On the association between valproate and polycystic ovary syndrome: a response and an alternative view

Comorbidity of childhood epilepsy

Epilepsy in children is occasionally associated with variable comorbidities although the frequency of such comorbidity is often difficult to determine. They can be divided into three categories: neurological, psychological, and physical comorbidities. The goal of the present review is to discuss the reported comorbidities of epilepsy in children. The possible mechanisms and associated risk factors-including the effect of seizure frequency and seizure control, types of epilepsy, age of seizure onset, duration of illness, and the possible detrimental effect of antiepileptic drugs-will be described.

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.

Antiepileptic drugs, sex hormones, and PCOS

Reproductive endocrine dysfunction in women with epilepsy is an important issue, and in recent years there is growing evidence to support the effect on sex hormones of both epilepsy per se and various antiepileptic drugs (AEDs). Focal epileptic discharges from the temporal lobe may have a direct influence on the function of the hypothalamic-pituitary axis, thereby altering the release of sex steroid hormones. The role of laterality and severity of epilepsy is still conflicting. The use of the liver enzyme-inducing AEDs--such as phenobarbital, phenytoin, and carbamazepine--can increase serum sex hormone-binding globulin concentrations, leading to diminished bioactivity of testosterone (T) and estradiol. Valproic acid, an enzyme inhibitor, has been associated with the occurrence of reproductive endocrine disorders characterized by high serum T, free androgen index, androstenedione, dehydroepiandrosterone sulfate concentrations, and with polycystic changes in ovaries and menstrual disorders. A better understanding of the effects of AEDs on sex hormones is key to selecting the appropriate AEDs and is crucial for reproductive health in female patients.

Polycystic ovaries and polycystic ovary syndrome in epilepsy: evidence for neurogonadal disease

Polycystic ovary syndrome (PCOS) is a mysterious reproductive disorder that results in subfertility. The underlying causes are not known, and even the definition is a moving target. Women with epilepsy have features of PCOS at a higher than expected rate, and polycystic ovaries (PCO) also are present at high rates in this population. Valproate is associated with weight gain and increased androgen levels, two features of PCOS. This review proposes that epilepsy, with its known adverse effects on luteinizing hormone pulsatility, could be a cause of PCOS and that valproate could be an imitator, if not also a cause of the syndrome.

Seizures and reproductive function: insights from female rats with epilepsy

OBJECTIVE

Chronic seizures in women can have adverse effects on reproductive function, such as polycystic ovarian syndrome, but it has been difficult to dissociate the effects of epilepsy from the role of antiepileptic drugs. To distinguish the effects of chronic seizures from medication, we used the laboratory rat, because an epileptic condition can be induced without concomitant anticonvulsant drug treatment.

METHODS

Adult female rats were administered the chemoconvulsant pilocarpine to initiate status epilepticus, which was decreased in severity by the anticonvulsant diazepam. These rats developed spontaneous seizures in the ensuing weeks, and are therefore termed epileptic. Controls were saline-treated rats, or animals that were injected with pilocarpine but did not develop status epilepticus. Ovarian cyclicity and weight gain were evaluated for 2 to 3 months. Serum hormone levels were assayed from trunk blood, which was collected at the time of death. Paraformaldehyde-fixed ovaries were evaluated quantitatively.

RESULTS

Rats that had pilocarpine-induced seizures had an increased incidence of acyclicity by the end of the study, even if status epilepticus did not occur. Ovarian cysts and weight gain were significantly greater in epileptic than control rats, whether rats maintained cyclicity or not. Serum testosterone was increased in epileptic rats, but estradiol, progesterone, and prolactin were not.

INTERPRETATIONS

The results suggest that an epileptic condition in the rat leads to increased body weight, cystic ovaries, and increased testosterone levels. Although caution is required when comparing female rats with women, the data suggest that recurrent seizures have adverse effects, independent of antiepileptic drugs.

Levetiracetam in absence epilepsy

The aim of the study was to assess the efficacy, tolerability, and safety of levetiracetam therapy in children and adolescents with absence epilepsy. Twenty-one participants (11 male, 10 female) with typical absence seizures were enrolled in this prospective study from seven centres in Italy. The mean age and age range at time of enrollment into the study were 8 years 9 months (SD 0.9) and 5 years 1 month to 13 years respectively. All patients were carefully evaluated at 6 months from baseline, and 12 patients were also re-evaluated at 12 months after the beginning of therapy with levetiracetam. At the 6-month evaluation, out of 21 patients studied, 11 were seizure free and one showed 'decreased' seizures (more than 50% reduction in seizures). A less than 50% reduction in seizures was observed in nine patients. At the 12-month evaluation, 10 patients were completely seizure free and two were seizure free with some anomalies in electroencephalograms. Two patients who had shown no improvement at 6 months had decreased seizures at the second follow-up. Our results suggest that monotherapy with levetiracetam could be effective and well tolerated in patients with childhood absence epilepsy and juvenile absence epilepsy. Prospective, large, long-term double-blind studies are needed to confirm these findings.

