Serum prolactin concentrations and epilepsy. A study which compares healthy subjects with a group of patients in presurgical evaluation and circadian variations with those related to seizures

Prolactin levels as a criterion to differentiate between psychogenic non-epileptic seizures and epileptic seizures: A systematic review

OBJECTIVE

Psychogenic non-epileptic seizures (PNES) are conversion disorders with functional neurological symptoms that can resemble epileptic seizures (ES). We conducted a systematic review to obtain an overview of the value of prolactin (PRL) levels in the differential diagnosis between PNES and ES.

METHODS

We searched PubMed, EMBASE, and Cochrane Library databases for studies published up to June 4th, 2020. Published studies were included if they fulfilled the following criteria: original research on PRL changes after ES and PNES. By applying Bayes' theorem, we calculated the predicted values of PRL with pretest probabilities of 90 % and 75 % in ES.

RESULTS

Sixteen studies were included in this review. All the studies showed that PRL levels increase after ES, especially 10-20 min after ES, when the elevation was most obvious. In studies where capillary PRL level measurements were included, the median sensitivity in the diagnosis of ES (all epileptic seizure types), generalized tonic clonic seizures (GTCS), focal impaired awareness seizures (FIAS), and focal aware seizures (FAS) was 67.3 %, 66.7 %, 33.9 %, and 11.1 %, respectively. The median specificity in the diagnosis of ES was 99.1 %. By using Bayes' theorem, when we used the median specificity and sensitivity for predictive value calculation, assuming a pretest probability of 90 %, a positive PRL measure was highly predictive (99 %) of all types of ES, and negative predictive values were all below 30 %. When we used the lowest specificity and sensitivity for predictive value calculation, assuming a pretest probability of 75 %, ES and GTCS had positive predictive values of 77.2 % and 81.0 %, respectively; the negative predictive values of PRL in ES and GTCS were 26.2 % and 29.6 %, respectively.

CONCLUSIONS

The use of PRL could be a useful adjunct to differentiate GTCS from PNES. However, PRL levels are of limited use for differentiating FIAS or FAS from PNES, and a negative PRL measure is not predictive of PNES.

Effects of physiological parameter evolution on the dynamics of tonic-clonic seizures

The temporal and spectral characteristics of tonic-clonic seizures are investigated using a neural field model of the corticothalamic system in the presence of a temporally varying connection strength between the cerebral cortex and thalamus. Increasing connection strength drives the system into ∼ 10 Hz seizure oscillations once a threshold is passed and a subcritical Hopf bifurcation occurs. In this study, the spectral and temporal characteristics of tonic-clonic seizures are explored as functions of the relevant properties of physiological connection strengths, such as maximum strength, time above threshold, and the ramp rate at which the strength increases or decreases. Analysis shows that the seizure onset time decreases with the maximum connection strength and time above threshold, but increases with the ramp rate. Seizure duration and offset time increase with maximum connection strength, time above threshold, and rate of change. Spectral analysis reveals that the power of nonlinear harmonics and the duration of the oscillations increase as the maximum connection strength and the time above threshold increase. A secondary limit cycle at ∼ 18 Hz, termed a saddle-cycle, is also seen during seizure onset and becomes more prominent and robust with increasing ramp rate. If the time above the threshold is too small, the system does not reach the 10 Hz limit cycle, and only exhibits 18 Hz saddle-cycle oscillations. It is also seen that the time to reach the saturated large amplitude limit-cycle seizure oscillation from both the instability threshold and from the end of the saddle-cycle oscillations is inversely proportional to the square root of the ramp rate.

Serum GFAP level: A novel adjunctive diagnostic test in differentiate epileptic seizures from psychogenic attacks

PURPOSE

There has been increasing interest in the use of different biomarkers to help distinguish psychogenic from epileptic seizures, in patients presenting acutely with seizure-like events. In the present study, we measured serum glial fibrillary astrocytic protein (GFAP) levels in patients presenting with such events who were subsequently diagnosed as epileptic seizures (ESs) or psychogenic non-epileptic seizures (PNESs) and compared GFAP levels obtained with those found in healthy subjects.

METHODS

Sixty-three patients with seizures (43 with ES and 20 with PNES), and 19 healthy subjects participated in the study. Venous blood samples were obtained within the first 6 h after seizures and serum GFAP levels were measured by protein quantification (ELIZA kit) with an electrochemical luminescence immunoassay.

