Sexuality in men and women with epilepsy

Impact of Occupational Therapy Interventions on Sexual Dysfunction in Epilepsy: A Case Report

Epilepsy is a chronic neurological disorder characterized by recurrent seizures, necessitating lifelong medication management. One common side effect of these medications is sexual dysfunction. In this case report, a 37-year-old male epilepsy patient who was an office clerk by occupation presented at the outpatient department (OPD) of occupational therapy with the chief complaints of anxiety, depression, and sexual dysfunction primarily reporting of anorgasmia, which required longer foreplay to reach an effective erection leading to delayed ejaculation. The patient reported a nine-year history of complicated, partial, and generalized seizures for which he consulted the physician who prescribed him AED (antiepileptic drug) carbamazepine twice a day; however, the symptoms persisted, and the medication was changed to pregabalin. In addition to this, the patient was advised for occupational therapy intervention by the physician. In the occupational therapy department, the patient was assessed for various parameters that involved sexual functioning using the Changes in Sexual Functioning Questionnaire-Male (CSFQ-M), for anxiety using the Generalised Anxiety Disorder-7 (GAD-7) questionnaire, for depression using the Patient Health Questionnaire-9 (PHQ-9), and quality of life (QOL) using the Quality of Life in Epilepsy Inventory - 31 (QOLIE-31) questionnaire. As part of the intervention, occupational therapy was provided to the patient for four months, which mainly focused on three major areas: health promotion, remediation, and modification. Each of these methods was used at all levels of the intervention, as outlined by the EX-Permission, Limited Information, Specific Suggestions, and Intensive Therapy model (P-LI-SS-IT), which reflected positive results, as there was enhanced sexual functioning, reduced symptoms of depression, and anxiety, and improved quality of life. In conclusion, occupational therapists along with doctors and other practitioners should focus on addressing intimacy and sexuality within their practice for epilepsy patients demonstrating symptoms of sexual dysfunction, which will consequently impact an individual's QOL. Additionally, screening and monitoring of sexual dysfunction should be included during the routine assessment of patients with epilepsy.

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.

Amygdaloid complex anatomopathological findings in animal models of status epilepticus

Temporal lobe epileptic seizures are one of the most common and well-characterized types of epilepsies. The current knowledge on the pathology of temporal lobe epilepsy relies strongly on studies of epileptogenesis caused by experimentally induced status epilepticus (SE). Although several temporal lobe structures have been implicated in the epileptogenic process, the hippocampal formation is the temporal lobe structure studied in the greatest amount and detail. However, studies in human patients and animal models of temporal lobe epilepsy indicate that the amygdaloid complex can be also an important seizure generator, and several pathological processes have been shown in the amygdala during epileptogenesis. Therefore, in the present review, we systematically selected, organized, described, and analyzed the current knowledge on anatomopathological data associated with the amygdaloid complex during SE-induced epileptogenesis. Amygdaloid complex participation in the epileptogenic process is evidenced, among others, by alterations in energy metabolism, circulatory, and fluid regulation, neurotransmission, immediate early genes expression, tissue damage, cell suffering, inflammation, and neuroprotection. We conclude that major efforts should be made in order to include the amygdaloid complex as an important target area for evaluation in future research on SE-induced epileptogenesis. This article is part of the Special Issue "NEWroscience 2018".

The impact of medications and medical comorbidities on sexual function in people with epilepsy

OBJECTIVE

People with epilepsy experience increased rates of sexual dysfunction, often affecting quality of life. Sexual dysfunction may result from the underlying disorder, antiseizure or other medications, or comorbid psychosocial factors. This study evaluated the incidence and clinical associations of sexual dysfunction in adult epilepsy patients.

METHODS

89 epilepsy patients 18 years and older admitted to the New York University Comprehensive Epilepsy Center epilepsy monitoring unit between 2016 and 2018 completed a survey on sexual functioning. The survey included demographic, clinical, and sexual functioning information with a validated measure of sexual function (the Arizona Sexual Experiences Scale (ASEX).