Levetiracetam in juvenile myoclonic epilepsy: long-term efficacy in newly diagnosed adolescents

The aim of this study was to evaluate the efficacy and tolerability of levetiracetam (LEV) monotherapy in juvenile myoclonic epilepsy (JME). The study group consisted of 32 patients with epilepsy (20 males, 12 females) with a mean age of 13 years 3 months (SD 7y 11mo) at seizure onset. LEV was administered as the first drug; all patients were followed up at 6 and 12 months. The dose that achieved seizure control ranged from 1000 to 2500mg/daily. At 6-month evaluation: 15 patients were seizure free; 14 patients were responders (>50% reduction in seizures); and three patients had marginal effects (<50% reduction of seizures). At 12-month evaluation: 29 patients were seizure free; three patients were responders. No patients reported adverse events. These data provide preliminary evidence that LEV may be effective for treating patients with newly diagnosed JME.

Women with epilepsy: hormonal issues from menarche through menopause

Epilepsy is a multilayered disorder complicated by numerous comorbid conditions and hormonal changes. More than 1.5 million girls and women with epilepsy face side effects that are compounded at different ages by menstruation, fertility, pregnancy, fetal health, bone health, and other health issues. Changes in hormonal balance during maturation, from menarche through menopause, affect seizure thresholds and antiepileptic drugs, and vice versa. This overview provides physicians with a background on the multiple issues relevant to women of all ages in the reproductive years, including those planning to conceive and those who are pregnant, and beyond the childbearing years.

Leptin and insulin homeostasis in epilepsy: relation to weight adverse conditions

During managing patients with epilepsy, there is a great risk of weight changes, particularly weight gain with some antiepileptic medications. Weight gain is not only a cosmetic problem that leads to non-compliance to medications but also increases the risk for atherosclerosis and its related complications. The mechanisms underlying weight gain in epilepsy are multiple and controversial and have been attributed to the effect of epilepsy and more commonly the effect of antiepileptic medications on the central and peripheral mechanisms regulating weight homeostasis including the two main homeostatic hormones, leptin, a protein product of obesity gene secreted by adipocytes and insulin, a protein product of pancreatic beta-cells. Increased blood levels of leptin and insulin due to leptin and insulin resistance is observed in patients with epilepsy. Leptin forms an important link between weight gain, insulin resistance, epilepsy and atherosclerosis. The knowledge of the novel roles of leptin in patients with epilepsy will help identification of early markers for the related adverse weight changes, thus allowing proper characterization of suitable antiepileptic medication as initial step during management and follow up of patients.

Thirty years of clinical experience with carbamazepine in the treatment of bipolar illness: principles and practice

Carbamazepine began to be studied in a systematic fashion in the 1970s and became more widely used in the treatment of bipolar disorder in the 1980s. Interest in carbamazepine has been renewed by (i) the recent US FDA approval of a long-acting preparation for the treatment of acute mania; (ii) studies suggesting some efficacy in bipolar depression; and (iii) evidence of prophylactic efficacy in some difficult-to-treat subtypes of bipolar illness. A series of double-blind controlled studies of the drug were conducted at the US National Institute of Mental Health from the mid-1970s to the mid-1990s. This review summarises our experience in the context of the current literature on the clinical efficacy, adverse effects and pharmacokinetic interactions of carbamazepine. Carbamazepine has an important and still evolving place in the treatment of acute mania and long-term prophylaxis. It may be useful in individuals with symptoms that are not responsive to other treatments and in some subtypes of bipolar disorder that are not typically responsive to a more traditional agent such as lithium. These subtypes might include those patients with bipolar II disorder, dysphoric mania, substance abuse co-morbidity, mood incongruent delusions, and a negative family history of bipolar illness in first-degree relatives. In addition, carbamazepine may be useful in patients who do not adequately tolerate other interventions as a result of adverse effects, such as weight gain, tremor, diabetes insipidus or polycystic ovarian syndrome. We review our clinical and research experience with carbamazepine alone and in combination with lithium, valproic acid and other agents in complex combination treatment of bipolar illness. More precise clinical and biological predictors and correlates of individual clinical responsiveness to carbamazepine and other mood stabilisers are eagerly awaited.

Currently available antiepileptic drugs

Many new antiepileptic drugs (AEDs) have become available over the past 15 years. At the same time, the emphasis on treating patients with epilepsy has grown from stopping seizures to avoiding side effects and maximizing quality of life. This review summarizes currently available AEDs, and presents general treatment principles and guidelines for AED selection. Unfortunately, despite the increased treatment options of today, seizure freedom without side effects remains unattainable for too many patients with epilepsy. Consequently, there remains a significant need for further development of new therapies.

Management of epilepsy in women of childbearing age: practical recommendations

Women with epilepsy should not be discouraged from becoming pregnant as the likelihood of having a healthy baby is very high. However, in such women, early and individualised counselling about pregnancy and contraception is essential. Ideally, pregnancies should be planned, folic acid (5 mg/day) given and antiepileptic drug (AED) treatment optimised well before conception to ensure that the lowest dosage that controls seizures is administered. When initiating AEDs in a woman of childbearing age, the most appropriate drug for the seizure type and syndrome should be chosen, although it is preferable to avoid valproate, because of a possible elevated risk of fetal malformations, when equi-effective agents are available for a given syndrome. In women who become pregnant while taking AEDs, fetal monitoring should include high-resolution ultrasonography before week 20 and measurement of serum alpha-fetoprotein levels. Amniocentesis is not routinely indicated. The measurement of blood concentrations of AEDs can be useful to ensure that the lowest possible maintenance dosage is being used, especially for those drugs whose pharmacokinetics are likely to change during pregnancy. Breastfeeding should be encouraged whatever the treatment administered.

