Neurology Pathology Flashcards
Patient presents with bilateral loss of pain and temperature sensation in cape like distribution across upper extremities. Fine touch preserved. Diagnosis?
:Syringomyelia; cystic fluid -filled cavity within the spinal cord @ C8-T1 disrupting anterior white commissar fibers = protopathic - may be congenital (Arnold Chiari malformation) or due to trauma -Can expand to involve 1. anterior horn cells = LMN in upper extremities 2. Intermedial lateral cell column = Horner syndrome (ptosis, anhidrosis, miosis) -Recall: Hypothlamospinal tract
What malformation is associated with syringomelia?
Arnold Chiari I malformation: congenital cerebellar tonsillar herniation through the foramen magum -ususally asymptomatic in childhood, presents as headaches and cerebellar symptoms
Poliomyelitis
Infection with poliovirus = fecal-oral route -presents as fever, sore throat, nausea, vomiting -damage to anterior horn cells =LMN signs
Werdnig-Hoffman disease
:Spinal muscular atrophy; congenital degeneration of anterior horn cells = LMN signs -presents in early infancy (“floppy baby”),marked hypotonia, tongue fasciculations -autosomal recessive -median age to death 7 months
UMN and LMN deficits with no sensory findings, cognitive, or oculomotor deficits. Diagnosis? Pathogenesis? Treatment?
:Amyotrophic lateral sclerosis or “Lou Gehrig Disease”; mostly sporadic -congenital forms caused by SOD = free radical injury to neurons -atrophy and weakness of hands may be early sign–> distinguish from syringomyelia b/c no sensory findings -treatment: Rilouzole
Patient: muscle weakness in the lower extremities, loss of DTRs, loss of vibratory sense and proprioception. Reports frequent falling and staggering. PE: nystagmus, dysarthria, high arches, hammer toes. Diagnosis? What is the usual cause of death?
: Fredreich ataxia; autosomal recessive trinucleotide repeat disorder (GAA) on chromosome 9 -gene encodes for frataxin (iron binding protein –> iron build up + free radical damage via fenton run) -cause of death = hypertrophic cardiomyopathy -presents in childhood with kyphoscoliosis
Tabes dorsalis. Pathogenesis? Signs/Symptoms?
:caused by tertiary syphilis; results in degeneration/demylination of dorsal columns and roots -impaired sensation and proprioception and progressive sensory ataxia (inability to sense of feel the legs -> poor coordination) -associated with charcot joints, shooting pain, argyll robertson pupil (constrict to accommodation but not light) -exam will demonstrate absence of DTRs and + Romberg
Vitamin B12 or vitamin E defeciency neurologic effects?
:subacute combined degeneration of spinal cord- demyelination of dorsal columns, lateral CST, and spinocerebellar tracts -results in ataxic gait, paresthesia, impaired position and vibration sense.
What are the microscopic changes seen in ischemic brain stroke and timeframes?
“1 day” : within 12 hrs -> red neurons
“1 week” : 24-72 hrs ->liquefactive necrosis + neutrophils; 3-5 days-> microglia (macrophages)
“1 month”: 1-2 weeks-> reactive gliosis (astrocytes) + vascular proliferation; 2 weeks or more -> fluid filled cystic cavity w/surrounding fibrotic tissue = glial scar
What are the imaging findings you expect with ischemic stroke? timeframe?
- MRI (highest sensitivity) - hyperintense (bright) area w/in 3-30 minutes
- Noncontrast CT scan- hypodense (dark) area 12-24 hrs
How can CT scan be used be used in the immediate treatment of ischemic stroke?
absence of hyperdense (bright) areas to exclude hemorrhage = can use tPA - tPA contraindicated in acute hemorrhage
Thrombotic stroke
: d/t clot formation directly at the site of infarction, usually over ruptured atherosclerotic plaque -results in pale infarct -usually in MCA territory -Risk factors: HTN, DM
Embolic stroke
:an embolus from another part of the body obstructs the vessel -results in hemorrhagic infarct -most common source of emboli is left side of heart -> atrial fibrillation
Lacunar stroke
:most commonly d/t lenticulostriate vessel, resulting in small cystic areas of infarction -secondary to hyaline arteriosclerosis –> HTN ! - internal capsule involvement = pure motor deficits - thalamus involvement = pure sensory deficits
What areas of the brain are particularly susceptible to hypoxia?