RESULTS

Serum GFAP levels were significantly higher in patients with ES compared to PNES or healthy controls. A cut-off point of 2.71 ng/ml was found optimally to differentiate ES from PNES (sensitivity 72%, specificity 59%).

CONCLUSION

Our study suggests that post-seizure serum GFAP levels could be used in future studies better to understand the underlying mechanism of seizures and may offer as an adjunctive diagnostic test in differentiating ES from PNES.

Comparing the frequency of polycystic ovary syndrome in women with and without epilepsy

Introduction:

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders; the impact of epilepsy and antiepileptic drugs influences the function of hypothalamic–pituitary–gonadal axis and dysfunction of the endocrine system and reproductive hormones in women with epilepsy. This study was carried out with an aim of determining and comparing the frequency and intensity of the complications of the hirsutism in women with and without epilepsy in Tehran in 2016–2017.

Materials and Methods:

This is a cross-sectional-comparative study which was carried out on 338 women of 18–35-year-old women with and without epilepsy who were selected by continuous sampling method. Data were collected and analyzed by Chi-square statistical test. The quantity of P was considered to be 0.05 as the level of significance.

Results:

The results of this study indicated that there was a statistically significant difference between the two groups with and without epilepsy in terms of the frequency of some of the clinical symptoms of the PCOS and affected by it. The results of this study showed that a higher percentage of women with epilepsy were affected PCOS. In the group of epileptic patients, some of the clinical symptoms of PCOS such as hirsutism, acanthosis nigricans, disordered menstruation, and amenorrhea were higher which as a result led to an increase in the frequency of PCOS.

Conclusion:

As a result, epilepsy can lead to an increase in the frequency of PCOS and some other clinical symptoms.

Vulnerability to psychogenic non-epileptic seizures is linked to low neuropeptide Y levels

Psychogenic non-epileptic seizures (PNES) is a conversion disorder that reflects underlying psychological distress. Female patients with PNES often present with a history of prolonged stressors, especially sexual abuse. In the current study, we studied the relationship between neuropeptide Y (NPY) and PNES symptoms in women with a history of sexual abuse. NPY has been associated with resilience to stress and we hypothesized that low levels would increase the extent and severity of PNES symptoms in this patient population. Serum levels of NPY, and related hormones were measured in fifteen female PNES patients and sixty female controls. PNES patients reported more severe abuse histories, feeling of abandonment, and decreased perception of quality of life than controls. Importantly, they also had lower NPY levels. Our analysis indicates that low levels of NPY in PNES may confer greater vulnerability to exhibit seizure-like symptoms and lower quality of life.

Biomarkers in the diagnosis and study of psychogenic nonepileptic seizures: A systematic review

OBJECTIVE

Video electroencephalography (vEEG) is the gold-standard method for diagnosing psychogenic nonepileptic seizures (PNES), but such assessment is expensive, unavailable in many centers, requires prolonged hospitalization, and many times is unable to capture an actual seizure episode. This paper systematically reviews other non-vEEG candidate biomarkers that may facilitate both diagnosis and study of PNES as differentiated from epileptic seizures (ES).

METHODS

PubMed database was searched to identify articles between 1980 and 2015 (inclusion: adult PNES population with or without controls, English language; exclusion: review articles, meta-analyses, single case reports).

RESULTS

A total of 49 studies were examined, including neuroimaging, autonomic nervous system, prolactin, other (non-prolactin) hormonal, enzyme, and miscellaneous marker studies. Functional MRI studies have shown PNES is hyperlinked with dissociation and emotional dysregulation centers in the brain, although conflicting findings are seen across studies and none used psychiatric comparators. Heart rate variability suggests increased vagal tone in PNES when compared to ES. Prolactin is elevated in ES but not PNES, although shows low diagnostic sensitivity. Postictal cortisol and creatine kinase are nonspecific. Other miscellaneous biomarkers (neuron specific enolase, brain derived neurotropic factor, ghrelin, leptin, leukocytosis) showed no conclusive evidence of utility. Many studies are limited by lack of psychiatric comparators, size, and other methodological issues.

CONCLUSION

No single biomarker successfully differentiates PNES from ES; in fact, PNES is only diagnosed via the negation of ES. Clinical assessment and rigorous investigation of psychosocial variables specific to PNES remain critical, and subtyping of PNES is warranted. Future investigational and clinical imperatives are discussed.