Menstrual cycle worsening of epileptic seizures in women with symptomatic focal epilepsy

INTRODUCTION

Hormonal fluctuation is responsible for worsening of epileptic seizures during the menstrual cycle.

OBJECTIVE

To identify irregularities in the menstrual cycles of women with mesial temporal lobe epilepsy (MTLE) and extratemporal focal epilepsy (ETFE) and correlate the frequency of seizures during the menstrual cycles.

METHOD

We evaluated prospectively women in the menacme with MTLE and ETFE. Calendars were provided for these patients, and they were asked to mark their seizure frequency according to the menses. Calendars were reviewed in each routine medical appointment.

RESULTS

Thirty-nine patients with MTLE and 14 with ETFE were evaluated. We registered 211 cycles in the patients with MTLE and 49 in those with ETFE. Irregular menstrual cycles were found in 28 (28/39, 71.7%) patients with MTLE and 6 (6/14, 42.8%) with ETFE (p=0.052). Premenstrual seizure worsening was observed in 46 (21.8%) patients with MTLE and 9 (18.3%) with ETFE (p=0.596). Menstrual worsening was observed in 47 (22.2%) patients with MTLE and 15 (30.6%) with ETFE (p=0.217). Ovulatory worsening was observed in 36 (17%) patients with MTLE and 13 (26.5%) with ETFE (p=0,126). Catamenial worsening was observed in 58 (27.4%) of the patients with MTLE and in 17 (34.7%) of the patients with ETFE (p=0.315).

CONCLUSION

There was no difference between the group of patients with MTLE and ETFE regarding the frequency of irregular cycles and seizure worsening during the premenstrual, menstrual, catamenial or ovulatory periods.

Serum insulin, leptin, and neuropeptide y levels in epileptic children treated with valproate

Weight gain is a common side effect of valproate treatment. The potential mechanisms of valproate-associated weight gain are not yet clear. Decreased blood glucose level, impairment of beta-oxidation of fatty acids, and increased insulin levels are some of the possible mechanisms. The aim of the present study is to evaluate the role of insulin, leptin, and neuropeptide Y in valproate-related weight gain in epileptic children. In 20 epileptic children treated with valproate before treatment and after a follow-up period of 3 and 6 months, body mass index and fasting insulin glucose ratio were calculated and serum glucose, insulin, cortisol, leptin, and neuropeptide Y levels were measured. At the end of 3 months, the mean body mass index values and the mean serum insulin, fasting insulin glucose ratio, and neuropeptide Y levels increased, whereas the serum glucose levels decreased. After 6 months of treatment, the mean serum cortisol and leptin levels were high, in addition to the body mass index, neuropeptide Y, and fasting insulin glucose ratio. These results suggest that weight gain during valproate treatment might be related to low glucose and high insulin, cortisol, leptin, and neuropeptide Y levels.

Will my child grow up and be normal?

Physical Growth and Endocrinal Disorders during Pubertal Maturation in Girls with Epilepsy

El-Khayat HA, Abd El-Basset FZ, Tomoum HY, Tohamy SM, Zaky AA, Mohamed MS, Hakky SM, Barbary NS, Nassef NM

Epilepsia 2004;45:1106–1115

Purpose

This study investigated the effect of epilepsy or antiepileptic drugs or both on the physical growth, pubertal development, and androgenic status of girls with epilepsy between ages 8 and 18 years.

Methods

Sixty-six female patients with epilepsy, their mean ages 13.47 ± 3.5 years, were included. Anthropometric measurements, staging of pubertal maturation, and clinical manifestations of hyperandrogenism were assessed, as well as measurement of serum levels of testosterone, dehydroepiandrosterone sulfate, sex hormone–binding globulin, and free androgen index. Of the included patients, 44 had transabdominal ultrasonic examination of the ovaries, and fasting serum insulin levels were measured. Forty healthy age-matched girls served as a control group.

Results

Patients showed reduced mean height percentile compared with controls ( z = 2.07; p = 0.04), which was negatively correlated with the duration of their epilepsy. Patients showed increased frequency of obesity, especially postpubertal girls taking valproate (67%), who also showed higher insulin levels ( t = 8.01; p = 0.0003). Patients showed increased frequency of clinical hyperandrogenemia in the different stages of puberty. High levels of testosterone and dehydroepiandrosterone sulfate were found in girls with epilepsy, especially pubertal and postpubertal girls. Hyperandrogenism (clinical and/or laboratory) was most affected by the types of antiepileptic drugs, with higher incidence in patients taking valproic acid compared with those taking enzyme-inducing antiepileptic drugs ( χ2 = 9.16; p = 0.01). Eighteen percent of the patients were diagnosed as having polycystic ovary syndrome. No difference was found in the types of seizures, degree of seizure control, types of antiepileptic drugs, or insulin levels between patients with and those without polycystic ovary syndrome.

Conclusions

Longer duration of the disease has a negative impact on the stature of girls with epilepsy. Postpubertal girls taking valproic acid are more liable to obesity, which is associated with increased incidence of hyperinsulinemia. Clinical or laboratory evidence or both of hyperandrogenism is seen at a high frequency in patients, especially with the use of valproic acid. Furthermore, girls with epilepsy especially in the postpubertal stage of sexual maturation, have a high prevalence of polycystic ovary syndrome, independent of the type of antiepileptic drug or the characteristics of the epilepsy disorder.