RESULTS

Of 89 surveys completed, 15 (16.9 %) patients had discussed sexual functioning with a medical professional and 20 (22.5 %) reported sexual dysfunction. For the group, the mean ASEX score was 13.6 (SD 4.8). 59 (66.3 %) participants reported not being asked about sexual health by their doctor or nurse practitioner in the last year. The two independent predictors of sexual dysfunction were self-identifying as overweight/obese (OR 6.1, CI 1.4-26.5, P = 0.02) or taking strong enzyme-inducing antiseizure medications (OR 7.8, CI 1.4-44.9, P = 0.02). Other factors such as age, relationship status, duration of epilepsy, the presence of depression or anxiety, cardiovascular risk factors, and opioid/stimulant use, did not predict sexual dysfunction.

SIGNIFICANCE

Our study showed that sexual dysfunction is common in epilepsy patients but infrequently discussed by medical professionals. Two modifiable risk factors, being overweight or taking strong enzyme-inducing antiseizure medications, were independently associated with sexual dysfunction, suggesting interventions to potentially improve sexual health.

Spermatorrhea in a Chinese patient with temporal lobe epilepsy: a case report

Epilepsy is a chronic neurological disorder that is characterized by episodes of seizure. Sexual dysfunction has been reported in patients with seizure, which mostly manifests as erectile dysfunction and premature ejaculation in men. In this study, we report the case of a 65-year-old Chinese man with frequent spermatorrhea. Electroencephalography suggested local epilepsy in the left temporal lobe. After treatment with anti-epilepsy drugs, the symptoms disappeared and did not recur. To the best of our knowledge, this is the first reported case of epilepsy-induced spermatorrhea. The symptoms of spermatorrhea are probably a rare manifestation of seizure. When repetitive stereotyped symptoms occur, seizure should be considered, and tentative anti-epileptic treatment may be a good option.

Erectile dysfunction in common neurological conditions: A narrative review

Neurogenic erectile dysfunction (NED) can be defined as the inability to achieve or maintain an erection due to central or peripheral neurologic disease. Neurologic diseases can also affect the physical ability and psychological status of the patient. All these factors may lead to a primary or secondary NED. Medication history plays an important role since there are many drugs commonly used in neurologic patients that can lead to ED. The assessment of NED in these patients is generally evolving with the application of evoked potentials technology in the test of somatic and autonomic nerves, and functional magnetic resonance imaging. With the electrophysiological examinations, neurogenic causes can be determined. These tools allow to categorize neurologic lesion and assess the patient prognosis. The first-line treatment for NED is phosphodiesterase inhibitors. Second-line treatments include intracavernous and intraurethral vasoactive injections. Third-line treatments are penile prostheses. The efficacy and safety of each treatment modality depend on the specific neurologic condition. This review discusses the physiology, pathophysiology, diagnosis, and treatment of ED in multiple peripheral and central neurologic conditions, as well as for future research.

Investigation of Sexual Satisfaction in Women with Epilepsy and Its Clinical Correlates

Women with epilepsy are at increased risk of sexual dysfunction. The aim of this cross-sectional study was to investigate the effect of antiepileptic drugs on sexual function and satisfaction in women with epilepsy. In this cross-sectional study, 80 married women with epilepsy who were under treatment with antiepileptic drugs for at least 1 year were evaluated. Sexual function in patients was assessed using the Female Sexual Function Index. The mean age (± standard deviation [SD]) of women was 28.8 (± 5.9) years. The mean (± SD) duration of epilepsy was 8.6 (± 4.1) years. Thirteen women (16.2%) had focal epilepsy and 67 (83.7%) had generalized epilepsy. The mean (± SD) overall sexual performance of patients was 20.5 (± 4.7). Fifteen patients (21.3%) had decreased sexual function and 78.2% had unfavorable sexual performance. Generalized epilepsy, multi-drug regimen, disease duration of more than 10 years, and age > 30 years were associated with sexual dysfunction. Due to the high prevalence of sexual dysfunction in women with epilepsy, special attention should be given to appropriate management of these patients.

