共查询到20条相似文献,搜索用时 15 毫秒
1.
Epilepsy, Sex Hormones, and Antiepileptic Drugs 总被引:2,自引:9,他引:2
Summary: Many factors associated with hormone function have an impact on the course of epilepsy. Patients with epilepsy may have disturbances in sexual function such as anovulatory cycles in women and decreased libido and potency in men. Data indicate seizures, especially those arising in the limbic system, may influence the hypothalamic pituitary axis. Antiepileptic drugs also influence sexual function through direct brain effects as well as through induced changes in pharmacokinetics of the sex steroid hormones. Pregnancy has been reported to be a time of increased seizures; however, this has often been associated with low drug levels, for reasons that include inadequate drug dose, possible changes in pharmacokinetics, and noncompliance. Some evidence suggests that hormones affect seizure frequency. Changes in seizures during the menstrual cycle (catamenial epilepsy) have been found in some women: seizures were fewer during the luteal phase but increased when progesterone levels declined. Some improvement in seizure frequency has been shown in pilot studies using medroxyprogesterone acetate, a synthetic progesterone. Current concepts of the interrelationship among epilepsy, sex hormones, and antiepileptic drugs are discussed. 相似文献
2.
It is clear from both clinical observations of women, and research in laboratory animals, that gonadal hormones exert a profound influence on neuronal excitability, seizures, and epilepsy. These studies have led to a focus on two of the primary ovarian steroid hormones, estrogen and progesterone, to clarify how gonadal hormones influence seizures in women with epilepsy. The prevailing view is that estrogen is proconvulsant, whereas progesterone is anticonvulsant. However, estrogen and progesterone may not be the only reproductive hormones to consider in evaluating excitability, seizures, or epilepsy in the female. It seems unlikely that estrogen and progesterone would exert single, uniform actions given our current understanding of their complex pharmacological and physiological relationships. Their modulatory effects are likely to depend on endocrine state, relative concentration, metabolism, and many other factors. Despite the challenges these issues raise to future research, some recent advances have helped clarify past confusion in the literature. In addition, testable hypotheses have developed for complex clinical problems such as "catamenial epilepsy." Clinical and animal research, designed with the relevant endocrinological and neurobiological issues in mind, will help advance this field in the future. 相似文献
3.
In 2011, there are greater than 20 antiepileptic medications available. These medications work by modulating neuronal excitability.
Reproductive hormones have been found to have a role in the pathogenesis and treatment of seizures by also altering neuronal
excitability, especially in women with catamenial epilepsy. The female reproductive hormones have in general opposing effects
on neuronal excitability; estrogens generally impart a proconvulsant neurophysiologic tone, whereas the progestogens have
anticonvulsant effects. It follows then that fluctuations in the levels of serum progesterone and estrogen throughout a normal
reproductive cycle bring about an increased or decreased risk of seizure occurrence based upon the serum estradiol/progesterone
ratio. Therefore, using progesterone, its metabolite allopregnanolone, or other hormonal therapies have been explored in the
treatment of patients with epilepsy. 相似文献
4.
Martha J. Morrell 《Epilepsia》1992,33(Z4):49-61
Summary: Hormones influence brain function from gestation throughout life and may affect the seizure threshold by altering neuronal excitability. Estrogen enhances and progesterone diminishes neuronal excitability experimentally, whereas testosterone and corticosteroids have less consistent effects. Hormonal effects in the CNS also depend on the region of brain in which the hormone acts. Sites of action for most steroid hormones include the hypothalamus and limbic cortex, providing a mechanism for modulating behavior and endocrine function. Seizure patterns may change at certain life stages, perhaps as a result of alterations in hormones. At puberty, epilepsy and benign rolandic epilepsy often remit, while juvenile myoclonic and photosensitive epilepsy may arise. Other types of epilepsy do not respond predictably to events in the reproductive life or to advancing age. In some women, fluctuations in hormones over the menstrual cycle appear to increase seizure vulnerability, probably reflecting changes in relative amounts of estrogen and progesterone. Seizure patterns can be altered, for better or worse, during pregnancy. Whether this reflects the effects of hormones or changes in levels of antiepileptic drugs is not resolved. More information is needed about changes in established epilepsy at menopause and in the elderly. Better understanding of endocrine effects on seizures over a lifetime should lead to more effective epilepsy therapies. 相似文献
5.