Hormonal alterations following seizures

Postictal increases in prolactin (PRL), luteinizing hormone, and follicle-stimulating hormone have been recorded in patients with both generalized tonic-clonic and partial seizures. Elevations of PRL and luteinizing hormone were seen immediately and at 20 minutes after generalized tonic-clonic seizures in male and female patients. Usually, PRL blood levels return to normal values within 1 hour. Previous studies have evaluated the utility of the transient increases in PRL, neuron-specific enolase, and S-100 protein as markers of epileptic seizures in children and adults. The conclusion was that measurement of serum PRL is a reliable confirmatory test in the presence of a seizure, but only modestly effective as a screening test for suspected seizures. Temporal lobe epilepsy is associated with abnormalities of reproductive physiology, but the mechanisms of hormonal dysregulation are not clear. A direct influence of epilepsy on the reproductive endocrine system is suggested by acute changes in PRL and gonadotropin levels following generalized and partial seizures, pointing to a possible relationship between temporolimbic epileptiform discharges and particular reproductive endocrine disorders. Chronic effects of the epileptic state and the acute impact of seizures could alter hypothalamic function, as indicated by downstream pulsatile secretion of luteinizing hormone. The brain controls reproductive function primarily through hypothalamic regulation of pituitary secretion regions of the hypothalamus. These are areas that are involved in the regulation, production, and secretion of gonadotropin-releasing hormone and receive extensive direct connections from the cerebral hemispheres, especially from temporolimbic structures, most notably from the amygdala, that are commonly involved in temporal lobe epilepsy. Significant relationships have been uncovered through which ictal and postictal effects of seizures and epilepsy may influence the function of this complex neuroendocrine system.

Serum creatine phosphokinase is helpful in distinguishing generalized tonic-clonic seizures from psychogenic nonepileptic seizures and vasovagal syncope

OBJECTIVE

Distinguishing epileptic generalized tonic-clonic seizures (GTCS) from either psychogenic nonepileptic seizures (PNES) or vasovagal syncope (VVS) is important. In this study, we investigated the use of postictal serum creatine phosphokinase (CPK) concentrations in distinguishing between these events.

METHODS

Patients admitted to the Neurology Ward at Namazi Hospital in Shiraz, Iran, with an attack of transient loss of consciousness and abnormal movements witnessed by a neurologist were studied. We categorized the patients into three groups: 20 patients with GTCS, 22 with VVS, and 20 with PNES. A group of 20 normal healthy individuals were included in the study as the control group. Serum CPK concentration was measured 12-15 h after the attack in all patients and at one time in the control group. A P value less than 5% was considered significant.

RESULTS

There were no significant differences between the four groups with respect to age and sex. Mean CPK concentrations statistically significantly differed between the four groups, with higher levels in patients with GTCS (P=0.0001). Serum CPK concentration had a sensitivity of 75% and specificity of 86% for the diagnosis of GTCS. CPK concentration was above 160 mg/dl in 75% of patients with GTCS, 15% of patients with PNES, 13.6% of patients with VVS, and 15% of the control group (P=0.0001). The PNES, VVS, and control groups did not statistically significantly differ with respect to CPK concentrations.

CONCLUSION

In patients with a recent loss of consciousness and abnormal movements, serum CPK concentration is a useful, practical, and relatively accurate parameter to assist in the differentiation of epileptic seizures from either VVS or PNES.

The reproductive conditions and lipid profile in females with epilepsy

OBJECTIVE

To explore the reproductive conditions in women with epilepsy.

METHODS

Eighty-eight women were included; 37.5% and 62.5% had generalized and partial epilepsies, respectively. Ovarian sonogram, reproductive hormone and lipid profiles were assessed.

RESULTS

Compared with the control group and in accordance with our laboratory reference values, irregular menses and polycystic ovaries (PCO(s)) were reported in 70.5% and 39.8% versus 21.7% and 16.7% of controls. Abnormalities in leutinizing hormone (LH), follicle-stimulating hormone (FSH), LH-to-FSH ratio, testosterone (T) and prolactin (PRL) were identified. High values of FSH, LH and FSH-to-LH ratio were common with carbamazepine while that of T and PRL were common in untreated patients and with valproate. Low levels of high-density lipoprotein cholesterol was identified in approximately 59% but neither associated with duration and type of antiepileptic drugs nor patients' age, hormonal profile or PCO(s). Significant correlation was identified between menatrual irregularities, T, PRL, hormonal, lipid profile alterations, PCO(s) and seizure frequency but neither with epilepsy type nor focus.