- Pyramidal neurons of cortical layers 3, 5 & 6 = cortical laminar necrosis 2. Pyramidal neurons of hippocampus 3. Purkinje layer of cerebellum 4. watershed areas
Hypoxic stroke
: due to hypoperfusion (i.e. shock) or hypoxemia. -common during cardiovascular surgeries -effects watershed areas, cortex, hippocampus, cerebellum
Difference between stroke and TIA
Transient Ischemic Attack (TIA) is a brief reversible episode of focal neurologic dysfunction lasting <24 hours without acute infarction (- MRI) -d/t focal ischemia -majority resolve in 15 minutes
Hemorrhagic stroke
: intracerebral bleeding -classically d/t Charcot-Bouchard microaneuryms of lenticulostriate vessels -often due to HTN! anticoagulation, cancer (abnormal vessels) -may be secondary to ischemic stroke followed by reperfusion -common sites: internal capsule, basal ganglia
Berry aneurysm
aka saccular aneurysm; most common site is junction of the A Comm and ACA -rupture is common complication = subarachnoid hemorrhage (WHOML) -can cause bitemporal hemianopia via compression of optic chasm -risk factors: advanced age, HTN, smoking, black race
Which diseases are associated with berry aneurysms?
Autosomal dominant polycystic kidney disease (ADPKD)
Marfan syndrome
Ehlers-Danlos
Patient complains of “worst headache of my life.” Diagnosis?
Subarachnoid hemorrhage!; rupture of berry aneurysm -rapid time course -causes= HTN, Marfan, Ehlers- Danlos, ADPKD or AVM -lumbar puncture : bloody or xanthochromatic (yellow = bilirubin breakdown)
What complication are patients with subarachnoid hemorrhage at risk for?
- Vasospasm 2-3 days afterward –> not visible on CT, treat with nimodipine
- Rebleed –> visible on CT
Diagnosis?
:epidural hematoma; d/t ruputre of the middle meningeal artery often secondary to fracture of the temporal bone
- not crossing suture lines and can cross falx, tentorium
- Presents with lucid interval but have rapid progression
- Can progress to transtentorial herniation (uncal herniation)
Recall: tentorium is extension of dura mater
Diagnosis?
: subdural hematoma= between the dura and the arachnoid mater; cresent shaped that crosses suture lines but cannot cross falx, tentorium
- d/t rupture of the bridging veins = slow venous bleeding = develops over time
- can cause midline shift
- seen in elderly, alcoholics, blunt traum, shaken baby
Tonsillar herniation
:displacment of cerebellar tonsils into the foramen magnum
-Compression of brainstem –> cardiopulmonary arrest
Subfalcine herniation
:displacement of the cingulate gyrus under the flax cerebri
-compression of the anterior cerebral artery leads to infarction
Uncal herniation
:aka transtentorial herniation; displacement of the temporal lobe uncus under the tentorium cerebelli
- compression of cranial nerve III = oculomotor palsy (down and out gaze) & dilated pupil
- compression of posterior cerebral artery leads to infarction of the occipital lobe (contralateral homonymous hemianopsia
- contralateral crus cerebri = ipsilateral paralysis (false localizing sign)
- rupture of paramedian arteries (branches of basilar) leads to Duret (brainstem) hemorrhage
Metachromatic Leukodystrophy
:autosomal recessive, lysosomal storage disease
- commonly d/t arylsufatase A deficiency–> sulfatides cannot be degreaded = accumulate in lysosome of oligodentrocytes
- central and peripheral demyelination with ataxia, dementia
Krabbe Disease
:autosomal recessive, lysosomal storage disease
- deficiency of galactocerebrosidease –> galactocerbroside and psychosine destroys myelin sheath
- peripheral neuropathy, developmental delay, optic atrophy, globoid cells
Adrenoleukodystrophy
:X-linked, typically affecting males
- disrupts metabolism of very long chain fatty acids= accumulation in nervous system and adrenal gland, testes
- progressive disease that can lead to long-term coma/death and adrenal gland crisis
Patient- Female 25 y/o with scanning speech, incontinence , INO & nystagmus; relapsisng and remitting course.
