Epilepsy, sex hormones, and antiepileptic drugs

A comparative study of the efficiency of Withania somnifera and carbamazepine on lifespan, reproduction and epileptic phenotype - A study in Drosophila paralytic mutant

Background

Seizure disorders are considered a serious health issue because of the vast number of people affected globally and the limited treatment options. Approximately 15 million epileptic patients worldwide do not respond to any of the currently available medications. Carbamazepine (CBZ) is one of the most widely used antiepileptic drugs (AEDs) for the treatment of epilepsy, which is discontinued in less than 5% of epileptic patients due to its side effects. In traditional medicine, to establish the foundation of health care, plant extracts are utilized to a great extent to treat different pathologies. Withania somnifera (W. somnifera) is an herbal component with anticonvulsant properties.

Objectives

To compare the medicinal effects of W. somnifera on lifespan, fecundity, fertility and epileptic phenotype in Drosophila paralytic mutant (para^bss1) model system with CBZ, a commonly used AED.

Material and methods

Flies were exposed to three different doses of W. somnifera or CBZ in standard wheat flour-agar media for six days. Drosophila Oregon-R strain was used as a control.

Results

Results indicate that a high dose of W. somnifera increased the lifespan in Drosophila para^bss1 while remaining safe for fecundity and fertility. CBZ decreased the lifespan of para^bss1 mutant at higher dose (40 μg/ml), as expected, and also reduced the fecundity and fertility of the flies. Our findings indicate that W. somnifera was more effective than CBZ to control epileptic phenotype.

Conclusion

W. somnifera is an effective medication with no side effects for treating epilepsy in Drosophila paralytic mutant.

Understanding cardiovascular disease in older adults with epilepsy

OBJECTIVE

This study was undertaken to investigate the distribution of social, lifestyle/behavior, and chronic disease risk factors for cardiovascular disease (CVD) in people with epilepsy as compared to the general population. We also measured the cross-sectional association between epilepsy and CVD in older adults, with and without adjustments for a history of stroke.

METHODS

We analyzed data for 44 817 participants in the Canadian Longitudinal Study on Aging, including 751 individuals with a lifetime history of epilepsy. We modeled associations using ordinal and binomial logistic regression, as well as log-binomial regression, with multiple imputation for missing data. We measured the attributable fraction of CVD burden due to stroke.

RESULTS

The majority of the CVD risk factors were significantly more prevalent in people with epilepsy as compared to the general population without epilepsy, independent of age and sex. After adjusting for a history of stroke, people with epilepsy had a significantly higher prevalence of heart disease (prevalence ratio [PR] = 1.27, 95% confidence interval [CI] = 1.02-1.57) and peripheral vascular disease (PR = 1.88, 95% CI = 1.50-2.36). Stroke accounted for 36% (95% CI = 19.85-48.76) of the increased prevalence of any CVD among people with epilepsy, similar to the 32% (95% CI = 27.82-36.25) among people without epilepsy. After adjustment for all other CVD risk factors, peripheral vascular disease remained significantly more prevalent (PR = 1.65, 95% CI = 1.28-2.12) in people with epilepsy as compared to those without.

SIGNIFICANCE

CVD risk factors are more prevalent in people with epilepsy, independent of age and sex, and the association between epilepsy and CVD is independent of the association between epilepsy and stroke. The association between peripheral vascular disease and epilepsy may differ from the associations with other types of CVD. These findings are important steps in more comprehensively understanding the origins of CVD in people with epilepsy.

The effect of antiepileptic drugs on thyroid hormonal function: valproic acid and phenobarbital

The aim of this study was to evaluate the thyroid function alterations in a group of epileptic children taking antiepileptic drugs. The study included a total of 183 pediatric epilepsy patients, aged 15 months-16 years, comprising 114 patients treated with valproic acid, 69 patients treated with phenobarbital, and 151 age-matched healthy volunteers as the control group. Serum levels of thyroid hormones were measured before the beginning of the antiepileptic therapy and after 12 months of treatment. Thyroid-stimulating hormone levels were significantly higher in the 12th month of phenobarbital and valproic acid treatment. The level of free triiodothyronine before treatment was higher in epileptic patients than in the control group. Subclinical hypothyroidism at month 12 was determined in 15.2% of the valproic acid group and in 2.9% of the phenobarbital group. When compared with the pre-treatment values, there was a statistically significant difference in the incidence of subclinical hypothyroid in the valproic acid group and no significant difference in the phenobarbital group. Symptomatic hypothyroidism was not detected. It was concluded that the thyroid functions of patients using valproic acid and phenobarbital for a long time should be regularly monitored.

Management of Epilepsy Due to Hypothalamic Hamartomas

A hypothalamic hamartoma consists of hyperplastic heterotopic tissue growing in a disorganized fashion. These lesions occur in about one per 50,000 to 100,000 people. Hypothalamic hamartomas can cause intrinsic epileptogenesis leading to gelastic seizures. Surrounding cortical structures may also develop secondary epileptogenesis. Persistent seizures caused by hypothalamic hamartomas can be debilitating and result in significant cognitive and behavioral impairment. Early recognition and treatment is important in controlling seizures and in preventing further cognitive deterioration. Some patients experience improved cognition and behavior following early treatment, suggesting that hypothalamic hamartomas represent a reversible epileptic encephalopathy. The outcome of epilepsy associated with these lesions has significantly evolved with the availability of new treatment techniques and an improved understanding of its pathogenesis. Increasing evidence supporting the role of hypothalamic hamartomas as a cause of gelastic seizures and secondary epileptogenesis has led to more frequent use of surgery as the definitive treatment. Several minimally invasive procedures have been devised, including neuroendoscopic approaches and different stereotactic radio and laser ablation techniques. Each of these techniques can lead to unique adverse events. We review the various classification schemes used to characterize hypothalamic hamartomas and the recommended surgical approaches for each subtype. We also review the literature for currently available treatment modalities and compare their efficacy in controlling seizures and their safety profiles.

Sexual dysfunction related to antiepileptic drugs in patients with epilepsy

INTRODUCTION

Epilepsy is a common disease that is mostly treated with antiepileptic drugs (AEDs). However, the sexual dysfunction (SD) side effects related to the use of AEDs have not received sufficient attention.

AREAS COVERED

The purpose of this review is to examine the current evidence on SD-related side effects of AEDs. The incidence, clinical features and major types of SD are summarized. Furthermore, various AEDs that may cause SDs are addressed in detail. Finally, we briefly summarize the treatments for SD related to AEDs.

EXPERT OPINION

SD related to AEDs is common. Symptoms include erectile dysfunction (ED), hyposexuality, hypersexuality and ejaculatory dysfunction. Traditional AEDs such as valproate and enzyme-inducing AEDs (EIAEDs) may produce high incidences of decreased libido. Recently, sexual function changes related to new AEDs have been reported. Topiramate, pregabalin and gabapentin may cause SD, whereas oxcarbazepine, lamotrigine and levetiracetam may improve sexual function. Although the treatment for SD related to AEDs remains unclear, switching to another AED may be an option. Further studies are necessary to better understand and treat SD related to AEDs.

Seizures and intracranial hemorrhage

Seizures and intracranial hemorrhage are possible medical diseases that any obstetrician may encounter. This article reviews the cause, treatment, and medical management in pregnancy for seizures and intracranial hemorrhage, and how the two can overlap into preeclampsia or eclampsia. This article also highlights some challenging management issues from the obstetrician's perspective.

