Multiple Sclerosis

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management

Definition

Multiple sclerosis (MS) is a chronic autoimmune demyelinating disease of the central nervous system (CNS), characterised by inflammation, demyelination, and neurodegeneration. It results in episodic or progressive neurological dysfunction.

Aetiology

  • Autoimmune attack on myelin sheath and oligodendrocytes.
  • Possible environmental and genetic factors contributing.
  • Viral triggers such as Epstein-Barr virus (EBV) are implicated.

Pathophysiology

  • Immune mediated attack on the CNS leads to demyelination.
  • Formation of plaques (sclerotic lesions) in the brain and spinal cord.
  • Neuroaxonal degeneration results in irreversible disability.
  • Relapses occur due to inflammatory attacks on myelin, leading to remissions or progressive decline.

Risk factors

  • Female sex (3:1 ratio compared to males).
  • Age 20–40 years.
  • Family history of MS.
  • Low vitamin D levels.
  • Previous Epstein Barr virus (EBV) infection.
  • Smoking.
  • Geographic location (higher prevalence in northern latitudes).

Signs and symptoms

Neurological Symptoms:

  • Optic neuritis: painful monocular vision loss.
  • Uhthoff’s phenomenon: symptoms worsen with heat.
  • Internuclear ophthalmoplegia: impaired adduction of the affected eye.
  • Lhermitte’s sign: electric shock sensation down the spine when neck is flexed.
  • Fatigue: one of the most disabling symptoms.
  • Spasticity: stiffness and muscle tightness.
  • Sensory disturbances: paraesthesia, numbness, dysaesthesia.

Autonomic Symptoms:

  • Bladder dysfunction (urgency, incontinence).
  • Bowel dysfunction (constipation, incontinence).
  • Sexual dysfunction.

Cognitive and Psychiatric Symptoms:

  • Memory impairment.
  • Difficulty concentrating.
  • Depression and anxiety.

Investigations

  • MRI Brain and Spine:
    • Reveals white matter lesions (periventricular, juxtacortical, infratentorial, spinal).
    • Enhancing lesions on contrast indicate active disease.
  • Lumbar puncture:
    • Oligoclonal bands in cerebrospinal fluid (CSF) suggest MS.
  • Evoked potentials:
    • Delayed visual evoked potentials (VEPs) indicate optic nerve involvement.
  • Blood tests:
    • Rule out differential diagnoses (e.g., vitamin B12 deficiency, vasculitis, HIV, Lyme disease).

Management (refer patient to neurology)

1. Disease-Modifying Therapy (DMT):

  • Interferon beta, glatiramer acetate, natalizumab, ocrelizumab, fingolimod and dimethyl fumarate.

2. Acute Relapse Management:

  • High-dose corticosteroids (e.g., methylprednisolone 1g IV for 3–5 days).
  • Plasma exchange if severe relapse not responding to steroids.

3. Symptomatic Management:

Spasticity:
  • Baclofen or gabapentin.
Pain:
  • Amitriptyline, gabapentin, or pregabalin.
Bladder Dysfunction:
  • Anticholinergics for urgency.
  • Intermittent catheterisation for retention.

4. Rehabilitation and Supportive Care:

  • Physiotherapy for mobility.
  • Occupational therapy for daily living assistance.
  • Psychological support for depression and cognitive issues.
NeurologymypanotesMultiple Sclerosis