Psychoneuroendocrine aspects of temporolimbic epilepsy. Part II: Epilepsy and reproductive steroids

Anti-NMDAR encephalitis in Southeast Asia - A single-centre, longitudinal study

AIMS

To describe the clinical features and outcomes of anti-NMDA receptor encephalitis (ANMDARE) in Southeast Asian (SEA) patients.

METHOD

SEA patients diagnosed and treated for ANMDARE at Singapore General Hospital between January 2010 and June 2020 were included in this observational study, in which their clinical features and outcomes were retrospectively analysed.

RESULTS

We studied 20 patients: 11 Chinese, 3 Tagalogs, 2 Malays, 2 Indians, 1 Eurasian and 1 Javanese. Their median age was 28 years. 15 were females, amongst whom teratomas were demonstrated in 13 (12 ovarian, 1 mediastinal). Delirium and seizures were the two commonest events leading to their presentation at our facility. 1 male had biliary neuroendocrine tumour. Comparison between genders revealed a strong male predilection for early seizures and insomnia; females were four times likelier than males to develop movement disorders or have underlying neoplasms. Patients with dysautonomia required longer ICU stay beyond 14 days, but their outcomes at 1 year did not differ. When reviewed at 1 year, none had clinical relapses, and outcomes were favourable (mRS 0-2) in nearly two-thirds.

CONCLUSIONS

SEA patients with ANMDARE frequently present with delirium and seizures. Underlying neoplasms are very common in females. Differences in clinical characteristics may exist between the two genders. Recognition of these can facilitate diagnosis, and permit earlier initiation of appropriate treatment strategies, and thus improve outcomes of SEA patients.

Interactions of Aromatase and Seladin-1: A Neurosteroidogenic and Gender Perspective

Aromatase and seladin-1 are enzymes that have major roles in estrogen synthesis and are important in both brain physiology and pathology. Aromatase is the key enzyme that catalyzes estrogen biosynthesis from androgen precursors and regulates the brain’s neurosteroidogenic activity. Seladin-1 is the enzyme that catalyzes the last step in the biosynthesis of cholesterol, the precursor of all hormones, from desmosterol. Studies indicated that seladin-1 is a downstream mediator of the neuroprotective activity of estrogen. Recently, we also showed that there is an interaction between aromatase and seladin-1 in the brain. Therefore, the expression of local brain aromatase and seladin-1 is important, as they produce neuroactive steroids in the brain for the protection of neuronal damage. Increasing steroid biosynthesis specifically in the central nervous system (CNS) without affecting peripheral hormone levels may be possible by manipulating brain-specific promoters of steroidogenic enzymes. This review emphasizes that local estrogen, rather than plasma estrogen, may be responsible for estrogens’ protective effects in the brain. Therefore, the roles of aromatase and seladin-1 and their interactions in neurodegenerative events such as Alzheimer’s disease (AD), ischemia/reperfusion injury (stroke), and epilepsy are also discussed in this review.

Identification of Novel Scaffolds with Dual Role as Antiepileptic and Anti-Breast Cancer

Aromatase inhibitors with an $\mathrm{IC}_{50}$ IC 50 value ranging from 1.4 to 49.7 µM are known to act as antiepileptic drugs besides being potential breast cancer inhibitors. The aim of the present study is to identify novel antiepileptic aromatase inhibitors with higher activity exploiting the ligand-based pharmacophore approach utilizing the experimentally known inhibitors. The resultant Hypo1 consists of four features and was further validated by using three different strategies. Hypo1 was allowed to screen different databases to identify lead molecules and were further subjected to Lipinski's Rule of Five and ADMET to establish their drug-like properties. Consequently, the obtained 68-screened molecules were subjected to molecular docking by GOLD v5.2.2. Furthermore, the compounds with the highest dock scores were assessed for molecular interactions. Later, the MD simulation was applied to evaluate the protein backbone stabilities and binding energies adapting GROMACS v5.0.6 and MM/PBSA which was followed by the density functional theory (DFT), to analyze their orbital energies, and further the energy gap between them. Eventually, the number of Hit molecules was culled to three projecting Hit1, Hit2, and Hit3 as the potential lead compounds based on their highest dock scores, hydrogen bond interaction, lowest energy gap, and the least binding energies and stable MD results.

The effect of harmaline on seizures induced by amygdala kindling in rats

OBJECTIVE

Harmaline and other beta-carbolines act as an inverse agonist for GABA-A receptors and cause central nervous system stimulation and anxiety; thus, it may act hypothetically as a potential seizure augmenter. To examine the hypothesis, the effect of harmaline during the seizures induced by amygdala kindling is investigated here.