The effects of oxcarbazepine and valproate therapies on growth in children with epilepsy

AIM

This study aimed to evaluate the effects of monotherapy with valproate or oxcarbazepine on the linear growth of children with idiopathic epilepsy.

METHODS

Antiepileptic treatment with valproate or oxcarbazepine was initiated in 76 patients. These were evaluated at baseline and at 6 and 18 months after commencement of therapy to determine height standard deviations (height z-scores). Serum ghrelin, insulin-like growth factor-1, and insulin-like growth factor-binding protein-3 levels were measured.

RESULTS

In prepubertal patients receiving oxcarbazepine, height z-scores were elevated after 6 and 18 months of therapy (p = 0.008 and p = 0.001, respectively); in pubertal patients, a significant increase was noted at the 18th month of therapy (p = 0.004). In prepubertal patients receiving oxcarbazepine, serum standardized insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 levels were significantly higher at the 18th month of therapy compared with baseline (p = 0.005 and p = 0.004, respectively). In puber-tal patients receiving valproate, serum ghrelin levels were significantly decreased at the 18th month of therapy compared with baseline (p = 0.006).

CONCLUSION

Exposure to oxcarbazepine stimulated linear growth in epileptic patients through mechanisms involving the release of insulin-like growth factor-1 and insulin-like growth factor-binding protein-3. In contrast, expo-sure to valproate did not affect linear growth, but did lead to a decrease in serum ghrelin levels.

The antiepileptic effect of sodium valproate during different phases of the estrous cycle in PTZ-induced seizures in rats

Catamenial epilepsy is a form of epilepsy which is related to the menstrual cycle. Cyclic variation in the levels of ovarian hormones plays a pivotal role in its pathogenesis. Sodium valproate (VPA) is one of the oldest antiepileptic drugs (AEDs) which inhibits hepatic metabolizing enzymes. The aim of this study was to evaluate the antiepileptic effects of VPA during different phases of the estrous cycle in rats. 72 adult female Wistar rats in three groups (control, 75 and 100 mg/kg VPA), each with four subgroups (proestrous, estrous, metestrous and diestrous) were used (n = 6). Initially, puberty was assessed using vaginal smears and rats with two regular cycles were selected. VPA with doses 75 and 100 mg/kg was administered intraperitoneally (i.p) in the treatment groups followed by i.p. injection of 80 mg/kg pentylentetrazol (PTZ) in the treatment and control groups. After induction of seizure by PTZ, initiation time of myoclonic seizures (ITMS), initiation time of tonic-clonic seizures (ITTS), seizures duration (SD) and mortality rate (MR) were recorded for 30 min. Data were presented as mean±SD, one-way ANOVA followed by Tukey-Kramer multiple comparison post hoc test were used for analysis of data (P < 0.05). The results of this study showed that VPA significantly improved antiepileptic parameters including ITMS, ITTS, SD, and MR, in which they were significantly more prominent during the luteal phase than the follicular phase (P < 0.05). In addition, there was no significant difference neither between proestrous and estrous nor between metestrous and diestrous in each separately group of rats (P > 0.05).

Two cases of precocious puberty associated with hypothalamic hamartoma

Hypothalamic hamartoma (HH) is a congenital malformation diagnosed based on magnetic resonance imaging (MRI) and histological findings; it is often associated with central precocious puberty (CPP), gelastic seizures, abnormal behavior and mental retardation. In the present paper, we report our retrospective hypothesis that there is a relationship between symptoms and therapy, as well as the treatment for HH, and describe two cases of HH associated with CPP. Both cases had sessile masses located in the interpeduncular cistern, with extension to the hypothalamus on MRI (1.2 × 1.5 cm and 2.0 × 2.5 cm, respectively). The first case had intractable seizures, while the second had no seizures with paroxysmal discharge. In both patients, the hamartomas were partially removed, by γ-knife and surgical operation in the first case and surgically in the second, and a gonadotropin releasing hormone (GnRH) analogue was prescribed. One case showed improvement of both intelligence quotient (IQ) score and seizures, and the other showed improvements in IQ and abnormal behavior. It was difficult to determine any topology/symptom relationships. Surgery and GnRH analogue treatment can alleviate seizures, abnormal behavior and mental retardation associated with HH.

Development of spike-wave seizures in C3H/HeJ mice

C3H/HeJ mice have been reported to have relatively early onset of spike-wave discharges (SWD), and a defective AMPA receptor subunit Gria4 as the genetic cause. We investigated the time course of SWD development through serial EEG recordings in C3H/HeJ mice to better characterize this model. We found that at immature postnatal ages of 5-15 days, rare SWD-like events were observed at an average rate of 3 per hour, and with relatively broad spikes, irregular rhythm, slow frequency (5-6 Hz), and short duration (mean 1.75 s). This was followed by a transitional period of increasing SWD incidence, which then stabilized in mature animals at age 26-62 days, with SWD at an average rate of 45 per hour, narrower spike morphology, regular rhythm, higher frequency (7-8 Hz), and longer duration (mean 3.40s). This sequence of maturational changes in SWD development suggests that effects of early intervention could be tested in C3H/HeJ mice over the course of a few weeks, rather than a few months as in rats, greatly facilitating future research on anti-epileptogenesis.

Oxcarbazepine treatment in male epilepsy patients improves pre-existing sexual dysfunction

OBJECTIVE

To collect data on sexual dysfunction in a larger population of male patients with epilepsy treated with oxcarbazepine in a naturalistic setting.

PATIENTS AND METHODS

Six hundred seventy-three adult male patients with partial epilepsy in whom monotherapy with oxcarbazepine was indicated were evaluated at baseline and after approximately 12 weeks of treatment with regard to the number of seizures and occurrence of any adverse drug reactions. All patients were questioned regarding their sexual function.

RESULTS

Out of 228 patients with pre-existing sexual function impairment at baseline, an improvement was observed in 181 (79.4%) patients, 23 (10.1%) patients experienced no impairment at the final visit. The improvements were more marked in those patients, who were pretreated with enzyme-inducing antiepileptic drugs. No worsening of the sexual dysfunction was observed.

CONCLUSIONS

Oxcarbazepine was found to have beneficial effects on sexual dysfunction and to be effective and well tolerated in male patients with partial epilepsy.

Hormonal influences on seizures: basic neurobiology

There are sex differences and effects of steroid hormones, such as androgens, estrogens, and progestogens, that influence seizures. Androgens exert early organizational and later activational effects that can amplify sex/gender differences in the expression of some seizure disorders. Female-typical sex steroids, such as estrogen (E2) and progestins, can exert acute activational effects to reduce convulsive seizures and these effects are mediated in part by the actions of steroids in the hippocampus. Some of these anticonvulsive effects of sex steroids are related to their formation of ligands which have agonist-like actions at gamma-aminobutyric acid (GABAA) receptors or antagonist actions at glutamatergic receptors. Differences in stress, developmental phase, reproductive status, endocrine status, and treatments, such as anti-epileptic drugs (AEDs), may alter levels of these ligands and/or the function of target sites, which may mitigate differences in sensitivity to, and/or tolerance of, steroids among some individuals. The evidence implicating sex steroids in differences associated with hormonal, reproductive, developmental, stress, seizure type, and/or therapeutics are discussed.

