What an Active MS Flare Feels Like
An active MS flare (relapse or exacerbation) typically manifests as new or worsening neurological symptoms that develop over hours to days, persist for at least 24 hours, occur in the absence of fever or infection, and reflect inflammatory demyelination in the central nervous system. 1, 2
Common Sensory Symptoms
- Numbness and tingling are among the most frequently reported symptoms during an MS flare, often affecting the limbs, face, or trunk in a patchy distribution 1, 3
- Lhermitte sign - an electric shock-like sensation running down the spine into the limbs when bending the neck forward - is a characteristic symptom of MS relapses 1, 4
- Sensory disturbances can include altered sensation to touch, temperature, or pain, and may occur in various body regions depending on lesion location 2, 4
Motor and Coordination Problems
- Motor weakness affecting one or more limbs is a common manifestation, ranging from mild heaviness to complete paralysis depending on severity 1, 2
- Impaired coordination and balance problems frequently occur together, making walking and fine motor tasks difficult 3, 4
- Leg weakness specifically is one of the five most commonly reported symptoms during active disease 3
- Gait impairment often results from a combination of weakness, incoordination, and sensory deficits 2, 4
Visual Symptoms
- Optic neuritis presents as vision loss, typically in one eye, often accompanied by pain with eye movement 1, 2
- Vision problems during flares can range from blurred vision to complete blindness in the affected eye 4
Other Characteristic Symptoms
- Fatigue is one of the most common and disabling symptoms, though it can be difficult to distinguish whether it represents true relapse activity or ongoing MS-related fatigue 3, 5
- Heat intolerance frequently accompanies active disease, with symptoms worsening in warm environments or with fever 3, 2
- Bladder dysfunction including urgency, frequency, or retention may develop or worsen during a flare 1, 4
Important Clinical Distinctions
A true MS relapse must be distinguished from a "pseudo-relapse," which represents temporary worsening of pre-existing symptoms triggered by fever, infection, heat exposure, or other stressors rather than new inflammatory activity 6, 2. Pseudo-relapses resolve once the triggering factor is addressed and do not require corticosteroid treatment.
Symptoms must persist for at least 24 hours to be considered a true relapse, as transient neurological symptoms lasting only minutes to hours are common in MS but do not represent active inflammatory disease requiring treatment 2
Symptom Co-occurrence Patterns
Research has identified that MS symptoms tend to cluster together rather than occurring in isolation 3:
- Urinary symptoms often co-occur with other autonomic dysfunction
- Balance problems frequently appear alongside vision and heat-related symptoms
- Depression and sleep disturbances commonly occur together 3
Treatment Implications
Corticosteroids are the treatment of choice for acute, significant MS relapses that cause functional impairment 1, 4. However, not all relapses require treatment - mild sensory symptoms that do not impair function may be observed without intervention 4.
Patients who do not adequately respond to corticosteroids may benefit from plasmapheresis as a second-line therapy for severe, treatment-refractory relapses 4