Sex difference in seizure susceptibility is one of the unresolved issues of epilepsy. It is known that estrogen is excitatory and progesterone is inhibitory to the central nervous system. Therefore, it is to be expected that seizure susceptibility may be associated with the estrous cycle, which should be tested in epilepsy research. Otherwise, different results in epilepsy studies could be an artifact of the estrous cycle. Reports in the literature are inconsistent about testosterone effects on seizures. In light of these considerations, sex differences in seizure susceptibility were restudied in rats. There was no significant sex difference in mean latencies to picrotoxin-induced seizures; prestrous-females had the shortest latencies to epileptic seizures compared to males and estrousfemales. With testosterone-injected rats, there was either no sex difference in latencies (to akinetic and focal seizures) or females had significantly shorter latencies than males (to status epilepticus, generalized tonic-clonic seizures, and myoclonic seizures). Testosterone-treated male rats had a significantly longer mean latency than controls for status epilepticus only; otherwise, these males showed no significant differences between mean latencies before and after testosterone (to focal, myoclonic, or generalized tonic-clonic seizures). In females, mean latencies to myoclonic seizures and status epilepticus were significantly shorter after testosterone than before. It was concluded that there is a sex difference in susceptibility to epileptic seizures in rats, provided that the estrous cycle is taken into account. Testosterone may increase and decrease seizure susceptibility in females and males, respectively. These effects may be important for understanding the mechanisms of epileptic phenomena and may provide some important clues to epilepsy treatment. 相似文献
6.
Carlo Andrea Galimberti †Flavia Magri ‡Francesco Copello Carla Arbasino †Spyridon Chytiris §Massimo Casu §Pietro Ameri Piero Perucca §Giovanni Murialdo 《Epilepsia》2009,50(S1):28-32
Purpose: Reproductive dysfunction in epilepsy is attributed to the seizures themselves and also to antiepileptic drugs (AEDs), which affect steroid production, binding, and metabolism. In turn, neuroactive steroids may influence neuronal excitability. A previous study in this cohort of consecutive women with epilepsy showed that patients with more frequent seizures had higher cortisol and lower dehydroepiandrosterone sulfate levels than those with rare or absent seizures. The present study was aimed at evaluating, in these same women, the possible relationship between some clinical parameters, seizure frequency, AED therapies, and sex hormone levels.
Methods: Estradiol (E2), progesterone (Pg), sex hormone-binding globulin (SHBG), and free estrogen index (FEI) were measured during the luteal phase in 113 consecutive females, 16–47 years old, with different epilepsy syndromes on enzyme-inducing AED (EIAED) and/or non–enzyme-inducing AED (NEIAED) treatments, and in 30 age-matched healthy women. Hormonal data were correlated with clinical parameters (age, epilepsy syndrome, disease onset, and duration), seizure frequency assessed on the basis of a seizure frequency score (SFS), and AED therapies.
Results: E2, Pg, and FEI were lower, whereas SHBG levels were higher in the epilepsy patients than in the controls. However, sex steroid and SHBG levels were not different between groups of patients categorized according to SFS. Therapies with EIAEDs accounted for changes in E2 levels and FEI.
Conclusions: Despite globally decreased sex steroid levels in serum, actual hormone titers were not significantly correlated with SFS in consecutive epilepsy women; rather, these hormonal changes were explained by AED treatments, mainly when EIAED polytherapies were given. 相似文献
Methods: Estradiol (E2), progesterone (Pg), sex hormone-binding globulin (SHBG), and free estrogen index (FEI) were measured during the luteal phase in 113 consecutive females, 16–47 years old, with different epilepsy syndromes on enzyme-inducing AED (EIAED) and/or non–enzyme-inducing AED (NEIAED) treatments, and in 30 age-matched healthy women. Hormonal data were correlated with clinical parameters (age, epilepsy syndrome, disease onset, and duration), seizure frequency assessed on the basis of a seizure frequency score (SFS), and AED therapies.
Results: E2, Pg, and FEI were lower, whereas SHBG levels were higher in the epilepsy patients than in the controls. However, sex steroid and SHBG levels were not different between groups of patients categorized according to SFS. Therapies with EIAEDs accounted for changes in E2 levels and FEI.
