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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Steroid hormones, i.e., corticosteroids, estrogens, androgens and progestogens are formed in the adrenal cortex, male gonads, and the female placenta. Relatively little is known of their influence on behavior and their neuroendocrine function. On the cellular level, the rate of increase of RNA message to produce albumen and avidin is directly proportionate to the presence of steroids and their amount. Corticosteroid receptors are found in the thymus, liver, spleen and heart. The brain has receptors both for the corticosteroids and the sex hormones. These receptors are scattered throughout different regions of the brain, but the synthetic glucocorticoid dexamethasome is found only in the pituitary which accounts for its role in stopping the secretion of ACTH. Testosterone undergoes metabolic changes in the brain, affecting behavior. The A chain undergoes an enzyme reduction to 5aDHT and androstandiol. Following enzyme changes, the A chain of male testosterone can become female estradiol. Laboratory tests prove that sexual behavior in males is affected only by those androgens that can convert to estrogens, while in females it is dependent on the conversion of testosterone to estrogen. Lately psychiatrists have become very interested in the catechol estrogens, fairly new metabolites of estradiol which are produced in the hypothalamus and contain 2 hydroxyl groups (as compared with the 1 hydroxyl in estrogens). Catechol estrogens block estradiol receptors, behaving like antiestrogens. Researchers are investigating the possibility of signaling the desired neural messages without the concomitant effects that estrogen produces, through using catechol estrogens. They are examining this natural derivative of estradiol which may affect among others: sexual behavior, maturity, depression, migraines, and epileptic seizures.
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PMID:[Steroid hormones and the activity of the central nervous system]. 38 16

Androgen deficiency is unusually common among men with epilepsy. It may contribute to reproductive and sexual dysfunction and possibly exacerbate seizure frequency. The most important androgen is testosterone. it exists in the serum in a free form or bound to albumin or sex hormone-binding globulin (SHBG). Free testosterone levels have correlated significantly with measures of potency and sexual interest. The possibility that measures of non-SHBG-bound testosterone may provide a more sensitive assessment of biologically and perhaps clinically significant androgen levels is raised for consideration. Androgen deficiency may result from increased catabolism and binding induced by antiepileptic drugs (AEDs). It is a feature of the reproductive endocrine disorders that are often associated with epilepsy: hypogonadotropic hypogonadism, hypergonadotropic hypogonadism, and functional hyperprolactinemia. It may be a consequence of medication-induced elevations in serum estradiol. Estradiol exerts a potent inhibitory influence on luteinizing hormone secretion and may contribute to premature aging of the reproductive system, both at the level of the testes and the hypothalamus. Testosterone therapy may moderately benefit reproductive and sexual function. Despite its antiseizure effects in animal experiments, however, it has not been reported to improve seizures clinically. One possible explanation is that AEDs that induce enzyme synthesis may enhance the conversion of testosterone to estradiol by aromatase. This possibility is supported by the improved seizure control achieved with the adjunctive use of the aromatase inhibitor testolactone or the antiestrogen clomiphene.
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PMID:Reproductive endocrine considerations and hormonal therapy for men with epilepsy. 195 10

Picrotoxin (1 mg/kg, i.p.), evoked a single generalized seizure in 75% of ovariectomized rats. Pretreatment of matched pairs with silastic implants containing 100% estradiol had an anticonvulsant effect; it protected all rats against such seizures. Implants containing 10% estradiol in cholesterol were less effective in protecting against picrotoxin-induced seizures. With 2 mg/kg picrotoxin, 85% of the seizure-affected ovariectomized controls had multiple seizures. The incidence of seizures and the ratio of single to multiple seizures induced by the higher dose of picrotoxin were unaffected by estradiol silastic implants, intraperitoneal injections of progesterone (0.5 mg, 4-5 h before convulsant) or the combination of both hormones. At the 2 mg/kg dose, 8/8 intact males had no seizures while all paired ovariectomized females had seizures. By contrast, the incidence of seizures in pairs of gonadectomized males and females did not differ. Testosterone treatment improved the ratio of single to multiple seizures in males but not in females. Males had statistically fewer multiple seizures than did females after testosterone treatment. The distribution of latencies to a single seizure is statistically different from the distribution of latencies to the first of multiple seizures irrespective of dose, sex and hormone treatment. This suggests that the population of rats responding with a single seizure at the higher dose of picrotoxin have a higher threshold for acquiring multiple seizures and that testosterone predisposes males but not females to this population.
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PMID:Steroid hormone effects on picrotoxin-induced seizures in female and male rats. 270 66

