The epileptic mother and her child

Eclampsia, hippocampal sclerosis, and temporal lobe epilepsy: Accident or association?

BACKGROUND

Up to 30% of patients with temporal lobe epilepsy (TLE) have no identifiable risk factors.

OBJECTIVE

S: To report nine patients with TLE who had a history of eclampsia as the only risk factor for epilepsy and to investigate whether this possible association existed in a larger cohort of women with surgically treated TLE.

METHODS

The clinical data, video-EEG, neuroimaging, and neuropathology of 195 consecutive women undergoing anterior temporal lobectomy (ATL) were reviewed. Risk factors for TLE, age at epilepsy onset, and occurrence of pregnancy were identified in each patient.

RESULTS

Twenty-six women had no identifiable risk factors or seizures following a pregnancy. Nine of the 26 women had a history of eclampsia. The median age at the time of eclampsia was 16 years, and the latent period between the occurrence of eclampsia and onset of epilepsy ranged from 1 month to 2 years. The clinical, EEG, MRI, and neuropathologic findings were typical of hippocampal sclerosis (HS) and other than age at onset were no different from those of noneclampsia ATL patients. At mean follow-up of 57 months, seven patients were seizure-free and the other two markedly improved.

CONCLUSION

Eclampsia may be a risk factor for TLE and HS.

Fetal heart rate decelerations during ECT-induced seizures: is it important?

Electroconvulsive therapy (ECT) is sometimes indicated during pregnancy and may offer advantages over pharmacotherapy for the patient and the fetus (1,2). However, very little data is available on the impact of epileptic or ECT-induced seizures on the fetus. We report a case of brief fetal heart rate decelerations in a fetus associated with maternal ECT-induced convulsions.

The use of anticonvulsants during pregnancy

Antiepilepsy (AED) medications have revolutionized the treatment of epilepsy, transforming it from a chronic progressive disease with inevitable cognitive and motor decline to a disorder in which most effected persons operate largely in a normal fashion. As with all medications adverse experiences can occur. However, it has been clear that the alternative of uncontrolled seizures are more hazardous than pharmacological therapies. However, physicians are faced with a dilemma when treating fertile or pregnant women with epilepsy. Many AED impair the effectiveness of oral contraceptives. There is evidence that some AED may effect fertility. AED metabolism changes in pregnancy, making management of women with epilepsy more difficult. AED exposure in early pregnancy increases the risk of congenital malformations, and exposure during other phases may increase the risk of developmental delay and neonatal hemorrhage. AED can be secreted in breast milk, thus extending the exposure into infancy. The exclusion of women of childbearing age from clinical trials limits our ability to collect information on the pharmacokinetics and potential adverse experiences of AED in pregnancy. Thus, when new medications are marketed, clinicians and their patients have no information on how to best manage conception, pregnancy, and lactation. This article discusses these issues in detail and describes our current understanding of the use of AED in women of childbearing age.

CPD-Education and self-assessment: Epilepsy and pregnancy

Pregnancies in women with epilepsy are high risk and need careful management by both the medical and obstetric teams due to the increased incidence of complications and adverse outcomes of pregnancy. By the time a pregnant woman with epilepsy presents, the foetus is virtually fully formed and the opportunity for altering drug treatment has passed. Women need to be counselled and told to seek advice about their anticonvulsant therapy should they wish to become pregnant. All major anticonvulsant drugs are teratogenic but the main risk to the developing foetus appears to be when the mother is on polytherapy especially if sodium valproate forms part of the combination. Folate supplements (5 mg) before conception are advisable. There appears to be a minor but significant increased risk of maternal complications in women with epilepsy such as hyperemesis gravidarum, pre-eclampsia and eclampsia, vaginal bleeding and premature labour. In the majority of women seizure control will not alter during pregnancy. Oral vitamin K should be given to the mother receiving enzyme-inducing antiepileptic drugs. Post-natal infant development: there is an increased risk of prematurity (9-11%), stillbirth, neonatal and perinatal death, haemorrhagic disease of the newborn, low Apgar scores and low birth weight (7-10%). Breast feeding: virtually all the anticonvulsant drugs are excreted in breast milk in low concentrations. Feeding difficulties, irritability and lethargy can occur. However, the benefits of breast feeding usually far outweigh any minor risks to the baby.