Conclusions: Despite globally decreased sex steroid levels in serum, actual hormone titers were not significantly correlated with SFS in consecutive epilepsy women; rather, these hormonal changes were explained by AED treatments, mainly when EIAED polytherapies were given. 相似文献
7.
癫痫患者体内的性激素的水平与正常人不同,其癫痫发作与性激素水平有关。性激素、癫痫以及抗癫痫药物之间 相互影响。雌激素受体调节剂-克罗米酚以及天然或者合成的孕激素对一些癫痫患者的发作有效。 相似文献
8.
Giovanni Murialdo †Flavia Magri ‡Gianluca Tamagno Pietro Ameri †Antonella Camera §Silvia Colnaghi §Piero Perucca ¶Giambattista Ravera §Carlo Andrea Galimberti 《Epilepsia》2009,50(8):1920-1926
Purpose: Neuroactive sex steroids influence neuron excitability, which is enhanced by estradiol (E2) and decreased by progesterone (Pg). In epilepsy, the production, metabolism, biologic availability, and activity of sex hormones may be affected by seizures themselves or by antiepileptic drugs (AEDs). This cross-sectional observational study was aimed at evaluating the relationships between sex steroids, seizure frequency, and other clinical parameters in women with partial epilepsy (PE) on AED treatments.
Methods: Serum E2, Pg, sex hormone binding globulin (SHBG) levels, free E2 (fE2), and E2/Pg ratios were determined during the follicular and luteal phases in 72 adult women with PE, and in 30 healthy controls. Hormonal data were correlated with seizure frequency, age, body weight, body mass index (BMI), disease onset and duration, and AED therapies.
Results: In patients, E2, fE2, and Pg levels were lower in both ovarian phases, whereas those of SHBG were higher than in controls. No significant changes in hormone levels and in prevalence of anovulatory cycles were observed between patients grouped according to their seizure frequency. However, when compared with those in healthy controls, luteal fE2 and Pg levels were chiefly impaired in women with more frequent seizures, mostly undergoing AED polytherapies, but not in those with absent or rarer seizures.
Conclusions: The actual changes in sex steroid levels and E2/Pg ratios did not explain an increased seizure frequency in adult women with AED-treated PE, but patients with more severe disease showed more relevant changes in their sex hormone profile and impaired Pg levels during the luteal phase. 相似文献
Methods: Serum E2, Pg, sex hormone binding globulin (SHBG) levels, free E2 (fE2), and E2/Pg ratios were determined during the follicular and luteal phases in 72 adult women with PE, and in 30 healthy controls. Hormonal data were correlated with seizure frequency, age, body weight, body mass index (BMI), disease onset and duration, and AED therapies.
Results: In patients, E2, fE2, and Pg levels were lower in both ovarian phases, whereas those of SHBG were higher than in controls. No significant changes in hormone levels and in prevalence of anovulatory cycles were observed between patients grouped according to their seizure frequency. However, when compared with those in healthy controls, luteal fE2 and Pg levels were chiefly impaired in women with more frequent seizures, mostly undergoing AED polytherapies, but not in those with absent or rarer seizures.
Conclusions: The actual changes in sex steroid levels and E2/Pg ratios did not explain an increased seizure frequency in adult women with AED-treated PE, but patients with more severe disease showed more relevant changes in their sex hormone profile and impaired Pg levels during the luteal phase. 相似文献
9.
Andrew G. Herzog 《Epilepsia》1991,32(S6):S27-S33
Summary: Animal experimental and human clinical investigations show that estrogens lower and progestins raise many seizure thresholds. In women, seizure frequency varies with the serum estradiol to progesterone ratio. The fluctuation of this ratio during the menstrual cycle is a major factor in catamenial epilepsy. A decline in serum antiseizure medication levels premenstrually may be another factor. Estradiol to progesterone ratios are elevated in anovulatory or inadequate luteal phase cycles. This may explain a propensity for seizure onset at the time of menarche and the exacerbation of seizures during the months or years leading up to menopause. It may also be an important factor in the association between reproductive endocrine disorders and epilepsy. Specifically, polycystic ovarian syndrome and hypogonadotro-pic hypogonadism are significantly overrepresented among women with epilepsy. Epilepsy may promote the development of these disorders. These disorders, in turn, are characterized by inadequate luteal phase cycles that may promote the development or occurrence of seizures. In the setting of catamenial epilepsy or reproductive endocrine disorders, progestins, such as natural progesterone and parenteral medroxyprogesterone, or antiestrogenic agents, such as clomi-phene, constitute rational and effective adjuncts to therapy. 相似文献
10.
