MS is a disease that is more prevalent in premenopausal women than in other groups. While it is not entirely clear what effects hormonal changes have on neurologic symptoms in MS, it has long been observed that certain other disorders such as epilepsy or migraine headaches are worse just before and during the menses.
Many report symptoms worsen within a week of menses
To see if there is, in fact, a correlation between neurologic symptoms in women with MS and the menstrual cycle, researchers at an MS clinic distributed a questionnaire to female patients. Of the 149 women with MS who answered the questionnaire, 70% reported that their MS symptoms seemed to change at a regular time in their cycle. Most of those who reported a change indicated that the change, usually involving a worsening of their symptoms, occurred within one week of onset of menses. Weakness, imbalance, fatigue and depression were the symptoms most frequently reported to worsen. Other self report studies have replicated these data. More recently, MRI studies done in women at different times of the menstrual cycle indicate that disease activity as measured on MRI may vary according to differing hormonal environment.
These findings have all come from small, uncontrolled studies, and much more research is needed to characterize the relationship between MS and the menstrual cycle.
Estrogen replacement may help postmenopausal women
Another study, based on questionnaires completed by 30 women with MS attending an MS meeting in London, England, suggests that hormone replacement therapy (HRT) may have a beneficial effect on women who have already gone through menopause. Among 19 postmenopausal women, 54% reported that their symptoms became worse with menopause and 75% of those who had tried HRT said it had helped reduce their symptoms.
The researchers suggest that the results of the small study support the possibility that the drop in estrogen levels that accompanies menopause may have an adverse effect on the MS disease process. Thus, HRT may have a beneficial effect on MS symptoms. Further research is warranted in this area, particularly given the recent findings from the Women's Health Study that the overall risks of HRT may outweigh the benefits for all women.