What are the signs and symptoms of multiple sclerosis?

Signs and Symptoms of Multiple Sclerosis

Multiple sclerosis (MS) presents with a diverse range of neurological symptoms that reflect damage in different parts of the central nervous system, typically including unilateral optic neuritis, partial myelitis, sensory disturbances, and brainstem syndromes developing over several days. 1, 2

Common Presenting Symptoms

Visual Symptoms

• Optic neuritis (vision loss, eye pain)
• Diplopia (double vision)
• Internuclear ophthalmoplegia
• Visual field defects
• Impaired pupillary light responses 1, 2

Sensory Symptoms

• Numbness and tingling (paresthesia)
• Sensory loss
• Neuropathic pain
• Lhermitte's sign (electric shock sensation down spine with neck flexion) 1, 2, 3

Motor Symptoms

• Weakness (often unilateral)
• Spasticity
• Hyperreflexia
• Clumsiness of limbs
• Gait problems and imbalance 1, 2, 4

Brainstem and Cerebellar Symptoms

• Ataxia
• Dysarthria (slurred speech)
• Dysphagia (difficulty swallowing)
• Vertigo
• Tremors
• Incoordination 1, 3, 4

Bladder, Bowel, and Sexual Dysfunction

• Urinary urgency and retention
• Bowel dysfunction (constipation or incontinence)
• Sexual dysfunction 1, 3

Cognitive and Psychological Symptoms

• Cognitive impairment
• Memory problems
• Difficulty with concentration
• Depression
• Mood changes 1, 2, 3

Other Common Symptoms

• Fatigue (affects up to 90% of patients)
• Heat sensitivity (Uhthoff's phenomenon)
• Exercise intolerance
• Reduced anaerobic threshold 1, 3

Disease Patterns and Progression

MS symptoms typically follow one of several patterns:

1. Relapsing-Remitting MS (RRMS): Discrete episodes of neurological dysfunction followed by periods of stability between attacks 2

2. Secondary Progressive MS: Initially relapsing-remitting course that transitions to steady neurological deterioration with or without superimposed relapses 2

3. Primary Progressive MS: Insidious worsening of neurological function from onset without discrete relapses 2, 5

Complications and Associated Conditions

• Progressive multifocal leukoencephalopathy (rare but serious complication, especially with certain treatments) 6
• Herpes zoster and other opportunistic infections 6
• Lymphopenia (reduced lymphocyte counts) 6
• Autonomic nervous system dysfunction (dysautonomia) 1
• ME/CFS-like syndrome (myalgic encephalomyelitis/chronic fatigue syndrome) 1
• Hypothalamus-pituitary-adrenal axis dysfunction 1
• Increased risk of respiratory infections 1

Key Diagnostic Features

• Symptoms typically develop over days (not minutes or hours as in stroke)
• Neurological signs and symptoms that are disseminated in space (different parts of CNS) and time (occurring at least three months apart) 2, 5
• MRI findings showing multiple focal demyelinating lesions in both cerebral white and grey matter 1
• Presence of cerebrospinal fluid-specific oligoclonal bands 2

Important Considerations

• MS more commonly affects women (female to male ratio of nearly 3:1) 2
• Typically presents in young adults (mean age of onset 20-30 years) 2
• Symptoms may worsen with heat exposure or fever (Uhthoff's phenomenon) 3
• Falls are common (over 50% of MS patients fall at least once yearly) 4
• Early symptoms may be subtle or transient and can be overlooked 5
• Vitamin D deficiency is associated with increased disease activity 1

MS symptoms reflect the location and extent of demyelination and axonal damage in the central nervous system. The hallmark of MS is the dissemination of symptoms in both time and space, meaning different symptoms occur in different parts of the nervous system at different times. Recognizing these patterns is crucial for early diagnosis and treatment.