Effect of antiepileptic drugs on reproductive endocrine function in individuals with epilepsy

It is well known that epilepsy, antiepileptic drugs (AEDs), and the reproductive system have complex interactions. Fertility is lower in both men and women with epilepsy than in the general population. Moreover, reproductive endocrine disorders are more common among patients with epilepsy than among the population in general. These disorders have been attributed both to epilepsy itself and to use of AEDs. The use of the liver enzyme-inducing AEDs phenobarbital, phenytoin and carbamazepine increases serum sex hormone-binding globulin (SHBG) concentrations in both men and women with epilepsy. Over time, the increase in serum SHBG levels leads to diminished bioactivity of testosterone and estradiol, which may result in diminished potency in men and menstrual disorders in some women, and thus to reduced fertility. Liver enzyme-inducing AEDs also reduce the efficacy of oral contraceptives. Valproic acid medication may have effects on serum androgen concentrations and it reduces serum follicle stimulating hormone levels in men with epilepsy. However, the clinical significance of valproic acid-related reproductive endocrine changes in men is unknown. On the other hand, in women, use of valproic acid appears to be associated with a frequent occurrence of reproductive endocrine disorders characterised by polycystic changes in the ovaries, high serum testosterone concentrations (hyperandrogenism) and menstrual disorders. These disorders are especially common among women who have gained weight during valproic acid treatment. There are some discrepancies regarding the reported occurrence of reproductive endocrine disorders in women taking valproic acid for epilepsy. However, most studies also including patients receiving valproic acid for other reasons than epilepsy, and studies in different non-epileptic animal models, have shown an association between valproic acid medication and hyperandrogenism and related reproductive endocrine disorders. From a practical point of view, the length of the menstrual cycles and bodyweight should be monitored in women with epilepsy after commencement of treatment with valproic acid. A serum testosterone assay is helpful in following the possible biochemical endocrine changes. Ultrasonography of the ovaries (preferably transvaginal) is indicated if clinical assessment and serum testosterone measurement imply that there is a clinically significant valproic acid-related reproductive endocrine problem. That would be the case if the menstrual cycles were irregular or prolonged (usually >35 days) and serum testosterone levels elevated, especially with associated weight gain. The endocrine effects of the new AEDs have not been widely studied. However, it seems they may offer an alternative if reproductive endocrine problems emerge during treatment with the older AEDs.

Antiepileptic drugs alter reproductive endocrine hormones in men with epilepsy

Disturbances of reproductive endocrine hormones are more often found in men with epilepsy than in the general population. There is an ongoing debate whether this can be attributed to chronic use of antiepileptic drugs or to the epilepsy itself. The aim of the present study was to evaluate the degree of endocrine disturbances in men with epilepsy compared with healthy controls, and to investigate whether there was a drug-specific effect of valproate (VPA) or carbamazepine (CBZ). Men with epilepsy, 20-40 years old, having used either VPA (n = 16) or CBZ (n = 19) as monotherapy for >2 years were included and compared with age-matched controls. Men with epilepsy (VPA + CBZ) had significantly lower FSH values and higher C-peptide values compared with controls. Regarding possible drug-specific effects, the VPA treated patients had significantly higher dehydroepiandrosterone (DHEAS) levels and lower FSH and LH concentrations compared with the controls, whereas there were no differences in testosterone, testosterone/sexhormone-binding globulin (SHBG) ratio or androstenedione levels. Men on VPA also had significantly lower free carnitine/total carnitine, which may have implications for sperm motility, and also higher insulin and C-peptide concentrations. The CBZ treated patients had significantly lower testosterone/SHBG ratio than the controls. Compared with the CBZ treated patients, men on VPA had significantly higher DHEAS concentrations and lower levels of follicle stimulating hormone (FSH), luteinizing hormone (LH) as well as a lower free carnitine/total carnitine ratio. A marked age dependency was found in all three groups regarding several of the endocrine hormones. In conclusion, drug-specific endocrine effects of VPA and CBZ were found in men with epilepsy. Long-term VPA treatment leads to significant changes in DHEAS, FSH, LH, insulin, C-peptide and carnitine ratio. Long-term CBZ treatment leads to significant lower testosterone/SHBG ratio. A strict age matching were found to be of importance in the evaluation of endocrine function in men.

Physical Growth and Endocrinal Disorders during Pubertal Maturation in Girls with Epilepsy

PURPOSE

This study investigated the effect of epilepsy and/or antiepileptic drugs (AEDs) on the physical growth, pubertal development, and androgenic status of girls with epilepsy between ages 8 and 18 years.

METHODS

Sixty-six female patients with epilepsy, their mean ages 13.47 +/- 3.5 years, were included. Anthropometric measurements, staging of pubertal maturation, and clinical manifestations of hyperandrogenism were assessed, as well as measurement of serum levels of testosterone, dehydroepiandrosterone sulfate (DHEAS), sex hormone-binding globulin (SHBG), and free androgen index (FAI). Of the included patients, 44 had transabdominal ultrasonic examination of the ovaries and fasting serum insulin levels were measured. Forty healthy age-matched females served as a control group.

