Polycystic ovarian syndrome--relationship to epilepsy and antiepileptic drug therapy

Research Progress on the Effect of Epilepsy and Antiseizure Medications on PCOS Through HPO Axis

Epilepsy is a common chronic neurological disease that manifests as recurrent seizures. The incidence and prevalence of epilepsy in women are slightly lower than those in men. Polycystic ovary syndrome (PCOS), a reproductive endocrine system disease, is a complication that women with epilepsy are susceptible to, and its total prevalence is 8%-13% in the female population and sometimes as high as 26% in female epilepsy patients. The rate of PCOS increased markedly in female patients who chose valproate (VPA), to 1.95 times higher than that of other drugs. In addition, patients receiving other anti-seizure medications (ASMs), such as lamotrigine (LTG), oxcarbazepine (OXC), and carbamazepine (CBZ), also have reproductive endocrine abnormalities. Some scholars believe that the increase in incidence is related not only to epilepsy itself but also to ASMs. Epileptiform discharges can affect the activity of the pulse generator and then interfere with the reproductive endocrine system by breaking the balance of the hypothalamic-pituitary-ovarian (HPO) axis. ASMs may also cause PCOS-like disorders of the reproductive endocrine system through the HPO axis. Moreover, other factors such as hormone metabolism and related signalling pathways also play a role in it.

The Role of the Brain in the Pathogenesis and Physiology of Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disorder, affecting at least 10% of women of reproductive age. PCOS is typically characterized by the presence of at least two of the three cardinal features of hyperandrogenemia (high circulating androgen levels), oligo- or anovulation, and cystic ovaries. Hyperandrogenemia increases the severity of the condition and is driven by increased luteinizing hormone (LH) pulse secretion from the pituitary. Indeed, PCOS women display both elevated mean LH levels, as well as an elevated frequency of LH pulsatile secretion. The abnormally high LH pulse frequency, reflective of a hyperactive gonadotropin-releasing hormone (GnRH) neural circuit, suggests a neuroendocrine basis to either the etiology or phenotype of PCOS. Several studies in preclinical animal models of PCOS have demonstrated alterations in GnRH neurons and their upstream afferent neuronal circuits. Some rodent PCOS models have demonstrated an increase in GnRH neuron activity that correlates with an increase in stimulatory GABAergic innervation and postsynaptic currents onto GnRH neurons. Additional studies have identified robust increases in hypothalamic levels of kisspeptin, another potent stimulator of GnRH neurons. This review outlines the different brain and neuroendocrine changes in the reproductive axis observed in PCOS animal models, discusses how they might contribute to either the etiology or adult phenotype of PCOS, and considers parallel findings in PCOS women.

Women with epilepsy and infertility have different reproductive hormone profile than others

Purpose:

One-third of women with epilepsy (WWE) may experience infertility (failure to conceive after 12 months of regular unprotected intercourse). We aimed to compare the hormone profile of WWE and infertility (WWE-I) with that of WWE who had conceived earlier (WWE-F).

Materials and Methods:

In the Kerala Registry of Epilepsy and Pregnancy, we compared the clinical and hormone profile of 50 WWE-I and 40 age-matched WWE-F. Subjects were examined and blood samples were drawn in follicular phase (1-14 days) for 21 WWE-I and 18 WWE-F, in luteal phase (15-30 days) for 23 WWE-I and 15 WWE-F and beyond 30 days for 6 WWE-I and WWE-F who had irregular cycles.

Results:

The two groups were comparable regarding physical, epilepsy syndrome, duration of epilepsy, body mass index, and serum cholesterol levels. Menstrual periods were irregular for 6 WWE-I and 5 WWE-F. The WWE-I group (compared to the WWE-F group) had significantly (P < 0.01) higher levels of dehydroepiandrostenedione (2.0 ± 1.7 ug/mL vs. 1.0 ± 0.7 ug/mL) and luteinizing hormone-LH (26.4 ± 37.3 mIU/mL vs. 9.9 ± 14.5 mIU/mL) and lower levels of progesterone (5.2 ± 9.2 ng/mL vs. 10.4 ± 13.4 ng/mL). There was no significant difference in the levels of FT3, FT4, thyroid stimulating hormone, prolactin, follicle-stimulating hormone (FSH), progesterone, testosterone, or androstenedione levels. The WWE-I had 8.5 times higher risk (95% confidence interval 1.2-59.9) of abnormal LH/FSH ratio. WWE who were on antiepileptic drugs (AEDs) (compared to WWE who were not on AEDs) had higher risk of elevated LH/FSH ratio.

Conclusion:

The hormone profile of WWE-I is significantly different from that of WWE-F. These variations need to be interpreted with caution as a causal relationship to epilepsy or use of antiepileptic drugs need to be established through further studies.

Obesity, polycystic ovarian syndrome and thyroid dysfunction in women with epilepsy

Introduction:

Women with epilepsy (WWE) have an increased risk for several endocrine disorders. Obesity and Polycystic Ovarian Syndrome (PCOS) are common side-effects of anticonvulsant drugs.

