MS – TN 2014

A chronic inflammatory dz of CNS characterized by relapsing remitting, or progressive neurologic symptoms due to inflammation, demyelination and axonal degeneration

Clinical features
  1. Relapsing remitting (RRMS) 85% (0.4-0.6 relapses /yr, highest in the 1st year) – most go on to become SPMS
    • Relapse: acute/subacute onset of clinical dysfunction that peaks from days(>24hr) to weeks, followed by remission with variable symptom resolution
  2. Primary progressive (PPMS) 10%
    • poor prognosis, higer rates of disability, poor response to therapy
  3. Progressive relapsing (PRMS) 5%
  4. Secondary progressive (SPMS)
  5. Onset: 17-35; 3F:1M
Etiology
  • Genetic – polygenetic
  • Environmental:
    • More common in regions with less sun exposure & lower stores of Vit D
    • Linked to certain viruses (EBV)
Dx: Revised McDonald criteria
  1. Dissemination in time: ≥ 2 attacks, new gadolinium enhancing lesion 3 mo later, or new T2 lesions >1 mo after first attack
  2. Dissemination in space: clinical evidence of ≥ 2 lesions
Clinical features: Most symptoms in MS are due to cord, brainstem, and optic nerve lesions
  • Numbness, visual disturbance (optic neuritis), diplopia (INO), weakness, spasticity, impaired gait, vertigo, bladder dysfunction
  • Lhermitte’s sign: flexion of neck causes electric shock sensation down back into limbs (cervical cord lesion)
  • Uhthoff’s phenomenon: worsening of symptoms (classically optic neuritis) in heat
  • SPMS: weakness of legs in pyramidal distribution paired with cerebellar findings of arms (intention tremor)
  • NOT commonly found in MS: visual field defects, aphasia, apraxia, progressive hemiparesis
  • EDSS – Expanded Disability Status Scale – measure disability progression (0-10)
Ix
  • MRI: dymyelinating plaques – hyperdense lesions on T2
  • CSF: oligoclonal bands in 90%, increased IgG [ ]
  • Evoked potential (visual / auditory / somatosensory): delayed but wel-preserved wave forms
Tx
  1. Acute Tx: methylprednisolone 1g IV daily x 3-7 days – plasma exchange if poor response
  2. Disease modifying therapy (DMT)
    • Goals: ↓ relapse rate, progression of disability, slow accumulation of MRI lesions
    • 1st line: interferon-B (early Tx may delay potential second attack)
    • reduce RRMS rate of relapse by ~30%
    • No proven efficacy in PPMS / SPMS
  3. Education & counseling: MS society, support groups, psychosocial issues
  4. Symptomatic Tx
    • Spasticity: baclofen / BZD / botox
    • Bladder dysfunction: oxybutynin
    • Pain: TCA, gabapentin, carbamazepine
    • Fatigue: amantidine, methylphenidate
    • Depression: SSRI / Li
    • Constipation: high fibre, stool softner, laxatives
    • Sexual dysfunction: sildenafil
Good Prognostic indicators:
  • female, young
  • RRMS, presenting with optic neuritis
  • low burden of dz on initial MRI
  • low rate of relapse early in dz

References:
  • TN 2014
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Posted in FM 99 priority topics, Neuro

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