RESULTS

Patients showed reduced mean height percentile compared with controls (z = 2.07; p = 0.04), which was negatively correlated with the duration of their epilepsy. Patients showed increased frequency of obesity, especially postpubertal girls taking valproate (VPA; 67%), who also showed higher insulin levels (t = 8.01; p = 0.0003). Patients showed increased frequency of clinical hyperandrogenemia in the different stages of puberty. High levels of testosterone and DHEAS were found in female patients with epilepsy, especially pubertal and postpubertal girls. Hyperandrogenism (clinical and/or laboratory) was most affected by the types of AEDs, with higher incidence in patients taking VPA compared with those taking enzyme-inducing AEDs (chi2= 9.16; p = 0.01). Eighteen percent of the patients were diagnosed as having polycystic ovary syndrome (PCOS). No difference was found in the types of seizures, degree of seizure control, type of AEDs, or insulin levels between patients with and those without PCOS.

CONCLUSIONS

Longer duration of the disease has a negative impact on the stature of female patients with epilepsy. Postpubertal girls taking VPA are more liable to obesity, which is associated with increased incidence of hyperinsulinemia. Clinical and/or laboratory evidence of hyperandrogenism is seen at a high frequency in patients, especially with the use of VPA. Furthermore, female patients with epilepsy especially in the postpubertal stage of sexual maturation, have a high prevalence of PCOS, independent of the type of AED or the characteristics of the epilepsy disorder.

Interictal EEG discharges, reproductive hormones, and menstrual disorders in epilepsy

We evaluated reproductive endocrine function in women with unilateral temporolimbic epilepsy and normal control subjects to assess the effects of epilepsy, epilepsy laterality, and antiepileptic drug use on the cerebral regulation of hormonal secretion. The findings indicate that reproductive endocrine function differs between women with epilepsy and normal control subjects. Significant differences exist at all levels of the reproductive neuroendocrine axis, that is, hypothalamus, pituitary, and peripheral gland. Differences show significant relationships to the epilepsy itself as well as to medication use. Reproductive neuroendocrine changes occur in a stochastic manner such that the laterality of unilateral temporolimbic discharges is associated with predictable directional changes in hormonal secretion at all levels of the reproductive neuroendocrine axis. These directional changes are consistent with the finding that different reproductive disorders may develop in relation to left- and right-sided temporolimbic epilepsy. Hormonal changes can show close temporal relationship to the occurrence of interictal epileptiform discharges and may vary in relation to the laterality of the discharges. Antiepileptic drugs differ in their effects on reproductive hormone levels. There are notable differences between enzyme-inducing and noninducing drugs. Menstrual disorders are more common among women with interictal discharges as well as women with abnormal hormonal findings.

Levetiracetam does not alter body weight: analysis of randomized, controlled clinical trials

INTRODUCTION

Increases in body weight gain are important, and clinically significant adverse effects of several antiepileptic drugs (AED) including valproate and gabapentin. Weight gain may contribute to medication non-compliance, discontinuation, and importantly, may have secondary medical implications as well. Levetiracetam (LEV) is indicated for adjunctive treatment of partial seizures. The objective of the present evaluation was to examine the effects of LEV treatment on body weight in adult patients.

METHODS

We analyzed data derived from four prospective, placebo-controlled randomized, clinical trials conducted in both in the US and Europe. Patients included in the present analysis were both men and women, greater than 16 years old, and who had LEV exposure for at least 1 month. Body weight was measured at baseline and at the final LEV study visit. Data are analyzed for all patients, by gender, body mass index (BMI), duration of LEV exposure and by concomitant AED treatment. Wilcoxan Signed Rank, or Rank Sum test used where appropriate, with significance assigned at P<0.05. Data are presented as mean values+/-1 S.D.

RESULTS

Nine-hundred and seventy patients (age=37.5 years, 54% men/46% women) were evaluated. There were no significant differences in baseline demographics between LEV (n=631) or placebo (n=339) treated patient groups. Mean LEV dose and duration of treatment were 2053 mg/day (maximum dose of 4000 mg/day) and 125 days (maximum=181 days), respectively. Concomitant AED therapy included CBZ, PHT, VPA, PB, GBP, LTG, and VGB. For LEV-treated patients, no significant changes in body weight were noted. Mean body weight at baseline versus final study visit for LEV was 74.3+/-16.6 kg and 74.3+/-16.6 kg, respectively. For placebo-treated patients, baseline versus end of treatment weight was 72.4+/-15.4 kg and 72.7+/-15.9 kg, respectively, representing a slight, yet clinically trivial increase. Clinically significant weight change as defined as >7% change from baseline weight, occurred in 9% of LEV-treated patients (4.5% had increase in weight/4.5% decrease) versus 9.4% (5.9% had increase/3.5% decrease) in placebo-treated patients. Weight changes were not significantly different between groups. Neither baseline BMI, gender, or background AEDs, appeared to predispose to significant weight change for LEV-treated patients.

CONCLUSIONS

We conclude that treatment with LEV at clinically relevant dosages is not associated with significant weight change. LEV would, therefore, appear to be a weight neutral AED.

Medical comorbidities in the treatment of epilepsy

The treatment of epilepsy extends far beyond seizure control. Many comorbidities have a significant impact on the medical management and quality of life of patients with epilepsy. In this review, we examine interactions between epilepsy and some common medical conditions. Psychiatric disorders with a high prevalence in epilepsy include mood disorders, anxiety disorders, and psychosis. Depression is common, psychosis occurs both in direct relation to seizures and interictally, and suicide rates are increased. Changes in sexual function and reduced fertility and marriage rates are described, including a discussion of polycystic ovary syndrome, which is increased in women with epilepsy. The effects of other chronic medical comorbid conditions are reviewed, including the effects of antiepileptic medications on bone health and the impact of renal insufficiency on pharmacological therapy of epilepsy.