METHODS

Seven groups of male rats were kindled by daily electrical stimulation of the amygdala. After being kindled, Groups I-III, respectively, received 5, 15 and 50 mg/kg harmaline through intraperitoneal injection. The rats in Groups IV and V received vehicle daily (1 ml/kg) and harmaline (5 mg/kg) daily through intraperitoneal injection. Groups VI and VII received artificial cerebrospinal fluid and harmaline (50 mM) through intraventricular injection, respectively.

RESULTS

In addition to significant increase of some seizure parameters in the fully kindled groups, harmaline significantly increased cumulative afterdischarge duration (P < 0.05) and decreased stage 1 latency (P < 0.01) in the acquisition groups (Groups V and VII). In Group VII, seizure duration showed a significant increase (P < 0.01) while stage 1 latency and stage 4 latency decreased significantly (P < 0.01).

DISCUSSION

According to the results, it is suggested that harmaline may increase neuronal activity and the production of high-frequency action potentials by stimulating NMDA receptors and inhibiting GABA receptors. Overall, drugs and plants containing harmaline may be harmful to epileptic-susceptible people during some traditionally and costume treatments, so these should be avoided.

[About the comorbidity of affective and conversion disorders in epilepsy]

In this literature review, special attention is drawn to the pathogenesis of conversion disorders in patients with epilepsy, in particular, with psychogenic non-epileptic seizures. Diagnostic issues and pharmacotherapy of affective and conversion disorders in patients with epilepsy is discussed.

Neurosteroid interactions with synaptic and extrasynaptic GABA(A) receptors: regulation of subunit plasticity, phasic and tonic inhibition, and neuronal network excitability

RATIONALE

Neurosteroids are steroids synthesized within the brain with rapid effects on neuronal excitability. Allopregnanolone, allotetrahydrodeoxycorticosterone, and androstanediol are three widely explored prototype endogenous neurosteroids. They have very different targets and functions compared to conventional steroid hormones. Neuronal γ-aminobutyric acid (GABA) type A (GABA(A)) receptors are one of the prime molecular targets of neurosteroids.

OBJECTIVE

This review provides a critical appraisal of recent advances in the pharmacology of endogenous neurosteroids that interact with GABA(A) receptors in the brain. Neurosteroids possess distinct, characteristic effects on the membrane potential and current conductance of the neuron, mainly via potentiation of GABA(A) receptors at low concentrations and direct activation of receptor chloride channel at higher concentrations. The GABA(A) receptor mediates two types of inhibition, now characterized as synaptic (phasic) and extrasynaptic (tonic) inhibition. Synaptic release of GABA results in the activation of low-affinity γ2-containing synaptic receptors, while high-affinity δ-containing extrasynaptic receptors are persistently activated by the ambient GABA present in the extracellular fluid. Neurosteroids are potent positive allosteric modulators of synaptic and extrasynaptic GABA(A) receptors and therefore enhance both phasic and tonic inhibition. Tonic inhibition is specifically more sensitive to neurosteroids. The resulting tonic conductance generates a form of shunting inhibition that controls neuronal network excitability, seizure susceptibility, and behavior.

CONCLUSION

The growing understanding of the mechanisms of neurosteroid regulation of the structure and function of the synaptic and extrasynaptic GABA(A) receptors provides many opportunities to create improved therapies for sleep, anxiety, stress, epilepsy, and other neuropsychiatric conditions.

Sex and hormonal influences on seizures and epilepsy

Epilepsy is the third most common chronic neurological disorder. Clinical and experimental evidence supports the role of sex and influence of sex hormones on seizures and epilepsy as well as alterations of the endocrine system and levels of sex hormones by epileptiform activity. Conversely, seizures are sensitive to changes in sex hormone levels, which in turn may affect the seizure-induced neuronal damage. The effects of reproductive hormones on neuronal excitability and seizure-induced damage are complex to contradictory and depend on different mechanisms, which have to be accounted for in data interpretation. Both estradiol and progesterone/allopregnanolone may have beneficial effects for patients with epilepsy. Individualized hormonal therapy should be considered as adjunctive treatment in patients with epilepsy to improve seizure control as well as quality of life.

