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31 Cards in this Set
- Front
- Back
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name and define the 2 major types of white matter diseases.
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- demyelination: myelin is formed and then destroyed
- dysmyelination; myelin is never formed normally due to an inborn error of metabolism |
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what in general are leukodystrophies? name the 4 most common.
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- hereditary and metabolic dysmelinating disorders
- metachromatic leukodystrophy - Krabbe (Globoid) leukodystrophy - Adrenoleukodystrophy - Alexander disease |
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what age group is leukodystrophies most common?
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childhood
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which leukodystrophies are autosomal recessive?
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metachromatic leukodystrophy
Globoid leukodystrophy |
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which leukodystrophies are X linked?
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adrenoleukodystrophy
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what is the most common leukodystrophy? what is the abnormality?
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- metachromatic leukodystrophy
- deficiency in aryl sulphatase A causes and accumulation of sulphatide in the brain and peripheral nerves which destroys the myelin |
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leukodystrophies cause diffuse/focal myelin problems?
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diffuse
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where in relationship to the cell will one find sulphatide in MLD?
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extracellular
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what is the enzyme deficiency in Globoid leukodystrophy?
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galactocerebroside beta galactosidase which causes the accumulation of psychosine which is toxic to oligodendrocytes
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what is the pathologic finding in GLD?
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multi-nucleated cells
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where exactly would I find psychosine in GLD?
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inside the macrophages
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what is the enzyme deficiency in adrenoleukodystrophy?
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ABCD1 deficiency which leads to the accumulation of long chain fatty acids which will cause myelin loss
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which is the only leukodystrophy that will show inflammation?
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adrenoleukodystrophy
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how do we diagnose Alexander disease?
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must have a biopsy because we do not know the enzyme deficiency
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what will a brain biopsy of a patient with Alexander disease show?
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a large number of astrocytes in the white matte, the perivascular, periventricular, and subpial zones
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what is the most common demyelinating disease?
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multiple sclerosis
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what is the age and gender most often affected by MS?
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women in their 20's and 30's
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what parts of the nervous system are involved in MS?
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brain, brainstem or spinal cord
never are the peripheral nerves involved |
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what is the proposed pathogenesis of MS?
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CD+ Th1 cells react against self myelin antigens and secrete INF-gamma which will activate macrophages and these activate macrophages will cause demyelination
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where is the characteristic MS lesion in the brain?
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periventricular
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how do we diagnose MS?
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clinical symptoms
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what is one thing that you will see under microscope in an MS patient?
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foamy macrophges
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what are the 3 variants of MS?
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- neuromyelitis optica
- acute MS - tumefactive MS |
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Neuromyelitis optica
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- involves the optic nerve and spinal cord
- most aggressive form of MS - only form of MS you will see neutrophils - rapid progressive course that ends in death or severe disability |
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how do we diagnose neuromyelitis optica?
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serum autoantibody NMO-IgG + clinical symptoms
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tumefactive MS
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- single large lesion in white matter with edema
- may lead to classic MS |
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acute disseminated encephalomyelitis
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- monophasic (only one attack) demyelinating disease
- occurs after viral infection or vaccination - usually ends in a full recovery |
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a patient comes into the ER with a history of chronic alcoholism and is hyponatremic. a resident says we should give them a huge bolus of Na to correct the electrolyte imbalance. what disease is the resident going to cause the patient to develop? how will this disease manifest?
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Central Pontine Myelinolysis - caused by a rapid correction of hyponatremia
- a rapidly evolving quadriplegia |
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what causes Progressive Multifocal Leukoencephalopathy?
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JC virus
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T or F: most young adults that are infected by JC virus develop PML.
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false; ~70% of young adults are infected by JC virus but most do not develop PML
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what is the pathologic lesion seen in PML?
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soft cystic white matter lesions
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