A chronic inflammatory dz of CNS characterized by relapsing remitting, or progressive neurologic symptoms due to inflammation, demyelination and axonal degeneration
Clinical features
- 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
- Primary progressive (PPMS) 10%
- poor prognosis, higer rates of disability, poor response to therapy
- Progressive relapsing (PRMS) 5%
- Secondary progressive (SPMS)
- 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
- Dissemination in time: ≥ 2 attacks, new gadolinium enhancing lesion 3 mo later, or new T2 lesions >1 mo after first attack
- 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
- Acute Tx: methylprednisolone 1g IV daily x 3-7 days – plasma exchange if poor response
- 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
- Education & counseling: MS society, support groups, psychosocial issues
- 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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