Influence of sildenafil on the anticonvulsant action of selected antiepileptic drugs against pentylenetetrazole-induced clonic seizures in mice

The aim of the present study was to investigate the effect of sildenafil, a selective phosphodiesterase 5 (PDE5) inhibitor, on threshold for clonic seizures in mice. In addition, the effects of sildenafil on the anticonvulsant activity of selected antiepileptic drugs (AEDs), i.e., clonazepam (CZP), valproate (VPA), phenobarbital (PB), ethosuximide (ETS) and tiagabine (TGB), were also evaluated. The subcutaneous pentylenetetrazole (PTZ) test was used to determine the effects of sildenafil on convulsive susceptibility and the anticonvulsant activity of the studied AEDs in mice, while the acute side effects of sildenafil and its combinations with the studied AEDs were evaluated in the chimney test, step-through passive-avoidance task and grip-strength test in mice. Total brain concentrations of AEDs were also determined. Sildenafil (5–40 mg/kg) did not influence the threshold for PTZ-induced clonic seizures in mice, but increased the anticonvulsant activity of ETS in this test without any significant changes in the total brain concentration. The activity of the remaining AEDs was not significantly changed by sildenafil. Neither sildenafil alone nor its combinations with the studied AEDs produced any changes in the motor coordination, long-term memory and muscular strength in mice. Co-administration of sildenafil with ETS in male epileptic patients with co-existing erectile dysfunctions might lead to the pharmacodynamic interactions that may be beneficial for the patients. Combinations of sildenafil with CZP, VPA, PB and TGB appear to be neutral in terms of their influence on seizures.

Association between ovarian hormones and smoking behavior in women

Studies examining the association between menstrual cycle phases and smoking behavior in women have yielded mixed results. The purpose of this study was to elucidate the associations between ovarian hormones and smoking by directly measuring ovarian hormone levels and obtaining a laboratory assessment of smoking behaviors. Four hypotheses were tested: Increased smoking will be associated with (1) low absolute levels of estradiol and progesterone; (2) decreasing (i.e., dynamic changes in) estradiol and progesterone; (3) lower ratios of progesterone to estradiol; and (4) higher ratios of estradiol to progesterone. Female smokers (≥10 cigarettes/day) with regular menstrual cycles were recruited as part of a larger, ongoing study examining the influence of ovarian hormones on smoking cessation treatment. Participants completed 2 study visits, including a 1-hr ad lib smoking topography session, which provided a detailed assessment of smoking behavior. Both the change in hormone levels over time and the relative ratios of ovarian hormones were associated with smoking behavior, but each to a limited extent. Decreases in estradiol (r = -.21, p = .048) and decreases in progesterone (r = -.23, p = .03) were associated with increased puff intensity. Lower ratios of progesterone to estradiol were associated with a greater number of puffs (r = -.26, p = .01) and weight of cigarettes smoked (r = -.29, p = .005). The best predictors of smoking behavior were the ratio of progesterone to estradiol (z = -2.7, p = .004) and the change in estradiol and progesterone over time (z = -2.1, p = .02). This pattern of results may help to explain inconsistent findings in previous studies and suggest potential mechanisms by which hormones influence nicotine addiction.

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).

Aromatase inhibitors and antiepileptic drugs: a computational systems biology analysis

BACKGROUND

The present study compares antiepileptic drugs and aromatase (CYP19) inhibitors for chemical and structural similarity. Human aromatase is well known as an important pharmacological target in anti-breast cancer therapy, but recent research demonstrates its role in epileptic seizures, as well. The current antiepileptic treatment methods cause severe side effects that endanger patient health and often preclude continued use. As a result, less toxic and more tolerable antiepileptic drugs (AEDs) are needed, especially since every individual responds differently to given treatment options.

METHODS

Through a pharmacophore search, this study shows that a model previously designed to search for new classes of aromatase inhibitors is able to identify antiepileptic drugs from the set of drugs approved by the Food and Drug Administration. Chemical and structural similarity analyses were performed using five potent AIs, and these studies returned a set of AEDs that the model identifies as hits.

RESULTS

The pharmacophore model returned 73% (19 out of 26) of the drugs used specifically to treat epilepsy and approximately 82% (51 out of 62) of the compounds with anticonvulsant properties. Therefore, this study supports the possibility of identifying AEDs with a pharmacophore model that had originally been designed to identify new classes of aromatase inhibitors. Potential candidates for anticonvulsant therapy identified in this manner are also reported. Additionally, the chemical and structural similarity between antiepileptic compounds and aromatase inhibitors is proved using similarity analyses.

CONCLUSIONS

This study demonstrates that a pharmacophore search using a model based on aromatase inhibition and the enzyme's structural features can be used to screen for new candidates for antiepileptic therapy. In fact, potent aromatase inhibitors and current antiepileptic compounds display significant - over 70% - chemical and structural similarity, and the similarity analyses performed propose a number of antiepileptic compounds with high potential for aromatase inhibition.