From a few personal works and from a review of the literature, the authors discuss the current date of the endocrinological involvement of epileptic seizures, epileptic diseases, and anticonvulsants. Generalized epileptic seizures are followed by a constant, specific and significant rise of ACTH and Prolactin during the hour after the fit. That is a very good biological marker of the epileptic cause of a loss of consciousness. The duration and the repetition of the seizures involve the pituitary-gonadotropic+ axis that explains the anovulatory cycles and hypofertility in women, and the decrease of libido in men. Then, the anticonvulsants involve the hormonal balance, either by a direct action upon the hypothalamo-pituitary axis (ACTH, Prolactin) or by a direct action upon peripheral hormones (Testosterone, Thyroxine). These problems must be known for the follow-up of the epileptic patients, and for the interpretation of the hormonal dosage of these patients.
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PMID:[Epilepsy and endocrine modifications]. 283 31

Testosterone (T), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin (PRL) levels were obtained in 33 male epileptic patients and 11 age-matched normal controls. The patients had significantly higher mean levels of FSH, LH, and PRL; T was decreased but not significantly so. Patients who had reported difficulties with sexual arousal on the Bear-Fedio Inventory had significantly lower T levels than those who did not. Increased LH levels correlated with younger age at onset of epilepsy and longer history of tonic clonic seizures. Increased PRL levels were related to a positive family history of epilepsy and nonfocal tonic clonic seizures. Anticonvulsant levels were unrelated to hormonal changes except for carbamazepine which was positively correlated with PRL levels.
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PMID:Investigation of sex hormones in male epileptic patients. 643 51

The amounts of cortisol and testosterone in the plasma or urine of Mongolian gerbils exposed to stress factors or treated subcutaneously with insulin (2 IU), vasopressin (1 IU), ACTH (6 IU) or dexamethasone (50 micrograms) were determined. Increased plasma cortisol was observed in animals stressed by ether anesthesia or immobilisation (1-4 hours), or treated with insulin, vasopressin or ACTH. Cortisol levels were reduced after dexamethasone administration. Plasma testosterone was elevated in animals stressed by ether anesthesia or handling plus seizure; no other treatment altered testosterone levels. An augmented cortisol excretion, which lasted one day, occurred in gerbils immobilised for one as well as for four hours. A much more prolonged stimulation of cortisol excretion, lasting three days, was seen in animals receiving ACTH or dexamethasone plus ACTH. Testosterone excretion was stimulated by ACTH and dexamethasone plus ACTH; it was not influenced by any other treatment. The present study shows that analysis of circulating steroid levels is the only reliable approach to assess the secretory activity of Mongolian gerbil adrenals or testes. In some experimental conditions (e.g. after stressor application or ACTH treatment) cortisol excretion may be used as an index of adrenal secretory function. In contrast, the striking differences between cortisol values present in plasma and urine of peptide-or dexamethasone-treated gerbils indicate that urinary cortisol does not reflect short-term changes of adrenal function. Similarly, the striking differences of testosterone values in plasma and urine indicate that urinary testosterone monitoring cannot be used to determine the secretory activity of gerbil testes.
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PMID:Dissociation of plasma and urinary steroid values after application of stressors, insulin, vasopressin, ACTH, or dexamethasone in the Mongolian gerbil. 902 44