Special considerations for women with epilepsy

Women with epilepsy present health care providers with unique problems and opportunities for advancement of care. The fundamentals of epileptic pathophysiology are similar in both sexes. There are, however, some significant differences. Cosmetic effects of antiepileptic drugs (AEDs) may have different implications for women. Women who have seizures associated with their menstrual cycle may need special attention regarding their cyclic hormonal changes and AED selection. Antiepileptic drugs may reduce the effectiveness of hormonal contraception. Women with epilepsy have higher rates of infertility and an increased prevalence of reproductive and endocrine disorders. The majority of women with epilepsy have normal, healthy children, but their pregnancies are considered high risk due to an increase in seizure frequency, metabolic alterations of AEDs (which complicate management), and an increased risk of adverse pregnancy outcomes. These issues and an approach to optimize the management of women with epilepsy are discussed.

Monitoring of zonisamide in human breast milk and maternal plasma by solid-phase extraction HPLC method

An HPLC method was developed for the determination of zonisamide in human breast milk and plasma. Chromatographic separation was achieved using a Develosil CN analytical column with potassium dihydrogenphosphate buffer (pH 3.5 with milk, pH 2.5 with plasma)-acetonitrile as the mobile phase. Zonisamide and 1, 2-benzisoxazole-3-methansulfonamine acetate as internal standard were detected by ultraviolet absorbance at 240 nm. Zonisamide in breast milk and plasma was extracted by a rapid and simple procedure based on C(18) bonded-phase extraction. Determination of zonisamide in human breast milk and plasma was possible in the concentration range 0.05-20.0 microg/mL. The recoveries of zonisamide added to human breast milk and plasma were 79.5-85.0% and 86.3-93.1%, respectively, with coefficients of variation of less than 8.3% and 11.4% respectively. The mean concentrations of zonisamide in breast milk and plasma were 9.41 +/- 0.95 and 10.13 +/- 0.45 microg/mL, respectively. The average ratio between the breast milk concentration and plasma concentration (M/P ratio) was 0.93 +/- 0.09.

Monitoring of phenytoin in human breast milk, maternal plasma and cord blood plasma by solid-phase extraction and liquid chromatography

A rapid liquid chromatographic method for the quantitation of phenytoin in human breast milk, maternal plasma and cord blood plasma was developed using a Develosil C85 micron reverse phase column and a potassium dihydrogen phosphate buffer/acetonitrile mobile phase. Phenytoin and mephenytoin as an internal standard were detected by ultraviolet absorbance at 240 nm. The sample preparation method involves a rapid and simple procedure based on solid-phase extraction using a C18-bonded phase. Phenytoin could be determined in the concentration range of 0.05-3 micrograms ml-1. The recovery of phenytoin added to human breast milk and plasma were 91.6-94.7 and 91.6-96.0%, respectively, with coefficient of variation less than 4.2 and 8.7%. The method has been used for drug level monitoring in the human breast milk, maternal plasma and cord blood plasma samples that were taken from patients treated with phenytoin. The average ratio between the breast milk concentrations versus the plasma concentration was 0.28 +/- 0.1, with a rather poor correlation (r = 0.3033).

Maximizing the health of women with epilepsy: science and ethics in new drug development

Issues of unique concern to women with epilepsy largely arise from gender-based physiological differences. Female sex steroid hormones may alter the expression of epilepsy and the efficacy of antiepileptic drugs (AEDs). Seizures and AEDs in turn affect the hypothalamic-pituitary axis and can adversely impact reproductive function and bone health. Maternal seizures and exposure to AEDs may compromise fetal development. At this time, women with epilepsy and their medical caretakers do not have access to all the information necessary to formulate a treatment plan that will have the least impact on reproductive and general health. In part, this is because reproductive aged women are excluded from the earliest phases of drug testing and pregnant and lactating women are excluded from all aspects of new drug development. Therefore, as new AEDs enter the marketplace, women with epilepsy must decide whether a new AED is appropriate for therapy based on very limited information. Postmarketing surveillance of gender-specific adverse effects, as with all adverse effects, depends on voluntary reporting. Only a small percentage of significant adverse events are believed to be captured by the present system. Consumers, ethicists, and some physician groups are now arguing that women should be included in all aspects of the development of drugs they will ultimately use-even pregnant and lactating women. Some of the issues of concern for women with epilepsy regarding epilepsy treatment, reproductive function and general health will be reviewed, followed by a discussion of the drug development process and how it does, and could better, address the concerns of women.