Epilepsy, depression, and growth hormone

Depression affects a large proportion of patients with epilepsy, and is likely due in part to biological mechanism. Hormonal dysregulation due to the disruptive effects of seizures and interictal epileptiform discharges on the hypothalamic-pituitary-adrenal axis likely contributes to high rates of depression in epilepsy. This paper reviews the largely unexplored role of neuroendocrine factors in epilepsy-related depression, focusing on Growth Hormone (GH). While GH deficiency is traditionally considered a childhood disorder manifested by impaired skeletal growth, GH deficiency in adulthood is now recognized as a serious disorder characterized by impairments in multiple domains including mood and quality of life. Could high rates of depression in patients with epilepsy relate to subtle GH deficiency? Because GH replacement therapy has been shown to improve mood and quality of life in patients with GH deficiency, this emerging area may hold promise for patients suffering from epilepsy-related depression.

Sexual dysfunction and associated factors in Chinese Han women with epilepsy

PURPOSE

Women with epilepsy (WWE) are believed to be at risk of sexual dysfunction (SD) and face many sexual challenges because of multiple factors. This study aimed to assess the factors associated with SD in Chinese Han WWE.

METHODS

This cross-sectional study examined 112 married WWE in the Affiliated Hospital of Yangzhou University with focal (FE) or generalized epilepsy (GE) on antiepileptic drugs (AEDs), and 120 healthy controls without epilepsy, all of Chinese Han nationality. Data collection tools included the Chinese version of Female Sexual Function Index (FSFI), the Chinese version of Zung Self-Rating Anxiety Scale (SAS), the Chinese version of the Zung Self-Rating Depression Scale (SDS), the Chinese version of the revised Morisky Medication Adherence Scale (MMAS-8), and the Chinese version of the National Hospital Seizure Severity Scale (NHS3). Chi-square test, t-test, one-way analysis of variance (ANOVA), and binary logistic regression were used for statistical analysis.

RESULTS

A high rate (70.5%) of SD was detected in WWE, with 24.2% in controls. Sexual dysfunction affected all dimensions: desire (85.7%), arousal (56.3%), lubrication (47.3%), orgasm (66.1%), satisfaction (58.9%), and pain (41.1%). Elevated rates of anxiety (40.2%) and depression (33%) and poor medication adherence (31.3%) were also found in WWE. Binary logistic regression found that poor economic status (odds ratio (OR) = 13.904, 95% confidence interval (CI): 2.025-95.472, P = 0.007 and OR = 6.350, 95% CI: 1.323-30.477, P = 0.021), anxiety (OR = 1.222, 95% CI: 1.055-1.415, P = 0.007), and poor medication adherence (OR = 0.297, 95% CI: 0.124-0.707, P = 0.006) were associated with SD.

CONCLUSIONS

The associated factors of SD in Chinese Han WWE are multifactorial. The WWE have higher levels of anxiety, poor family economic status, and poor medication adherence. Medical professionals should not only better control seizures but also evaluate and improve patients' sexual function so as to improve the quality of life of WWE.

Which information on women's issues in epilepsy does a community pharmacist need to know? A Delphi consensus study

OBJECTIVE

The aim of this study was to develop and achieve consensus on a core list of important knowledge items that community pharmacists should know on women's issues in epilepsy.

METHODS

This was a consensual study using a modified Delphi technique. Knowledge items were collected from the literature and from nine key contacts who were interviewed on their views on what information community pharmacists should have on women's issues in epilepsy. More knowledge items were suggested by five researchers with interest in women's issues who were contacted to rate and comment on the knowledge items collected. Two iterative Delphi rounds were conducted among a panel of pharmacists (n=30) to achieve consensus on the knowledge items to be included in the core list. Ten panelists ranked the knowledge items by their importance using the Analytical Hierarchy Process (AHP).

