Multple Sclerosis

Question 1

What is it

Answer 1

A chronic autoimmune demyelinating disease of the central nervous system (CNS), leading to progressive neurological dysfunction.

Question 2

Clinical Presentation

Answer 2

Relapsing-remitting (most common) → Episodes of symptoms followed by partial or full recovery.

Primary progressive → Gradual worsening without relapses.

Secondary progressive → Initial relapsing-remitting course that transitions to steady decline.

Question 3

Epidemiology

Answer 3

More common in women (3:1 ratio).
Higher prevalence in temperate climates (Europe, North America).

Question 4

Age Groups Affected

Answer 4

Peak onset: 20–40 years old

Question 5

Risk Factors

Answer 5

Genetic: HLA-DR2 association.
Environmental: Low vitamin D, smoking, Epstein-Barr virus (EBV) infection.
Geographical: More common in higher latitudes (farther from the equator).

Question 6

Clinical Features

Answer 6

Motor Symptoms → Weakness, spasticity.
Sensory Symptoms → Numbness, tingling, Lhermitte’s sign (electric shock-like sensation down spine).
Optic Neuritis → Painful vision loss, decreased color vision.
Internuclear Ophthalmoplegia (INO) → Impaired eye movement due to MLF lesion.
Cerebellar Dysfunction → Ataxia, intention tremor, dysarthria.
Bladder Dysfunction → Urge incontinence.
Cognitive Changes → Memory and attention deficits.
Fatigue → One of the most common symptoms.

Question 7

Prognosis

Answer 7

Highly variable:
Relapsing-remitting → Better prognosis, but may progress.
Primary progressive → Worse prognosis.
Factors for poor prognosis:
Male, older age at onset, motor/cerebellar symptoms at first episode.