The letters PCOS stand for "polycystic ovary syndrome." As you probably know, an ovary is the organ in a woman's body that produces eggs as well as hormones such as estrogen. (Each woman has a pair of ovaries.) If an ovary is "polycystic" (POL-e-SIS-tic), it contains many small sacs (cysts), each measuring 2 to 8 millimeters across. These actually are immature follicles, the bubble-like structures that release egg cells when they mature. The doctor can see them without performing surgery by using ultrasound to examine the ovary—the same kind of ultrasound that's used to look at babies before they're born.

The usual definition of a polycystic ovary (PCO) is one that contains at least 10 of these cysts. The ovary also is generally larger than normal.

The polycystic ovary syndrome (PCOS) refers to a group of signs and symptoms that sometimes occur in women who have polycystic ovaries. Not all women with polycystic ovaries have PCOS.

What are the symptoms of PCOS?

Women with PCOS can experience many different symptoms, as well as other abnormalities that can only be detected by laboratory tests. Some of the same symptoms also occur in other disorders, so testing may be needed to identify PCOS with certainty.

Menstrual cycle disorders are the most typical symptoms of PCOS. Periods may be irregular, may be unusually far apart or close together, may be scanty or heavy, or may not occur at all. All these things can happen because ovulation (release of an egg) does not occur. This condition is called anovulation (AN-ov-u-LAY-shun). Pregnancy is impossible if no egg is released.

Another typical symptom of PCOS is excessive growth of hair on the body or face, called hirsutism. This condition will be more apparent in certain ethnic groups than in others.

The menstrual disorders and hirsutism of PCOS are related to high levels of male hormones (testosterone and others) in the blood. A woman's ovaries normally produce only small amounts of these hormones. Abnormal levels of certain female reproductive hormones may also be found.

Other symptoms that are sometimes reported in women with PCOS include acne and other skin problems, hair loss, and obesity. Doctors disagree about the relationship of these to PCOS. High blood levels of insulin and triglycerides (a type of fat), increased risk of diabetes, hardening of the arteries, and high blood pressure also are often associated with PCOS, but they are not necessarily present in every case.

Is PCOS related to epilepsy?

The percentage of women reported to have PCOS varies widely because different researchers have used different definitions of the syndrome and have studied different groups. Estimates range from as low as 3-4% to as high as 18-19% of all women.

Studies of women with epilepsy have suggested that PCOS occurs in 13% to 25%, depending on the definition used and on characteristics such as the type of epilepsy and the kinds of seizure medicines used by the women studied. It does appear that PCOS occurs significantly more often in women with epilepsy than in others, especially among certain groups. Studies using much larger groups will be needed for doctors to find out the details of how PCOS is related to the many types of epilepsy and seizure medicines.

One explanation for the connection between PCOS and epilepsy is that women whose seizures begin in the left temporal lobe may be more likely to have certain hormonal abnormalities that prevent the follicles in the ovary from maturing. This leads to anovulation, the collection of cysts, and the release of more male hormones—all the criteria for a diagnosis of PCOS.

PCOS has another link to epilepsy: it may increase or worsen seizures. The hormonal abnormalities related to anovulation include a lack of progesterone, which the ovaries usually produce in the days after ovulation. Progesterone has antiseizure and mood-stabilizing properties. The ovaries of women with PCOS, on the other hand, continue to produce estrogen, which promotes seizures and anxiety.

Is PCOS related to seizure medicines?

Some (but not all) studies of women with epilepsy have found that PCOS is more common in those who have been taking Depakote (valproate) than in those taking some other seizure medicines. Teenagers who take Depakote may be at the highest risk.

A possible explanation for the effect of Depakote is that it is one of the few seizure medicines that are not "enzyme-inducing." Enzyme-inducing medications promote the liver's production of substances that lower blood levels of the male hormones involved in PCOS. In effect, enzyme-inducing seizure medicines like Tegretol/Carbatrol (carbamazepine) or Dilantin/Phenytek (phenytoin) treat PCOS but Depakote does not. Lamictal (lamotrigine) is another seizure medicine that has been found to reverse the features of PCOS.

Depakote also promotes weight gain, which is associated with higher levels of insulin and of active male hormones, both factors linked to PCOS.

What should I do about it?

Much larger studies are needed before we can be certain about the interactions between various types of epilepsy, seizure medicines, and problems like PCOS. Until those studies are completed, women and their doctors should watch closely for problems of this kind and treat them as needed. Blood tests to monitor hormone levels may be appropriate.

Decisions about seizure medicines should be based mainly on the type of epilepsy and other factors, but the possibility of PCOS is one thing to consider, particularly for teenagers, women who are considering pregnancy, and those experiencing large weight gains. Weight loss and exercise have been found to help eliminate PCOS in some women.

Look for more information at PubMed, a service of the National Library of Medicine: www.ncbi.nlm.nih.gov/pubmed.

Here are links to a few articles relevant to this subject:

• Genton P, Bauer J, Duncan S, et al. On the association between valproate and polycystic ovary syndrome. Epilepsia 42(3):295-304, 2001. PMID: 11442143.
• Isojärvi JIT, Taubøll E, Tapanainen JS: On the association between valproate and polycystic ovary syndrome: A response and an alternative view. Epilepsia 42(3):295-304, 2001. PMID: 11442144.
• Herzog A and Schachter SC. Valproate and polycystic ovarian syndrome: Final thoughts. Epilepsia 42(3):311-315, 2001. PMID: 11442145.
• Betts T, Dutton N, Yarrow H. Epilepsy and the ovary (cutting out the hysteria). Seizure 11 Suppl A:220-228, 2002. PMID 12185760.
• Herzog AG, Seibel MM, Schomer DL. Reproductive endocrine disorders in women with partial seizures of temporal lobe origin. Arch Neurol 43(4):341-346, 1986. PMID: 2937394.

Topic Editor: Steven C. Schachter, M.D.
Last Reviewed: 12/22/06