Demyelinative disorders

Question 1

What components of CNS maintain myelin of axons>

Answer 1

Oligodendrocytes/shwann cells

trophic factors of axons

Question 2

What causes primary demyelination?

Answer 2

axon is spared by myelin undergoes injury

Question 3

What causes secondary demyelintaion?

Answer 3

atrophy/degeneration of axon, leading to myelin degeneration bc stimulus is lost

Question 4

What is the pathological characterization of MS? The clinical characterization?

Answer 4

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

Question 5

How are MS plaques described on gross specimen?

Answer 5

multiple, asymmetric, well circumscribed lesions surrounding white matter

Question 6

What are the histological findings of MS?

Answer 6

early: demyelination, pallow, m@ and perivascular inflammation
late: above and gliosis, progressive worsening of disease

Question 7

The clinical picture of MS is decribed as?

Answer 7

young adults, decreased sensation/focal weakness, visual changes and some ataxia/nystagmus

Typically nonprogressive over time

Question 8

What are the genetic associations of MS?

Answer 8

IL7 and IL2 receptor genes (SNP)

HLA DR2, A3, B7

Question 9

What are the typical lab findings of MS patients?

Answer 9

elevated CSF IgG- oligoclonal

Question 10

What other pathogenesis does MS resemble? What features are similar?

Answer 10

allergic encephalomyelitis

CD4 Th1 T-lymphocytes activates myelin-destructing m@

Question 11

What is tumefactive multiple sclerosis?

Answer 11

Acute inflammatory demyelination mimicking CNS neoplasia

Pt with no hx of MS comes in with acute space occupying lesion

Question 12

A biopsy of the afore mentioned Acute inflammatory MS shoes what on histology?

Answer 12

hypercellular, well-demarcated lesion with abundant foamy M@ and decreased myelin staining and spared axons

Question 13

What is neuromyelitis optica?

Answer 13

Devic’s disease, synchronous bilateral optic neuritis and spinal cord demyelination

Autoantibodies to AQP4 of astrocyte foot processes of BBB

Question 14

What causes acute disseminated encephalomyelitis?

Answer 14

viral infection and post-immunzation

Question 15

What is the histological picture of ADEM MS? Where can it be found?

Answer 15

multi-microfoci perivenous demyelination and inflammation, found in:
cerebrum, brainstem, SC, cerebellum and optic nerves.

Question 16

What is acute necrotizing hemorrhagic leukoencephalopathy? Where are the lesions commonly located?

Answer 16

Post-infectious inflamm demyelination dz, showing perivenous inflammatory necrotizing/hemorrhagic lesions in WM of cerebrum

Question 17

What is PML? What patients do we commonly see this with?

Answer 17

infection demyelination caused by the JC papovavirus of oligodendrocytes leading to coalescing foci of demyelination.

Immunosuppressed patients

Question 18

How is adrenoleukodystrophy characterised?

Answer 18

X-linked peroxisome disease following a parieto-occipital demyelination

Question 19

metachromatic leukodystrophy is described as:

Answer 19

diffuse demyelination following a occiptal to frontal progression seen as palor of WM, with sparing of subcortical U fibers

Question 20

What causes metachromatic leukodystrophy?

Answer 20

accumulation of metachromatic sulfatides and aryl sulfatase A deficiency (of peroxisomes)

Question 21

What is Krabbes leukodystrophy?

Answer 21

globoid cells: enlarged M@ with galactosylphyngosine within WM of perivascular spaces

Question 22

Alexander’s disease is described aS:

Answer 22

inherited metabolic disease with a mutation of GFAP gene, follwing an autosomal dominant inheritance

Question 23

What is the histological findings of Alexander’s disease?

Answer 23

rosenthal fibers around WM blood vessels

Question 24

What are rosenthal fibers?

Answer 24

densely compact glial Intermediate filaments, they are common in many disorders thus not exclusive of Alexander’s