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.

Selection criteria for the clinical use of the newer antiepileptic drugs

In recent years, several new antiepileptic drugs (AEDs) have been licensed: felbamate, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tiagabine, topiramate, vigabatrin and zonisamide. These drugs have proven efficacy as add-on therapy in patients with difficult-to-treat partial epilepsy, as 20-50% of patients treated in add-on trials experienced a seizure reduction of >or=50%. Relatively few trials have been conducted to evaluate these drugs as monotherapy for patients with newly diagnosed epilepsy. In the monotherapy trials that have been conducted, the newer drugs were often as efficacious as conventional drugs, and their tolerability was often better. However, the methodology of these trials can be criticised. Because of the relative lack of robust data for the newer agents, the conventional drugs have thus far maintained their status as first-line monotherapy. However, when first-line monotherapy fails, an alternative drug has to be chosen from the available conventional and newer drugs. This article aims to give detailed background information on the newer AEDs in order to enable physicians to make a rational choice from the available drugs for individual patients. Data are provided for the different newer AEDs on mechanisms of action; efficacy in refractory partial epilepsy, newly diagnosed epilepsy in adults and generalised seizure types; adverse effects; pharmacokinetics; and use in special patient categories.

Valproate: past, present, and future

Preclinical studies have been carried out during the past four decades to investigate the different mechanisms of action of valproate (VPA). The mechanisms of VPA which seem to be of clinical importance include increased GABAergic activity, reduction in excitatory neurotransmission, and modification of monoamines. These mechanisms are discussed in relation to the various clinical uses of the drug. VPA is widely used as an antiepileptic drug with a broad spectrum of activity. In patients, VPA possesses efficacy in the treatment of various epileptic seizures such as absence, myoclonic, and generalized tonic-clonic seizures. It is also effective in the treatment of partial seizures with or without secondary generalization and acutely in status epilepticus. The pharmacokinetic aspects of VPA and the frequent drug interactions between VPA and other drugs are discussed. The available methods for the determination of VPA in body fluids are briefly evaluated. At present, investigations and clinical trials are carried out and evaluated to explore the new indications for VPA in other conditions such as in psychiatric disorders, migraine and neuropathic pain. Furthermore, the toxicity of VPA, both regarding commonly occurring side effects and potential idiosyncratic reactions are described. Derivatives of VPA with improved efficacy and tolerability are in development.

Valproic acid fails to induce polycystic ovary syndrome in female rats

PURPOSE

Valproic acid (VPA) treatment in female patients is suggested to be associated with the occurrence of a variety of endocrine side effects that include many characteristic symptoms of polycystic ovary syndrome (PCOS). The aim of our study was to prospectively measure whether VPA treatment was associated with the presentation of PCOS symptoms in rats, as well as determine whether this model could be used to examine the underlying mechanism by which these effects are induced.

METHODS

Normal estrus-cycling female rats (n=22) were treated perorally three times daily with VPA (300 mg/kg/day), divalproex sodium (DVS) (330 mg/kg/day), or phosphate-buffered saline for a minimum of 30 days. PCOS-associated symptoms (estrus cycle, weight, estradiol and testosterone levels, aromatase activity, and ovarian morphology) were assessed at baseline, mid-, and endpoint.

RESULTS

There was no significant difference in the mean number of days animals were in proestrus-estrus or metestrus-diestrus between the three groups. All groups of animals gained weight during the study and there were no appreciable differences in mean weight gain or leptin between groups. Total serum estradiol or testosterone levels and ovarian aromatase activity were not significantly different between the groups. The number of corpora lutea was not significantly different between the groups; however, cystic follicles were present in 50% of the drug-treated animals compared to 25% of saline-treated animals.

CONCLUSIONS

VPA and DVS treatment were associated with a higher proportion of animals developing cystic follicles but did not mimic the VPA-induced PCOS that is observed in women. Thus, it appears that the rat has limited usefulness for modeling VPA-induced symptoms associated with PCOS.

Endocrine and metabolic responses to long-term monotherapy with the antiepileptic drug valproate in the normally cycling rhesus monkey

An association between epilepsy and reproductive disturbances with an apparent increase in a polycystic ovarian syndrome (PCOS) has been reported. Whether this association can be attributed to epilepsy itself or is related to antiepileptic drug therapy, in particular valproate (VPA), remains controversial. We studied effects of a long-term VPA treatment on cycling monkeys, postulating that, if VPA monotherapy were to promote abnormal endocrine and metabolic parameters that are characteristic of PCOS, changes in cyclicity would be readily demonstrated. After a 2-month control, a 12- to 15-month VPA monotherapy was initiated in 7 regularly cycling rhesus monkeys. Overall mean levels of VPA were 88.7 +/- 4.0 (SE) microg/ml. Mean body weight increased progressively during VPA treatment from 8.5 +/- 0.5 kg before treatment to 9.6 +/- 0.7 kg in the last week of treatment (P < 0.05). Monkeys continued to have regular ovulatory menstrual cycles throughout VPA monotherapy. Length of the cycles was 28 +/- 0.58 d in control and 28.4 +/- 1.18 d in the last 3 months of VPA treatment. Follicular and luteal lengths and peak preovulatory estradiol and integrated luteal progesterone levels did not differ between control and treatment. Ovaries from VPA-treated monkeys showed histological evidence of ovulation, and none had characteristic features of PCOS. Endocrine PCOS markers, such as increased early follicular LH/FSH ratio and androgen levels were not different in control and VPA treatment cycles. LH and 17-hydroxyprogesterone responses to GnRH agonist challenges and the insulin response to glucose tolerance tests were similar in control and VPA groups. Lipid profiles were not affected by VPA treatment. The data indicate that a 12- to 15-month therapeutic exposure to VPA does not induce cyclic hormonal or morphological ovarian abnormalities or characteristics of the PCOS when administered to nonepileptic normally cycling nonhuman primates.

