Acute relapses of multiple sclerosis

Mild relapses (eg tingling in the extremities) can occur in multiple sclerosis (MS). If the patient has no signs of disability (eg no objective neurological signs, no increase in urinary symptoms or bowel dysfunction), reassure the patient and monitor to ensure resolution. Refer for expert advice if unsure whether the relapse is mild.

Moderate to severe acute relapses of MS usually have objective neurological signs, and are treated with corticosteroids. Therapy hastens recovery from the relapse and improves clinical outcomes in the short term, and may also prevent neuronal loss and improve outcomes in the longer term. A minority of relapses cause permanent disability, so it is important to recognise and treat relapses.

When a patient with MS presents with symptoms that suggest a relapse, the clinician needs to determine whether these are due to:

• an inflammatory lesion of the central nervous system (CNS), and corticosteroid therapy is justified
• other conditions that mimic a relapse, and corticosteroid therapy is inappropriate.

Diagnosing a relapse in patients with significant disability can be difficult—refer for expert advice if unsure.

Any MS symptom can occur as part of a relapse. However, transient symptoms which last for minutes to hours and then resolve, are less likely to be due to a relapse—these are often associated with fatigue, sleep deprivation, stress or increased body temperature (eg during exercise). Also, chronic symptoms are less likely to be due to a relapse. Longstanding symptoms can be exacerbated by fever, illness and metabolic disturbance.

If the symptoms are short-lived (eg Lhermitte phenomenon recurs) but an acute inflammatory lesion is a concern, magnetic resonance imaging with gadolinium contrast is useful.

Treatment for moderate to severe relapses of MS is high-dose corticosteroids—intravenous therapy is preferred. Oral formulations¹ have slightly more adverse effects (eg insomnia) but are convenient when intravenous therapy is not available (eg in rural settings). Intravenous formulations can be given as a day-patient, but severe relapses warrant admission for multidisciplinary care. For moderate to severe relapses of MS in a child, seek expert advice. For moderate to severe relapses in an adult, an appropriate dosage is:

If the patient with a moderate to severe relapse of MS deteriorates despite corticosteroid treatment, refer for expert advice.