocampus
what’s the condition?
Alzheimer’s
neuritic (senile) plaques of EC beta amyloid surround dystrophic neurites (Congo+ and often hippocampal)
Histopatho of brain shows:
Eosinophilic, round cytoplasmic neuronal inclusions
what’s the condition?
Rabies
Negri bodies, especially in Purkinje and hippocampal pyramidal cells
Histopatho of brain shows:
profound neuronal loss in caudate nucleus
what’s the condition?
Huntington disease (AD)
choreiform movement, psych disturbance, dementia
Histopatho of brain shows:
Slit-like white matter cavities with surrounding gliosis
what’s the condition?
Lacunar infarction
recurrent in vascular dementia, with stepwise cognitive decline + focal deficits (older pt with CV risk factors such as DM and htn)
Histopatho of brain shows:
Microglial nodules and multinucleated giant cells
what’s the condition?
HIV-associated dementia
HIV enters CNS via infected macrophages and infects microglia > subcortical dementia with memory deficits, executive dysfunction + slow info processing
CD4 < 200/mm3
Meningioma: histo, signs / sx, etc.
slow-growing benign tumor of arachnoid meningothelium
“whorled” cell pattern of syncytial nests; psammoma bodies
well-circ round mass attached to dura at falcine, parasagittal, tentorial or lateral brain convexities
s/s are seizure via compression; HA/nausea/vom via ICP (worse lying or sleeping); focal neuro deficits by size/location
Ependymoma: epidemiology, histo, site
10% of posterior fossa tumors in kids
histo = characteristic perivascular rosettes (pink fibrous material around vessel); GFAP+ processes tapering towards vessels
paraventricular tumors in kids (eg, floor of fourth ventricle, other sites of ependymal cells); spinal ependymomas in adults
Glioblastoma: histo, morpho, site, epidemiology
1 primary malignant brain tumor of adults (40-70)
soft + poorly defined; can be very large –> mass effects and midline shift; areas of necrosis + hemorrhage with microvascular prolif.
seen in cerebral hemispheres (frontal, temporal, basal ganglia) + may cross corpus callosum with “butterfly glioma” appearance on img
histo = hypercellular areas of atypical astrocytes that border regions of necrosis (“pseudo-palisading”); poorly diff, pleomorphic astrocytes; nuclear atypia + many mitoses
Medulloblastoma: epidemiology + histo
malignant cerebellar tumors in children
small blue cells (primitive neuroectodermal tumor, PNET) with high mitotic index
Homer-Wright rosettes (cells surround neuropil) in 20%
Oligodendroglioma: site, morpho + histo
white matter of cerebral hemispheres; well-circumscribed gray mass with calcification
“fried egg” cells (round nucleus + halo of clear cytoplasm)
Pilocytic Astrocytoma: epidemiology; site; histo
usually benign in cerebellum (or brainstem, hypothalamus, optic path) of kids / young adults
histo = eosinophilic granular bodies and elongated hairlike processes (Rosenthal fibers: pink fibrous material); well-diff with spindle cells + hair-like glial processes + microcysts
Schwannoma: site, histo
mostly benign; vestibular branch of CN VIII at cerebellopontine angle
histo = spindle cells with palisading nuclei around “Verocay bodies” with an eosinophilic core (Antoni A pattern)
Craniopharyngioma: epidemiology, site, histo
benign suprasellar tumor in kids
cords/nests of palisading squamous epithelium with internal areas of lamellar “wet keratin”
Primary CNS Lymphoma: epidemiology, morpho
immunocompromised (HIV, transplant) pts; in HIV can be via EBV infection
multiple lesions in deep grey matter, white matter + cortex
Brain metastases: morphology / imaging, common primary tumor sites
lung, breast, kidney and skin (melanoma)
typically multiple, well-circ masses at grey-white matter junction
Neuroblastoma:
site, epidem, histo + markers
mutation
1 extracranial solid tumor in kids
small, round, blue cell tumors; “neuropil” (neuritic process pathognomonic of neuroblastoma cells)
NSE, chromogranin, synaptophysin and S-100 positive on IHC
urinary HVA and/or VMA high in 90%
N-MYC (chr. 2) is mutated
Pituitary Apoplexy: etiology, s/s, dx and tx
how to diff from aneurysm rupture near optic chiasm?
acute pituitary hemorrhage assoc. with pituitary adenoma
sudden severe HA bitemporal hemianopsia ophthalmoplegia (CN III) hemodynamic instability (low cortisol) altered sensorium antecedent loss of libido (high PRL) chronic mild HAs
dx by CT or MRI
tx by surgery and steroids
diff from saccular aneurysm rupture by history of pituitary dysfunction prior to acute event + CV collapse during event
Basal ganglia hemorrhage: etiology, s/s
usually via chronic hypertensive vasculopathy
neuro deficits that gradually worsen over minutes - hrs
contralateral hemiparesis, hemianesthesia (corticospinal + somatosensory tract disruption)
Carotid dissection: etiology, s/s
trauma, chronic htn, CT disease or smoking can cause
unilateral HA, transient vision loss, ptosis + miosis (partial Horner syn.)