Influence of sex hormones on brain excitability and epilepsy

Epilepsy is one of the most common neurologic problems worldwide. In spite of the many studies carried out, our understanding of generalized epileptogenesis remains far from complete. In recent years many data have clarified the effects of sexual hormones on brain excitability. Female and male sexual hormones may be considered pharmacoactive compounds that alter the seizure threshold, changing the frequency and semeiology of the seizures. In particular, estrogens may increase neuronal excitability while progesterone enhances inhibitions and increases the seizure threshold; on the other hand, androgens can decrease ictal activity in the human brain. This review provides an overview of the current knowledge in this field and highlights some of the prevailing hypotheses about the effects of sexual hormones on neuronal excitability analysing data from both animal and clinical studies.

Steroids in relation to epilepsy and anaesthesia

Increasing numbers of reports indicate direct effects of ovarian steroids on the central nervous system. Effects of progesterone and its metabolites on brain excitability in humans and in experimental animals have been studied. Anti-epileptic effects have been shown in cats and in women with partial epilepsy and well-defined epileptic foci. The reduced progesterone metabolite 5 alpha-pregnan-3 alpha-ol-20-one and its 5 beta analogue also decreased the epileptic activity resulting from a penicillin-induced cortical focus in cats. 5 alpha-Pregnan-3 alpha-ol-20-one protected mice against metrazol-, bicuculline- and picrotoxin-induced seizures but not against electroshock-and strychnine-induced seizures. Progesterone, 5 alpha-pregnan-3 alpha-ol-20-one and 5 beta-pregnan-3 alpha-ol-20-one also induce anaesthesia in humans and animals; in a rat model of anaesthesia 5 alpha-pregnan-3 alpha-ol-20-one was eight times more potent than methohexitone (the most potent anaesthetic barbiturate). Anaesthesia with loss of the eyelash reflex was observed in humans 75-90 seconds after the intravenous injection of 5 beta-pregnan-3 alpha-ol-20-one in lipid emulsion. The in vivo production and brain distribution of centrally active steroids has also been studied in relation to the phases of the ovarian and menstrual cycle. A subset of women with epilepsy show changes in seizure frequency in relation to hormonal variations during the menstrual cycle. In the luteal phase when progesterone levels are high the number of generalized seizures is low. It is possible that progesterone and its metabolites play a role in epileptic seizures and also in the premenstrual syndrome.

Epileptic fits and epilepsy in the elderly: general reflections, specific issues and therapeutic implications

Seizures and epilepsy are commonly encountered in the elderly. Diagnosis is not always straightforward as reliable history is often difficult to obtain and EEG findings can be non-specific. When to treat and how may be difficult choices as adequate studies in elderly are rather scarce. Treatment should be based on careful assessment and comparison of risk/benefit profiles of various anti-epileptic drugs (AEDs) in this specific elderly population. Since most AEDs are effective in terms of seizure control in the elderly, the choice of treatment is often determined by tolerability, pharmacokinetic profile and drug interactions of AEDs. As recently introduced AEDs have a better safety profile compared to older agents it seems logical to initiate treatment in the frail elderly patient with those more modern AEDs. In this review some distinctive clinical features of epilepsy in the elderly are discussed in three sections (general issues, special issues and selected treatment options with special reference to medicinal treatment).

Effects of carbamazepine and oxcarbazepine on the reproductive endocrine function in women with epilepsy

PURPOSE

The aim of the study was to compare the effects of carbamazepine (CBZ) and oxcarbazepine (OXC) on the reproductive endocrine function in women with epilepsy. OXC is a novel antiepileptic drug (AED), and the occurrence of reproductive dysfunction in women treated with OXC monotherapy for epilepsy has not been studied previously.

METHODS

Thirty-five women with epilepsy were examined in the Department of Neurology at Oulu University Hospital. Sixteen patients were treated with CBZ monotherapy, and nineteen patients were treated with OXC monotherapy. The subjects were clinically examined, vaginal ultrasonography was performed, and serum sex hormone concentrations were measured.

RESULTS

The women taking CBZ or OXC had lower serum testosterone (T) levels and lower free androgen indexes (FAIs) than the control subjects. CBZ medication was associated with increased concentrations of serum sex hormone-binding globulin (SHBG). The patients taking OXC had higher concentrations of dehydroepiandrosterone sulfate (DHEAS) and androstendione (A) than did the women taking CBZ. Moreover, the prevalence of polycystic ovaries (PCOs) was high in the OXC-treated women.

CONCLUSIONS

CBZ and OXC have different effects on the reproductive endocrine function. Although both drugs were associated with low serum T concentrations and low FAIs, only OXC was associated with a high frequency of elevated levels of A and DHEAS and with an increased prevalence of PCOs. These findings suggest that OXC may be disadvantageous for women with epilepsy and hyperandrogenism, whereas CBZ may be beneficial for these women.

The role of estrogens in seizures and epilepsy: the bad guys or the good guys?

Estrogens influence neuronal activity and are important for normal brain functions. Effects of estrogens on seizures are contradictory. It is commonly accepted that estrogens may increase neuronal excitability and thus mediate proconvulsant effects. However, clinical and animal data show that estrogen may also have no effect or anticonvulsant effects. The action of estrogens on seizures depends on various factors, such as treatment duration and latency prior to the seizure testing, estrogen dose, hormonal status (naïve vs gonadectomized animals), estrogenic substance, the region/neurotransmitter system involved, the seizure type/model used, and sex. Besides the effects on seizure susceptibility, estrogens may also play an important role in seizure-induced damage. Pretreatment with beta-estradiol in ovariectomized female rats has neuroprotective effects on status epilepticus-induced hippocampal damage and prevents the loss of inhibition in the dentate gyrus during the early post-status epilepticus period determined by the in vitro paired pulse paradigm. Several signaling pathways may be involved in the neuroprotective effects of beta-estradiol on status epilepticus-induced hippocampal damage but at least one of these pathways involves interactions with neuropeptide Y.

Reproductive function and risk for PCOS in women treated for bipolar disorder

INTRODUCTION

This study examined the reproductive function and prevalence of polycystic ovary syndrome (PCOS) in women with bipolar disorder taking antimanic medications.

METHOD

Women aged 18-45 treated for bipolar disorder and not taking steroid contraceptives were recruited to complete questionnaires about their menstrual cycle and to provide blood samples for measurement of a range of reproductive endocrine and metabolic hormone levels. Eighty women participated in completing the questionnaires and 72 of them provided blood samples.

RESULTS

Fifty-two of the 80 women (65%) reported current menstrual abnormalities, 40 of which (50%) reported one or more menstrual abnormalities that preceded the diagnosis of bipolar disorder. Fifteen women (38%) reported developing menstrual abnormalities since treatment for bipolar disorder, 14 of which developed abnormalities since treatment with valproate (p = 0.04). Of the 15 patients reporting menstrual abnormalities since starting medication, 12 (80%) reported changes in menstrual flow (heavy or prolonged bleeding) and five (33%) reported changes in cycle frequency. No significant differences were observed between women receiving or not receiving valproate in mean levels of free or total serum testosterone levels. This was true for the total sample and for the sub-group without preexisting menstrual problems. However, within the valproate group, duration of use was significantly correlated with free testosterone levels (r = 0.33, p = 0.02). Three of the 50 women (6%) taking VPA, and 0% of the 22 taking other antimanic medications, met criteria for PCOS (p = 0.20). Other reproductive and metabolic values outside the normal range across treatment groups included elevated 17 alpha-OH progesterone levels, luteinizing hormone: follicle-stimulating hormone ratios, homeostatic model assessment (HOMA) values, and low estrogen and dehydroepiandrosterone sulfate (DHEAS) levels. Preexisting menstrual abnormalities predicted higher levels of 17 alpha-OH progesterone, free testosterone, and estrone as well as development of new menstrual abnormalities. Body mass index (BMI) was significantly positively correlated with free testosterone levels and insulin resistance (HOMA) across all subjects, regardless of medication used.