The offspring of epileptic mother

The offspring of an epileptic mother is an issue-currently getting attention because of its several implications. A complex interaction between epilepsy during pregnancy and its adverse impact on foetus, labor, neonate, congenital malformation, psychosocial and medico-social concern and treatment challenges of such cases is increasingly being realised. Some of the significant observations has been reviewed extensively in this article. Maternal epilepsy is likely to adversely affect the off-spring at its various stages of development amounting to increased morbidity and mortality. Increased seizure frequency during pregnancy with resultant increased risk is well documented but its mechanism is poorly understood. Low apgar score, increased still birth rates (1.3 to 14%) in offspring of epileptic mother (OEM) is reported. So also, the neonatal and perinatal deaths are twice more common in OEMS than normal control. Small for dates, and prematurity in OEM is reported to be 7 to 10% and 4-11% respectively. Adverse impact on labor and delivery like preclampsia, abruptio placentae, polyhydramnios, assisted delivery, cesarean section and IUGR poses particular challenges to the obstetrician. Pediatrician's alertness is needed to anticipate and deal with the bleeding manifestation due to deficiency of Vit-K dependent clotting factors and various anticonvulsant drug (AED) withdrawal symptoms. Significant risk of developing congenital malformation is the result of epilepsy perse and the AED used during pregnancy. AED exposure leads to other distinct clinical syndromes, the orofacial clefts and cardiac anomalies being the commonest manifestation. Epilepsy in mother but not in father has significant adverse impact. Management strategies in the context of available observation has been discussed.

Pregnancy with epilepsy--a retrospective analysis

OBJECTIVES

To study the course of epilepsy in pregnancy and to assess the perinatal outcome.

METHODS

A retrospective analysis of 219 pregnant patients with epilepsy. The type of epilepsy, drug therapy and seizure frequency were documented. The perinatal outcome of 157 pregnancies with epilepsy was analyzed and compared with that of 471 normal gravidas of similar age and parity.

RESULTS

Generalized seizures occurred in 203 patients, partial seizures in 13 patients and complex partial seizures in three patients. One hundred fifty-two patients (69.41%) were on monotherapy. Carbamazepine was the most common drug (56.58%) used. Ninety-five patients (43.38%) had seizures in the current pregnancy, five of whom had status epilepticus. There was no maternal mortality in status epilepticus. There was no difference in perinatal outcome between the study and control groups. The incidence of congenital malformations was higher in the control group (5/476, 1.05%) than in the study group (1/160, 0.63%). The incidence of low-birth-weight babies was higher in the study group in patients with gestational seizures.

CONCLUSION

The course of pregnancy and perinatal outcome was not altered by epilepsy. There was no increase in the incidence of congenital malformations with the use of monotherapy.

Disposition of carbamazepine and phenytoin in pregnancy

Free and total plasma concentrations of phenytoin (PHT) and carbamazepine (CBZ) and its active metabolite carbamazepine-10, 11-epoxide (CBZ-E) were determined in a prospective study of 86 pregnant epileptic women. The pharmacokinetics of PHT and CBZ during the three trimesters were compared with kinetics at least 10 weeks postpartum. Plasma clearance and unbound CBZ clearance were slightly decreased during the last trimester. Total and free plasma CBZ-E concentrations did not change significantly during pregnancy. Plasma PHT clearance, on the other hand, increased from the first trimester. A less pronounced increase was observed for clearance of unbound PHT; the increase was statistically significant only during the third trimester.