Effects of valproate and carbamazepine monotherapy on neuroactive steroids, their precursors and metabolites in adult men with epilepsy

Only limited data is available concerning the role of unconjugated Δ(5) C19-steroids and almost no data exists regarding the neuroactive C21 and C19 3α-hydroxy-5α/β-metabolites in men with epilepsy. To evaluate the alterations in serum neuroactive steroids and related substances in adult men with epilepsy on valproate and carbamazepine monotherapy, we have measured 26 unconjugated steroids, 18 steroid polar conjugates, gonadotropins and sex hormone binding globulin (SHBG) in 6 and 11 patients on valproate and carbamazepine monotherapy, respectively, and in 19 healthy adult men, using the GC-MS and immunoassays. Decreased testosterone, free androgen index, free testosterone, androstenediol, 5α-androstane-3α,17β-diol (androstanediol), androsterone, epiandrosterone, DHEA, 7β-hydroxy-DHEA, and DHEAS levels were associated with epilepsy per se. Valproate (VPA) therapy increased 5α-dihydrotestosterone, androsterone, epiandrosterone, DHEA, DHEAS, and 7β-hydroxy-DHEA levels. Decrease in pregnenolone and 17-hydroxypregnenolone were associated with epilepsy with no effect of antiepileptic drugs (AEDs). Alternatively, the increase in progesterone levels was linked to epilepsy and VPA further increased progesterone levels. Reduced steroid 20α-hydroxy-metabolites and cortisol were connected with epilepsy without an effect of AEDs. Carbamazepine induced only slight decrease in isopregnanolone, 5α,20α-tetrahydroprogesterone, and androstanediol levels.

Monotherapy of epilepsy in women: psychiatric and neuroendocrine aspects

The aim of the present work was to perform a comparative assessment of the efficacy and safety of traditional and contemporary antiepileptic agents in women of reproductive age. The experimental group consisted of 65 patients, of whom 48 had partial epilepsy and 17 had idiopathic generalized epilepsy. A number of issues were addressed in studies of a larger group of patients (110), including both women (65) and men (45). The following agents were studied: Topamax, valproates, carbamazepine, and barbiturates, all used as monotherapy. Patients' status was evaluated using clinical (neurological, psychiatric), psychometric, neuropsychological, and hormonal parameters. The data led to the general conclusion that Topamax had advantages over the other study agents in the treatment of women with epilepsy.

Hospitalization in adolescence affects the likelihood of giving birth: a Swedish population-based register study

AIM

To examine the effect of hospitalization during adolescence on the likelihood of giving birth.

METHODS

142 998 women born in 1973-75 were followed with the help of the Swedish Medical Birth Register (MBR) and the Swedish Total Population Register (TPR) up until the end of 2000 with respect to their likelihood of giving birth. All analyses were adjusted for parental socio-economic characteristics and factors related to the studied women's own birth.

RESULTS

The likelihood of giving birth between 20 and 27 years of age was positively affected by hospitalization at least once during adolescence according to the Swedish Hospital Discharge Register (HDR); adjusted hazard ratio (HR) = 1.32, 95% confidence interval: 1.29-1.35. Women hospitalized due to genitourinary diseases, respiratory diseases, abdominal problems and abuse of alcohol and drugs were more likely to have given birth during the study period, while hospitalizations according to cerebral palsy and congenital malformations tended to decrease childbearing. Women hospitalized due to psychiatric diseases had an increase likelihood of given birth at 20-24 years but a reduced thereafter.

CONCLUSION

A majority of the causes of hospitalization during adolescence increased the likelihood of giving birth between ages 20 to 27.

Catamenial epilepsy

Catamenial epilepsy is defined by the cyclical seizure exacerbation seen in almost 40% of women with epilepsy. The pattern appears to be related to predominance of estrogen over progesterone during the pre-ovulatory and/or perimenstrual days of the ovulatory menstrual cycle or during the broad period between day 14 and menstruation in anovulatory cycles with inadequate luteal progesterone levels. Progesterone affects central nervous excitability in an "inhibitory" manner, slowing kindling and decreasing seizure susceptibility in animal models. Estrogen enhances kindling and decreases after discharge threshold. These neurosteroidal hormones alter the GABA-A receptor in cell cultures and in animal models. Treatment of this clinical syndrome has been empirical and reported in a small series of women. Progesterone therapy and possible new approaches with synthesized neurosteroids may offer a promising approach to improve seizure control in women with catamenial epilepsy.

Consensus statement: the evaluation and treatment of people with epilepsy and affective disorders

Affective disorders in people with epilepsy (PWE) have become increasingly recognized as a primary factor in the morbidity and mortality of epilepsy. To improve the recognition and treatment of affective disorders in PWE, an expert panel comprising members from the Epilepsy Foundation's Mood Disorders Initiative have composed a Consensus Statement. This document focuses on depressive disorders in particular and reviews the appearance and treatment of the disorder in children, adolescents, and adults. Idiosyncratic aspects of the appearance of depression in this population, along with physiological and cognitive issues and barriers to treatment, are reviewed. Finally, a suggested approach to the diagnosis of affective disorders in PWE is presented in detail. This includes the use of psychometric tools for diagnosis and a stepwise algorithmic approach to treatment. Recommendations are based on the general depression literature as well as epilepsy-specific studies. It is hoped that this document will improve the overall detection and subsequent treatment of affective illnesses in PWE.