Page B. Pennell 《Epilepsia》2006,47(S1):46-53
Summary: Although most female-specific considerations for treatment of epilepsy cannot be answered by Class I evidence, significant progress in our knowledge base has occurred in the past few years. Open-label studies of progesterone supplementation showed promising results; an ongoing randomized trial may provide definitive evidence for therapeutic use of progesterone in women. A randomized trial of hormone replacement therapy demonstrated a dose-related increase in seizure frequency in postmenopausal women with epilepsy. The use of different AED regimens during pregnancy cannot be explored with randomized, controlled trials; we must rely on the best available evidence from ongoing observational studies. The consistent findings of large prospective pregnancy registries reveal a consistent pattern of amplified risk for major congenital malformations in pregnancies exposed to valproate. These registries have also highlighted the concern for the effect of shifting hormones on AED concentrations. An increased frequency of seizures during pregnancy has been noted with lamotrigine (LTG) and oxcarabazepine, both of which undergo glucuronidation. Other studies have demonstrated an increased clearance of LTG during pregnancy and with exogenous estrogen use. It may be prudent to closely monitor serum concentrations of these AEDs with hormonal changes. An increased risk for neurodevelopmental consequences has been demonstrated for the fetus exposed to AED polytherapy, valproic acid, or frequent maternal convulsive seizures. Preliminary information about breastfeeding with LTG and levetiracetam is available. These newly released findings provide the tools to begin to practice evidence-based medicine when treating our female patients during their reproductive and postmenopausal years. 相似文献
11.
Role of neurosteroids in catamenial epilepsy 总被引:3,自引:0,他引:3
Reddy DS 《Epilepsy research》2004,62(2-3):99-118
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. 相似文献
12.
目的了解癫痫发作频率、抗癫痫单药/联合用药治疗及围经期癫痫对女性癫痫患者性激素水平的影响。方法测定入组的87例女性癫痫患者血清泌乳素、雌激素、孕激素、睾酮水平,根据发作频率、单药/联合用药治疗及是否围经期癫痫分组,并比较不同组间性激素的变化。结果高发作频率组泌乳素升高率及发病年龄明显高于低发作频率组和无癫痫发作组;其孕激素下降率高于低发作频率组(P均0.05)。联合用药治疗组睾酮升高率明显高于单药治疗组(P0.05)。围经期癫痫组泌乳素升高率、孕激素下降率及雌/孕比值明显高于非围经期癫痫组(P均0.05)。结论泌乳素升高与近期癫痫发作有关;孕激素下降与癫痫发作严重性有关;抗癫痫药物影响性激素水平,尤以联合应用丙戊酸钠对睾酮作用显著。孕激素、雌/孕比与围经期癫痫密切相关,孕激素补充疗法可能是治疗围经期癫痫的一条有效途径。 相似文献
13.
Seizure occurrence during ovulatory and anovulatory cycles in patients with temporal lobe epilepsy: a prospective study 总被引:1,自引:0,他引:1
We investigated the influence of ovulatory and anovulatory menstrual cycles on seizure occurrence in female patients with complex partial seizures. We prospectively documented seizures in relation to menstrual cycles (defined by measurement of basal body temperature and progesterone serum concentrations) in 39 female patients. One hundred and thirty-two cycles of 35 patients entered final analysis. Only eight patients had anovulatory cycles, in 18 patients all cycles were ovulatory. In the remaining nine patients anovulatory as well as ovulatory cycles were documented. In ovulatory cycles the mean frequency of seizures during the days of menstruation was significantly higher as compared to the periovulatory or the luteal phase of the cycles. During anovulatory cycles seizure frequency was significantly lower during menstruation than in the remaining days of the cycles. Since progesterone is known to exhibit anticonvulsant effects, seizure occurrence during menstruation seems to be related to ovulatory cycles, possibly due to the premenstrual decrease of progesterone. Therapeutic recommendations for the treatment of seizures related to the menstrual cycle (catamenial seizures) include the administration of hormones, as progesterone (recommended especially for women with catamenial epilepsy who have a documented inadequate luteal phase) or the suppression of the menstrual hormonal cycle by synthetic gonadotropin releasing hormone analogs. 相似文献
14.
