What multiple sclerosis is
Multiple sclerosis (MS) is a chronic, immune-mediated disease of the central nervous system in which the body's immune system attacks myelin — the insulating sheath surrounding nerve fibres in the brain and spinal cord. This produces inflammation, demyelination and axonal damage, leading to a wide range of neurological symptoms depending on the location of lesions. MS typically presents between ages 20 and 40, with women affected approximately twice as often as men.
The most common initial presentation is a clinically isolated syndrome (CIS) — a single episode of neurological symptoms lasting weeks. Relapsing-remitting MS (RRMS), with clearly defined attacks followed by partial or complete recovery, accounts for approximately 85% of initial diagnoses. Secondary progressive MS (SPMS) and primary progressive MS (PPMS) represent later or alternative disease courses. Accurate classification using the McDonald criteria guides prognosis and treatment decisions.
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Common presentations
MS symptoms depend on lesion location and may include optic neuritis (painful vision loss in one eye), sensory symptoms (numbness, tingling, Lhermitte's sign — electric sensation with neck flexion), motor weakness, balance and coordination problems (cerebellar ataxia), double vision, bladder dysfunction and fatigue. Symptoms may be monophasic or relapsing, and fatigue is among the most disabling and common symptoms regardless of lesion location.
Symptoms are often exacerbated by heat (Uhthoff's phenomenon), infection and stress. Cognitive impairment (slowed processing speed, memory difficulties) affects approximately 40–70% of patients over time. Accurate characterisation of symptom pattern, frequency and triggers during evaluation helps distinguish MS from mimics including neuromyelitis optica spectrum disorder (NMOSD), MOG antibody disease, sarcoidosis and migraine.
- Optic neuritis — painful vision loss in one eye
- Sensory symptoms — numbness, tingling, Lhermitte's sign
- Motor weakness — limb weakness, spasticity
- Cerebellar ataxia — balance and coordination problems
- Bladder dysfunction — urgency, frequency, retention
- Fatigue — often the most disabling symptom
Evaluation and management
Diagnosis requires clinical evidence of CNS lesion dissemination in space and time, supported by MRI showing characteristic T2 hyperintense lesions in periventricular, juxtacortical, infratentorial and spinal cord locations. CSF analysis may show oligoclonal bands; visual evoked potentials assess subclinical optic nerve involvement. Blood tests exclude NMOSD (AQP4-IgG, MOG-IgG) and other mimics.
Disease-modifying therapies (DMTs) reduce relapse frequency and slow disability accumulation in relapsing forms of MS. Options include injectable therapies (interferon beta, glatiramer acetate), oral agents (fingolimod, dimethyl fumarate, teriflunomide) and high-efficacy infusion therapies (natalizumab, ocrelizumab, alemtuzumab). Acute relapses are treated with high-dose corticosteroids. Symptom management addresses fatigue, spasticity, pain, bladder dysfunction and cognitive impairment through rehabilitation, medication and lifestyle strategies. Dr. Jitendra Prasad Yadav (NMC 8029) provides evaluation and long-term management planning at Kathmandu Neurology Clinic & Cognitive Center, Durbar Marg, Opposite of Yak & Yeti Hotel.