Premenstrual multiple sclerosis pseudoexacerbations: Role of body temperature and prevention with aspirin

Background: Many women with multiple sclerosis (MS) experience transient neurologic symptom worsening and fatigue in conjunction with the menstrual cycle. Aspirin reduces MS fatigue in some patients. Objective: To describe 3 women with MS who experienced stereotypic, temperature-independent neurologic symptoms and diurnal fatigue in the mid-to-late luteal phase of the menstrual cycle. Aspirin treatment prevented the symptoms. Design and Setting: Case series at the Mayo Clinic outpatient MS clinics, Scottsdale, Ariz, and Rochester, Minn. Patients: Three women with relapsing-remitting MS. Interventions: Body temperature measurement, symptom diary, and oral aspirin. Main Outcome Measures: Body temperature, Modified Fatigue Impact Scale, and evaluation of neurologic symptoms and signs. Results: Morning oral body temperature did not differ during symptomatic vs asymptomatic portions of the luteal phase (P= .55). Aspirin (650 mg twice daily) prevented symptoms but did not significantly alter the luteal phase body temperature. Conclusions: Aspirin prophylaxis may prevent luteal phase-associated MS pseudoexacerbations. However, the observed relationship between the luteal menstrual phase and MS symptom worsening is not fully explained by thermoregulation, which implicates other hormonal or immunologic mechanisms.