Questions and Answers about Hormone Therapy

By Andrew G. Herzog, M.D., M.Sc.
Posted: March 21, 2003

Q: What are hormones?

Hormones exist throughout the plant and animal kingdoms. They are chemical messengers that coordinate systems that are involved in growth, metabolism and reproduction. Reproductive hormones are critical for the development of reproductive organs, and coordinate the timing of functions like ovulation with behaviors like sexual responses.

Q: Why are reproductive hormones important to the brain?

Reproductive hormones play an important role in the growth and maturation of the brain, the development of differences between male and female brains, and differences between the left and right sides of the brain.

Many reproductive hormones can affect the excitability of nerve cells and their effects on the brain and behavior.

Generally, estrogen has neuroexcitatory properties, whereas natural progesterone has metabolites that have powerful neuroinhibitory effects. Reproductive hormone actions on the brain influence energy, mood, attention, memory and language, as well as reproduction.

Q: How do hormones affect seizures and other conditions?

The neuroactive and psychoactive effects of hormones can influence neurological disorders (e.g. epilepsy, migraine) and psychiatric disorders (e.g. depression, anxiety). For example, seizure occurrence in over two-thirds of women with epilepsy varies with different phases of the menstrual cycle.

One-third, in fact, may experience a twofold or greater increase in seizure frequency at certain times of the cycle, for example, 1) around the time of menstruation, 2) before ovulation or 3) throughout the second half of the cycle.

These are usually times when estrogen levels increase, progesterone decreases or estrogen to progesterone level ratios are high.

Modification of hormonal levels with the use of hormone supplements, especially progesterone, may provide benefit for seizure control in some women.

Likewise, changes in hormonal levels may be associated with emotional symptoms such as anxiety and depression, whether it be premenstrually, postpartum (following childbirth), in relation to oral contraceptive pills, or during menopause.

Q: What is the effect of hormone therapy on seizures in menopausal women with epilepsy?

Women with seizure disorders go through menopause earlier than women in the general population. The effects of hormone therapy on seizures, anti-epileptic drug levels, emotions, sleep and bone density in women with seizure disorders is currently under investigation.

Editor's note: the writer is Associate Professor of Neurology at Harvard Medical School and is a member of the Epilepsy Foundation's Professional Advisory Board.