Pathology Flashcards
Bleed on the bottom of the brain? What is the presentation?
Subarachnoid hemorrhage! (only thing that does this)
Presentation: “worst headache of my life”, nuchal rigidity, xanthochromia (yellow hue due to bilirubin breakdown) on LP
What is the earliest change in ischemic stroke? How long after infarction does this develop? What type of necrosis?
Red neurons
develops 12 hours after infarction
(shrinkage of cell body, eosinophilia of cytoplasm, pyknosis/shrinking of nuclei, loss of Nissl substance/RER)
liquefactive necrosis
What lesions causes hemiballismus? Due to what? Ipsilateral or contralateral?
lesion to the subthalamic nucleus
most commonly due to a lacunar stroke
CONTRALATERAL
What vitamin deficiencies result in posterior column degeneration?
Vitamin B12 and Vitamin E deficiencies
Lesions or atrophy of the mammillary bodies? What can trigger this? What is the triad?
Wernicke encephalopathy
associated with thiamine/B1 deficiency and excessive alcohol use
can be triggered by glucose infusion to a B1-deficient pt
Triad (CAN of beer):
Confusion
Ataxia
Nystagmus
Most common presentation of cerebral amyloid angiopathy?
recurrent hemorrhagic stroke
multiple, small lobar hemorrhages with history
due to deposition of beta-amyloid into arterial wall, resulting in weakening
lower mortality rate and more benign course than hemorrhagic storkes associated with HTN
usually in cerebral hemispheres (lobar strokes) and involve smaller areas, where HTN strokes are larger and tend to involve deep structures like the basal ganglia
Where is the pineal gland? What is its function?
dorsal midbrain, between midbrain and cerebellum
melatonin secretion, circadian rhythms
45yo with bouts of nausea and ringing in left ear, feels fine between episodes?
Ménière’s disease - increased volume of endolymph in vestibular apparatus
- tinnitus
- vertigo
- sensorineural hearing loss
Lake-like cavitary lesions in the internal capsule – due to? Pathogenesis?
Lacunar infarcts
occur secondary to hyaline arteriolosclerosis (complication of HTN)
leads to small, cystic areas/spaces areas of infarction weeks later due to necrotic liquefactive tissue lined by astrocytes/gliosis
Lacunar infarct vs. Charcot-bouchard?
lacunar infarct – OBSTRUCTION of lacunar vessels, resulting in lacunae on healing
Charcot-Bouchard – HEMORRHAGE
Brain tumor positive for synaptophysin?
indicates neuronal origin (NOT glial origin)
synaptophysin – protein found in presynaptic vesicles of neurons, neuroendocrine, and neuroectodermal cells
Small bilateral pupils that constrict to accommodation but not to light?
Argyll Robertson pupils
associated with tabes dorsalis (tertiary syphilis)
What are the features of tabes dorsalis? due to?
degeneration of dorsal columns and roots
- impaired sensation and porprioseption
- progressive sensory ataxia
also associated with
- Argyll Robertson pupils
- absence of deep tendon reflexs
- positive Romberg
5yo with midline posterior fossa mass – sheets of primitive cells and many mitotic figures?
Medulloblastoma
sheets of small cells with deeply basophilic nuclei and scant cytoplasm (small, round, blue cells)
abundant mitoses – undifferentiated and aggressive (bad prognosis)
Thunderclap headache / worst headache of my life?
Subarachnoid hemorrhage
usually due to berry aneurysm rupture
Potential complications 2-3 days after subarachnoid hemorrhage? Symptoms? Findings on CT
- secondary arterial vasospasm in the vessels surrounding the ruptured aneurysm
- causes cerebral ischemia
- new onset confusion and/or focal neurological deficit
- NOT visible on CT, treat with nimodipine (selective Ca channel blocker) - rebleeding
- sudden development of a severe headache, severe nausea/vomiting, change in consciousness, new neurological deficits
- seen on CT
Headache that is recurrent, on the right side, starts with pain around eye for about 30minutes, and associated with tearing and nasal congestion?
Cluster headache
most common in males (only one)
lasts >15 minutes (vs. trigeminal neuralgia which lasts <1 minute)
What tracts do vitamin B12 and E deficiencies result in?
- dorsal columns
- lateral corticospinal (descending)
- spinocerebellar (part of ALS)
Sporadic encephalitis that targets the temporal lobes? Findings?
HSV-1 sporadic encephalitis
reactivation of latent virus in trigeminal ganglion and spread to the cerebral vault
Bilateral paresthesias of the thumb, index, and middle finger?
Carpal tunnel syndrome
compression of median nerve in carpal tunnel
(can also see weakness of thumb adduction and thenar atrophy in advanced cases)
Common causes:
- chronic repetitive stress (typing, knitting)
- conditions with fluid retention (renal failure, pregnancy, hypothyroidism)
- DM, RA, and acromegaly
- dialysis-associated amyloidosis
Worsening weakness/tingling of feet ascending to knees with absent DTRs in legs and history of mild respiratory infection?