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.

Ethanol-induced elevation of 3 alpha-hydroxy-5 alpha-pregnan-20-one does not modulate motor incoordination in rats

BACKGROUND

Ethanol administration elevates the levels of GABAergic neuroactive steroids in brain and contributes to some of its behavioral actions. In the present study, we investigated whether such elevation of GABAergic neuroactive steroids contributes to the motor incoordinating effects of ethanol.

METHODS

Sprague-Dawley rats were administered ethanol (2 g/kg intraperitoneally) or saline, and the level of 3alpha-hydroxy-5alpha-pregnan-20-one (3alpha,5alpha-THP) was measured across time in cerebral cortex and in various brain regions at the peak time by radioimmunoassay. To study whether increases in GABAergic neuroactive steroids are responsible for the motor incoordinating actions of ethanol, rats were subjected to chemical (5alpha-reductase inhibitor, finasteride) and surgical (adrenalectomy) manipulations before receiving ethanol (2 g/kg intraperitoneally) injections. The rats were then subjected to different paradigms to evaluate motor impairment including the Majchrowicz motor intoxication rating scale, Rotarod test, and aerial righting reflex task at different time points.

RESULTS

The radioimmunoassay of 3alpha,5alpha-THP in different brain regions showed that ethanol increases 3alpha,5alpha-THP levels by 3- and 9-fold in cerebral cortex and hippocampus, respectively. There was no change in 3alpha,5alpha-THP levels in cerebellum and midbrain. The time course of 3alpha,5alpha-THP elevations in the cerebral cortex showed significant increases 20-min after ethanol injection with a peak at 60 min. In contrast, motor toxicity peaked between 5 and 10 min after ethanol injections and gradually decreased over time. Furthermore, adrenalectomy or pretreatment with finasteride (2 x 50 mg/kg, subcutaneously) did not reduce motor incoordinating effects of ethanol as assessed by the Majchrowicz intoxication rating score, Rotarod test, or aerial righting reflex task.

CONCLUSIONS

Ethanol increases GABAergic neuroactive steroids in a time- and brain region-selective manner. The role of neuroactive steroids in alcohol action is specific for certain behaviors. Alcohol-induced deficits in motor coordination are not mediated by elevated neuroactive steroid biosynthesis.

Similarities between actions of estrogen and BDNF in the hippocampus: coincidence or clue?

The principal ovarian estrogen, estradiol, and brain-derived neurotrophic factor (BDNF) have widespread effects on the CNS that have usually been studied independently. This article examines the similarities in the effects of estradiol and BDNF in the hippocampus, in light of the evidence that estradiol can induce BDNF expression, and recent data suggesting that structural and electrophysiological effects of estradiol in the hippocampus might be mediated by BDNF. The possible role of BDNF as a signaling molecule downstream of estrogen in the hippocampus has implications for our understanding of several cellular and behavioral hippocampal functions, including dendritic and synaptic plasticity, learning and cognitive behavior. Furthermore, disruption of the relationship between estrogen and BDNF could contribute to neurological and psychiatric disorders that have been associated with the hippocampus, such as Alzheimer's disease, depression and epilepsy.

Androgens in the hippocampus can alter, and be altered by, ictal activity

Steroid hormones, such as androgens, can modulate seizure processes. This review summarizes prior research and presents new data that support the role of androgens in modulating seizure processes. Testosterone, the primary endogenous androgen, has antiseizure effects in people and in animal models of epilepsy. Furthermore, testosterone's antiseizure effects may involve actions of its 5alpha-reduced metabolite and neuroactive steroid, 5alpha-androstane-3alpha,17beta-diol (3alpha-diol). The hippocampus is a target for androgen action and is involved in many types of seizure disorder. Data suggest that actions of androgens in the hippocampus may be important for androgens' antiseizure effects. Interestingly, there may also be a reciprocal relationship between androgens and seizures. Ictal activity can alter the gonadal responsiveness of people with epilepsy and in animal models of seizure disorder. Thus, this paper will review data in support of androgens' antiseizure effects. Further understanding of androgens' role in seizure processes is important for potential therapeutic effects.