RESULTS

Consensus was achieved to include 68 knowledge under 13 categories in the final core list. Items ranked by their importance were related to the following: teratogenicity (10.3%), effect of pregnancy on epilepsy (7.4%), preconception counseling (10.3%), bone health (5.9%), catamenial epilepsy (7.4%), menopause and hormonal replacement therapy (2.9%), contraception (14.7%), menstrual disorders and infertility (8.8%), eclampsia (2.9%), breastfeeding (4.4%), folic acid and vitamin K (5.9%), counseling on general issues (14.7%), and sexuality (4.4%).

CONCLUSION

Using consensual knowledge lists might promote congruence in educating and/or training community pharmacists on women's issues in epilepsy. Future studies are needed to investigate if such lists can improve health services provided to women with epilepsy (WWE).

Theory of Planned Behavior including self-stigma and perceived barriers explain help-seeking behavior for sexual problems in Iranian women suffering from epilepsy

PURPOSE

To apply the Theory of Planned Behavior (TPB) and the two additional concepts self-stigma and perceived barriers to the help-seeking behavior for sexual problems in women with epilepsy.

METHODS

In this 18-month follow-up study, TPB elements, including attitude, subjective norm, perceived behavioral control, and behavioral intention along with self-stigma and perceived barriers in seeking help for sexual problems were assessed in n=818 women with epilepsy (94.0% aged ≤40years). The basic TPB model (model 1) and the TPB model additionally including self-stigma and perceived barriers (Model 2) were analyzed using structural equation modeling (SEM).

RESULTS

Both SEM models showed satisfactory model fits. According to model, attitude, subjective norms, perceived behavioral control, and intention explained 63.1% of the variance in help-seeking behavior. Variance was slightly higher (64.5%) when including self-stigma and perceived barriers (model 2). In addition, the fit indices of the models were better highlighting the importance of self-stigma and perceived barriers in help-seeking behavior for sexual problems.

CONCLUSION

Theory of Planned Behavior is useful in explaining help-seeking behavior for sexual problems in women with epilepsy. Self-stigma and perceived barriers are additional factors that should be considered in future interventions aiming to adopt TPB to improve help-seeking behavior for sexual problems.

Family and sexual life in people with epilepsy

Having epilepsy is much more than having seizures. Epilepsy can have a severe negative effect on quality of life, affecting social relationships, academic achievement, housing, employment, and the ability to live and function independently. We undertook a cross-sectional study in a tertiary epilepsy center in Lithuania, aiming to assess the influence of epilepsy and aspects relating to epilepsy (employment, stigma, anxiety) on patients and their families, and to estimate their quality of family life and sexual functioning. We asked patients to complete a questionnaire about their socio-demographic situation, their seizure types and antiepileptic medications, and their quality of family and sexual life. Our results confirmed that epilepsy seriously influences family life. One third of our patients are lonely and half are childless. Epilepsy leads to difficulty in finding a job, especially for men, and unemployment affects their status in the family. People with epilepsy are uncomfortable interacting with those of the opposite sex and tend to conceal their medical condition from their partner. One third have sexual dysfunction, yet only a quarter of them seek professional help. There is a clear need to improve self-confidence and to reduce social stigma in people with epilepsy, and to encourage them to discuss their problems with specialists.

Sexual problems in people with refractory epilepsy

Sexual dysfunction is an important but often neglected aspect of epilepsy. The objective of this study was to explore the prevalence and types of sexual problems in patients with epilepsy and compare the results with similar data obtained from a representative sample of the general population. At the National Centre for Epilepsy in Norway, 171 of 227 consecutive adult inpatients and outpatients with epilepsy (response rate: 75.3%) and their neurologists participated in a questionnaire study about epilepsy and sexuality. The results were compared with data available from 594 adult Norwegians who had completed the same questionnaire. Patients with epilepsy had a significantly higher prevalence of sexual problems (women: 75.3% vs. 12.0%; men: 63.3% vs. 9.6%). The most commonly reported problems (>30%) were reduced sexual desire, orgasm problems, erection problems, and vaginal dryness. The patients reported considerable dissatisfaction regarding sexual functioning. Significantly more sexual problems were found in patients of both sexes with reduced quality of life and in women with symptoms of depression. We found no significant association between sexual problems and age of epilepsy onset, type of epilepsy, or use of enzyme-inducing antiepileptic drugs. Whereas age at sexual debut did not differ between the patients with epilepsy and the general population, men with epilepsy had a lower number of partners during the last 12months, and the proportion of women with a low frequency of intercourse was higher in the group with epilepsy. In conclusion, sexual problems are significantly greater in Norwegian patients with epilepsy than in the general adult population. As no single epilepsy type or treatment could be identified as a specific predisposing factor, it seems likely that there are multiple causes underlying our results, including both organic and psychosocial factors.

