Neurology - Pathology

veranellasel's version from 2015-07-04 17:34

Brain Lesions

Area of LesionConsequence
amygdala (bilateral)Kluver-Bucy syndrome (hyperorality, hypersexuality, disinhibited behavior)
frontal lobedisinhibition and deficits in concentration orientation, and judgement; may have reemergence of primitive reflexes
right parietal lobespatial neglect syndrome (agnosia of the contralateral side of the world)
reticular activating system (midbrain)reduced levels of arousal and wakefulness (coma)
mammillary bodiesWernicke-Korsakoff syndrome
basal gangliamay result in tremor at rest, chorea, or athetosis
cerebellar hemisphereintention tremor, limb ataxia; ipsilateral deficits (fall toward side of lesion)
cerebellar vermistruncal ataxia, dysarthria
subthalamic nucleuscontralateral hemiballismus
hippocampusanterograde amnesia- inability to make new memories
paramedian pontine reticular formationeyes look away from side of lesion
frontal eye fieldseyes look toward lesion

Circle of Willis

RegionAssociated Area/Deficit
anterior spinal arterycontralateral hemiparesis (lower extremities), medial lemniscus (decrease contralateral proprioception), ipsilateral paralysis of hypoglossal nerve
PICAcontralateral loss of pain and temperature, ipsilateral dysphagia, hoarseness, decreased gag reflex, vomiting, ipsilateral Horner's
AICAipsilateral facial paralysis, ipsilateral cochlear nucleus, vestibular (nystagmus), ipsilateral facial pain and temperature
posterior cerebral arterycontralateral homonymous hemianopia with macular sparing, supplies occipital cortex
middle cerebral arterycontralateral face and arm paralysis and sensory loss, aphasia (dominant sphere), left-sided neglect
anterior cerebral arterysupplies medial surface of the brain, leg-foot area of motor and sensory cortices
anterior communicating arterymost common site of circle of Willis aneurysm; lesions may cause visual field defects (Berry aneurysm)
posterior communicating arterycommon area of aneurysm; causes CN III palsy
lateral striatedivision of middle cerebral artery; supply internal capsule, caudate, putamen, globus pallidus
watershed zonesbetween anterior cerebral/middle cerebral, posterior cerebral/middle cerebral arteries
basilar arteryinfarct causes "locked-in syndrome" (CN III is typically intact)

Spinal Cord Lesions

poliomyelitiscaused by poliovirus, signs of LMN lesions, CSF with lymphocytic pleocytosis, virus recovered from stool or throat, lesion in anterior horns
Werdnig-Hoffman diseaseinfantile spinal muscular atrophy, "floppy baby", tongue fasciculations, LMN involvement only, lesion in anterior horns
amyotrophic lateral sclerosisboth LMN and UMN signs, caused by defect in superoxide dismutase 1 (SOD1)
tabes dorsalisdegeneration of dorsal columns and dorsal roots due to tertiary syphilis
Friedreich's ataxiatrinuleotide repeat (GAA), impairment in mitochondrial functioning, staggering gait, frequent falling, hypertrophic cardiomyopathy, kyphoscoliosis
Brown-Sequard syndromehemisection of spinal cord, ipsilateral UMN signs (corticospinal tract) below lesion, ipsilateral loss of tactile, vibration, proprioception sense (dorsal column) below lesion, contralateral pain and teperature loss (spinothalamic tract) below lesion, ipsilateral loss of all sensation and LMN signs at level of lesion
Horner's syndromeptosis, anhidrosis, and miosis, associated with lesion of spinal cord above T1

Dementia and Neurodegenerative Diseases

Alzheimer'smost common cause, associated with APP, presenilin-1, presenilin-2, ApoE4,
neurofibrillary tangles (phophorylated tau protein that are intracellular)
senile plaques (extracellular)
Pick'sfrontotemporal dementia, change in personality, Pick bodies (intracellular, aggregated tau protein)
Lewy body dementiaParkinson's movement disorders with Alzheimer's memory loss (dementia)
visual hallucinations, alpha-synuclein defect
Creutzfeldt-Jakobrapidly progressive with myoclonus, spongiform cortex, prions
multi-infarctsecond most common cause in the elderly
Parkinson's diseaseassociated with Lewy bodies, depigmentation of the substantia nigra, loss of dopaminergic neurons
Parkinson's diseasecan be caused by MPTP
Huntington's diseasetrinucleotide repeat disorder (CAG) on chromosome 4, anticipation
Huntington's diseaseneuronal death via NMDA-R binding and glutamate toxicity
Huntington's diseasethe caudate nucleus loses ACh and GABA

Demyelinating Diseases

multiple sclerosisdemyelination of CNS, optic neuritis, MLF syndrome, bladder/bowel incontinence, increase IgG in CSF
Guillain-Barre syndromeinflammation and demyelination of peripheral nerves and motor fibers of ventral roots, symmetric ascending muscle weakness, facial paralysis, increase CSF protein causing papilledema, associated with C. jejuni
progressive multifocal leukoencephalopathydemyelination of CNS due to derstruction of oligodendrocytes, associated with JC virus
acute disseminated encephalomyelitismultifocal perivenular inflammation and demyelination after infection or certain vaccines
metachromatic leukodystrophylysosomal storage disease due to arylsulfatase A deficiency, build up of sulfatides leads to impaired production of myelin sheath
Charcot-Marie-Tooth diseasenerve disorders related to the defective production of proteins involved in the structure and function of peripheral nerve or the myelin sheath

Primary Brain Tumors

Question Answer
glioblastoma multiformemost common, grade IV astrocytoma, can cross corpus callosum, stain with GFAP, "pseudopalisading" pleomorphic tumor cells
meningiomaarises from arachnoid cells, convexities of hemispheres and parasagittal region, psammoma bodies
schwannomalocalized to CN VIII, founds at cerebellopontine angle, S-100 positive, found in neurofibromatosis type 2
oligodendrogliomamost often in frontal lobes, chicken-wire capillary pattern, "fried egg" cells
pituitary adenomaprolactinoma, bitemporal hemianopia, Rathke's pouch
pilocytic astrocytomawell circumscribed, GFAP positive, Rosenthal fibers, found in posterior fossa
medulloblastomamalignant cerebellar tumor, form of PNET, can compress 4th ventricle causing hydrocephalus, rosettes, small blue cells
ependymomafound in 4th ventricle, causes hydrocephalus, perivascular pseudorosettes, rod-shaped blepharoplasts
hemangioblastomaassociated with von Hippel-Lindau syndrome when found with retinal angiomas, can cause polycythemia through secondary EPO production, foamy cells
craniopharyngiomacan cause bitemporal hemianopia, derived from remnants of Rathke's pouch, tooth enamel-like calcifications