CONCLUSION

This is the first study in our country that aimed at evaluation of reproductive conditions in women with epilepsy. This study indicates that reproductive dysfunction is common, hence, characterization of seizure-associated neuroendocrine adverse effects is important while managing women particularly during choice of antiepileptic medications as initial step and during patients' follow-up.

Reproductive and sexual dysfunction in men with epilepsy

Disturbances of reproductive and sexual health are common in people with epilepsy. Their etiology is not well understood but appears to be multifactorial, and both epilepsy itself and drugs used to treat it are implicated. Physiologically, sex steroid hormone levels, the hypothalamic-pituitary axis, and testicular function can be affected in men with epilepsy. Psychosocial complications associated with epilepsy can also affect reproductive health and sexuality. Clinicians need to investigate such problems carefully, both because of their multifactorial nature and because patients and physicians alike may often fail to recognize or be reluctant to acknowledge them; in particular, patients whose epilepsy had its onset before puberty may lack subjective awareness of impairments of sexual response and function. Treatments for reproductive and sexual dysfunction in men with epilepsy have been inadequately studied. Modalities such as medications for erectile dysfunction and surgery may be useful. Therapy with exogenous testosterone and an aromatase inhibitor may be helpful for men with epilepsy and sexual dysfunction due to testosterone deficiency.

Epilepsy and erectile dysfunction: a review

The association between epilepsy and erectile dysfunction (ED) has often been described but not clearly defined. This is a review of the literature regarding the current theories on the causes of ED in epilepsy, as well as the evaluation and treatment options available.

Serum neuron-specific enolase, prolactin, and creatine kinase after epileptic and psychogenic non-epileptic seizures

PURPOSE

To evaluate the discriminative power of serial, simultaneous determinations of serum neuron-specific enolase (NSE), prolactin (PRL) and creatine kinase (CK) in differentiating psychogenic non-epileptic seizures (PNES) from epileptic seizures (ES).

METHODS

Prospective measurement of the three markers after 44 single seizures (32 ES and 12 PNES) during continuous video-EEG monitoring at seven different sampling points.

RESULTS

Patients with ES had a significantly greater increase in PRL at 10, 20, 30 min, 1 and 6 h. The sensitivity for elevated NSE and CK was low. PRL showed a higher sensitivity. However, the corresponding positive predictive value was lower than in CK and NSE. Additionally, PRL had the lowest specificity of all parameters.

CONCLUSIONS

The limited discriminative power of PRL, CK, and NSE calls into question if these markers are helpful in differentiating PNES and ES.

Reproductive dysfunction in women with epilepsy: recommendations for evaluation and management

BACKGROUND

Epilepsy is commonly associated with reproductive endocrine disorders. These include polycystic ovary syndrome (PCOS), isolated components of this syndrome such as polycystic ovaries, hyperandrogenaemia, hypothalamic amenorrhoea, and functional hyperprolactinaemia.

OBJECTIVE

To summarise the currently known relations between epilepsy and reproductive endocrine disorders.

METHODS

A review of clinical experience and published reports.

RESULTS

The most likely explanations for endocrine disorders related to epilepsy or antiepileptic drugs are: (1) a direct influence of the epileptogenic lesion, epilepsy, or antiepileptic drugs on the endocrine control centres in the brain; (2) the effects of antiepileptic drugs on peripheral endocrine glands; (3) the effects of antiepileptic drugs on the metabolism of hormones and binding proteins; and (4) secondary endocrine complications of antiepileptic drug related weight changes or changes of insulin sensitivity. Regular monitoring of reproductive function at visits is recommended, including questioning about menstrual disorders, fertility, weight, hirsutism, and galactorrhoea. Particular attention should be paid to patients on valproate and obese patients or those experiencing significant weight gain. Single abnormal laboratory or imaging findings without symptoms may not constitute a clinically relevant endocrine disorder. However, patients with these kinds of abnormalities should be monitored to detect the possible development of a symptomatic disorder associated with, for example, menstrual disorders or fertility problems.

CONCLUSIONS

If a reproductive endocrine disorder is found, antiepileptic drug treatment should be reviewed to ensure that it is correct for the particular seizure type and that it is not contributing to the endocrine problem. The possible benefits of a change in treatment must be balanced against seizure control and the cumulative side effect of alternative agents.