CONCLUSIONS

Rates of menstrual disturbances are high in women with bipolar disorder and, in many cases, precede the diagnosis and treatment for the disorder. Treatment with valproate additionally contributes significantly to the development of menstrual abnormalities and an increase in testosterone levels over time. A number of bipolar women, regardless of type of medication treatment received, have reproductive and metabolic hormonal abnormalities, yet the etiology of such abnormalities requires further study. Women with preexisting menstrual abnormalities may represent a group at risk for development of reproductive dysfunction while being treated for bipolar disorder.

Seizures in the Developing Brain

PURPOSE

Development and sex hormones are important determinants of seizure susceptibility. Seizures develop in the immature brain more readily than in the mature brain. Male children experience a higher incidence of epilepsy or unprovoked seizures than do female children. Sex-specific differences in the development of seizure-suppressing neuronal networks may account, at least in part, for this increased age- and sex-related susceptibility to seizures. The control of seizures can be influenced by the substantia nigra pars reticulata (SNR) in an age- and sex-specific manner. In the adult male rat SNR, two topographically discrete regions (SNRanterior and SNRposterior) mediate distinct effects on seizures, by using divergent output networks in response to localized infusions of gamma-aminobutyric acid (GABA)A agents, such as muscimol. The GABAA-sensitive "anticonvulsant" region is located in the SNRanterior, whereas the GABAA-sensitive "proconvulsant region is in the SNRposterior. In immature postnatal day (PN)15-21 male rats, the SNR is not topographically segregated, and GABAAergic drug infusions produce similar effects when applied in the SNRanterior or SNRposterior. Only a GABAA-sensitive proconvulsant network is evident. By contrast, female SNR does not contain any region that mediates muscimol-related proconvulsant effects. As with the adult, immature female rats do not develop a proconvulsant SNR region at any age.

METHODS

We measured the effects of SNR muscimol infusions on seizures in male rats castrated at birth to better understand the effects of testosterone on the formation of age- and sex-specific features of the SNR.

RESULTS

Neonatal castration permanently alters the maturation of the muscimol-sensitive SNR effect on seizures. The SNR of neonatally castrated rats develops functionally like the "female" SNR. The "proconvulsant" SNR region does not develop in the absence of testosterone in the immediate postnatal period. The "male" type of SNR effects can be induced in neonatally castrated rats by restoration of testosterone levels or in female rats by artificially increasing testosterone levels. Dihydrotestosterone and estrogen, produced by the reduction and aromatization of testosterone, respectively, are the direct mediators of testosterone actions. At PN0, only beta estrogen receptors are equally expressed in the SNRs of males and females and may be responsible for testosterone-mediated effects in both sexes.

CONCLUSIONS

The phenotype of SNR GABAergic neurons, as characterized by GABAA-receptor subunit composition, by muscimol-induced electrophysiologic responses, and by connectivity of output networks each may be altered by the presence of testosterone. Higher KCC2 messenger RNA (mRNA) expression in female PN15 SNR neurons compared with males may be responsible for sex-related differences in muscimol-induced electrophysiologic responses. In summary, a growing body of compelling evidence identifying sex-related differences in the SNR implicates postnatal testosterone as a critical factor in the development of pro- or anticonvulsant circuits. The recognition of sex- and age-related features in the SNR holds the promise that these findings can be translated into the development of specific and effective treatments for seizure disorders.

Gonadal, adrenal, and neuroactive steroids' role in ictal activity

Of the many people that have epilepsy, only about 70% achieve seizure control with traditional pharmacotherapies. Steroids have long been known to influence ictal activity and may have a therapeutic role. This review summarizes recent investigations that have enhanced knowledge of the effects and mechanisms of gonadal, adrenal, and neuroactive steroids on seizure processes. Progesterone, which varies across reproductive cycles, pregnancy, and as a function of aging, has been shown to have anti-seizure effects among women with epilepsy and in animal models of epilepsy. Further, data suggest that progesterone's anti-seizure effects may involve its metabolism to the neuroactive steroid, 5 alpha-pregnan-3 alpha-ol-20-one (3 alpha,5 alpha-THP), and its subsequent actions at GABA(A) receptors. Androgens also have anti-seizure effects. Androgens' anti-seizure effects may be mediated, in part, through actions of the testosterone metabolite, and neuroactive steroid, 5 alpha-androstane-3 alpha,17 alpha-diol (3 alpha-diol) at GABA(A) receptors. Stress can alter seizure susceptibility, suggesting a role of adrenal steroids on seizure processes. In animal models of epilepsy, acute or chronic stress can increase ictal activity. Notably, stress and seizures can alter levels of gonadal, adrenal, and neuroactive steroids, which may then influence subsequent seizure activity. Thus, this review summarizes recent progress in the role of gonadal, adrenal, and/or neuroactive steroids in seizure processes which suggest that greater understanding of these steroids' effects and mechanisms may ultimately lead to improved seizure control for people with epilepsy.

Influence of sexual hormone antagonists on the anticonvulsant action of conventional antiepileptic drugs against electrically- and pentylenetetrazol-induced seizures in mice

The present results refer to the action of three gonadal steroid antihormones, tamoxifen (TXF, an estrogen antagonist), cyproterone acetate (CYP, an antiandrogen) and mifepristone (MIF, a progesterone antagonist) on seizure phenomena in mice. TXF and CYP at their lowest protective dose in the electroconvulsive threshold test, enhanced the antiseizure efficacy of some antiepileptic drugs. TXF (20 mg/kg) potentiated the protective activity of valproate, diphenylhydantoin and clonazepam, but not that of carbamazepine or phenobarbital, against maximal electroshock-induced convulsions in female mice. CYP (40 mg/kg) enhanced the anticonvulsant action of valproate, carbamazepine, diphenylhydantoin and clonazepam, but not that of phenobarbital, against maximal electroshock in male animals. MIF failed to affect the electroconvulsive threshold or the efficacy of antiepileptic drugs in maximal electroshock. The effect of TXF or CYP upon the electroconvulsive threshold and on the action of antiepileptics was not reversed by sex steroid hormones (estradiol, testosterone, progesterone). However, the TXF-induced elevation of the electroconvulsive threshold was abolished by bicuculline, N-methyl-D-aspartic acid and kainic acid, and partially reversed by aminophylline, strychnine being ineffective in this respect. The action of CYP on the threshold for electroconvulsions was partially reversed by bicuculline and aminophylline. Both glutamatergic agonists and strychnine remained ineffective in this respect. Moreover, the action of TXF or CYP on the activity of antiepileptics was not influenced by strychnine, and reversed to various extents by the remaining convulsants. In contrast to maximal electroshock, none of the three antihormones affected the protective action of antiepileptic drugs against pentylenetetrazol-induced seizures in mice. Neither TXF nor CYP altered the free plasma levels of antiepileptic drugs, so a pharmacokinetic interaction is not probable. The combined treatment of the two antihormones with antiepileptic drugs, providing 50% protection against maximal electroshock, did not affect motor performance in mice, and did not result in significant long-term memory deficits. Our data indicate that steroid receptor-mediated events may be indirectly associated with seizure phenomena in the central nervous system and can modulate the protective activity of some conventional antiepileptic drugs.

