Antiepileptic drug use and birth rate in patients with epilepsy--a population-based cohort study in Finland.

BACKGROUND: Antiepileptic medication use affects reproductive endocrine function, but its impact on fertility is not well known. METHODS: All epilepsy patients, who were approved as being eligible for reimbursement for antiepileptic drug (AED) costs from the Social Insurance Institution (SII) of Finland for the first time 1985-94, were identified from the SII database. A reference cohort without epilepsy was identified from the Finnish Population Register Centre. Information on AED purchases 1996-2000 was obtained from the SII database through computerized record linkage with the unique personal identification number assigned to all residents of Finland. The three AEDs included were carbamazepine, oxcarbazepine (OXC) and valproate. RESULTS: Birth rate was lower in both men and women with epilepsy on AEDs than in the reference cohort without epilepsy. However, compared with patients not using AED during the study period, the birth rate was lowered only among men on OXC [rate ratio (RR) = 0.52, 95% confidence interval (CI) = 0.32, 0.84]. CONCLUSIONS: The birth rate was lower in both women and men on any of the three AEDs compared with the reference cohort without epilepsy. However, a statistically significant difference between treated and untreated patients was only seen in men on OXC. It is unclear to what extent the differences found in this study are due to social or biological factors.

Suppressed circadian heart rate dynamics in temporal lobe epilepsy.

OBJECTIVES: To measure interictal circadian rhythm of heart rate (HR) variability in patients with temporal lobe epilepsy (TLE) using a 24 hour ECG recording. METHODS: Various conventional and dynamic fractal measures of HR variability were analysed in 17 patients with refractory TLE, 20 patients with well controlled TLE, and 37 healthy age and sex matched control subjects. RESULTS: The SD of all RR intervals (p < 0.01), the measured power spectral components of HR variability (low frequency power (p < 0.01), high frequency power (p < 0.05)), and the SD1 (p < 0.05) and SD2 (p < 0.01) Poincaré two dimensional vector analysis measurements were suppressed in the patients. This suppression was observed during both day and night time; however, it was more pronounced at night, and nocturnal increase in HR variability usually seen in the normal population could not be detected in the patients. The HR variability measures did not correlate with the duration of epilepsy, the age of the patients, or with the anti-epileptic drugs used. CONCLUSION: TLE was associated with reduced HR variability, which was more pronounced during night than day, and the nocturnal increase in HR variability was abolished in patients with TLE. The alteration in autonomic regulation of HR variability was similar in patients with both refractory and well controlled TLE.

Birth rate among patients with epilepsy: a nationwide population-based cohort study in Finland.

Few reports on population-based studies of birth rate among epilepsy patients have been published. In most previous studies, fertility has been lower among epilepsy patients than in the rest of the population. However, conflicting results have also been reported. Because of small samples and selective material, the generalizability of these results is also limited. The authors conducted a population-based cohort study of birth rate (1985-2001) in a nationwide Finnish cohort of patients with newly diagnosed epilepsy and a population-based reference cohort. All patients (n = 14,077) approved as eligible for reimbursement for antiepileptic medication from the Social Insurance Institution of Finland (KELA) for the first time between 1985 and 1994 were identified from the KELA database. A reference cohort (n = 29,828) was identified from the Finnish Population Register Center, with frequency-matching on age. Information on follow-up status and livebirths were also obtained from the Finnish Population Register Center. The birth rate was lower in patients with epilepsy than in the reference cohort among both men (hazard ratio = 0.58, 95% confidence interval: 0.54, 0.62) and women (hazard ratio = 0.88, 95% confidence interval: 0.83, 0.93). There were a clear decreasing trend by age at observation in men with epilepsy and a moderate decreasing trend by age at start of follow-up in women with epilepsy.

Effect of epilepsy and antiepileptic drugs on male reproductive health.

