6.2.3 Myelin Disorders

Question 2

What are the main presentation features of central pontine myelitis?

Answer 2

Rapid quadriplegia, basis pontis lesion

Question 3

What are the two main subtypes of myelin disorders?

Answer 3

Demyelinating disease and leukodystrophies

Question 4

What are some of the unique features of acute hemorrhagic encephalomyelitis (Weston Hurst)?

Answer 4

Question 5

Acquired chronic inflammatory disorder of CNS with distinct episodes of neurological deficits, separated in time, attributable to white matter lesions that are separated in space

Answer 5

Multiple sclerosis

Question 6

What are the diagnostic criteria (main features) of NMO?

Answer 6

Optic Neuritis + Myelitis + NMO-IgG seropositivity

Question 7

Name this condition

Answer 7

Acute hemorrhagic encephalomyelitis

Question 8

What are some of the unique features of acute disseminated encephalomyelitis (ADEM)?

Answer 8

Question 9

What gene is commonly associated with MS in most populations?

Answer 9

HLA-DR15 (a split of DR2)

Does not follow Mendelian genetics

Cytokine-receptor genes have been linked to MS susceptibility (IL2RA, IL7RA)

Question 10

Which cranial nerve is commonly affected by MS and why?

Answer 10

Optic nerve (and chiasm) because the nerve is covered in meninges and still has central myelination

Question 11

Name this condition and its characteristic cell that is being encircled

Answer 11

Neuromyelitis optica; Creutzfeldt cell

Question 12

What are the key features of Krabbe’s?

Answer 12

Lysosomal Disease

Globoid cells

Question 13

What virus is associated progressive multifocal leukoencephalopahty (PML)? What causes someone infected with this virus to progress to PML?

Answer 13

JC Virus; Becoming immunocompromised

Question 14

What are leukodystrophies?

Answer 14

Progressive inherited diseases with abnormal synthesis or turnover of myelin; most are AR in inheritance

Question 15

What are some of the unique characteristics of Acute MS?

Answer 15

Childhood to young adults, rapid progression, relatively unresponsive to steriods

Question 16

What is the pathogenesis of MS?

Answer 16

Question 17

What is being shown in this image?

Answer 17

Inactive MS plaque (no blue due to destruction of myelin, few macrophages surrounding the blood vessels)

Question 18

Where is demyelination confined to in MS?

Answer 18

CNS

Question 19

What is the autoimmune target of neuromyelitis optica (NMO) that distinguishes it from MS?

Answer 19

NMO-Ab towards aquaporin-4

Question 20

What is the typical symptomalogy of PML? What is the typical course and end result?

Answer 20

Progressive visual, motor, dementia, and sensory symptoms

Short course (6-12 months) leading to death

Question 21

Who typically presents with adrenoleukodystrophy? Why?

Answer 21

Young boys; x-linked

Question 22

Name this condition

Answer 22

Adrenoleukodystrophy; black lines pointing at gemistocytic astrocytes

Parieto-occipital white matter preferentially affected

Perivascular CD8 T-lymphocytes

Macrophages, adrenal cortical cells, Schwann, Leydig cells: trilaminar lipid inclusions

Question 23

What is the inheritance of alexander’s dz?

Answer 23

AD due to de novo/mutation in GFAP gene

Question 24

What is shown in the center of this histological image?

Answer 24

Active MS plaque

Neurofilament: indicates the preservation of axons

Macrophages: presence indicates active destruction (active)

Question 25

What is the difference between an active and inactive plaque of MS?

Answer 25

Active plaque: Pink and swollen with presence of macrophages Inactive plaque: inflammation and macrophages have cleared out, lack of myelin

Question 26

Name this condition

Answer 26

Alexander's disease (more rosenthal fibers than any other disease)

Question 27

What are the key features of Metachromtic LD?

Answer 27

Metachromatic material

Question 28

Fill in the classification and key pathologic features of these leukodystrophies

Answer 28

Question 29

How will Alexander's disease present in young children?

Answer 29

Seizures, spasticity, megalencephaly, developmental delay

Question 30

What are the key features of Adreno-LD?

Answer 30

Perivascular inflammation Peroxisomal

Question 31

What is the most common form of MS?

Answer 31

Charcot, chronic relapsing and remitting

Question 32

What are the three arrows pointing at?

Answer 32

Orange: Schwann cell Blue: corpora amylacea body Red: oligodendrocytes

Question 33

What are some potential causes of central pontine myelitis?

Answer 33

Alcoholism, liver transplant, electrolyte imbalances Rapid sodium correction association

Question 34

What gene is associated with adrenoleukodystrophy?

Answer 34

ABCD1 Transporter gene (Xq28)

Question 35

What is being shown in this histo slide?

Answer 35

Transition from central to peripheral myelin

Question 36

What category of diseases: Myelin damage with relative preservation of axons?

Answer 36

Demyelinating disease

Question 37

What is elevated in the CSF of MS?

Answer 37

mild elevation in protein (oligoclonal bands), lymphoctes