Signs and Symptoms of Multiple Sclerosis
Multiple sclerosis typically presents in young adults aged 20-30 years with acute or subacute neurological episodes including optic neuritis, sensory disturbances, motor weakness, diplopia, myelopathy, and balance dysfunction that develop over hours to days, stabilize, and often resolve spontaneously. 1, 2, 3
Common Clinical Presentations
Relapsing-Remitting MS (RRMS) affects approximately 85% of patients at onset and is characterized by acute inflammatory episodes followed by periods of remission. 2 The most frequent presenting symptoms include:
Visual Symptoms
- Optic neuritis is one of the most common initial presentations, typically presenting as unilateral vision loss developing over several days 2, 3
- Patients may experience pain with eye movement 2
- The Pulfrich phenomenon (altered depth perception) can occur 4
Sensory Disturbances
- Numbness and tingling are extremely common presenting symptoms 2, 3, 5
- Lhermitte sign (electric shock sensation down the spine with neck flexion) is a characteristic finding 6, 4
- Sensory symptoms typically develop over hours to days 2
Motor Symptoms
- Weakness affecting limbs, often asymmetric 2, 3
- Gait impairment and incoordination are frequent presentations 2, 3, 5
- Partial myelitis can present with motor and sensory deficits 3
Brainstem and Cerebellar Signs
- Diplopia (double vision) from internuclear ophthalmoplegia or other brainstem involvement 2, 3
- Balance dysfunction and ataxia 2, 3
- Dysarthria (speech difficulties) 1
Bladder and Bowel Dysfunction
- Urinary urgency, frequency, or incontinence commonly occurs 5, 6
- Bladder dysfunction is a frequent symptom throughout the disease course 5
Key Temporal Characteristics
True MS relapses last at least 24 hours and represent new inflammatory demyelinating activity. 2 Symptoms typically:
- Develop over hours to days (not minutes or weeks) 2, 3
- Stabilize after reaching peak severity 2
- Often resolve spontaneously, though residual deficits may persist 2, 5
- Between attacks, patients tend to be stable but may experience fatigue and heat sensitivity 5
Additional Common Symptoms
- Uhthoff phenomenon: worsening of symptoms with heat exposure or exercise 4
- Fatigue: extremely common between relapses 5
- Tonic spasms: brief, stereotyped episodes of limb stiffness or spasms 4
- Cognitive impairment: can affect memory, processing speed, and executive function 3
Demographic Features
MS predominantly affects young to middle-aged adults with peak onset between ages 20-30 years. 3 The disease shows a strong female predominance with a female-to-male ratio of nearly 3:1. 3 The typical diagnostic age range is 10-59 years. 1, 2
Red Flags Suggesting Alternative Diagnoses
Atypical features that should prompt consideration of MS mimics include: 1, 2
- Subacute onset over weeks rather than hours to days 2
- Progressive evolution without stabilization 2
- Dementia, epilepsy, or aphasia as presenting features 2
- Bilateral sudden hearing loss 1, 2
- Extensive leptomeningeal enhancement on MRI 7
- Symptoms developing over minutes (suggests stroke or seizure) 1
Primary Progressive MS (PPMS)
Approximately 15% of patients present with Primary Progressive MS, characterized by steadily increasing neurological disability from onset without distinct relapses. 2 This subtype requires more extensive workup including spinal cord imaging and often CSF analysis. 8
Important Clinical Pearls
The diagnosis requires at least one clinical event consistent with acute demyelination - symptoms alone without objective findings are insufficient. 1, 8 Patients presenting with typical symptoms in the 10-59 age range should undergo immediate brain MRI with gadolinium to assess for dissemination in space and time. 8
Common pitfall: Not all neurological symptoms in MS patients represent new relapses. Transient worsening with heat, infection, or stress (pseudorelapses) should not be confused with true inflammatory activity requiring treatment. 2, 4