Interactions between hormones and epilepsy

There is a complex, bidirectional interdependence between sex steroid hormones and epilepsy; hormones affect seizures, while seizures affect hormones thereby disturbing reproductive endocrine function. Both female and male sex steroid hormones influence brain excitability. For the female sex steroid hormones, progesterone and its metabolites are anticonvulsant, while estrogens are mainly proconvulsant. The monthly fluctuations in hormone levels of estrogen and progesterone are the basis for catamenial epilepsy described elsewhere in this issue. Androgens are mainly anticonvulsant, but the effects are more varied, probably because of its metabolism to, among others, estradiol. The mechanisms for the effects of sex steroid hormones on brain excitability are related to both classical, intracellularly mediated effects, and non-classical membrane effects due to binding to membrane receptors. The latter are considered the most important in relation to epilepsy. The different sex steroids can also be further metabolized within the brain to different neurosteroids, which are even more potent with regard to their effect on excitability. Estrogens potentiate glutamate responses, primarily by potentiating NMDA receptor activity, but also by affecting GABA-ergic mechanisms and altering brain morphology by increasing dendritic spine density. Progesterone and its main metabolite 5α-pregnan-3α-ol-20-one (3α-5α-THP) act mainly to enhance postsynaptic GABA-ergic activity, while androgens enhance GABA-activated currents. Seizures and epileptic discharges also affect sex steroid hormones. There are close anatomical connections between the temporolimbic system and the hypothalamus controlling the endocrine system. Several studies have shown that epileptic activity, especially mediated through the amygdala, alters reproductive function, including reduced ovarian cyclicity in females and altered sex steroid hormone levels in both genders. Furthermore, there is an asymmetric activation of the hypothalamus with unilateral amygdala seizures. This may, again, be the basis for the occurrence of different reproductive endocrine disorders described for patients with left-sided or right-sided temporal lobe epilepsy.

Contribution of estradiol in sex-dependent differences of pentylenetetrazole-induced seizures in rats

In the present study the contribution of estradiol in sex-dependent differences of pentylenetetrazole (PTZ)-induced seizures was investigated in rats. The rats were divided into four groups: 1) sham, 2) ovariectomized (OVX), 3) ovariectomized-estradiol (OVX-Est) and 4) male. The OVX-Est group received estradiol valerate (2 mg/kg; i.m/4 weeks) while, male, sham and OVX groups received vehicle. The animals were injected by PTZ (90 mg/kg). The latencies to minimal clonic seizures (MCS) and generalized tonic-clonic seizures (GTCS), were recorded. Serum 17β-estradiol and testosterone levels were also determined using an Elisa kit. GTCS latency in OVX rats was higher than in sham-operated animals (P < 0.05). MCS and GTCS latency in the male group was significantly higher than in the sham, OVX and OVX-Est groups (P < 0.001 and P < 0.01). There was no significant difference in MCS or GTCS latencies among OVX-Est, sham and OVX groups. Serum 17β-estradiol level in the OVX group was significantly lower than in the sham (P < 0.01) and in the OVX-Est group it was higher than in the sham, OVX and male groups (P < 0.01 and P < 0.001). Serum testosterone level in the male group was significantly higher than in all the other three groups (P < 0.001). It seems that testosterone probably has a more efficient role than estradiol in the gender dependent difference in seizure caused by PTZ in rats.

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.

Hormonal consequences of epilepsy and its treatment in men

PURPOSE OF REVIEW

Epilepsy and anticonvulsant medications may substantially alter endocrine homeostasis, including the male reproductive hormonal system.