The temporolimbic structures of the brain that subserve emotional representation are highly epileptogenic and play an important role in the modulation of hormonal secretion and mediation of hormonal feedback. Estrogen is highly epileptogenic and exerts energizing and antidepressant effects. Excessive estrogen influence produces anxiety, agitation, irritability, and lability. It can promote the development of anxiety manifestations (e.g., panic, phobias, and obsessive-compulsive disorder). Progesterone and its metabolites inhibit kindling and seizure activity. They have potent anxiolytic effects, possibly by virtue of their GABAergic activity. Excessive progesterone influence produces sedation and depression. Testosterone has two major metabolites: estradiol, which can exacerbate seizures, and dihydrotestosterone, which blocks NMDA-type glutamate transmission and may be responsible for antiseizure effects. Testosterone has energizing effects and increases sexual desire in both men and women. In excess, however, it may promote aggressive, impulsive, and hypersexual behavior. Hormonal effects tend to be exaggerated or idiosyncratic in the setting of an abnormal or anomalous temporolimbic substrate, especially temporolimbic epilepsy. This may reflect altered neuronal responsivity to hormonal exposure perhaps by virtue of changes in the number of dendritic spines and receptors.
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PMID:Psychoneuroendocrine aspects of temporolimbic epilepsy. Part I. Brain, reproductive steroids, and emotions. 1010 Apr 30

Neuroprotective effects of androgens have not been well-characterized, but there is evidence that 5 alpha-androstane-3 alpha, 17 beta-diol (3 alpha-diol) has anti-seizure effects. To further examine androgens' neuroprotective effects, testosterone (T), dihydrotestosterone (DHT), 3 alpha-diol (1.0 mg/kg SC daily), or sesame oil vehicle was administered to adrenalectomized or sham-operated, young, female Long Evans rats (N = 52). After seven days, animals were perfused and trunk blood was collected for radioimmunoassay of plasma corticosterone and androgens. No pyknotic cells were seen in the dentate of the sham-operated animals or those animals that had incomplete adrenalectomies (n = 20); however, cresyl violet and TUNEL stains revealed pyknotic cells in the granule layer of the dentate gyrus of adrenalectomized rats (n = 28). Testosterone, DHT, or 3 alpha-diol significantly reduced the number of pyknotic cells in the dentate gyrus compared to vehicle administered, adrenalectomized rats. Steroid-administered animals had levels of T, DHT, or 3 alpha-diol within physiological concentrations. These findings suggest that T, DHT, or 3 alpha-diol may have neuroprotective effects via a common mechanism of action.
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PMID:Androgens are neuroprotective in the dentate gyrus of adrenalectomized female rats. 1093 79

Pseudohypoparathyroidism (PHP) is characterized by hypocalcemia and hyperphosphatemia due to PTH resistance. PHP type Ia is due to diminished G(s)alpha activity in several tissues, causing resistance to hormones whose action is mediated by cAMP. Only two cases of males with PTH type Ia who paradoxically showed sexual precocity have been described in the literature. We describe an 11.5 year-old boy affected by PHP without AHO but with associated true precocious puberty, who came to the I.C.U. for tetanic seizures and drowsiness due to severe hypocalcemia. Hyperphosphatemia, increased PTH levels and normal 25-OH-vitamin D values were present. Skeletal X-ray showed mild osteopenia. Brain MRI revealed symmetric calcifications in basal ganglia and in frontal areas. Thyroid and thyreotropinic function were normal. Testosterone levels were in the adult range, as well as basal and stimulated gonadotropin levels. Tanner stage P4, G4; testicular volume 12-15 mi. Molecular cytogenetics studies are now underway to further elucidate the etiology of this form of PHP.
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PMID:Gonadotropin-dependent sexual precocity in a boy affected by pseudohypoparathyroidism. 1096 32

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.
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PMID:Neuroactive steroids and seizure susceptibility. 1132 70


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