Demyelinative disorders Flashcards
What components of CNS maintain myelin of axons>
Oligodendrocytes/shwann cells
trophic factors of axons
What causes primary demyelination?
axon is spared by myelin undergoes injury
What causes secondary demyelintaion?
atrophy/degeneration of axon, leading to myelin degeneration bc stimulus is lost
What is the pathological characterization of MS? The clinical characterization?
multiple, random disseminated/demyelinated lesions with chronic inflammation due to auto-AB against myelin proteins
Chronic, epidoside- exacerbating and remitting, neurological deficits affecting CNS fnx
How are MS plaques described on gross specimen?
multiple, asymmetric, well circumscribed lesions surrounding white matter
What are the histological findings of MS?
early: demyelination, pallow, m@ and perivascular inflammation
late: above and gliosis, progressive worsening of disease
The clinical picture of MS is decribed as?
young adults, decreased sensation/focal weakness, visual changes and some ataxia/nystagmus
Typically nonprogressive over time
What are the genetic associations of MS?
IL7 and IL2 receptor genes (SNP)
HLA DR2, A3, B7
What are the typical lab findings of MS patients?
elevated CSF IgG- oligoclonal
What other pathogenesis does MS resemble? What features are similar?
allergic encephalomyelitis
CD4 Th1 T-lymphocytes activates myelin-destructing m@
What is tumefactive multiple sclerosis?
Acute inflammatory demyelination mimicking CNS neoplasia
Pt with no hx of MS comes in with acute space occupying lesion
A biopsy of the afore mentioned Acute inflammatory MS shoes what on histology?
hypercellular, well-demarcated lesion with abundant foamy M@ and decreased myelin staining and spared axons
What is neuromyelitis optica?
Devic’s disease, synchronous bilateral optic neuritis and spinal cord demyelination
Autoantibodies to AQP4 of astrocyte foot processes of BBB
What causes acute disseminated encephalomyelitis?
viral infection and post-immunzation
What is the histological picture of ADEM MS? Where can it be found?
multi-microfoci perivenous demyelination and inflammation, found in:
cerebrum, brainstem, SC, cerebellum and optic nerves.
What is acute necrotizing hemorrhagic leukoencephalopathy? Where are the lesions commonly located?
Post-infectious inflamm demyelination dz, showing perivenous inflammatory necrotizing/hemorrhagic lesions in WM of cerebrum
What is PML? What patients do we commonly see this with?
infection demyelination caused by the JC papovavirus of oligodendrocytes leading to coalescing foci of demyelination.
Immunosuppressed patients
How is adrenoleukodystrophy characterised?
X-linked peroxisome disease following a parieto-occipital demyelination
metachromatic leukodystrophy is described as:
diffuse demyelination following a occiptal to frontal progression seen as palor of WM, with sparing of subcortical U fibers
What causes metachromatic leukodystrophy?
accumulation of metachromatic sulfatides and aryl sulfatase A deficiency (of peroxisomes)
What is Krabbes leukodystrophy?
globoid cells: enlarged M@ with galactosylphyngosine within WM of perivascular spaces
Alexander’s disease is described aS:
inherited metabolic disease with a mutation of GFAP gene, follwing an autosomal dominant inheritance
What is the histological findings of Alexander’s disease?
rosenthal fibers around WM blood vessels
What are rosenthal fibers?
densely compact glial Intermediate filaments, they are common in many disorders thus not exclusive of Alexander’s
