Multiple Sclerosis

What is multiple sclerosis?

In MS, the immune system attacks myelin — the insulating sheath around nerve fibres in the central nervous system. This disrupts nerve signal transmission, causing the wide range of neurological symptoms that characterise the condition. Over time, repeated inflammatory attacks can cause scarring (sclerosis) and permanent nerve damage.

MS most commonly develops between the ages of 20 and 50 and is approximately twice as common in women as in men. It is the most common acquired neurological disability in young adults. The cause is not fully understood but involves a combination of genetic susceptibility and environmental factors including vitamin D deficiency and Epstein-Barr virus infection.

Types of MS

• Relapsing-remitting MS (RRMS) — the most common type (85% at diagnosis); distinct episodes of new or worsening symptoms (relapses) followed by partial or complete recovery (remission)
• Secondary progressive MS (SPMS) — many people with RRMS eventually transition to a phase of gradual worsening without distinct relapses
• Primary progressive MS (PPMS) — affects around 10–15% of people; gradual worsening from onset without distinct relapses

Symptoms

MS symptoms are highly variable and depend on which parts of the nervous system are affected:

• Fatigue — the most common and often most disabling symptom
• Visual disturbance — blurred vision, double vision, or optic neuritis (painful vision loss in one eye)
• Weakness, numbness, or tingling in limbs
• Problems with balance, coordination, and walking
• Bladder and bowel dysfunction
• Cognitive difficulties — memory, concentration, and processing speed
• Spasticity — muscle stiffness and spasms
• Pain — neuropathic pain and musculoskeletal pain are common
• Heat sensitivity — symptoms often worsen temporarily in hot weather (Uhthoff's phenomenon)

When to see a doctor

Seek urgent neurological assessment if you develop sudden onset visual loss, new weakness, numbness, or coordination problems. For those already diagnosed, any significant new symptoms or relapse requires prompt medical assessment. Expats who have moved abroad should re-establish neurological care as a priority to ensure disease-modifying therapy is continued without gaps.

Treatment options

Disease-modifying therapies (DMTs)

• Interferons and glatiramer acetate — established injectable DMTs for RRMS
• Oral DMTs — dimethyl fumarate, teriflunomide, siponimod, and ozanimod
• High-efficacy therapies — natalizumab, ocrelizumab, and alemtuzumab for more active disease

Symptomatic treatment

• Corticosteroids — to shorten the duration of acute relapses
• Medication for fatigue, spasticity, bladder dysfunction, and neuropathic pain
• Physiotherapy and rehabilitation — essential for maintaining function and quality of life
• Psychological support — CBT and counselling for the emotional impact of living with MS

How eMedClinic can help

Our neurologists provide MS consultations for both assessment and ongoing management. We are particularly well placed to support people with MS who have recently relocated to Portugal or Spain and need to bridge the gap between their previous neurology team and establishing care locally — including prescription continuations, relapse assessment, and referrals to local MS specialists.