RECENT FINDINGS

Seizures in medial temporal lobe structures, through their connectivity to the hypothalamus, alter the secretion of gonadotropins. Levels of circulating bioavailable testosterone are affected by changes in the level of binding proteins, which in turn may be affected by seizure medications. The use of older generation medications that induce the cytochrome P450 system is associated with an increase in sex hormone-binding globulin and lower bioactive testosterone. Sexual dysfunction, including decreased libido and decreased potency, and infertility, is seen commonly in men with epilepsy. However, its relation to sex hormone levels remains unclear. Comorbid depression and anxiety may be important confounding factors. Testosterone and sexual function appear not to be affected by the newer generation (noninducing) anticonvulsants.

SUMMARY

Epilepsy and its drug treatments are associated with alterations in hormonal and sexual function in men. Further study is needed to clarify the precise mechanisms behind these alterations, as some of the data conflict. More attention should be paid to this issue in male patients with seizures; when appropriate, treatment for psychiatric comorbidity and switches in anticonvulsant therapy may be worth consideration.

Sexual side effects of pharmacological treatment of psychiatric diseases

Since the introduction of psychiatric medications with relatively good safety profiles, such as selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors, increasing attention has been given to side effects such as sexual dysfunction (SD), which, although unrelated to risks of mortality, could undermine compliance with treatment regimens and impair quality of life. Indeed,there is consistent evidence to suggest that a large number of psychiatric medications adversely affect one or more of the three phases of normal sexual response: desire, arousal, and orgasm.

Kainic acid-induced early genes activation and neuronal death in the medial extended amygdala of rats

The medial extended amygdala modulates pheromonal perception, influencing emotional and social behavior. As the amygdala is part of neuronal circuits that are very sensitive to excitability, its neurons are targets of seizures in temporal lobe epilepsy. It has been suggested that the hippocampus is strongly involved this pathology. There is less consistent information, however, on the effects of this disease in the amygdala. The effects of status epilepticus on the medial extended amygdala were analyzed by immunohistochemistry for neural stress and by the amino-cupric-silver technique for neuronal death in rats after kainic acid (KA) administration. Sixty adult Wistar male rats were used. Thirty animals received an injection of KA, and 30 were injected with saline. After 2, 4, 12, 24 and 48 h survival the brains were stained for Fos and FosB and for neuronal death. In the present study we show that KA induces Fos and FosB expression in neurons of the medial extended amygdala after 2, 4-48 h, with time courses that are different between them and from control animals. While Fos-IR peaks at 2-4 h post KA and then decreases, FosB-IR increases in the same period reaching its highest expression at 24-48 h. Moreover, KA injection produced massive neuronal death with a peak at 24 h. This neurodegeneration paralleled FosB-IR protein expression. These findings show that KA produces neuronal stress and activation of early genes and neuronal death in the medial extended amygdala, demonstrating the vulnerability of its neurons to the epileptogenic effects of KA.

Effect of sildenafil on the anticonvulsant action of classical and second-generation antiepileptic drugs in maximal electroshock-induced seizures in mice

PURPOSE

The goal of the present study was to evaluate the effects of sildenafil on the threshold for electrically induced seizures in mice. In addition, interactions between sildenafil and classical and second-generation antiepileptic drugs (AEDs), that is, carbamazepine (CBZ), phenobarbital (PB), phenytoin (PHT), valproate (VPA), lamotrigine (LTG), topiramate (TPM), and oxcarbazepine (OXC) were evaluated.

METHODS

Two electroconvulsive tests were used: maximal electroshock seizure threshold (MEST) and maximal electroshock seizure (MES) tests in mice. Acute adverse effects of the studied combinations were investigated in the chimney test, step-through passive avoidance task, and grip-strength test. Total brain and free plasma concentrations of AEDs were also determined.