Pharmacological and therapeutic properties of valproate: a summary after 35 years of clinical experience

Thirty-five years since its introduction into clinical use, valproate (valproic acid) has become the most widely prescribed antiepileptic drug (AED) worldwide. Its pharmacological effects involve a variety of mechanisms, including increased gamma-aminobutyric acid (GABA)-ergic transmission, reduced release and/or effects of excitatory amino acids, blockade of voltage-gated sodium channels and modulation of dopaminergic and serotoninergic transmission. Valproate is available in different dosage forms for parenteral and oral use. All available oral formulations are almost completely bioavailable, but they differ in dissolution characteristics and absorption rates. In particular, sustained-release formulations are available that minimise fluctuations in serum drug concentrations during a dosing interval and can therefore be given once or twice daily. Valproic acid is about 90% bound to plasma proteins, and the degree of binding decreases with increasing drug concentration within the clinically occurring range. Valproic acid is extensively metabolised by microsomal glucuronide conjugation, mitochondrial beta-oxidation and cytochrome P450-dependent omega-, (omega-1)- and (omega-2)-oxidation. The elimination half-life is in the order of 9 to 18 hours, but shorter values (5 to 12 hours) are observed in patients comedicated with enzyme-inducing agents such as phenytoin, carbamazepine and barbiturates. Valproate itself is devoid of enzyme-inducing properties, but it has the potential of inhibiting drug metabolism and can increase by this mechanism the plasma concentrations of certain coadministered drugs, including phenobarbital (phenobarbitone), lamotrigine and zidovudine. Valproate is a broad spectrum AED, being effective against all seizure types. In patients with newly diagnosed partial seizures (with or without secondary generalisation) and/or primarily generalised tonic-clonic seizures, the efficacy of valproate is comparable to that of phenytoin, carbamazepine and phenobarbital, although in most comparative trials the tolerability of phenobarbital was inferior to that of the other drugs. Valproate is generally regarded as a first-choice agent for most forms of idiopathic and symptomatic generalised epilepsies. Many of these syndromes are associated with multiple seizure types, including tonic-clonic, myoclonic and absence seizures, and prescription of a broad-spectrum drug such as valproate has clear advantages in this situation. A number of reports have also suggested that intravenous valproate could be of value in the treatment of convulsive and nonconvulsive status epilepticus, but further studies are required to establish in more detail the role of the drug in this indication. The most commonly reported adverse effects of valproate include gastrointestinal disturbances, tremor and bodyweight gain. Other notable adverse effects include encephalopathy symptoms (at times associated with hyperammonaemia), platelet disorders, pancreatitis, liver toxicity (with an overall incidence of 1 in 20,000, but a frequency as high as 1 in 600 or 1 in 800 in high-risk groups such as infants below 2 years of age receiving anticonvulsant polytherapy) and teratogenicity, including a 1 to 3% risk of neural tube defects. Some studies have also suggested that menstrual disorders and certain clinical, ultrasound or endocrine manifestations of reproductive system disorders, including polycystic ovary syndrome, may be more common in women treated with valproate than in those treated with other AEDs. However, the precise relevance of the latter findings remains to be evaluated in large, prospective, randomised studies.

Effects of chronic valproate treatment on reproductive endocrine hormones in female and male Wistar rats

Valproate (VPA) has been claimed to induce endocrine disorders in both sexes in humans. There is sparse information regarding the mechanisms behind these disturbances. By using an animal model, we wanted to study the effect of valproate on hormonal function in non-epileptic rats. Female rats were given 0 (vehicle control, n=15), 200mg/kg (n=15), or 300 mg/kg (n=20) valproate twice daily by gavage for 90 days, resulting in mean valproate concentrations within the therapeutic range 4-6h after the last dose given. Serum testosterone concentrations remained unchanged, while estradiol levels were significantly reduced in both treatment groups, leading to significantly increased testosterone/estradiol ratios. Follicle stimulating hormone (FSH) levels remained unaltered in valproate treated rats, whereas the luteinizing hormone (LH) concentrations were reduced at the lowest valproate dose. Male rats received 0 (vehicle control, n=15), 200mg/kg (n=15), or 400mg/kg (n=20) valproate twice daily by gavage for 90 days, resulting in mean valproate concentrations within the therapeutic range 4-6h after the last dose. Serum testosterone levels were not significantly changed, but there was a highly significant increase in FSH and LH concentrations at the high dose. In conclusion, the study demonstrates a drug-induced effect of valproate on endocrine function in both male and female rats. The results indicate that the drug exerts its effect primarily at the gonadal level, although a centrally mediated effect cannot be ruled out.

