What are the common signs and symptoms of multiple sclerosis (MS)?

Multiple Sclerosis Signs and Symptoms

Core Clinical Presentations

Multiple sclerosis typically presents in young adults aged 20-30 years with optic neuritis, partial myelitis, sensory disturbances, or brainstem syndromes developing over hours to days. 1, 2

Common Neurological Manifestations

• Optic neuritis is a frequent presenting symptom, characterized by unilateral vision loss, eye pain with movement, and color desaturation 1, 2
• Sensory disturbances including numbness, tingling, or burning sensations in limbs or trunk are common initial symptoms 1, 3
• Motor symptoms manifest as limb weakness, spasticity, and difficulty with coordination 1
• Brainstem syndromes such as internuclear ophthalmoplegia (diplopia with impaired adduction) and other cranial nerve palsies occur frequently 1, 2
• Myelopathy presents with partial spinal cord dysfunction, including weakness, sensory level changes, and sphincter disturbances 1
• Balance and gait dysfunction including ataxia and vertigo are characteristic symptoms 1

"Invisible" Symptoms

• Fatigue is highly prevalent and represents one of the most disabling symptoms despite not being externally visible 4
• Cognitive impairments including problems with memory, attention, processing speed, and executive function affect quality of life significantly 4
• Mood disorders such as depression and anxiety are common and multifactorial in origin 4
• Bladder and bowel dysfunction including urgency, frequency, incontinence, and constipation occur frequently 4
• Sexual dysfunction affects many patients but is often underreported 4
• Pain syndromes including neuropathic pain and musculoskeletal pain are prevalent 4
• Vision changes beyond acute optic neuritis, including subtle visual processing deficits 4

Temporal Pattern of Symptoms

• True relapses last at least 24 hours and represent new inflammatory demyelinating activity, typically developing over hours to days 1
• Symptoms typically stabilize after the acute phase and often resolve spontaneously, though residual deficits may persist 1
• Uhthoff's phenomenon (worsening of symptoms with increased body temperature) is characteristic but does not represent a true relapse 3

Disease Course Patterns

Relapsing-Remitting MS (RRMS)

• Affects approximately 85% of patients at disease onset 1, 5, 3
• Characterized by acute inflammatory episodes (relapses) followed by periods of remission with stable neurological function 1
• Nerve conduction is affected during acute phases but tends to improve during remission periods 1
• Cumulative myelin damage occurs over time with progressive neuronal loss despite remissions 1

Primary Progressive MS (PPMS)

• Affects approximately 15% of patients at disease onset 1, 5
• Presents with steadily increasing neurological disability from onset without distinct relapses or remissions 1
• Progressive neurological damage rather than episodic inflammation characterizes the pathogenesis 6

Red Flag Symptoms Suggesting Alternative Diagnoses

Atypical Temporal Patterns

• Subacute onset over weeks rather than hours to days should raise concern for non-MS diagnoses 1
• Progressive evolution without stabilization is atypical for typical MS relapses 1
• Bilateral sudden hearing loss is extremely rare in MS and suggests alternative pathology 1

Atypical Neurological Features

• Dementia, epilepsy, or aphasia as presenting features are uncommon in MS and warrant investigation for alternatives 1
• Isolated cranial nerve involvement is rare in MS (10.4%), and isolated eighth nerve palsy is extremely rare (<1%) 7
• Concurrent severe bilateral vestibular loss should prompt consideration of other diagnoses 7

Nutritional and Systemic Manifestations

• Weight loss and malnutrition are well-recognized features in MS patients 6
• Reduced mobility and fatigue contribute to nutritional decline 6
• Dysphagia can develop and contribute to malnutrition risk 6
• Physical difficulty with eating or drinking may occur due to motor impairment 6
• Poor appetite and reduced cognition can affect nutritional intake 6

Important Clinical Pitfalls

• Paroxysmal symptoms occurring multiple times over 24 hours count as a single attack, not multiple relapses 7
• Subjective symptoms alone without objective neurological findings are insufficient for diagnosis 1
• Symptoms must be separated by at least 30 days from onset to onset to qualify as separate attacks 7
• Gaze-evoked or downbeat nystagmus suggests non-MS pathology and warrants further investigation 7