Conditions affecting the onset, severity, and progression of a spontaneous pain-like behavior after excitotoxic spinal cord injury

Intraspinal injection of quisqualic acid (QUIS) is associated with the development of spontaneous excessive grooming behavior in male Sprague Dawley rats. To further characterize this pain-like behavior we evaluated the relationship between the onset of this behavior and the rostrocaudal spread of injury-induced neuronal loss in 3 different strains of male rats. The severity and progression of this behavior also were evaluated. Unilateral intraspinal injections of 125 mmol/L QUIS were made in the following groups: Sprague Dawley males (SDMs, n = 21); Long Evans males (LEMs, n = 17); and Wistar Furth males (WFMs, n = 11). Because of differences in grooming characteristics between male and female rats, the modulatory effects of female gonadal hormones also were evaluated in Sprague Dawley females (SDFs, n = 17); bilaterally ovariectomized Sprague Dawley females (OVXs, n = 11); and SDMs treated with either 17-beta-estradiol (50 microg/kg; SDM-Est, n = 9) or progesterone (5 mg/kg; SDM-Pro, n = 11). The results showed that the development of excessive grooming behavior in males of all strains and ovariectomized females is related to the rostrocaudal spread of a specific pattern of neuronal loss in the dorsal horn. Excessive grooming behavior in SDFs was similar in many respects to that found in SDMs; however, SDFs did not show a dependence on the longitudinal extent of injury for the onset of this behavior. The onset, severity, and progression of excessive grooming in OVX females were similar to that found in SDMs. Furthermore, 8 of 9 estradiol-treated SDMs developed severe grooming characterized by an early onset and progressive time course, whereas progesterone treatment delayed the onset of grooming and attenuated its severity and progression. Strain-related differences in some, but not all, grooming characteristics also were observed, eg, WFMs exhibited more aggressive grooming than SDMs or LEMs. In conclusion, the results showed gender, strain, and gonadal hormones influence the onset and progression of injury-induced excessive grooming behavior. A causal relationship also was found between the onset of this behavior and the longitudinal extent of injury.

Do women with epilepsy have increased frequency of menstrual disturbances?

PROBLEM

Menstrual disorders, reduced fertility and sexual problems seem to be more frequent in women with epilepsy than in the general population. Most investigations concerning menstrual disturbances in epilepsy patients, however, are small and based on selected materials. We therefore wanted to investigate the frequency of menstrual disturbances in a large, unselected population of epilepsy patients.

METHODS

A retrospective, questionnaire study of a cohort of female outpatients, aged 18-45 was conducted. Each patient chose a close female friend who served as control, to optimise matching regarding age and lifestyle.

RESULTS

Answers were received from 265 patients and 142 controls. Menstrual disturbances were more frequent in patients with epilepsy (48.0%) than in controls (30.7%) (P=0.004). Menstrual disturbances were more frequent in patients on polytherapy versus monotherapy (P=0.049) and more frequent in patients with high seizure frequency (>5seizures/year) compared to patients with a lower seizure frequency or those seizure free (P=0.006). The frequency of menstrual disturbances was higher in patients on valproate compared to carbamazepine monotherapy (P=0.045).

CONCLUSION

This investigation confirms that women with epilepsy have an increased frequency of menstrual disturbances compared to women without epilepsy. In women with high seizure frequency and in those on polytherapy, the frequency of menstrual disturbances are further increased. The highest frequency of menstrual disturbances occurred in women using valproate.

Polycystic ovary syndrome and epilepsy--a gynaecological perspective

The prevalence of polycystic ovaries (PCO) and polycystic ovary syndrome (PCOS) in the general population is approximately 20 and 10%, respectively, and published studies suggest a similar prevalence in women with epilepsy. These data do not suggest that epilepsy is associated with a higher prevalence of the condition, and it would appear that the background prevalence of PCO and PCOS is the same as in the general population.

Influence of sex hormone antagonists on the anticonvulsant action of conventional antiepileptic drugs against amygdala-kindled seizures in male and female rats

The effects of three gonadal steroid antihormones, tamoxifen (TXF, an estrogen antagonist), cyproterone acetate (CYP, an antiandrogen) and mifepristone (MIF, a progesterone antagonist) alone or combined with conventional antiepileptics were evaluated in amygdala-kindled seizures in male and female rats. None of the three antihormones used in this study affected any seizure parameter. TXF (50 mg/kg) and CYP (50 mg/kg), when combined with carbamazepine, or phenobarbital applied at their subprotective doses of 15 mg/kg, resulted in significant reductions of the seizure and afterdischarge durations, both in male and female rats. Additionally, the combination of carbamazepine and CYP markedly increased the afterdischarge threshold in fully-kindled rats of both genders. The interaction between antihormones and carbamazepine, or phenobarbital, was not reversed by respective sex steroid hormones (estradiol, testosterone). However, the TXF- and CYP-induced anticonvulsant effects in combinations with carbamazepine were attenuated by bicuculline, N-methyl-D-aspartate (NMDA) and aminophylline. Kainic acid and strychnine remained ineffective in this respect. The effect of a combination of TXF with phenobarbital was reversed by bicuculline and NMDA and that of CYP with phenobarbital-by bicuculline and aminophylline. Neither TXF nor CYP altered the free plasma concentrations of carbamazepine or phenobarbital, so a pharmacokinetic interaction is not probable. The combined treatment of the two antihormones with antiepileptic drugs did not affect motor performance, and did not result in significant long-term memory deficits. Our data confirm the hypothesis that sex hormone antagonist-mediated events may play some role in seizure processes in the central nervous system and can modulate the protective activity of some conventional antiepileptic drugs against kindled seizures.

Finasteride inhibits the progesterone-induced spike-wave discharges in a genetic model of absence epilepsy

Previously, it was found that progesterone aggravates spike-wave discharges (SWD) in WAG/Rij rats in a nongenomic way. In order to elucidate whether the regulatory effect of progesterone depends on its conversion to allopregnanolone, the effect of finasteride, a 5alpha-reductase inhibitor, on progesterone-induced increase in SWD was studied in the same model for absence epilepsy. Progesterone (10 and 20 mg/kg ip) dose-dependently increased the number of SWD (by 54% and 97%, respectively) during the first hour postinjection. Pretreatment of rats with finasteride (50 mg/kg sc) blocked the progesterone-induced enhancement of SWD. Finasteride alone had no effect on the number of SWD, up to 24 h following its administration. It is concluded that finasteride blocked the progesterone-induced increase in SWD, which indicates that this action of progesterone is mediated by its neuroactive metabolite allopregnanolone.

Estradiol alters afterdischarge threshold and acquisition of amygdala kindled seizures in male rats

We have previously shown that estradiol (E(2)) can initially increase and then decrease kindle seizure parameters in amygdala kindled male rats. This study focuses on the effects of estradiol benzoate (EB) on afterdischarge (AD) threshold and electrical kindling acquisition in intact male rats. After implantation of tripolar and monopolar electrodes in amygdala and dura surface respectively, effects of EB on AD threshold and electrical kindling acquisition were investigated by daily injection of EB (microg/kg) or sesame oil (EB solvent) in different groups of male rats. AD threshold was reduced significantly 0.25 h post EB treatment and reached to the lowest value after 24 h and remained almost constant at low values. Also, the number of trials for stage 5 (S(5)) and cumulative seconds of AD to complete kindling decreased significantly, when compared to rats without EB treatment. These results support a marked influence of E(2) on seizure process and convulsive pattern in the brain of male rats. Base on the previous reports about female rats and our findings, these E(2) effects are probably not sex dependent.