RESULTS

Sildenafil raised the threshold for electroconvulsions in a dose-dependent manner. It also increased the anticonvulsant activity of CBZ, VPA, and TPM in the MES test, whereas the activity of the remaining AEDs was not significantly changed. Sildenafil increased total brain and free (protein unbound) plasma CBZ concentrations and total brain VPA concentration. Neither sildenafil nor its coadministration with the studied AEDs affected motor coordination and long-term memory in mice. Interestingly, sildenafil dose-dependently enhanced the skeletal muscle strength in mice, although combinations of sildenafil with AEDs were ineffective in this respect.

CONCLUSIONS

Sildenafil significantly raised the threshold for electroconvulsions in mice without any impairment of motor performance and long-term memory, but it enhanced muscle strength. Treatment of patients on CBZ or VPA with sildenafil may not be recommended due to pharmacokinetic interactions. Coadministration of sildenafil with other AEDs, especially with TPM, seems to be a reasonable choice.

The effect of L-arginine and L-NAME on pentylenetetrazole induced seizures in ovariectomized rats, an in vivo study

The role of ovarian hormones and nitric oxide (NO) on seizure and their interaction have been widely investigated. The present study carried out to evaluate the effect of chronic administration of L-arginine (LA) and L-NAME (LN) on pentylenetetrazole (PTZ) induced epilepsy in ovariectomized (OVX) and naïve female rats. Fourty-eight female rats were randomly divided into six groups (n=8) as follows: (1) sham, (2) ovarectomized (OVX), (3) sham-LA, (4) sham-LN, (5) OVX-LA, and (6) OVX-LN. The animals of sham-LA and OVX-LA received daily injection of 500 mg/kg L-arginine (i.p.) during 4 weeks. Sham-LN and OVX-LN were treated by 10 mg/kg L-NAME (i.p.) daily for 4 weeks. The animals of sham and OVX groups received 1 ml/kg saline (i.p.) instead of L-arginine and L-NAME. The latencies to minimal clonic seizures (MCS) and generalized tonic-clonic seizures (GTCS) after intraperitoneal injection of penetylenetetrazole (PTZ, 90 mg/kg) was recorded and compared between groups. A significant increase in the GTCS, but not MCS, latency was seen in OVX rats in comparison with sham-operated animals. Pretreatment of animals with L-NAME resulted in a significant increase in the GTCS and MCS latencies in sham group while no significant effects were seen in OVX rats. On the contrary, while pretreatment with L-arginine had no effects on MCS and GTCS latencies in sham group, a significant decrease in GTCS latency was observed in OVX rats. It is concluded that ovarian sex hormones affect seizure thresholds induced by PTZ and NO has a role on seizures susceptibility following PTZ administration. This NO effect might be differing in the presence or absence of ovarian hormones, but further investigations need to be done.

Pathology and pathophysiology of the amygdala in epileptogenesis and epilepsy

Acute brain insults, such as traumatic brain injury, status epilepticus, or stroke are common etiologies for the development of epilepsy, including temporal lobe epilepsy (TLE), which is often refractory to drug therapy. The mechanisms by which a brain injury can lead to epilepsy are poorly understood. It is well recognized that excessive glutamatergic activity plays a major role in the initial pathological and pathophysiological damage. This initial damage is followed by a latent period, during which there is no seizure activity, yet a number of pathophysiological and structural alterations are taking place in key brain regions, that culminate in the expression of epilepsy. The process by which affected/injured neurons that have survived the acute insult, along with well-preserved neurons are progressively forming hyperexcitable, epileptic neuronal networks has been termed epileptogenesis. Understanding the mechanisms of epileptogenesis is crucial for the development of therapeutic interventions that will prevent the manifestation of epilepsy after a brain injury, or reduce its severity. The amygdala, a temporal lobe structure that is most well known for its central role in emotional behavior, also plays a key role in epileptogenesis and epilepsy. In this article, we review the current knowledge on the pathology of the amygdala associated with epileptogenesis and/or epilepsy in TLE patients, and in animal models of TLE. In addition, because a derangement in the balance between glutamatergic and GABAergic synaptic transmission is a salient feature of hyperexcitable, epileptic neuronal circuits, we also review the information available on the role of the glutamatergic and GABAergic systems in epileptogenesis and epilepsy in the amygdala.