BACKGROUND: Men with epilepsy have reduced fertility, and antiepileptic drugs may affect semen quality. Moreover, animal studies suggest that valproate (VPA) may be associated with testicular atrophy. OBJECTIVE: To evaluate reproductive function in men with epilepsy. METHODS: Sixty men with epilepsy and 41 control men were evaluated for their reproductive health. Fifteen men were taking carbamazepine (CBZ) and 18 men oxcarbazepine (OXC) for partial epilepsy, and 27 men were taking VPA for generalized epilepsy. Reproductive hormones were assayed from serum samples, semen analysis and ultrasonography of the testicles were performed, and testicular volume was calculated. RESULTS: Men on CBZ had low serum dehydroepiandrosterone sulfate concentrations (p < 0.001), and men on VPA had high concentrations of serum androstenedione (p < 0.001). The frequency of morphologically abnormal sperm was higher among CBZ-treated (p < 0.01), OXC-treated (p < 0.05), and VPA-treated men (p < 0.01) than among the control men. Moreover, both CBZ and VPA were associated with poor motility of sperm (p < 0.05). In addition, the frequency of abnormally low sperm concentration was high in men on CBZ (p < 0.001), and the frequency of any sperm abnormality was high in men on VPA (p < 0.01). The VPA-treated men with abnormal sperm had smaller testicular volumes than the control men (p = 0.003). CONCLUSIONS: CBZ, OXC, and VPA are associated with sperm abnormalities in men with epilepsy. In addition, VPA-treated men with generalized epilepsy who have abnormal sperm may have reduced testicular volume.

Fasting serum insulin and lipid levels in men with epilepsy.

BACKGROUND: Previous studies suggest that obese women taking valproate (VPA) for epilepsy are insulin resistant. OBJECTIVE: To assess the effects of antiepileptic drugs on serum insulin and lipid levels in men with epilepsy. METHODS: Body mass index (BMI) and fasting serum concentrations of insulin and lipids were measured in 102 men with epilepsy who were treated with VPA, carbamazepine (CBZ), or oxcarbazepine (OXC) monotherapy. Thirty-two healthy men served as control subjects. RESULTS: Obesity was not more common among VPA-treated men than among other men with epilepsy or the control subjects. However, the obese VPA-treated men had higher serum insulin levels (p < 0.001) than the obese control subjects despite similar BMI. CBZ and OXC did not have any significant effect on any of the measurements. Fasting serum insulin concentrations above the normal range were observed in seven obese VPA-treated patients (35%) but in only one obese control subject (5%). Five obese VPA-treated patients (25%) and one obese control subject (5%) had serum triglyceride levels above the normal range, and a low high-density lipoprotein/total cholesterol ratio was observed in two obese VPA-treated patients (10%). CONCLUSIONS: Obese valproate-treated men have high serum insulin levels, indicating insulin resistance. Moreover, some of the valproate-treated men cluster cardiovascular risk factors such as obesity, hyperinsulinemia, and elevated serum triglyceride concentrations. CBZ and OXC do not seem to have any significant effects on serum insulin or lipid levels in men with epilepsy.

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.

Heart rate dynamics in refractory and well controlled temporal lobe epilepsy.

OBJECTIVES: Disorders of cardiovascular and other autonomic nervous system functions are often found in patients with temporal lobe epilepsy (TLE). Cardiovascular dysregulation in TLE has previously been quantified assessing traditional time and frequency domain measures of heart rate (HR) variability from short term ECG recordings. However, new complexity and fractal measures of HR variability based on non-linear dynamics and fractals ("chaos theory") may disclose certain patterns of HR dynamics that cannot be detected using only conventional measures. METHODS: In addition to the traditional spectral and non-spectral components of HR variability, fractal correlation properties, approximate entropy (ApEn) of RR interval dynamics, and the slope of the power law relation were measured from 24 hour ambulatory ECG recordings to evaluate interictal autonomic cardiovascular regulatory function in 19 patients with refractory TLE, 25 patients with well controlled TLE, and in 34 healthy age and sex matched control subjects. RESULTS: The traditional time and frequency domain measures were lower in patients with TLE than in controls (p<0.05). In addition, the power law slope (p<0.005) and ApEn (p<0.05) were also reduced in TLE patients. Furthermore, ApEn was smaller in patients with refractory TLE than in patients with well-controlled TLE ( p<0.01), whereas the long term fractal correlation value alpha2 was lower in patients with well controlled TLE (p<0.05). An altered HR variation was not associated with any particular AED regimen. CONCLUSIONS: In addition to reduced overall HR variability, the long term fractal organisation and complexity of HR dynamics seem to be altered in TLE. These abnormalities in HR behaviour may partly contribute to the occurrence of adverse cardiovascular events, such as life threatening arrhythmias in patients with TLE.