Sex differences in hippocampal slice excitability: role of testosterone

In vivo fluctuations in gonadal hormones alter hippocampal excitability and modulate both physiological and pathological hippocampal processes. To assess hormonal effects on excitability within a functional hippocampal circuit, extracellular CA1 field responses were compared in slices from intact male, intact female, orchidectomized male, and ovariectomized female rats. Secondly, the effects of in vitro applications of 17-beta estradiol, progesterone, or testosterone on baseline excitability of slices from gonadectomized rats were assessed versus pre-hormone baseline measures. Finally, using the in vitro kindling model of slice epileptogenesis, steroid hormone effects on interictal-like activity were also examined. Significant sex differences in excitatory postsynaptic potential amplitude were observed, with slices from males having larger excitatory postsynaptic potential amplitudes than those from females. Gonadectomy significantly decreased excitatory postsynaptic potential amplitude in slices from male rats. Slices from gonadectomized male and female rats also showed a decreased dendritic excitatory postsynaptic potential slope relative to slices from intact male and females rats. In vitro application of testosterone significantly increased excitatory postsynaptic potential amplitudes in slices from both orchidectomized males and ovariectomized females and the population spike amplitude of slices from ovariectomized females. Following in vitro kindling, slices from intact males showed greater spontaneous burst rates than slices from intact females, further suggesting an excitatory effect of testosterone. These results suggest: (1) a sex difference in the level of baseline excitability between slices from intact males and females as measured by excitatory postsynaptic potential amplitudes, (2) testosterone has excitatory effects on baseline physiology and kindled hippocampal responses, and (3) slices from males show a greater level of excitability than those from females in the in vitro kindling model.

Neuroactive steroids and central nervous system disorders

Steroid hormones are vital for the cell life and affect a number of neuroendocrine and behavioral functions. In contrast to their endocrine actions, certain steroids have been shown to rapidly alter brain excitability and to produce behavioral effects within seconds to minutes. In this article we direct attention to this issue of neuroactive steroids by outlining several aspects of current interest in the field of steroid research. Recent advances in the neurobiology of neuroactive are described along with the impact of advances on drug design for central nervous system (CNS) disorders provoked by neuroactive steriods. The theme was selected in association with the clinical aspects and therapeutical potentials of the neuroactive steroids in CNS disorders. A wide range of topics relating to the neuroactive steroids are outlined, including steroid concentrations in the brain, premenstrual syndrome, estrogen and Alzheimer's disease, side effects of oral contraceptives, mental disorder in menopause, hormone replacement therapy, Catamenial epilepsy, and neuractive steroids in epilepsy treatment.

Hyperandrogenism, postprandial hyperinsulinism and the risk of PCOS in a cross sectional study of women with epilepsy treated with valproate

Among a sample of 43 women with epilepsy treated for at least 2 years with valproate (n=22) or other antiepileptic drugs (AEDs) (n=21), polycystic ovary syndrome (PCOS) was diagnosed in three women, two of them were treated with valproate. Although the rate of PCOS and of menstrual disturbances, weight body mass index (BMI) and waist to hip ratio as well as fasting blood glucose levels, fasting insulin, proinsulin and C-peptide values was similar in this small sample of women treated with valproate and other AEDs, valproate exposure was associated with higher androgen levels, higher postprandial (pp) insulin and proinsulin levels, as well as lower cholesterol and low density lipoprotein (LDL) cholesterol levels. The pronounced increase in pp insulin levels during VPA treatment may indicate an effect of the fatty acid derivate VPA on pancreatic islet cells.

Effects of carbamazepine on the first ovulation in gonadotropin-primed immature female rats

1. The effects of carbamazepine (CBZ) and its possible mechanisms on the first ovulation were investigated in immature female rats. The first ovulation was induced by administration of equine chorionic gonadotropin (eCG) at 0800 h at 26 days of age. 2. A single s.c. injection of 360 mg x kg(-1) CBZ at 1300 h on the first pro-oestrus (day 28) completely inhibited the first ovulation on the morning of day 29. A marked elevation in 13, 14-dihydro-prostaglandin F2alpha (13, 14H2-PGF2alpha) forming capacity, a sensitive indicator of luteinizing hormone (LH) surge, was not detected in the CBZ-treated group at 0800 h on day 29 (72 h after eCG treatment). The elevation in serum LH levels at 57 h after eCG treatment was not observed in the CBZ-treated group, either. The blocking of the first ovulation and 13, 14H2-PGF2alpha forming capacity were recovered by an i.p. injection of human CG on day 28 in all animals. 3. However, the first ovulation was not blocked by repeated injections of 360 mg x kg(-1) CBZ at 1300 h once daily for 3 days (days 26 - 28). The repeated injections of CBZ caused a great fall (64% decrease) in the serum levels of CBZ at 4 h after the final CBZ injection as compared with the case of a single injection of CBZ and resulted in a delay for 5 h the occurrence of LH surge, which is normally observed around 57 h after eCG injection. 4. A significant increase in the activity of microsomal CBZ catabolism by the repeated injections of CBZ was quantitatively verified by the HPLC analysis. But, the activity of CBZ metabolism in the single injected-animals showed almost similar levels to that in the control. 5. The present results demonstrated that a single injection of CBZ blocks the ovulation by inhibiting LH surge but that the failure of the inhibition of ovulation by repeated injections of CBZ is due to a decrease in serum CBZ levels mediated through CBZ-induced hepatic enzyme induction.

Prenatal morphine exposure induces age- and sex-dependent changes in seizure susceptibility

1. Prenatal exposure to morphine induces long-term alterations in seizure susceptibility, which are age-, sex-, and seizure model-specific. 2. Adult male and female rats exposed prenatally to morphine show decreased susceptibility to GABA-regulated seizures. 3. Prenatally morphine-exposed, adult male rats are more sensitive to excitatory amino acid receptor-mediated seizures than control males, control females, or morphine-exposed females.

Brain damage, sex hormones and recovery: a new role for progesterone and estrogen?

Estrogen and progesterone, long considered for their roles as primary hormones in reproductive and maternal behavior, are now being studied as neuroprotective and neuroregenerative agents in stroke and traumatic brain injuries. Collectively, the hormones reduce the consequences of the injury cascade by enhancing anti-oxidant mechanisms, reducing excitotoxicity (altering glutamate receptor activity, reducing immune inflammation, providing neurotrophic support, stimulating axonal remyelinization), and enhancing synaptogenesis and dendritic arborization. Estrogen seems more effective as a prophylactic treatment in females at risk for cardiac and ischemic brain injury, whereas progesterone appears to be more helpful in the post-injury treatment of both male and female subjects with acute traumatic brain damage. However, a recent clinical trial with estradiol replacement therapy in elderly women that have a history of cerebrovascular disease, showed that this hormone was unable to protect against reoccurrence of ischemia or to reduce the incidence of mortality compared to a placebo.