Epilepsy and pregnancy: a prospective study of seizure control in relation to free and total plasma concentrations of carbamazepine and phenytoin

Seizure control and plasma concentrations of antiepileptic drugs (AEDs) were determined in a prospective, population-based study of 93 pregnancies (cases) of 70 patients with epilepsy. Seventy-seven cases were treated with monotherapy, which in 70 cases consisted of carbamazepine (CBZ) or phenytoin (PHT). Dosage was kept constant unless poor seizure control prompted an increase. Plasma concentrations were determined at monthly intervals throughout pregnancy and compared with baseline levels obtained at least 10 weeks postpartum. Both free and total CBZ and PHT concentrations were analyzed. Seizure frequency during pregnancy for the group as a whole was not different as compared with the 9 pregestational months and was unaltered or improved in 85% of cases. Total CBZ concentration was slightly lower during the third trimester as compared with baseline, whereas free concentration was unchanged. In contrast, PHT levels decreased steadily as pregnancy progressed. Total plasma concentration was 39% of baseline during the third trimester, whereas free PHT concentration decreased far less, being 82% of baseline level during the third trimester. No clear-cut relation could be demonstrated between seizure control and plasma concentrations, which may be explained by the limited changes in free AED concentrations and the small number of cases with an increased seizure frequency. Our results indicate that total plasma concentrations may be misleading and that monitoring of free concentrations, in particular of PHT concentrations, may be advantageous during pregnancy.

Practices of epilepsy during pregnancy: a survey of Canadian neurologists

The optimal management of epilepsy in epileptic pregnancies remains controversial. We surveyed all neurologists in Canada to determine their usual practice in managing epilepsy during pregnancy. We identified 436 neurologists in the 1990 edition of the Canadian Handbook of Medical and Surgical Specialists. We mailed a questionnaire enquiring with respect to details of management of epilepsy during pregnancy to all neurologists; in the case of nonrespondents, a follow-up questionnaire was mailed eight weeks later. We achieved a 65% response rate. We found that carbamazepine was the antiepileptic drug of first choice for the management of epilepsy during pregnancy among the majority of neurologists (75%), while phenobarbital (10%) and phenytoin (11%) were recommended much less frequently. Eight percent of respondents never used polytherapy during pregnancy. Despite recent controversy over the reproductive safety of carbamazepine, monotherapy with carbamazepine is regarded by the vast majority of Canadian neurologists as the therapy of first choice for epilepsy during pregnancy.

Pharmacokinetics of valproate in pregnancy: mother-foetus-newborn

An increased risk of seizures during and immediately after labour has been observed in epileptic women, and it is recognized that serum levels of antiepileptic drugs may decrease in pregnancy. Several studies have suggested that total valproate levels fall, but that free fractions increase during pregnancy. Recent findings suggest that the actual metabolism of valproate is not altered by pregnancy and that the changes of the plasma clearance are due primarily to decreased protein binding. The levels of free drug will not change significantly as pregnancy advances. However, dose reduction after delivery may be necessary to avoid toxicity. Valproate and its metabolites undergo placental transfer. In the foetus the plasma level of valproate and the protein binding are higher than in maternal plasma, and the half-life of valproate following placental transfer is considerably longer than in adults. Only small amounts of valproate appear in breast milk and those are not likely to cause any problems. During pregnancy and the first month after delivery preferably both total and free valproate serum levels should be closely monitored to determine the lowest effective dose.

Pregnancy and epilepsy

Women with epilepsy account for approximately 0.5% of all pregnancies. Their pregnancies are high risk because of an increased frequency of maternal seizures, complications of pregnancy, and adverse pregnancy outcomes. The increase in seizure frequency is associated with a progressive decline in antiepileptic drug (AED) levels during pregnancy even with constant dosing. Fetal deaths after a generalized seizure, although rare, have been reported, and a marked decline in fetal heart rate has been demonstrated after such seizures during delivery. AEDs have been implicated in causing a twofold increase in the rate of congenital malformations, a variety of minor physical anomalies, mostly involving the midface, and a neonatal hemorrhagic disorder. The clinician caring for a pregnant woman with epilepsy is therefore faced with a dilemma and must carefully chart a middle ground providing effective seizure control while minimizing fetal exposure to AEDs.