Guillain-Barré syndrome
autoimmune destruction of peripheral myelin and Schwann cells
leads to symmetric ascending muscle weakness/paralysis beginning in lower extremities
What fibers are at the interior of CN III? What fibers are at the periphery of the nerve? What damages each and what are the results?
Interior/central part of CN III:
- motor fibers (controls levator palpebrae and extraoculars)
- primarily affected by vascular disease (DM2)
- ptosis, “down and out” gaze
Periphery of CN III:
- parasympathetic fibers (sphincter of the iris, ciliary muscle)
- primarily affected by compression
- diminished/absent pupillary light reflex, blown pupil
Angiomatous lesions of the cerebellum and cystic mass in kidney? Inheritance and other features?
Von Hippel-Lindau disease
autosomal dominant
mutated VHL tumor suppressor on chromosome 3
- cavernous hemangiomas in skin, mucosa, organs
- bilateral renal cell carcinomas
- hemangioblastoma (retina, brain stem, cerebellum)
- pheochromocytoma
Findings in Von Recklinghausen’s disease?
Neurofibromatosis type 1
- cafe-au-lait spots
- Lisch nodules (pigmented iris hamartomas)
- neurofibromas in skin (derived from neural crest)
- optic gliomas
- pheochromocytomas
mutated NF1 tumor suppressor gene (chromosome 17)
Sturge-Weber syndrome?
congenital non-inherited/somatic neurocutaneous disorder
- cutaneous facial angiomas (port-wine stain of the face, a non-neoplastic “birthmark” in CN V1/V2 distribution)
- leptomeningeal angioma (ipsilateral)
- seizures/epilepsy
- intellectual disability
- episcleral hemangioma
STURGE Sporadic port-wine Stain Tram track calcifications Unilateral Retardation Glaucoma (increased intraocular pressure) GNAQ gene Epilepsy
Tuberous sclerosis?
HAMARTOMAS
Hamartomas in CNS and skin Angiofibromas Mitral regurgitation Ash-leaf spots Rhabdomyomas (cardiac) (Tuberous sclerosis) dOminant, autosomal Mental retardation Angiomyolipoma, renal Seizures Shagreen patches
increased incidence of subependymal astrocytomas and ungual fibromas
What is the most important neurotransmitter abnormality in Alzheimer’s disease? Where is this most notable?
decrease in ACh level
due to deficiency of choline acetyltransferase
most notable in the basal nucleus of Meynert (participates in memory and cognition) at the base of the forebrain, projecting widely to the neocortex
What NT is synthesized in the locus ceruleus? Location?
Norepinephrine
caudal pontine gray matter (pons)
plays a role in pathogenesis of panic attacks and panic disorder
- increased in anxiety
- decreased in depression
Where is serotonin made?
Raphe nucleus (pons, medulla, midbrain)
Where is GABA made? Levels are decreased in which disorders?
Nucleus accumbens
decreased in anxiety and in Huntington’s
Where is dopamine synthesized? What are levels in Huntington’s and Parkinson’s? Depression?
ventral tegmentum and SNc (midbrain)
increased in Huntington’s
decreased in Parkinson’s
decreased in depression
Pt with confusion, horizontal nystagmus, and ataxia? Region of brain affected? What effects are permanent?
Wernicke-Korsakoff syndrome: CAN Confusion Ataxia Nystagmus
Mamillary bodies
Memory loss/impairment is permanent
65yo with memory problems, longstanding HTN, diabetes, no focal neurologic deficits, and patchy amyloid deposition in temporal cortex and hippocampus as well as cerebral arterioles?
amyloid angiopathy from Alzheimer’s disease
amyloid deposits in vascular walls damage media and adventitia to cause thickening, stenosis, and fragmentation of vessel components.
What tumors are S-100 positive?
Schwannoma and melanoma
both derived from neural crest
Intracranial mass that is S-100 positive? What autosomal disease may it be associated with?
Schwannoma
bilateral acoustic Schwannomas associated with Neurofibromatosis 2: - juvenile cataracts - meningiomas - ependymomas autosomal dominant, chromosome 22
65yo with inappropriate jokes, irritable, aggressive, some dysarthria? What regions affected? What aggregates are associated?
Pick disease (frontotemporal dementia) pronounced atrophy of frontal and temporal lobes
Pick bodies – spherical tau protein aggregates
What is an uncal herniation? What structures are compressed and what is the result of each?
medial temporal lobe (uncus) herniates through the gap at the free margin of the tentorium cerebelli
- CN III compression: blown pupil, down-and-out gaze
- PCA (posterior cerebral artery) compression: contralateral homonymous hemianopsia with macular sparing
- compression of contralateral cerebral peduncle against tentorium: ipsilateral hemiparesis “false localization”
- pulling on basilar/paramedian artery along brainstem: brainstem hemorrhages (Duret hemorrhage)
What is a cingulate or subfalcine herniation? Compression of?
cingulate gyrus herniates under the falx cerebri
compresses anterior cerebral artery (causes infarction)
Proximal muscle weakness in pt with lung cancer - which cancer and paraneoplastic syndrome? Pathogenesis?