Seizures, hormones and sexuality

Sexual disorders (both hyposexuality and sexual dysfunction) are common in people with epilepsy, occurring in up to two-thirds of patients. However, characteristically, patients do not spontaneously report these problems. Nocturnal penile tumescence testing suggests that the erectile dysfunction has a neurophysiological component. The aetiology remains uncertain but is likely to be multifactorial, involving neurological, endocrine, iatrogenic, cognitive, psychiatric and psychosocial factors. Epilepsy-related factors include the age of onset/duration of epilepsy along with the seizure type and focus. In addition, seizure frequency might be relevant as successful epilepsy surgery can result in an improvement in sexual functioning despite remaining on anticonvulsant medication. Endocrine changes (raised sex hormone binding globulin and reduced free testosterone) have been reported in men with epilepsy, especially when treated with hepatic-enzyme inducing antiepileptic drugs. Studies have not been performed evaluating anticonvulsants that do not induce hepatic enzymes such as lamotrigine. The association between these endocrine changes and hyposexuality is not known. The relationship between seizures, hormones and anticonvulsant medication in women is explored, focusing on issues such as catamenial epilepsy, the menopause, hormone replacement therapy and the polycystic ovarian syndrome. Suggestions for future research and treatment issues are discussed.

Effects of chronic estradiol benzoate treatment on amygdala kindled seizures in male rats

In the female species, effect of estrogens on seizure activity is well documented, but not much is known on the effect of this ubiquitous steroid hormone on the seizure activity of the male species. In the present study, fully kindled male rats were treated with various doses (10, 30 and 50 microg/kg, i.p.) of estradiol benzoate (EB) daily, and kindled seizure parameters such as seizure stage (SS), after discharge duration (ADD) and stage 5 duration (S(5)D) were recorded at various times (0.25, 3 h and every 24 h for 96 h) after the first of daily EB treatments. While the 10-microg/kg dose of EB failed to produce any significant effect, the 30-microg/kg dose induced a triphasic effect on seizure parameters. An initially rapid increment of ADD (after 0.25 h), followed by significant decrease of all parameters at 48 h and later a significant increase in S(5)D was observed 96 h after the first of daily EB treatments. The 50-microg/kg dose of EB produced almost a similar but less marked pattern of effects. Pre-treatment with a 3-mg/kg dose of tamoxifen citrate (TAM), not only blocked the EB (30 microg/kg) effects till 72 h but also reduced the ADD and S(5)D significantly after 0.25 h, when compared to its control group. While pre-treatment with the 10-mg/kg dose of TAM only blocked the inhibitory effects of EB 48 h after the first of daily EB treatments. Administration of the latter dose of TAM alone induced a profile similar to EB treatment. These results may suggest that in male rats, estradiol treatment can both potentiate and attenuate kindled seizure parameters in a time dependent manner, and the stimulatory effects can not be blocked by TAM pre-treatment.

Valproate, but not lamotrigine, induces ovarian morphological changes in Wistar rats

Valproate (VPA) medication is associated with development of polycystic ovaries, menstrual disorders and hormonal changes in women with epilepsy. We sought to determine if changes in the ovaries also occurred in an animal model without epilepsy, and whether this effect could be related to a carcinogenic effect expressed by overexpression of p53. A potentially alternative antiepileptic drug, lamotrigine (LTG), was evaluated simultaneously. To this end, female Wistar rats were fed perorally with VPA 400 mg/kg/day (n = 15), VPA 600 mg/kg/day (n = 20), LTG 10 mg/kg/day (n = 15) or control solution (n = 15) for 90-95 days. There was a significant, dose-dependent increase in the number of follicular cysts, reduction in the number of corpora lutea and reduction of ovarian weight in the VPA group. No ovarian pathology was observed in the LTG group. In neither of the groups were morphological changes seen in other organs, nor was there any overexpression of the tumor suppressor gene p53 found. An alternative antiepileptic drug, LTG, showed no ovarian pathology, and there were no light microscopic changes in other organs, or evidence of pathologic p53 overexpression in the LTG-treated animals.

The effect of seizures and kindling on reproductive hormones in the rat

Reproductive dysfunction and endocrine disorders are common among both women and men with epilepsy, and, in particular, with temporal lobe epilepsy. In clinical studies, it is hard to separate the effects of seizures from the effects of medication and life style. Studies in rodents, however, suggest that seizures per se can contribute to reproductive dysfunction. In female rats, generalized seizures disrupt normal ovarian cyclicity in adults, and repeated electroshock seizures delay the onset of puberty in juveniles. Right amygdala kindling in adult female rats causes acyclicity, the development of polycystic ovaries and premature aging of the hypothalamic-pituitary neuroendocrine axis, leading to chronic anovulation and continuous estrogen exposure. In adult male rats, repeated electroshock seizures result in transient hypogonadism, characterized by decreased serum testosterone levels and lowered gonadal tissue weight. In contrast, right amygdala kindling increases serum testosterone, estradiol levels and gonadal weight. These findings suggest that reproductive dysfunction in women and men with epilepsy may result from recurrent seizure activity, due to seizure-related interference with the normal functions of the hypothalamic-pituitary-gonadal axis.

Phenytoin inhibits both the first ovulation and uterine development in gonadotropin-primed immature rats

This study was planned to determine the effects and possible mechanism of action of phenytoin on development of the reproductive tract and first ovulation in immature rats. Rats were injected s.c. with 5 IU of equine chorionic gonadotrophin (equine CG) on day 26 to induce ovarian and uterine development. Treatment with phenytoin (140 mg/kg) at 1200 h on day 28, which induces serum levels approximately twice those reached with the clinical dose as anticorvulsant drug for humans, was effective for inhibiting the first ovulation and normal secretion of serum follicle - stimulating hormone and luteinizing hormone (LH) on day 29 as well as the preovulatory gonadotrophin surge on day 28. The block of ovulation was overcome by administration of human chorionic gonadotrophin or LH-releasing hormone on day 28. Simultaneous treatment with equine CG and phenytoin at 0800 h on day 26 did not affect either ovarian weight or ovarian hormones secretion, whereas phenytoin clearly inhibited the normal increase in uterine weight on day 27. Furthermore, phenytoin suppressed uterine growth after 17beta-oestradiol injection. These results indicate that phenytoin inhibits the first ovulation by inhibiting the gonadotrophin surge and further, that the drug impairs the stimulatory effects of oestrogen on uterine proliferation in the gonadotropin-induced ovulation model.

Sexual dysfunction in epilepsy: identifying the psychological variables

In order to evaluate the psychological variables that affect sexual dysfunction (SD) in epilepsy, where compared 60 epileptics (Group 1) with 60 healthy individuals (Group 2), through the State-Trait Anxiety Inventory (Spielberger et al., 1970), Beck Depression Inventory (Beck, 1974) and Sexual Behavior Interview (Souza, 1995). Sexual dysfunction (SD), anxiety and depression were found more frequently in Group 1 than in Group 2 and were not related to sex. Variables such as the onset duration and frequency of seizures as well as the use to medication were not associated with SD. Temporal lobe epilepsy was related to SD (p = 0.035) but not to anxiety or depression. Anxiety and depression were related to SD in both groups. Perception in controlling the seizures was closely related to anxiety (p = 0) and depression (p = 0.009). We conclude that psychological factors play an important role in the alteration of sexual behavior in epileptics and that suitable attention must be given to the control of these variables.