Sexual hormones and epilepsy: threat and opportunities 总被引:3,自引:0,他引:3
PURPOSE OF REVIEW: This article reviews recent developments in our knowledge of the reciprocal interactions between epilepsy and sex hormones and how these interactions may play a role in the pathophysiology and treatment of both. RECENT FINDINGS: Community studies confirm that menstrual disorders are overrepresented among women with epilepsy, especially among women with high seizure frequency and in those on valproate or polytherapy. Reproductive function is not affected in women with epilepsy who discontinued antiepileptic drug therapy during pubertal maturation. While valproate has been implicated as having particularly notable disruptive effects on reproductive function in women with epilepsy (polycystic ovaries and hyperandrogenemia), this was not evident in non-epileptic primates. The role of epilepsy itself is evident from a study that showed that the laterality of unilateral temporolimbic discharges is associated with predictable directional changes in hormonal secretion at all levels of the reproductive neuroendocrine axis. Epilepsy in men is associated with reduced levels of sexual function, bioactive testosterone and sperm. Various antiepileptic drugs may differ in this regard. SUMMARY: Epilepsy and antiepileptic drugs can alter sex hormone levels to promote the development of reproductive endocrine disorders in both women and men. Reproductive endocrine disorders may adversely affect both reproductive function and seizure control. Treatment of epilepsy and selection of antiepileptic drugs may be important to reproductive health in women and men with epilepsy. Sex steroids and their metabolites may also provide treatment for seizures. 相似文献
15.
Motta E 《Neurologia i neurochirurgia polska》2000,34(Z1):31-36
The paper contains a review of reports concerned with how for hormones, epileptic seizures and antiepileptic drugs can be influenced by one another. Hormones influence brain excitability but, on the other hand, both epileptic seizures and antiepileptic drugs may alter hormone secretion and metabolism. Effect of hormones on seizures--Experimental studies revealed the properties which inhibit or stimulate convulsive reactivity of different hormones. Progesterone, testosterone, adrenocorticotropin and desoxycorticosterone are responsible for an increase in seizure threshold, while estradiol, cortisol and thyroid hormones cause a reduction. Effect of seizures on hormones--Epileptic seizures, chiefly tonic-clonic, also complex partial and sometimes simple partial seizures, result in "the hormonal storm". Immediately after an epileptic seizure, an increase is found in serum concentrations of prolactin, cortisol, adrenocorticotropin, triidothyronine, thyroxin, thyrotropin, luteotropin, follicular stimulating hormone and growth hormone. These changes may persist for two hours, while prolactin concentration even for 24 hours after a seizure. Effect of antiepileptic drugs on hormones--Antiepileptic drugs may affect hypothalamus-pituitary function directly or indirectly through neurotransmitter system. By induction of hepatic microsomal enzymes, some antiepileptic drugs cause acceleration of hormone metabolism, reducing hormone serum concentrations. Moreover, antiepileptic drugs enhance sex hormone binding globulin SHBG/synthesis, increase binding of these hormones and reduce their active fraction concentration in serum. Recognition of the relationship between epilepsy and hormonal system is necessary to obtain better understanding of this disease. 相似文献
16.
Cynthia L Harden 《Seizure》2008,17(2):176-180
Interest in the years of reproductive changes for women with epilepsy (WWE), specifically perimenopause, menopause and postmenopause has been emerging in the epilepsy community. This article discusses evidence for changes in seizure frequency during perimenopause and postmenopause. Further, a catamenial epilepsy pattern during the reproductive years may be a hallmark for the observed seizure frequency change during these years; that is, an increase at perimenopause but a decrease at menopause. This finding implies that a subset of WWE are particularly susceptible to endogenous reproductive hormonal changes. An adverse effect on seizure frequency with the use of hormone replacement therapy (HRT) during postmenopause for WWE was reported in questionnaires, and was later borne out in a clinical trial. The laboratory counterpart of this human trial, HRT in ovariectomized rodent seizure models, shows that estrogen and progesterone are neuroprotective and do not uniformly increase seizure frequency. Possible reasons for the discrepancy between "the lab and the clinic" are presented. Strategies for managing HRT in symptomatic postmenopausal WWE using estrogenic and progestogenic compounds that may be less likely to promote seizures are discussed. 相似文献
17.