Role of neurosteroids in catamenial epilepsy

Catamenial epilepsy is a menstrual cycle-related seizure disorder that affects up to 70% of women with epilepsy. Catamenial epilepsy is characterized by an increase in seizures during particular phases of the menstrual cycle. Three distinct patterns of catamenial epilepsy - perimenstrual, periovulatory, and inadequate luteal phase - have been described. Currently, there is no specific treatment for catamenial epilepsy. The molecular mechanisms involved in the pathophysiology of catamenial epilepsy are not well understood. Recent studies suggest that cyclical changes of ovarian hormones estrogens (proconvulsant) and progesterone (anticonvulsant) appear to play a key role in the genesis of catamenial seizures. Progesterone reduces seizure susceptibility partly through conversion to neurosteroids such as allopregnanolone, which enhances GABA(A) receptor function and thereby inhibits neuronal excitability. In animal models, withdrawal from chronic progesterone and, consequently, of allopregnanolone levels in brain, has been shown to increase seizure susceptibility. Natural progesterone therapy has proven effective in women with epilepsy. Moreover, neurosteroids have been shown to be very effective inhibitors of catamenial seizures in animal models. Thus, synthetic neuroactive steroids, such as ganaxolone, which are orally active and devoid of hormonal side effects, represent a novel treatment strategy for catamenial epilepsy. However, their clinical efficacy in catamenial epilepsy has yet to be explored. A greater understanding of the molecular mechanisms is clearly needed for designing effective treatment and prevention strategies of catamenial epilepsy in women at risk.

The recognition and management of mood disorders as a comorbidity of epilepsy

Mood disorders, especially as a comorbid finding in people with medical disorders in general, and in those with epilepsy in particular, have become increasingly recognized as a serious health concern. Unfortunately, affective disorders are underrecognized, and appropriate treatment is infrequent. The consequences of poor detection of mood disorders in people with epilepsy are discussed, along with a review of risk factors and the appearance of the disorder in this population. Prevalence rates of both depressive and bipolar spectrum disorders in people with epilepsy appear to be higher than in the general population. Recent data from community samples show elevated rates of both disorders in people with epilepsy, significantly above those in people with and without other chronic diseases. Assessment issues, including the positive and negative side effects of antiepileptic drugs, are reviewed. Treatment options are discussed, along with caveats concerning the use of antidepressants in people with epilepsy, with a focus on safety, utility, and drug interactions. Electroconvulsive therapy can also be used safely in people with epilepsy, and vagus nerve stimulation may have some utility in the treatment of depressive disorders as well. However, despite improved detection methods and effective treatments, implementation of this knowledge in neurology outpatient clinics is still problematic.

Relationship of sexual dysfunction to epilepsy laterality and reproductive hormone levels in women

Sexual dysfunction has been reported to be common among women with epilepsy. Controlled studies, quantitative data, and investigations of potentially contributory factors, however, have been few. The purpose of this investigation was to determine if (1) sexual dysfunction is unusually common among women with partial seizures of temporal lobe origin (TLE), and (2) sexual dysfunction varies in relation to the laterality of EEG epileptiform discharges, antiepileptic drug use, and serum gonadal steroid levels. This controlled prospective investigation used a quantitative sexual rating scale and reproductive hormone measures to compare sexual dysfunction in women with left and right unilateral temporolimbic epilepsy and controls. Sexual dysfunction scores were significantly higher in women with TLE, and sexual dysfunction affected substantially more women with epilepsy than controls. Women with right-sided foci were affected more than women with left-sided foci. There was a significant inverse correlation between sexual dysfunction and bioactive testosterone levels in women with epilepsy as well as in controls. Serum estradiol was lower in women with TLE but did not correlate significantly with overall sexual dysfunction. The findings suggest that sexual dysfunction is significantly more common in women with right-sided epileptiform discharges than in controls and is inversely correlated with bioactive testosterone levels. The value of hormonal replacement or supplementation remains to be explored.

Bicuculline seizure susceptibility and nigral GABAA alpha1 receptor mRNA is altered in adult prenatally morphine-exposed females

Prenatal morphine exposure (5-10 mg/kg twice daily on gestation days 11-18) can adversely affect neurological development, including seizure susceptibility. The present study examines the effects of prenatal morphine exposure on seizure susceptibility to the GABA antagonist and convulsant bicuculline and GABA(A) alpha(1) receptor mRNA in the substantia nigra (SN) of female rats. The results demonstrate that prenatally morphine-exposed ovariectomized (OVX) females and OVX females with estradiol benzoate (EB) replacement have an increased latency to seizure onset compared to controls. In addition, prenatal morphine exposure decreases the area covered by grains of GABA(A) alpha(1) receptor mRNA in the anterior SN in both OVX and EB+progesterone (P)-treated groups, and decreases the number of GABA(A) alpha(1) receptor mRNA-labeled cells/field in EB females. Furthermore, prenatally morphine- and saline-exposed EB and EB+P females had decreased GABA(A) alpha(1) receptor mRNA-labeled cells/field in the anterior SN compared to OVX animals of the same prenatal exposure. These results demonstrate that the long term effects of prenatal morphine exposure in female rats is dependent on their hormonal status, and suggest that seizure susceptibility may be altered via neuropharmacological changes in the GABA system in the SN.