Valproate irreversibly alters steroid secretion patterns from porcine follicular cells in vitro

The aim of the present study was to investigate whether exposure of porcine ovarian follicular cells to clinically relevant concentrations of valproate affected steroid production in vitro and to which extent these effects were reversed by removal of the drug from the culture medium. Small and medium follicles were obtained from ovaries collected, respectively, at days 8-10 and 14-16 of the estrous cycle. Theca and granulosa cells were collected from follicles and co-cultured in one well. To show whether the effect of valproate was reversible, cells were cultured for 24, 48, or 72 h with valproate 100 or 250 microg/ml. The medium was then changed to fresh medium without drugs for an additional 24, 48, or 72 h. Valproate added to the culture medium caused a significant reduction of estradiol secretion with concomitant increase in both testosterone and progesterone secretion by small follicles. In medium-sized follicles, 100 microg/ml valproate was without effect on estradiol secretion while 250 microg/ml caused a small, but statistically significant decrease. The effects of valproate on steroid secretion patterns were irreversibly independent of concentration, exposure time, and time of restoration after drug exposure up to 72 h in both small and medium follicles. In conclusion, the present study demonstrated that even short-term valproate treatment disrupted follicular steroidogenesis in isolated ovarian follicular cells resulting in increased testosterone and progesterone and decreased estradiol secretion. It was not possible to reverse the steroidogenic effects of valproate by removing the drug from the cell cultures.

Bodyweight gain and anticonvulsants: a comparative review

Bodyweight gain is a common and frequent undesirable effect associated with the use of anticonvulsant drugs. This has been observed for many years with valproic acid (sodium valproate) and carbamazepine, and also, more recently, with some of the newer anticonvulsants such as vigabatrin and gabapentin. Very often bodyweight gain in children, adolescents and adults with epilepsy taking such anticonvulsants results in cosmetic adverse effects. On the other hand, bodyweight gain is disturbing to general health, with a possible increase in the risk of diabetes mellitus or heart disease. Other potential adverse effects, such as the association of obesity with polycystic ovaries, have been reported with the use of valproic acid. Potential mechanisms of anticonvulsant-associated bodyweight gain are not yet clear and differ between drugs used. The involvement of lowered blood glucose level, which may stimulate eating through an effect on the hypothalamus, constitutes one of the possible mechanisms. Lowered blood glucose levels may result from a competition between the binding of the drug and long chain fatty acids. An increased availability of the latter stimulates insulin production and lowers the serum glucose levels. Another possible explanation for lowered blood glucose may be a deficiency in carnitine directly caused by the drug, that would result in a reduction of fatty acid metabolism and an increase in glucose consumption. An enhancing effect of gamma-aminobutyric acid-mediated neurotransmission may increase appetite for carbohydrates and reduce energy expenditure. An antidiuretic hormone-like effect or effects on norepinephrine (noradrenaline) or serotonin-mediated neurotransmission are more rarely considered. Many studies on anticonvulsant-associated bodyweight gain illustrate how we could better define the risk factors for the development of anticonvulsant-induced bodyweight gain and uncover the mechanisms behind it.

Treatment of typical absence seizures and related epileptic syndromes

Typical absences are brief (seconds) generalised seizures of sudden onset and termination. They have 2 essential components: clinically, the impairment of consciousness (absence) and, generalised 3 to 4Hz spike/polyspike and slow wave discharges on electroencephalogram (EEG). They differ fundamentally from other seizures and are pharmacologically unique. Their clinical and EEG manifestations are syndrome-related. Impairment of consciousness may be severe, moderate, mild or inconspicuous. This is often associated with motor manifestations, automatisms and autonomic disturbances. Clonic, tonic and atonic components alone or in combination are motor symptoms; myoclonia, mainly of facial muscles, is the most common. The ictal EEG discharge may be consistently brief (2 to 5 seconds) or long (15 to 30 seconds), continuous or fragmented, with single or multiple spikes associated with the slow wave. The intradischarge frequency may be constant or may vary (2.5 to 5Hz). Typical absences are easily precipitated by hyperventilation in about 90% of untreated patients. They are usually spontaneous, but can be triggered by photic, pattern, video games stimuli, and mental or emotional factors. Typical absences usually start in childhood or adolescence. They occur in around 10 to 15% of adults with epilepsies, often combined with other generalised seizures. They may remit with age or be lifelong. Syndromic diagnosis is important for treatment strategies and prognosis. Absences may be severe and the only seizure type, as in childhood absence epilepsy. They may predominate in other syndromes or be mild and nonpredominant in syndromes such as juvenile myoclonic epilepsy where myoclonic jerks and generalised tonic clonic seizures are the main concern. Typical absence status epilepticus occurs in about 30% of patients and is more common in certain syndromes, e.g. idiopathic generalised epilepsy with perioral myoclonia or phantom absences. Typical absence seizures are often easy to diagnose and treat. Valproic acid, ethosuximide and lamotrigine, alone or in combination, are first-line therapy. Valproic acid controls absences in 75% of patients and also GTCS (70%) and myoclonic jerks (75%); however, it may be undesirable for some women. Similarly, lamotrigine may control absences and GTCS in possibly 50 to 60% of patients, but may worsen myoclonic jerks; skin rashes are common. Ethosuximide controls 70% of absences, but it is unsuitable as monotherapy if other generalised seizures coexist. A combination of any of these 3 drugs may be needed for resistant cases. Low dosages of lamotrigine added to valproic acid may have a dramatic beneficial effect. Clonazepam, particularly in absences with myoclonic components, and acetazolamide may be useful adjunctive drugs.