Plasma antiepileptic drug concentrations during pregnancy

Steady-state plasma antiepileptic drug (AED) concentrations were measured at intervals throughout pregnancy and during the postnatal period in 105 women who underwent 134 pregnancies. Phenytoin (PHT) dosage had to be increased in 85% of pregnancies in which the drug was received, carbamazepine (CBZ) dosage in 70%, and phenobarbital (PB) or methylphenobarbital (MPB) dosage in 85%, in an attempt to prevent or correct a fall in plasma concentrations of the respective drugs as pregnancy progressed. The altered disposition of the AEDs usually began in the first 10 weeks of pregnancy (often before epileptic pregnant women are referred for neurological supervision), and had returned to baseline value within 4 weeks of childbirth in two thirds of the women receiving PHT. The return to the nonpregnant situation appeared to be slower for CBZ, PB, and MPB. In women studied during more than one pregnancy, the changes in AED dosage to plasma concentration ratios tended to be greater in the first than in the subsequent pregnancies. Full seizure control prior to pregnancy was associated with a more favorable outcome for freedom from seizures during pregnancy. However, the plasma level monitoring-dosage adjustment policy produced no marked improvement in overall seizure control in pregnancy. This may have occurred because some patients were seen too late in their pregnancies for the policy to have been applied optimally.

Emergency department approach to managing seizures in pregnancy

Seizures in pregnancy pose risks for both the mother and the fetus and must be managed aggressively. Antiepileptic drugs have some teratogenic potential, but the risks are not as profound as reported in earlier literature. There is definitely less risk to the fetus from anticonvulsant exposure than from uncontrolled seizures. The evaluation of a pregnant woman with new-onset seizures is the same as for the nonpregnant patient, including head computed tomography with appropriate abdominal shielding. Status epilepticus management is based on IV benzodiazepines, phenytoin, or phenobarbital. Good fetal outcome is dependent on rapid seizure control. Management of eclampsia is controversial. There is little evidence that magnesium sulfate has anticonvulsant properties, and its use as such will probably decline steadily in the future. At present, it is reasonable to manage eclamptic seizures in the same way that status epilepticus is managed.

Anticonvulsants in pregnancy

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Parental epilepsy, anticonvulsant drugs, and reproductive outcome: epidemiologic and experimental findings spanning three decades; 2: Human studies

Evidence accumulated over the past three decades has established AEDs as human teratogens. Important developments in the delineation of these compounds as human teratogens include: the demonstration of a consistent association between in utero exposure to AEDs and an increased occurrence of single major malformations, the description of AED-induced dysmorphogenic syndromes; demonstration of a dose-response relationship, both in terms of the number and dosage of AEDs; and evidence that pharmacogenetic differences in the metabolism of AEDs are strongly correlated with the occurrence of congenital malformations. Furthermore, the experimental animal findings, having accumulated in parallel to those of human studies, strongly support the teratogenic role of AEDs. Areas that require further amplification and clarification in future studies are the relative contribution of AEDs and other factors, such as genetic predisposition and maternal seizures, particularly with respect to the occurrence of minor anomalies, growth retardation, and developmental outcome; the relative teratogenicity of specific monotherapies and polytherapies; the predictive role of pharmacogenetic differences in the metabolism of AEDs in the occurrence of structural and functional abnormalities; and characterization of the precise nature of the pharmacogenetic defect underlying the aforementioned differences in AED metabolism. Attempts should also be made in future prospective studies to monitor metabolite levels of AEDs, particularly the oxidative metabolites, in order to further elucidate the relative contribution of individual differences in metabolism in the determination of adverse fetal outcome. Similarly, further efforts should be made to assess the clinical significance of decreased growth parameters in terms of mental and neurologic development, and to ascertain whether there is any risk for such abnormalities in children who do not display overt or persistent reductions in physical growth parameters. This is critically important in light of the animal studies that have shown functional abnormalities at doses that do not necessarily produce structural defects. Future investigations would be conducted through collaborative studies that would encompass sufficiently large numbers of women to provide adequate power to the statistical analyses of the data obtained. Care would have to be exercised to establish a uniform protocol for the collaborating centers. Regionally based investigations would be preferable to studies based at special centers, in order to assess the relative role of risk factors associated with abnormal pregnancy outcomes in the epileptic population at large.(ABSTRACT TRUNCATED AT 400 WORDS)

Outcome of pregnancies complicated by epilepsy in Tasmania 1981-1988

Epilepsy in pregnancy is associated with an adverse pregnancy outcome. In 347 pregnancies in an 8-year retrospective study of all private and public patients in Tasmania from 1981 to 1988, epilepsy was found to be associated with an increased risk of hypertension (21%), antepartum haemorrhage (4.9%), postpartum haemorrhage (11.2%), fetal abnormality (3.5%) and perinatal mortality (2.3%).