Effects of ovarian hormones on human cortical excitability

Ovarian steroids appear to alter neuronal function in women, but direct physiological evidence is lacking. In animals, estradiol enhances excitatory neurotransmission. Progesterone-derived neurosteroids increase GABAergic inhibition. The effect of weak transcranial magnetic stimulation of the motor cortex on the motor evoked potential (MEP) from transcranial magnetic stimulation given milliseconds later is changed by GABAergic and glutamatergic agents. Using this technique previously, we showed more inhibition in the luteal phase relative to the midfollicular menstrual phase, which is consistent with a progesterone effect. To detect the effects of estradiol, we have now divided the follicular phase. We tested 14 healthy women during the early follicular (low estradiol, low progesterone), late follicular (high estradiol, low progesterone), and luteal (high estradiol, high progesterone) phases, with interstimulus intervals from 2 to 10msec (10 trials at each interval and 40 unconditioned trials). We calculated the ratio of the conditioned MEP at each interval to the mean unconditioned MEP: the higher the ratio, the less inhibition and the more facilitation caused by the first stimulus. The combined ratios increased significantly from the early follicular phase to the late follicular phase and then decreased again in the luteal phase. These findings demonstrate an excitatory neuronal effect associated with estradiol and confirm our earlier finding of inhibition associated with progesterone.

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.

The forgotten female: Pediatric and adolescent gynecological concerns and their reproductive consequences

Future reproductive performance is not often addressed in pediatric and adolescent gynecological conditions. This overview reviews conditions that present in childhood and adolescence and discusses what is known about the future fertility in these women. The following topics are selected: STD exposure, dysfunctional uterine bleeding, eating disorders, adolescent athletics, polycystic ovarian syndrome, premature ovarian failure, childhood cancer survivors, Mullerian duct anomalies, congenital adrenal hyperplasia, cystic fibrosis, and epilepsy.

Diminished allopregnanolone enhancement of GABA(A) receptor currents in a rat model of chronic temporal lobe epilepsy

1. Neurosteroid modulation of GABA(A) receptors present on dentate granule cells (DGCs) acutely isolated from epileptic (epileptic DGCs) or control rats (control DGCs) was studied by application of GABA with or without the modulators and by measuring the amplitude of peak whole-cell currents. 2. In epileptic DGCs, GABA efficacy (1394 +/- 277 pA) was greater than in control DGCs (765 +/- 38 pA). 3. Allopregnanolone enhanced GABA-evoked currents less potently in epileptic DGCs (EC50 = 92.7 +/- 13.4 nM) than in control DGCs (EC50 = 12.9 +/- 2.3 nM). 4. Pregnenolone sulfate inhibited GABA-evoked currents with similar potency and efficacy in control and epileptic DGCs. 5. Diazepam enhanced GABA-evoked currents less potently in epileptic (EC50 = 69 +/- 14 nM) compared to the control DGCs (EC50 = 29.9 +/- 5.7 nM). 6. There were two different patterns of zolpidem modulation of GABA(A) receptor currents in the epileptic DGCs. In one group, zolpidem enhanced GABA(A) receptor currents but with reduced potency compared to the control DGCs (EC50 = 134 +/- 20 nM vs. EC50 = 52 +/- 13 nM). In the second group of epileptic DGCs zolpidem inhibited GABA(A) receptor currents, an effect not observed in control DGCs. 7. Epileptic DGCs were more sensitive to Zn2+ inhibition of GABA(A) receptor currents (IC50 = 19 +/- 6 microM) compared to control (IC50 = 94.7 +/- 7.9 microM). 8. This study demonstrates significant differences between epileptic and control DGCs. We conclude that (1) diminished sensitivity of GABA(A) receptors of epileptic DGCs to allopregnanolone can increase susceptibility to seizures; (2) reduced sensitivity to diazepam and zolpidem, and increased sensitivity to Zn2+ indicate that loss of allopregnanolone sensitivity is likely to be due to altered subunit expression of postsynaptic GABA(A) receptors present on epileptic DGCs; and (3) an inverse effect of zolpidem in some epileptic DGCs demonstrates the heterogeneity of GABA(A) receptors present on epileptic DGCs.