Three Patterns of Catamenial Epilepsy 总被引:25,自引:11,他引:14
Summary: Purpose: On the basis of the neuroactive properties of estradiol and progesterone and the menstrually related cyclic variations of their serum concentrations, we propose the existence of three hormonally based patterns of seizure exacerbation. Because previous reports both support and refute the concept of catamenial epilepsy, we test the hypothesis by charting seizures and menses and measuring midluteal serum progesterone levels to estimate the frequency of epileptic women with catamenial seizure exacerbation. Methods: One hundred eighty-four women with intractable complex partial seizures (CPS) charted their seizure occurrence and onset of menstruation on a calendar for one cycle during which they had a midluteal blood sample taken for serum progesterone determination on day 22. Levels >5 ng/ml were considered ovulatory. The cycle was divided into four phases with onset of menstruation being day 1: menstrual (M) = -3 to +3, follicular (F) = 4 to 9, ovulatory (O) = 10 to -13, and luteal (L) =?12 to ?4. Average daily seizure frequency for each phase was calculated and compared among phases by repeated-measures analysis of variance (ANOVA) and the Student-Newman-Keul's test, separately for ovulatory and anovulatory cycles. Results: The 1,324 seizures recorded during 98 ovulatory cycles occurred with significantly greater (p < 0.001) average daily frequency during the M (0.59) and O (0.50) phases than during the F (0.41) and L (0.40) phases, offering support for perimenstrual (catamenial 1) and preovulatory (catamenial 2) patterns of seizure exacerbation. The 1,523 seizures recorded during 86 anovulatory cycles occurred with significantly lower (p < 0.001) average daily frequency during the F phase (0.49) than during all other phases (M = 0.78, O = 0.74, L = 0.74), offering support for seizure exacerbation throughout the second half of inadequate luteal phase cycles (catamenial pattern 3). Although 71.4% of the women with ovulatory cycles and 77.9% with inadequate luteal phase cycles had seizure exacerbation in relation to one of the three patterns of catamenial epilepsy, approximately one third of the women showed at least a twofold increase in average daily seizure frequency. We propose a twofold or greater increase as a reasonable definition of catamenial epilepsy. Conclusions: Charting of seizures and menses and determination of day 22 progesterone levels during each cycle may be sufficient to establish the existence of three distinct patterns of catamenial epilepsy. Approximately one third of women with intractable CPS may have catamenial epilepsy. 相似文献
18.
Libor Velí
ek Jana Velí
kov Anne M. Etgen Patric K. Stanton Solomon L. Mosh 《Brain research》1999,842(1):141-138
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. 相似文献
19.
Circulating levels of allopregnanolone, an anticonvulsant metabolite of progesterone, in women with partial epilepsy in the postcritical phase 总被引:1,自引:1,他引:0
PURPOSE: Several lines of evidence indicate that there exists a relation between ovarian hormones and epilepsy. Estrogens decrease seizure threshold and increase brain excitability, whereas progesterone has an inhibitory effect and reduces epileptiform activity. Recently considerable interest has turned to neuroactive steroids, a group of progesterone metabolites, as endogenous modulators of excitability of the central nervous system (CNS). Their ability to alter neuronal firing rapidly occurs through interaction with gamma-aminobutyric acid (GABA) A receptor complex. In a previous experience, serum allopregnanolone (3alpha-OH-5alpha-pregnan-20-one) levels were measured in 15 women with partial epilepsy in the intercritical phase, and no significant differences were found between patients and control subjects. METHODS: To find out if there are changes in serum allopregnanolone levels after epileptic seizure, blood samples were drawn immediately, 15 min, and 6 h after a seizure in seven fertile females with partial epilepsy. RESULTS: The most interesting finding is that allopregnanolone increases in serum during the first 15 min after partial seizures (p < 0.05) and decreases after 6 h. CONCLUSIONS: These data are consistent with a role for allopregnanolone in the control of neuronal excitability and seizures. 相似文献