:multiple sclerosis; autoimmune inflammation and demyelination of CNS
Presentation: optic neuritis (sudden loss of vision resulting in Marcus Gunn pupil), INO, hemiparesis, hemisensory symptoms, bladder/bowel incontinence
What do you expect to find in LP of MS patient? What findings are on MRI?
- increased lymphocytes, increased protein (IgG) in CSF; oligoclonal IgG bands on electrophoresis (diagnositc), myelin basic protein
- MRI shows periventricular plaques (oligodendryte loss and reactive gliosis)
- MRI is the gold standard
Diagnosis?
MS; dawsons fingers = specific for MS
Central Pontine myelinolysis
:focal demyelination of the pons; d/t rapid correction of hyponatremia
- Presents as acute paralysis, dysarthria, dysphagia, diplopia, and LOC –> can cause locked in syndrome
- Physiology: hyponatremia causes neurons to initally swell; during rapid correction ECF becomes hypernatremic and cells shrink =CMP
- occurs in severely malnourished patients –> alcoholics, patients with liver disease, etc
- causes “locked in” syndrome
What histologic findings would you expect in a patient with Alzheimers disease?
- Senile plaques: extracellular core comprosed of ABeta amyloid
- amyloid may deposit around vessels = increased risk of hemorrhage
- Neurofibrillary tangles: intracellular hyperphosphorylated tau protein = insoluble cytoskeleton elements; tangles correlate with degree of dementia
Creutzfeldt-Jacob disease
:most common spongiform encephalopathy: rapidly progressive dementia (weeks to months) with ataxia & startle myoclonus (involuntary contraction of muscle with minimal stimulus)
- Pathogenesis: Prions normally in PCP-c (alpha configuration) get converted to PCP-sc (beta-pleated sheet configuration) –> resistant to proteases and converts normal PRP-c to PRP-sc
- results in neuron and glial cell damage; characterized by intracelluar vacuoles
What primary brain tumor? cell lineage? Histology findings?
:Glioblastoma multiforme -adult; highly malignant -grade IV tumor of astrocytes; in cerebral hemispheres
- can cross corpus callosum = “butterfly glioma”
- Astrocytes stain from GFAP
- Pseudopalisading = tumor cells surrounded by necrosis and hemorrhage
- median survival ~ 1 year
Brain biopsy of a cerebral mass reveals the following:
:adult; pseudopallisading seen in glioblastoma multiforme; pleomorphic tumor cells surrrounding necrosis and hemorrhage
Recall: primary tumor of astrocytes
Patient- female presents with seziure, head CT reveals the following: Diagnosis? Histology?
:adult; meningioma (dural tails); benign tumor that arises from the arachnoid cells
- compresses but does not invade cortex; often asymptomatic
- treatment: resection and/or radiography
- histology: whorled pattern of spindle cells + psammoma bodies (laminted calcifications)
Schwannoma
:adult; benign tumor of schwanna cells; often localized to cerebellopontine angle= CN VIII -> acoustic schwannoma
- presents with hearing loss and tinnitus
- tumor cells are S-100 positive
- resectable or treated with sterotactic radiosurgery
- bilateral acoustic schwannoma associated with neurofibromatosis type 2
Oligodendroglioma
:adult; malignant tumor of oligodendrocytes; imaging reveals calcified tumor in white mass
-usually involves frontal lobes; may present with seizures
Histology: fried-egg appearing tumor cells + chicken wire capillary pattern
What type of brain tumor? Histology?
:Pilocytic astrocytoma -children; benign tumor of astrocytes = GFAP positive; often found in posterior fossa (ie. cerebellum)
- good prognosis
- Gross appearance: cystic + solid
histology: rosenthal fibers = brightly eosinophilic, corkscrew fibers
Medulloblastoma -what is the name of this finding?
:children; malignant tumor derived from granular cells of cerebellum ( of primative neuroectoderm)
- can compress the 4th ventricle = hydrocephalus
- can send drop metastasis to spinal cord
- histology- Homer-wright rosettes + small blue cells
Ependymoma
:children; malignant tumor of ependymal cells, most commonly in the 4th ventricle; poor prognosis
- may present as hydrocephalus
- characteristic perivasicular pseudorosettes on biopsy
Craniopharyngioma
:benign childhood tumor, arises from epithelial remnants of rathkes pouch
- may compress the optic chiasm = bitemporal hemianopsia
- only childhood supratentorial tumor
- calcification on imaging is common (tooth like