Testosterone reduces pentylenetetrazole-induced ictal activity of wildtype mice but not those deficient in type I 5alpha-reductase

Testosterone's (T) anti-seizure effects may be mediated in part by actions of its 5alpha-reduced metabolites. To test this hypothesis, T was administered to knockout mice deficient in the 5alpha-reductase type I enzyme and wildtype controls and their ictal activity following pentylenetetrazole (PTZ; 85 mg/kg i.p.) was compared to mice administered vehicle. T to wildtype mice increased latencies to forelimb clonus, tonic clonic seizures, hindlimb extension, and death compared to that seen with vehicle administration. Moreover, incidence of tonic clonic seizures and hindlimb extension were reduced in wildtype mice administered T compared to vehicle-administered mice. T administration to wildtype mice reduced ictal activity compared to T to knockout mice, which were not different than vehicle-administered control mice. T to wildtype mice increased the latencies and decreased the incidence of forelimb clonus compared to T to knockout mice, which were not different from vehicle-administered mice. These data are consistent with T having anti-convulsant effects and that 5alpha-reduced metabolites may mitigate some of T's anti-seizure effects.

Epilepsy, depression and antidepressant drugs

Apart from constituting an important management problem, depression coexisting with epilepsy is also an interesting psychiatric phenomenon, with multiple interacting biological, psychological and social factors involved in its causation. New research approaches to the study of epilepsy and depression, including neuroimaging, neurochemical and neuroendocrine techniques, and the arrival of new classes of antidepressants in recent years, suggest it is timely to reconsider this topic. We review current knowledge of the prevalence and causes of interictal depression in epilepsy, focussing mainly on neurobiological factors, and give an overview of recent concepts concerning the management of depression. We also discuss pharmacological treatment of depression in epilepsy, focussing on the association between antidepressants and seizures, and drug interactions.

Neuroactive steroids and seizure susceptibility

There is increasing clinical and experimental evidence that hormones, in particular sex steroid hormones, influence neuronal excitability and other brain functions. The term 'neuroactive steroids' has been coined for steroids that interact with neurotransmitter receptors. One of the best characterized actions of neuroactive steroids is the allosteric modulation of GABA(A)-receptor function via binding to a putative steroid-binding site. Since neuroactive steroids may interact with a variety of other membrane receptors, excitatory as well as inhibitory, they may have an impact on the excitability of specific brain regions. Neuronal excitability is enhanced by estrogen, whereas progesterone and its metabolites exert anticonvulsant effects. Testosterone and corticosteroids have less consistent effects on seizure susceptibility. Apart from these particular properties, neuroactive steroids may regulate gene expression via progesterone receptors. Based on their molecular properties, these compounds appear to have a promising therapeutical profile for the treatment of different neuropsychiatric diseases including epilepsy. This review focuses on the effects of neuroactive steroids on neuronal excitability and their putative impact on the physiology of epileptic disorders.

Effects of testosterone and clomiphene on spectral EEG and visual evoked response in a young man with posttraumatic epilepsy

The effects of testosterone and clomiphene on epilepsy was studied in a young man with posttraumatic seizures. In the control period, digital EEG and visual evoked potentials (VEPs) were recorded under carbamazapine therapy. After testosterone (T), seizures lessened and almost disappeared; the theta, delta, alpha, and beta powers decreased; VEPs increased. After clomiphene, VEPs considerably increased in size; clinical picture slightly improved; EEG power spectrum remained unchanged. It was suggested that T may be beneficial for epilepsy treatment by suppressing the EEG synchronization (slow wave activity) and attenuating the entropy state of the epileptic brain.

The hypothesized hormonal control of offspring sex ratio: evidence from families ascertained by schizophrenia and epilepsy

Schizophrenic women reportedly have significant excesses of daughters. People with convulsions or seizures reportedly have excesses of brothers. And photosensitive probands reportedly have excesses of sisters. Steroid hormones affect neurotransmission in the brain. So these curious sex ratios are construed here as support for my hypothesis that parental hormone levels around the time of conception partially control the sexes of the resulting offspring.

The effects of epilepsy and its treatment on sexual and reproductive function

Male and female sexuality and reproductive functions are complex systems with cortical, limbic system, hypothalamic, pituitary, and end organ interactions. Sexual steroids are produced in the sexual glands, the adrenals, and the brain. They undergo interconversion in the brain, bind to different brain areas, and have multiple effects behaviorally and neurophysiologically. Progesterone, estrogen and testosterone have neuroendocrine effects that alter epileptogenicity. Seizure frequency may change throughout the life cycle as a result of hormonal status. Changes in central control, peripheral hormone levels, and/or medication effects may all contribute to decreased libido, potency, and fertility. Antiepileptic drugs (AEDs) interact with hormone-binding metabolism, resulting in altered human reproductive function. AEDs alter contraceptive hormone treatments. Information on the effects of new AEDs is being gathered by the National Pregnancy Registry. Catamenial epilepsy and some sexual dysfunction in men may be treatable.