Anti-seizure effects of progesterone and 3alpha,5alpha-THP in kainic acid and perforant pathway models of epilepsy

The mechanism by which progesterone has its anti-seizure effects is unknown. Progesterone has a high affinity for intracellular progestin receptors, but has weak actions at gamma-aminobutyric acid (GABA)(A) receptors complexes. The progesterone metabolite, 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP) is devoid of activity at intracellular progestin receptors but is a highly effective modulator of GABA(A) receptor complexes. Whether progesterones anti-seizure actions are due to effects of progesterone itself or its metabolite 3alpha,5alpha-THP was investigated. In experiment 1, 25 ovariectomized Long-Evans rats were subcutaneously (s.c.) injected with 0.0, 4.0 or 8.0 mg/kg progesterone or 3alpha,5alpha-THP, 10 min prior to systemic administration of 32 mg/kg kainic acid. Four and 8.0 mg/kg progesterone significantly reduced the duration of partial and full seizures, without influencing the latency to partial or full seizures, or the number of partial or full seizures. 3alpha, 5alpha-THP (4.0 mg/kg) significantly increased the latency to initial partial seizure, and decreased the number and duration of partial seizures. In experiment 2, 60 ovariectomized Long-Evans rats were stereotaxically implanted with bipolar electrodes into the perforant pathway. Prior to perforant pathway stimulation, rats were s.c. injected with either progesterone (4.0 mg/kg, n = 12), 3alpha, 5alpha-THP (4.0 mg/kg, n = 13), progesterone (4.0 mg/kg)+4MA (10.0 mg of a 5alpha-reductase inhibitor, 17b-N, N-diethylcarbamoyl-4-methyl-4-aza,5alpha-androstan-3-one, n = 12), 4MA+vehicle (n = 10), or sesame oil vehicle (n = 13). Administration of progesterone or 3alpha, 5alpha-THP, but not vehicle control, P+4MA, or 4MA, resulted in significant decreases in partial seizures. In experiment 3, whole brain progesterone and 3alpha,5alpha-THP were measured by radioimmunoassay in additional rats (n = 66) administered the hormonal milieu indicated in experiments 1 and 2. Data suggest anti-seizure effects of progesterone may be due, in part, to metabolism to 3alpha,5alpha-THP and subsequent actions at GABA(A) receptor complexes.

Gender-based differences and menstrual cycle-related changes in specific diseases: implications for pharmacotherapy

Pharmacists should be aware of gender-based differences and menstrual cycle-related changes in six diseases: asthma, arthritis, migraine, diabetes, depression, and epilepsy. In general, women report symptoms of physical illness at higher rates, visit physicians more frequently, and make greater use of other health care services than men. Whereas reasons for these gender differences are not fully clear, a combination of biologic, physiologic, social, behavioral, psychologic, and cultural factors most likely contributes. A significant percentage of women with asthma, arthritis, migraine, diabetes, depression, or epilepsy experience worsening of their disease premenstrually. The mechanism is unknown, but is speculated to be multifactorial because of many endogenous and exogenous modulators and mediators of each disease. As part of general therapy for cycle-related exacerbations of any one of these disorders, patients should be encouraged to use a menstrual calendar to track signs and symptoms for two to three cycles; if cyclic trends are identified, the women should anticipate exacerbations and avoid triggering factors. Cyclic modulation with pharmacotherapy may be attempted. If unsuccessful, a trial of medical ovulation suppression with a gonadotropin-releasing hormone (GnRH) analog may be warranted. If that is successful, continuous therapy with a GnRH analog and steroid add-back therapy or less expensive alternatives may be effective. If pharmacotherapy is impractical, hysterectomy and bilateral oophorectomy with estrogen replacement therapy is a last resort. Gender differences and menstrual cycle-related changes are important areas for clinical and mechanistic research.

Region-specific modulation of limbic seizure susceptibility by ovarian steroids

Gonadal steroid hormones can markedly affect seizure susceptibility. Ovariohysterectomized female rats given ovarian steroid hormone supplements were used to evaluate the effects of ovarian steroids on epileptiform activity in hippocampal slices in vitro and on flurothyl-induced seizures in vivo. Seizure susceptibility was compared in the entorhinal cortex (EC) and CA1 regions of the hippocampus perfused with Mg(2+)-free medium, which leads to epileptiform discharges caused by a relief of voltage-dependent NMDA receptor block. After in vivo treatment with 500 microg of progesterone for 2 h prior to slice preparation, the latency to onset of low Mg(2+)-induced epileptiform activity of slices was significantly prolonged compared to slices from controls. In contrast, progesterone replacement accelerated the development of epileptiform activity in the CA1 region. Neither estrogen alone (2 x 2 microg of estradiol benzoate, 48 and 24 h prior to the experiment), nor a combined treatment with estrogen plus progesterone, significantly affected seizure susceptibility in either CA1 or the EC. There were no consistent effects of estrogen or progesterone, alone or in combination, on flurothyl-induced seizures in vivo. The data suggest that in vitro, progesterone alters seizure susceptibility in a site- and seizure model-specific fashion. The differential effects of progesterone may be due to differential expression of progesterone receptor isoforms or metabolites in specific brain areas suggesting that selective modulation of NMDA receptor-dependent epileptiform activity may play a role in hormonal effects on epileptogenesis.

Testosterone and its metabolites affect afterdischarge thresholds and the development of amygdala kindled seizures

In boys with epilepsy, pubertal increases in seizure frequency may be associated with rising androgen levels. The present study tested the hypothesis that testosterone (T) and/or its metabolites might affect amygdala seizure thresholds and the development of secondary generalization from amygdala foci (kindling). Afterdischarge thresholds and kindling rate were measured in gonadectomized (GDX) male rats, with or without T replacement therapy. Drugs that block either androgen or estradiol (E(2)) receptor-mediated responses were also tested.

METHODS

Kindling electrodes were implanted in the basolateral amygdala of adult male Wistar rats. In Experiment 1, subjects were GDX and implanted with a silastic capsule containing either: cholesterol (control); T; 5% E(2) in cholesterol; or 5alpha-dihydrotestosterone (DHT). In Experiment 2, intact subjects were treated with daily injections of vehicle (control); daily injections of flutamide (an androgen receptor antagonist); or Silastic implants containing 1,4,9-androstatriene 3,17-dione (ATD; an aromatase inhibitor).

RESULTS

In Experiment 1, initial afterdischarge (AD) thresholds were significantly lowered by E(2) treatment, as compared to cholesterol controls, and remained low throughout the kindling paradigm. In T replaced males, AD threshold significantly decreased over the kindling period, a response that was not observed in DHT treated rats. Rates of kindling were significantly faster as a result of T, E(2) and DHT treatment, as compared to cholesterol controls. E(2) treated males kindled the fastest of all 3 groups. In Experiment 2, initial AD thresholds were significantly lowered by flutamide treatment, as compared to cholesterol controls, and remained low throughout the kindling paradigm. AD threshold significantly decreased over the kindling period in intact males, a response that was blocked by ATD treatment. Both flutamide and ATD significantly slowed the rate of kindling, as compared to intact controls. ATD had the most dramatic inhibitory effect on kindling rate.

CONCLUSIONS

In males, T and its two metabolites, E(2) and DHT, all appear to enhance the development of amygdala-kindled seizures. E(2) has the most potent epileptogenic effect. Antagonism of E(2) mediated effects in the brain may have potential therapeutic value for males with epilepsy.