A team of Japanese researchers investigated if the autonomic nervous system (which plays a vital role in equilibrium within the human body), changed during the menstrual cycle. The team measured variations in heart rate and hormone levels and used questionnaires to evaluate physical, emotional and behavioural symptoms of 62 women's menstrual cycles. A control group who experienced little or no PMS was used to compare the results.
The findings of the research discovered that the women with PMS had significantly decreased autonomic and parasympathetic nerve activity in the week before menstruation and the women with the most severe PMS (known as PMDD - premenstrual dysphoric disorder) has the most reduced rates of nerve activity than any women in the PMS or control groups.
The lead researcher, Dr Tamaki Matsumoto from the International Buddhist University in Osaka said, "Our findings indicate that the occurrence of premenstrual symptomatology could be attributable to an altered functioning of the autonomic nervous system in the symptomatic late luteal phase." For women with PMDD, findings indicate that sympathovagal activity was altered even in the follicular phase. Matsumoto asked: "Does this imply that women with lower autonomic function regardless of the menstrual cycle are vulnerable to more severe premenstrual disorders? At the moment, the underlying biomechanisms of PMS remain enigmatic."
PMS happens in the days before menstruation (but can last as much as two weeks or longer, from ovulation until menstruation) and basically most women will experience some form of PMS at some point in their reproductive life.
References
BioMed Central (2007, December 20). Bad PMS May Mean A Depressed Nervous System. ScienceDaily. Retrieved February 2, 2008, from http://www.sciencedaily.com /releases/2007/12/071219202940.htm