A review of diagnostic techniques in the differential diagnosis of epileptic and nonepileptic seizures

The diagnosis of psychogenic nonepileptic seizures (PNES) is complex. Long-term electroencephalogram monitoring with video recording (video EEG) is the most common method of differential diagnosis of epilepsy and PNES. However, video EEG is complex, costly, and unavailable in some areas. Thus, alternative diagnostic techniques have been studied in the search for a diagnostic method that is as accurate as video EEG, but more cost effective, convenient, and readily available. This paper reviews the literature regarding possible diagnostic alternatives and organizes findings into 7 areas of study: demographic and medical history variables, seizure semiology, provocative testing, prolactin levels, single photon emission computed tomography, psychological testing, and neuropsychological testing. For each area, the literature is summarized, and conclusions about the accuracy of the technique as a diagnostic tool are drawn. Overall, it appears unlikely that any of the reviewed alternative techniques will replace video EEG monitoring; rather they may be more successful as complementary diagnostic tools. An important focus for further investigations involves combinations of diagnostic techniques for the differential diagnosis of epilepsy and PNES.

Interactions between hormones and epilepsy in female patients

Epilepsy and epileptic seizures may influence the release of hormones from the hypothalamus and the pituitary. After complex-partial seizures or generalized tonic-clonic seizures, serum prolactin increases in about two thirds of cases. Apart from this transient effect, interictal epileptic discharges from the temporal lobe may exert a prolonged influence on hormone release. Changes in luteinizing hormone (LH) pulse frequency and increased prolactin levels have been reported. As a consequence, menstrual cycles may be disturbed. The cyclic change of sex serum hormones during the ovulatory menstrual cycle may have an impact on seizure occurrence during the days of ovulation and/or menstruation (e.g., catamenial seizures). By a supplementation of progesterone during the second half of anovulatory cycles, a decrease of seizure frequency can be achieved.

Seizures, hormones and sexuality

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

On the association between valproate and polycystic ovary syndrome

Recent studies by Isojärvi et al. have raised the issue of an increased incidence of polycystic ovary syndrome (PCOS) in women with epilepsy treated with valproate (VPA) and have proposed replacement with lamotrigine (LTG). Polycystic ovaries (PCO) are a common finding, with a prevalence >20% in the general population, and are easily detected by pelvic or vaginal ultrasonography, whereas PCOS is comparatively rare: few women with PCO have fully developed PCOS, which includes hirsutism, acne, obesity, hypofertility. hyperandrogenemia, and menstrual disorders. From an extensive review of the current literature, it appears that there are no reliable data on the actual prevalence of PCOS in normal women and in women with epilepsy. The pathogenesis of PCO is multifactorial, including genetic predisposition and the intervention of environmental factors, among which weight gain and hyperinsulinism with insulin resistance may play a part. The roles of central (hypothalamic/pituitary), peripheral, and local ovarian factors are still debated. PCO and PCOS appear to be more frequent in women with epilepsy, but there are no reliable data showing a greater prevalence after VPA. The recent studies by Isojärvi et al. may have been biased by the retrospective selection of patients. To date, there is no reason to contraindicate the use of VPA in women with epilepsy. However, patients should be informed about the risk of weight gain and its consequences.

Serum androgens return to normal after temporal lobe epilepsy surgery in men

BACKGROUND

Epileptic discharges from the temporal lobe may influence the release of hormones from the hypothalamic-pituitary axis. If epilepsy surgery influences the underlying epileptic disorder one might expect serum hormone concentrations to return to normal following surgery.

PATIENTS

Twenty-two men with epilepsy aged 25 to 48 years (mean, 34.9 years) were investigated before surgery and at 3, 6, and 12 months after surgery. Medication (all patients received carbamazepine) was maintained following surgery.

METHODS

Hormone measurements included luteinizing hormone, follicle stimulating hormone, estradiol, testosterone, free testosterone, androstenedione, prolactin, dehydroepiandrosterone sulfate, cortisol, growth hormone, and sex hormone-binding globulin. These hormone levels were compared with those of 105 healthy men (mean age, 33.9 years).

RESULTS

Fourteen of the 22 patients (63.6%) achieved total seizure control following epilepsy surgery. The 14 patients with successful seizure control entered further analysis. Before surgery these patients' free testosterone and androstenedione concentrations were significantly lower compared with healthy men. In seven of the 14 patients a significant increase of hormone serum concentrations could be demonstrated for testosterone, free testosterone, and androstenedione. Laterality of epileptic focus, enzyme-inducing medication, stress, and the decreasing number of patients during the follow-up did not correlate with the finding of a normalization of serum androgens. PATIENTS without complete seizure control did not show an increase in serum androgen concentrations.