Aim:

To study the prevalence of Obesity, PCOS, Thyroid dysfunction in WWE on monotherapy with Carbamazepine (CBZ), Sodium Valproate (VAL) and Phenytoin (DPH)

Material and Methods:

Sixty WWE in the reproductive age group (13 – 45 yr) who are on atleast 6 months of monotherapy with either CBZ (20) or VAL (20) or DPH (20) are subjects of the study. Their Anthropometric data is recorded. They are interviewed and investigated for PCOS and thyroid dysfunction. Twenty healthy women in the reproductive age group served as controls. BMI>25 is taken as cut-off for Obesity. PCOS is defined as menstrual irregularity and/or clinical /biochemical hyperandrogenism with ultrasound evidence of PCO as per the Rotterdam criteria. TSH <0.1 and >4 is taken as evidence of thyroid dysfunction. Women are grouped according to the anticonvulsant drug received and the data analyzed in each group.

Results:

The mean BMI among VAL and CBZ users is significantly higher than among DPH users (23.3 & 23.4 vs 20.4). There is no significant difference in incidence of PCOS among WWE using either DPH or VAL or CBZ. Elevated TSH>4 is seen more often in WWE on VAL (9/20) compared to CBZ (6/20) and DPH (3/20). WWE on CBZ, VAL and DPH did not differ in mean BMI, Obesity, PCOS compared to healthy controls. As compared to healthy controls, more WWE on drug therapy had significantly elevated TSH (1/20 vs20/60).

Conclusions:

WWE on VAL and CBZ had significant weight gain compared to DPH users. Despite weight gain, there was no difference in the incidence of PCOS between the users of VAL, CBZ and DPH. As compared to healthy controls, more WWE on drug therapy had significantly elevated TSH, more so in the VAL group.

Menstrual cycle dysfunction associated with neurologic and psychiatric disorders: their treatment in adolescents

Epilepsy, bipolar disorder, and migraines are common disorders that are often associated with disturbances in menstrual function in adolescent girls. Women with untreated epilepsy are more likely to have irregular menstrual cycles than are nonepileptic controls, indicating that the disease itself plays a role in the etiology of these reproductive abnormalities. In addition, many girls with these disorders require chronic maintenance treatment with agents that may perturb the hypothalamic-pituitary-ovarian axis. Valproate is a highly effective antiepileptic drug used widely to treat epilepsy, bipolar disorder, and migraines. Valproate induces features of the polycystic ovary syndrome (PCOS) in approximately 7% of women. Girls with epilepsy, and possibly bipolar disorder, appear particularly susceptible to developing PCOS features on valproate, perhaps on account of the relative immaturity of their hypothalamic-pituitary-ovarian axes. Antipsychotics are highly effective drugs used widely to treat adolescents with bipolar disorder, psychotic disorders, and behavioral disturbances. Some, but not all of the antipsychotic, induce hyperprolactinemia, which may result in oligo- or amenorrhea. Prolonged amenorrhea in association with hyperprolactinemia incurs significant risks for bone health in adolescent girls. Because of the potential reproductive health risks associated with use of specific antiepileptic drugs and selective antipsychotics, these agents are vital treatments for adolescents with severe illnesses. Use of these agents should be considered and weighed against the risk of using alternative agents, which have their own side effects, or not treating these serious neurologic and psychiatric disorders.

Polycystic ovary syndrome in adolescence

Polycystic ovary syndrome (PCOS) is a syndrome of variable combinations of menstrual irregularity, hirsutism or acne, and obesity. It can be diagnosed in adolescence and has early childhood antecedents. PCOS is the single most common endocrine cause of an ovulatory infertility and a major risk factor for the metabolic syndrome and, in turn, development of type 2 diabetes mellitus in women. Thus, it appears that PCOS increases a woman's risk of developing cardiovascular disease. Therefore, identifying girls at risk for PCOS and implementing treatment early in the development of PCOS may be an effective means of preventing some of the long-term complications associated with this syndrome. This article reviews the definition, clinical features, diagnosis, and treatment of PCOS.

Polycystic ovary syndrome and epilepsy: a review of the evidence

Overrepresentation of polycystic ovary syndrome (PCOS) in women with epilepsy has been described since the early 1980s. While some authors attribute this association to an effect of the seizure disorder on the hypothalamic control of reproductive function, others have reported a relationship with the use of the antiepileptic drug valproic acid (VPA). In this article we review the literature on this complex issue, with a detailed analysis of the different reports which describe the reproductive endocrine assessment in women with epilepsy. In spite of the large number of patients assessed, a clear picture does not emerge, mostly because of the wide variability of methodology employed in the different study projects and of the small size of many patient samples especially when divided in subgroups. However, on the whole these studies suggest that women with epilepsy are at risk for developing reproductive endocrine disorders, even if there is not yet definite evidence that PCOS may be over-represented in these patients nor that VPA may be the cause of endocrine problems. It is likely that both the epileptic disorder and the antiepileptic treatment play different roles in the development of such disturbances. This hypothesis deserves further prospective study in large samples of patients; consistency in methodology, diagnostic criteria and presentation of results should always be encouraged in the researchers dealing with these projects. In the meantime, women with epilepsy should be carefully monitored with regard to menstrual function, bodyweight and hyperandrogenism, and evaluation of these parameters should become part of the routine evaluation in baseline and follow-up consultations.