Cerebral venous sinus thrombosis: etiology, s/s
thrombophilia, pregnancy, contraceptives, malignancy or infection can cause
presents with HA, vomiting, seizure and focal neuro deficits
anoxic brain injury MRI findings
loss of grey-white matter differentiation
sulcal effacement
(common in cardiac arrest)
pupillary reflex pathway
retina > optic nerve > superior colliculus-level midbrain > pretectal nucleus > BILATERAL Edinger-Westphal nuclei > oculomotor nerve (preganglionic PSNS) > ciliary ganglion > postganglionic fibers to sphincter pupillae
Epidural hematoma: vessel, location, clinical s/s, CT
middle meningeal artery; btwn skull + dura
lucid interval, followed by loss of consciousness
biconvex hematoma on CT
Subdural hematoma: vessel, location, clinical s/s, CT
bridging cortical veins; btwn dura + arachnoid
gradual onset HA/confusion
crescent shaped hematoma on CT
SAH hematoma: vessel, location, clinical s/s, CT
ruptured aneurysm/AV malformation of ant/post communicating arteries or MCA; btwn arachnoid + pia
sudden severe headache, fever, NUCHAL RIGIDITY (develops within 24 hrs as blood irritates meninges)
may see PAPILLEDEMA or PUPILLARY DILATION (but no focal neuro deficits)
blood in basal cisterns on CT
L2 radiculopathy: sensory + motor sx
upper anteromedial thigh
weak hip flexion (iliopsoas)
L3 radiculopathy: sensory + motor sx
lower anteromedial thigh
weak hip flexion (iliopsoas), hip adduction, knee extension (quad)
L4 radiculopathy: sensory + motor sx
lower anterolateral thigh, knee, medial calf + foot
weak hip adduction, knee extension (quad) and PATELLAR reflex
L5 radiculopathy: sensory + motor sx
buttocks, posterolateral thigh, anterolateral leg, dorsal foot
weak foot dorsiflexion + inversion (tibialis anterior), foot eversion (peroneus), and toe extension (extensor hallucis + digitorum)
S1 radiculopathy: sensory + motor sx
buttocks, posterior thigh + calf, lateral foot
weak hip extension (glut max), knee flexion (hamstrings), foot plantarflexion (gastroc) and ACHILLES reflex
Babinski sign
what does it indicate, how is it done, associated sx
stroke sole from lateral heel to ball of foot
dorsiflexion with toe spreading is positive in adults + indicates UPPER MOTOR NEURON LESION
assoc. findings are spasticity, hyperreflexia, muscle weakness/paralysis
(dorsiflexion normal in babies due to incomplete myelination of corticospinal tracts)
Acute cerebellitis
AKA? epidemiology + causes? Sx and course?
aka post-viral cerebellar ataxia
children 2-3 wks old via varicella, measles, or EBV
ataxia, nystagmus + dysarthria; usually resolves by 3 weeks
Cerebellar Infarction
presentation? biopsy/autopsy findings?
vertigo, nystagmus, IPSILATERAL limb ataxia, and TRUNCAL LATEROPULSION (fall toward lesion)
autopsy shows liquefactive necrosis (acute infarct) and glial scarring (chronic infarct)
Opsoclonus-Myoclonus syndrome
s/s, association
nonrhythmic conjugate eye movements, involuntary limb + trunk jerking
rare paraneoplastic condition from NEUROBLASTOMA (thought to be via an auto-ab)
(N-myc, SRB cells, Homer-Wright rosettes and urinary HVA/VMA)
Hypothalamic nuclei functions:
ventromedial, lateral, anterior, posterior
ventromedial - monitors blood glucose; mediates SATIETY; lesions cause HYPERPHAGIA
lateral - mediates HUNGER; lesions cause ANOREXIA
anterior - mediates heat dissipation; lesions cause HYPERthermia
posterior - mediates heat conservation; lesions cause HYPOthermia
Hypothalamic nuclei functions:
arcuate
paraventricular
supraoptic
suprachiasmatic
arcuate - secretes dopamine (inhibits PRL), GHRH and GnRH
paraventricular - ADH, CRH, oxytocin + TRH secretion
supraoptic - ADH + oxytocin secretion
suprachiasmatic - circadian rhythm + pineal gland function
Tumors of hypothalamus
most common in kids? most common in adults?