Lambert-Eaton syndrome
due to underlying small cell lung cancer
autoantibodies against presynaptic Ca2+ channel
leads to decreased ACh release
What is the presentation of myasthenia gravis? Pathogenesis? Better or worse with use? What other condition is it associated with?
extraocular muscles affected first – ptosis, diplopia, weakness
due to autoantibodies against postsynaptic ACh recpetor
worsens with use (vs. Lambert-Eaton which improves with use)
associated with thymoma and thymic hyperplasia
What area is most vulnerable in global cerebral ischemia (e.g., due to cardiac arrest)? What other areas are particularly vulnerable?
Hippocampus (pyramidal cells; most vulnerable, first area damaged)
- pyramidal cells of the neocortex
- Purkinje cells of the cerebellum
- watershed areas
Child with cystic tumor in the cerebellum containing:
spindle cells with hair-like glial processes and thick eosinophilic corkscrew fibers?
Pilocytic astrocytoma
spindle cells with hair-like glial processes associated with microcysts, mixed with:
- Rosenthal fibers
- granular eosinophilic bodies
What is Wallerian degeneration? What happens to the cell body?
Axon injury leads to Wallerian degeneration – degeneration distal to injury and axonal retraction proximal to injury (to allow for potential regeneration of axon)
Cell body undergoes AXONAL REACTION:
- round, cellular swelling/edema
- displacement of nucleus to periphery
- dispersion of Nissl substance throughout cytoplasm
reflects increased protein synthesis in order to regenerate the severed axon
What does Nissl substance stain?
rough ER
Diagnosis of multiple sclerosis?
- increased protein (IgG) level in the CSF – oligoclonal bands on electrophoresis suggest activation of B cells and are diagnostic!!
- MRI is gold standard – shows multiple white matter lesions and plaques separated in time and space
Intracranial mass with spindle cells in whorled pattern and psammoma bodies? Most commonly seen in which demographic?
Meningioma
only CNS tumor with psammoma bodies
classically seen in adult female!!
What cancers can psammoma bodies be seen in?
PSaMMoma bodies seen in: Papillary carcinoma of the thyroid Serous papillary cystadenocarcinoma of the ovary Meningioma Malignant mesothelioma
What is the pathogenesis of communicating hydrocephalus? Sequelae of?
dysfunction or obliteration of subarachnoid villi
- usually a sequelae of meningeal infection or subarachnoid/intraventricular hemorrhage
- in elderly, due to gradual decline in reabsorptive capacity of arachnoid villi
Neurofibromatosis 1 vs. 2? What chromosome and main clinical features for each?
NF-1: neurofibromin on chromosome 17
- cafe-au-lait spots
- multiple neurofibromas
- Lisch nodules
NF-2: merlin on chromosome 22
- bilateral acoustic neuromas (bilateral Schwannoma tumors at cerebellopontine angle)
HIV positive pt with solitary intracranial mass positive for EBV?
Primary CNS lymphoma
most frequent CNS tumor in immunosuppressed pts (associated with AIDS)
majority arise from B cells – diffuse large B-cell lymphoma is the most common subtype
Rapidly progressive dementia and myoclonic jerks with gray matter changes and many uniform vacuoles between neuron cell bodies and in perikaryon of neurons? NO inflammation present.
Creutzfeldt-Jakob disease
associated with corneal transplants, implantable electrodes, preparation of growth hormone
15yo with kyphoscoliosis and high plantar arch; family history of brother with neurologic disorder? Mutation? Cause of death?
Friedrich ataxia
frataxin gene mutation on chromosome 9 (iron binding protein) – leads to impaired mitochondrial functioning and degeneration of multiple spinal cord tracts (spinocerebellar, etc.)
associated with hypertrophic cardiomyopathy (cause of death)
Hemiparesis of the right side with arm more affected than leg – which artery affected? What if leg were more affected than arm?
left middle cerebral artery – right hemiparesis with involvement of arm than leg
left anterior cerebral artery – right hemiparesis with involvement of leg more than arm
Embolus occlusion of which artery would give you Broca’s aphasia?
LEFT middle cerebral artery
(left hemisphere of brain most often dominant in both right- and left-handed people)
Broca’s area located in the inferior frontal gyrus in the dominant (usually left) hemisphere.
Calcified intracranial cystic mass with thick brownish fluid in a 25yo? Derived from what tissue?
Craniopharyngioma
cystic filled with yellow, viscous fluid rich in cholesterol
derived from remnants of Rathke’s pouch (oral/surface ectoderm)
