Krafts

Question 1

Multiple Sclerosis

Answer 1

“multiple firm plaques” on fresh section

• Most common demyelinating disorder
• F>>M, onset usually before 50
• Autoimmune demyelinating disorder
• Characterized by distinct episodes of neurologic deficits (separated in time)
• Due to white matter lesions (separated in space

Question 2

Pathogenesis of MS

Answer 2

• Immune attack on myelin sheath
• Genetic plus environmental factors
• Linked to HLA-DR2; also linked to some IL-2 and IL-7 receptor polymorphisms
• Disease probably caused by T-cells that react against myelin antigens and secrete cytokines, which tell other cells what to do.
• Do B cells play a role?

Question 3

Active plaques

Answer 3

• Lipid-stuffed macrophages
• T cells cuffing vessels
• Axons preserved

Question 4

Inactive plaques

Answer 4

• No myelin
• Decreased oligodendrocytes
• Gliosis (astrocytes proliferation)
• Decreased number of axons

Question 5

Shadow plaques

Answer 5

Plaque border indistinct; thin myelin sheaths at edges
Remyelination?

Question 6

Central manifestations of MS

Answer 6

• Unilateral visual impairment frequent initial manifestation (optic nerve involvement)
• Cranial nerve signs, ataxia, nystagmus (brainstem involvement)

Question 7

Spinal manifestations of MS

Answer 7

• Motor/sensory impairment of trunk and limbs
• Spasticity
• Problems with voluntary bladder control

Question 8

Most common way for MS to present

Answer 8

optic nerve trouble (vision problems)

Question 9

• Diffuse, monophasic demyelination following a viral infection; usually in children
• Rapid onset headache, lethargy, coma
• Fatal in 10%; rest recover completely
• May be an acute autoimmune reaction against myelin

Answer 9

Acute Disseminated Encephalomyelitis

Across whole CNS

Question 10

• Fulminant (rapid onset) CNS demyelination
• Young adults, children
• Preceded by upper respiratory infection
• Fatal in many patients; significant deficits in survivors
• May be a hyperacute variant of ADEM

Answer 10

Acute Necrotizing Hemorrhagic Encephalomyelitis

Question 11

• Symmetric loss of myelin in basis pontis and part of pontine tegmentum
• Rapid correction of hyponatremia
• Rapidly evolving quadriplegia
• Monophasic disease (so all lesions are at the same stage of myelin loss)

Answer 11

Central Pontine Myelinolysis

caused by correcting a Na+ level too quickly!!!