CONCLUSION

Successful temporal lobe epilepsy surgery may lead to a normalization of serum androgen concentrations in men with epilepsy.

The impact of epilepsy surgery on sex hormones and the menstrual cycle in female patients

We investigated the impact of temporal lobe epilepsy surgery on sex hormones and menstrual cycles. Sixteen female patients with temporal lobe epilepsy were investigated prior to surgery and 3, 6, and 12 months after surgery. The patients received carbamazepine (CBZ) as monotherapy (10 patients) or in combination with other antiepileptic drugs (six patients). Antiepileptic drugs were maintained after surgery. During the 1-year follow-up after surgery eight patients (50%) remained completely free of seizures. In another four patients (25%) only rare disabling seizures occurred. There were no significant differences between pre-surgical and post-surgical serum concentrations of testosterone, free testosterone, prolactin, dehydroepiandrosterone sulfate, growth hormone, cortisol and sex hormone binding globulin. There was, however, a significant increase in serum androstenedione concentration 6 months post-surgically (P < 0.02). Documentation of menstrual cycles in addition to laboratory parameters revealed individual post-surgical changes of the menstrual cycle in eight patients. Four patients had a change in menstrual periodicity: two patients with complete seizure control had regular cycles instead of oligomenorrhoea and two patients with incomplete seizure control had oligomenorrhoea instead of regular cycles. These data indicate that at least in some patients with temporal lobe epilepsy surgical treatment influences menstrual periodicity.

Seizure occurrence during ovulatory and anovulatory cycles in patients with temporal lobe epilepsy: a prospective study

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.

Epilepsy and prolactin in adults: a clinical review

Serum levels of prolactin may increase as a consequence of epileptic seizures. The hormone release is caused by the propagation of epileptic activity, usually from the temporal lobe to the hypothalamic-pituitary axis. Due to the intensity of the epileptic afterdischarge, a rise is seen in approximately 60% of complex partial seizures. Prolactin usually fails to rise after psychogenic seizures, therefore, postictal prolactin levels can be used to differentiate between epileptic and psychogenic seizures. However, a subclassification of epileptic seizures by means of prolactin measurement is not possible. In repetitive seizures, prolactin may show a decrease in its postictal release. This is more common in status epilepticus, probably as a result of a diminished propagation of ictal activity during the course of status epilepticus. The influence of chronic epileptic discharges and anticonvulsant medication on prolactin release is moderate.

Transcranial magnetic stimulation. Its role in the evaluation of patients with partial epilepsy

Transcranial magnetic stimulation (TMS) is a relative new method in the evaluation of patients with various neurological diseases. With the introduction of repetitive (rapid rate) transcranial magnetic stimulators (RTMS), it has been possible to apply cortical stimuli with a stimulus rate up to 100 Hz. The preliminary results with TRMS suggest that it may be used in the study of speech lateralization. Seizures have been reported in patients with partial epilepsy during TMS. In these cases it remains uncertain whether the seizures were induced by the TMS or coincidentally with it. Minor changes in paroxysmal activity have been reported in some patients. These data suggest, that TMS is neither sensitive nor specific as an activation procedure of the epileptic focus in patients with partial epilepsy. Seizures have been provoked using RTMS, but its use as a seizure-inducing method is not yet evaluated.

Serum prolactin response to repetitive epileptic seizures

We measured postictal prolactin (PRL) levels during repetitive seizures in 14 patients (10 men and 4 women) suffering from epilepsy with focal and/or secondarily generalized seizures. Between two and six seizures occurred per patient (mean 2.7). The interveral between seizures was 15 min and 8 h 40 min (mean 3 h 32 min). Five of the 14 patients showed a marked postictal PRL rise after each seizure (i.e. concentrations above 700 microU/ml for women, 500 microU/ml for men). In the remaining 9 patients there was no detectable rise in PRL. A decrease in PRL did not occur in any of the 14 patients. In those patients who had shown a marked PRL increase after the first seizure, the PRL continued to rise in subsequent seizures. Unlike previous investigations, these results show that repetitive epileptic seizures are not necessarily followed by a decrease in postictal PRL levels. A decrease in PRL response is known to occur if there is progression to status epilepticus.