Multiple Sclerosis: Causes, Symptoms & Treatment

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (brain and spinal cord) in which the immune system mistakenly attacks myelin -- the protective sheath that covers nerve fibers. This damage (demyelination) disrupts communication between the brain and the rest of the body, causing a wide range of neurological symptoms. Over time, the disease can lead to permanent nerve damage and disability.

MS affects approximately 1 million people in the United States and 2.8 million worldwide. It is typically diagnosed between ages 20 and 40 and affects women about three times more often than men.

• Relapsing-remitting MS (RRMS): Most common form (~85% at diagnosis). Clearly defined relapses (new or worsening symptoms) followed by partial or complete recovery
• Secondary progressive MS (SPMS): Develops after RRMS; steady worsening of disability with or without relapses
• Primary progressive MS (PPMS): ~10-15% of cases. Gradual worsening from onset without distinct relapses
• Clinically isolated syndrome (CIS): First episode of neurological symptoms that may or may not progress to MS

MS symptoms vary greatly depending on which nerves are affected:

• Vision problems: Optic neuritis (pain and vision loss in one eye), double vision, blurred vision
• Numbness and tingling: Often in the face, arms, legs, or trunk
• Muscle weakness and spasticity: Difficulty walking, stiffness
• Fatigue: The most common symptom (affects up to 80% of patients), often debilitating
• Balance and coordination problems: Dizziness, unsteady gait
• Bladder and bowel dysfunction: Urgency, frequency, incontinence, constipation
• Cognitive changes: Memory problems, difficulty concentrating, slowed processing
• Pain: Neuropathic pain, musculoskeletal pain
• Depression and emotional changes: Common; can be both reactive and neurological
• Lhermitte's sign: Electric-shock sensation down the spine when bending the neck
• Heat sensitivity: Symptoms worsen with heat exposure (Uhthoff phenomenon)

• MRI: The most important diagnostic tool -- shows characteristic white matter lesions (plaques) disseminated in space and time
• Lumbar puncture: CSF analysis may show oligoclonal bands (antibodies suggesting immune activity in the CNS)
• Evoked potentials: Measure nerve signal speed (slowed in demyelination)
• Blood tests: To rule out other conditions (lupus, vitamin B12 deficiency, neuromyelitis optica)

Disease-modifying therapies (DMTs) -- reduce relapses and slow progression:

• Injectable: Interferon beta (Avonex, Rebif, Betaseron), glatiramer acetate (Copaxone)
• Oral: Dimethyl fumarate, fingolimod, siponimod, teriflunomide, cladribine
• Infusion: Natalizumab, ocrelizumab (also approved for PPMS), alemtuzumab, ofatumumab
• Early and effective treatment is increasingly emphasized

Acute relapse treatment:

• High-dose intravenous corticosteroids (methylprednisolone 1g daily for 3-5 days)
• Plasma exchange (plasmapheresis) for severe relapses not responding to steroids

Symptom management:

• Fatigue: Amantadine, exercise programs, energy conservation techniques
• Spasticity: Baclofen, tizanidine, physical therapy, stretching
• Pain: Gabapentin, pregabalin, duloxetine, carbamazepine
• Bladder dysfunction: Anticholinergics, intermittent catheterization
• Depression: SSRIs, cognitive behavioral therapy
• Walking difficulty: Dalfampridine, physical therapy, assistive devices

Rehabilitation:

• Physical therapy, occupational therapy, speech therapy
• Regular exercise (shown to improve fitness, fatigue, mood, and quality of life)
• Cognitive rehabilitation

See a neurologist if you experience unexplained numbness or tingling, vision problems (especially pain with eye movement), unusual weakness, balance problems, or persistent fatigue. Early diagnosis and treatment of MS can significantly improve long-term outcomes.