gliomas in kids
metastases in adults
Cavernous Hemangioma in CNS
where? s/s? complications?
in brain parenchyma ABOVE TENTORIUM CEREBELLI
seizures + progressive neuro deficits due to mass effects
tend to bleed > intracerebral hemorrhage
Transtentorial Herniation
what is it? cause?
ocular sx?
herniation of the medial-most portion of the temporal lobe (uncus) around/below the tentorium cerebelli
large cerebral hemorrhages, tumors etc. with mass effects can cause it
ipsilateral CN III disruption > ipsilateral fixed DILATED pupil with “DOWN AND OUT” deviation
herniation progression > midbrain + upper pons injury causes MID-POSITION and fixed pupil BILATERALLY w/ loss of vestibulo-ocular reflex
Decerebrate Posturing
what is it? what causes it?
EXTENSOR posturing via loss of RUBROSPINAL descending upper limb flexor excitation and unopposed VESTIBULOSPINAL extensor output
BRAINSTEM damage AT/BELOW RED NUCLEUS (midbrain tegmentum / pons)
Decorticate posturing
what is it? what causes it?
FLEXOR posturing due to loss of DESCENDING INHIBITION of the red nucleus (upper limb flexion)
damage to structures ABOVE RED NUCLEUS such as CEREBRAL HEMISPHERES or INTERNAL CAPSULE
Cerebellar vermis damage
signs?
vermis controls AXIAL/PROXIMAL LIMB muscle coordination
damage causes GAIT / TRUNCAL ATAXIA; may also cause nystagmus/vertigo via role in vestibular function
Thalamus damage
signs?
thalamus is relay station for almost all ascending sensory info
damage > sensory loss; bilateral damage may cause coma
Multiple Sclerosis
signs + symptoms
sx are EPISODIC + PROGRESSIVE
sensory disturbance; motor weakness; bowel/bladder issues
ocular issues: OPTIC NEURITIS (painful movement, intermittent vision decrease, optic disc swelling); INTERNUCLEAR OPHTHALMOPLEGIA (impaired adduction on lateral gaze)
cerebellar dysfunction: INTENTION TREMOR and BROAD GAIT
LHERMITTE SIGN: electrical sensation in limbs/back with neck flexion
UHTHOFF PHENOMENON: sx worse with increased body temp (slow conduction in damaged nerves)
Multiple Sclerosis
risk factors (race, gender, genetics, environment)
white females
HLA-DRB1
US / Europe; colder climates
low vitamin D and smoking
Multiple Sclerosis
diagnosis (clinical, imaging, other)
episodic/progressive sx disseminated over time/space
MRI shows HYPERINTENSE T2 lesions (demyelinating plaques)
CSF shows OLIGOCLONAL IgG bands
Wallenberg syndrome
cause? s/s?
LATERAL MEDULLA lesion - affects pain/temp tracts plus CN V 5, 9, 10 and 11
vertigo/nystagmus; ipsilateral ataxia + dysmetria (cerebellar)
loss of pain/temp in IPSILATERAL FACE + CONTRALATERAL BODY
bulbar weakness (dysphagia)
ipsilateral Horner
Colloid cyst
what? where? histo? complications?
BENIGN cyst in THIRD VENTRICLE
rare mitoses
lethal obstructive hydrocephalus
Pleomorphic Xanthoastrocytoma
what? in whom? histo? progression?
astrocytoma in KIDS / YOUNG ADULTS
RETICULIN deposits and CHRONIC WBC INFILTRATES
may progress to glioblastoma multiforme (rarely)
What is Wallerian degeneration?
How does it occur in CNS? Timeline?
axon damage > axon degeneration + myelin sheath breakdown DISTAL TO INJURY (begins few days after lesion)
in CNS, occurs more slowly due to BBB
macros/microglia enter more slowly > MYELIN DEBRIS PERSISTS FOR YEARS causing slower axonal growth
GLIAL SCAR in weeks/months after injury also slows process
Substructures + sheathing of nerves
Nerve is surrounded by EPINEURIUM and made up of FASCICLES (bundles of axons) surrounded by PERINEURIUM
Each axon is surrounded by an ENDONEURIUM
Guillain Barre histo
ENDONEURIAL inflammation
perivenular lymphos and macros btwn vessel and its assoc. axon
macros may appear LIPID LADEN after engulfing myelin
1 diagnosed movement disorder
cause? s/s? tx?
Essential tremor
(aka familial tremor, sometimes follows AD inheritance)
worsens while maintaining a certain posture (eg, holding an object)
improves with alcohol consumption
PROPRANOLOL is first-line
Thalamus VPL nucleus
inputs from where? what sensations?
contralateral…
spinothalamic tract - touch, pain, temp
dorsal columns - vibration + proprioception