Demyelinating Disorders - Kraft

Question 1

Describe the pathogenesis of MS.

Answer 1

• Immune attack on myelin sheath
• Genetic factors + environmental factors
• Disease probably caused by T-cells that react against myelin antigens and secrete cytokines

Question 2

Do B-cells play a role in the pathogenesis of MS?

Answer 2

Yes, probably some role, because organisms with depleted B-cells usually get MS.

Unknown mechanism.

Question 3

What genetic receptors (human leukocyte antigen/major histocompatibility) is MS linked to?

Answer 3

HLA-DR2

(some IL-2 & IL-7 receptor polymorphism)

Question 4

What shows up when comparing CSF to blood in an MS patient?

Answer 4

Oligoclonal bands in CSF in MS

Question 5

What type of morphology develops on the brain in MS?

Answer 5

Plaques! Lots of them in all different stages.

Usually adjacent to ventricles.

Question 6

What do active plaques look like in the morphology of MS?

Answer 6

• Lipid-stuffed macrophages (from eating myelin)
• T-cells cuffing vessels
• Preserved axons

Question 7

What do inactive plaques look like in the morphology of MS?

Answer 7

• No myelin
• Decreased oligodendrocytes
• Gliocis (increased astrocytes)
• Decreased number of axons

Question 8

What structures do plaques often follow?

Answer 8

Blood vessels

Question 9

What color does myelin appear in a myelin stain of the brain?

Answer 9

Blueish-Purple

(plaques show up pale/pink)

Question 10

In terms of clinical features, what are the central manifestations of MS?

Answer 10

• Unilatearl visual impairment
  
  • frequent initial manifestation
  • optic nerve involvement
• Cranial nerve deficits
• Ataxia
• Nystagmus

Question 11

In terms of clinical features, what are the spinal manifestations of MS?

Answer 11

• Motor/sensory impairment of trunk & limbs
• Spasticity (hyperreflexia)
• Problems with voluntary bladder control

Question 12

What is Acute Disseminated Encephalomyelitis?

Answer 12

Diffuse, monophasic demyelination following a viral infection

(may be an acute autoimmune reaction against myelin)

Question 13

What are the clinical symptoms of Acute Disseminated Encephalomyelitis?

Answer 13

• rapid onset headache
• lethargy
• coma
• usually in children

Question 14

What is the prognosis of Acute Disseminated Encephalomyelitis?

Answer 14

Fatal in 10%,

rest recover completely

Question 15

What is Acute Necrotizing Hemorrhagic Encephalomyelitis?

Answer 15

• Fulminant CNS demyelination (severe & sudden)
• may be hyperacute variant of Acute Disseminated Encephalomyelitis (ADEM)

Question 16

What are the clinical features of Acute Necrotizing Hemorrhagic Encephalomyelitis?

Answer 16

• Young adults, children
• Preceded by URI
• SUPER RARE

Question 17

What is the prognosis of Acute Necrotizing Hemorrhagic Encephalomyelitis?

Answer 17

Fatal in many patients,

significant deficits in survivors

Question 18

What is Central Pontine Myelinolysis?

Answer 18

• Symmetric loss of myelin in basis pontis and part of pontine tegmentum
• Monophasic disease
  
  • all lesions are at the same stage of myelin loss

Question 19

What do we think Central Pontine Myelinolysis is due to?

Answer 19

• Rapid correction of hyponatremia
• Physician error!

Question 20

What are the main symptoms of Central Pontine Myelinolysis?

Answer 20

• Rapidly evolving quadriplegia
• Flaccid paralysis –> Spastic paralysis –> DEATH!

(Patient is usually already very sick and in hospital when this occurs)