MS

Question 1

Diagnostic Criteria + 3 Diagnostic Tools

Answer 1

Criteria

- At least 2 sep areas of CNS involvement; occur > 1 mo apart or progress over 1 yr
- Must have abnormal near exam
- Must r/o other explanations for neuro findings

Tools

• CT not very useful (MRI much better) - look for white matter lesions (> 5 mm)
• CSF - if inc IgG + might have elevated leukocytes
• Evoked potential tests (picks up deficit but not cause)

Question 2

What 3 conditions are highly suspicious of MS?

Answer 2

• Optic neuritis - unilateral vision loss & pain w/ eye movements (INFLAMMATION)
• Internuclear opthalmoplegia (INO) - de-myelination of MLF (b/n CN IV & III nuc)
• *trouble w/ medial rectus except for convergence
• Partial myelitis - focal de-myelination of SC; associated w/ antibodies against aquaporin 4 in SC

Question 3

Pathogenesis + Histology (acute and chronic)

Answer 3

• Focal inflammation/de-myelination; immune response against CNS myelin
• Histology
  • Where are the lesions? most commonly peri-ventricular lesions or follow post-capillary venues
  • Gliosis; oligodendrocyte loss; can have loss of axons themselves
  • Acute - contrast enhancing lesions
  • Chronic - global or multi-focal atrophy + black holes (axons, myelin and tissue matrix gone)

Question 4

Epidemiology of MS

Answer 4

• Women (75%) > men
• Caucasian most common
• Conc in US, UK, Canada, Australia, NZ
• Mean age of onset = 28
• Factors
  
  • 200+ genes (30% heritability in identical twins)
  • Also environments (tobacco, EBV, lack of vitamin D)

Question 5

5 Tx that Halt Progression

Answer 5

• Interferon-beta - injections; dec T cell proliferation and dec MMPs
• Copaxone (glatiramer acetate) - binds to MHC to compete w/ antigens; also injection
• Natalizumab - antibody against VLA-4 which normally binds VCAM on endothelial cells; given as IV; RISK OF PML if have JC virus
• Alemtuzumab - antibody against CD52 marker on all lymphocytes—> kills them; high risk of VIRAL infections
• Ocrelizumab - only monoclonal antibody approved for primary progressive MS (antibody against CD20 on B cells)

Question 6

How do you treat MS exacerbation?

Answer 6

Corticosteroids or ACTH injections (expensive)

Question 7

Drugs for MS Symptom Management

Answer 7

• Baclofen, stretching, cannabis for spasticity
• Modanifil, amantadine for fatigue
• Anticonvulsants of SNRIs for neuropathic pain
• Bladder - use botulinum or anti-cholingerics/anti-muscarinics if hyperactive/spastics; use alpha agonists or self-cath if problem w/ emptying

Question 8

What makes MS better or worse?

Answer 8

• What makes it worse?
  
  • Heat inc symptoms (Uhtoff’s phenomenon)
  • Infection triggers symptoms/exacerbations
• What makes it better?
  
  • Pregnancy (dec exacerbation rate) - prolactin & estriol
  • May have inc risk of postpartum exacerbations

Question 9

Symptoms

Answer 9

• Exacerbations happen over hours to days and can last 4-12 wks in relapsing-remitting stage
• Sensory = Loss or dec sensation; burning, tingling, tightness (MS hug), Loss of vibration/proprioception&raquo_space; pain/temp b/c dorsal columns more dependent on myelin, Vision problems (blurry or dbl vision or photopsias - flashes of light)
• Motor = Weakness of 1 limb, both legs, half body; Spasticity; Hyperreflexive; pos Babinski; Gait ataxia, tremor, dysmetria
• Brainstem = vertigo, slurred speech, trouble swallowing, nystagmus, facial pain/weakness/numbness
• Cognitive = Depression, anxiety; Fatigue; Lhermitte’s Phenomenon - electric shock w/ neck flexion
• Other = Bladder retention, urgency, incontinence; constipation