Facial clefts and congenital heart defects in children of parents with epilepsy: genetic and environmental etiologic factors

Increased prevalence of cleft lip with or without cleft palate (CL(P], isolated cleft palate (CP), and congenital heart defects (CHD) in children of epileptic mothers have been ascribed to early fetal exposure to antiepileptic drugs (AED). However, common genetic factors responsible for both the malformations in question and the epileptic disorder might be of relevance for the increased rate of CL(P), CP, and CHD, rather than the influence of AED. The present review analyzes the literature on genetic and environmental etiologic factors (i.e. AED and epileptic seizures) that have been reported to increase the rate of CL(P), CP, and CHD in children of parents with epilepsy. Our data suggest that genetic factors are of minor importance for the etiology of facial clefts in offspring of epileptic patients. The rate of facial clefts was increased by a factor of 4.7 in children of AED-treated mothers with epilepsy compared with the background population values. Children of fathers with epilepsy and sibs of epileptic patients had no more facial clefts than expected. The rate of CHD in children of mothers and fathers with epilepsy was comparable to population figures. The role of epileptic seizures as a causative factor for CL(P), CP, and CHD is not settled, but seems to be of limited importance. Areas of future research are outlined concerning the teratogenic role of AED and their metabolites, especially on the postnatal intellectual development of the exposed children. Finally, the need for studies on prophylactic measures as well as the necessity of international surveillance systems on new AED teratogenicity are emphasized.

Problems and management of the pregnant woman with epilepsy

Pregnancies occurring in women who are epileptic are considered to be high risk. These women are at increased risk of seizures during pregnancy, labor, and delivery and of pregnancy complications and adverse pregnancy outcomes. Pregnancy alters the pharmacokinetics of anticonvulsant drugs, the levels of which decline as pregnancy advances. Not all drugs are altered in a similar manner, however. The rate of congenital malformations in infants of epileptic mothers is 2.4 times higher than in the general population. Malformations occur with all of the commonly used anticonvulsant drugs. The possible mechanisms of teratogenicity include folic acid antagonism, fetal tissue binding, and toxic effects of metabolic intermediates. Therapy with more than one drug increases the risk of congenital malformations. A unique hemorrhagic phenomenon in the infants of epileptic mothers has been reported and appears to be the result of a deficiency of vitamin K-dependent clotting factors. When taken by a pregnant woman, all antiepileptic drugs except valproic acid manifest themselves in breast milk, but only if the infant exhibits evidence of sedation should breastfeeding be discontinued. The dilemma for the physician treating the pregnant epileptic woman is to protect the mother from seizures and the fetus from unnecessary exposure to anticonvulsant medications.

Otologic manifestations of the hydantoin syndrome

The temporal bones of a newborn infant with hydantoin syndrome showed multiple middle ear and inner ear anomalies. There was a constellation of bony and membranous defects involving the oval and round windows, cochlear ducts, cochlear aqueducts, endolymphatic ducts and sacs, and vestibular labyrinths. To the authors' knowledge, supernumerary vestibular sensory epithelial structures and an inner ear epidermoid cyst have not been previously reported. Wide communications between the subarachnoid space and inner ear were of surgical relevance.

Generalized seizure triggering threshold and serum phenobarbital levels during pregnancy in rats

In experiments using pregnant rats, the following results were noted: (a) Of the amygdaloid kindled rats, the generalized seizure triggering threshold of the pregnant group was significantly higher than that of the nonpregnant group. (b) Of the rats taking oral phenobarbital, 4 mg/kg once a day, there was no significant difference of serum levels between the pregnant group and the nonpregnant group. (c) Of the amygdaloid kindled rats taking oral phenobarbital, 4 mg/kg once a day, the generalized seizure triggering threshold of the pregnant group was significantly higher than that of the nonpregnant group. It may be suggested that, when the drug dose remains the same, the rise in threshold by gestational physiological changes antagonizes the fall in threshold by decreased serum levels of anticonvulsants because of increasing distribution volume due to increasing body weight during pregnancy.

Pregnancy complications and outcomes in a cohort of women with epilepsy

To assess the possible adverse effects of maternal epilepsy on the course and outcome of pregnancy, all 138,780 Washington State birth certificates for the years 1980-81 were screened, and 204 births to epileptic mothers were identified. This was a lower than expected frequency of pregnancies in epileptic women. These births were compared with 612 randomly chosen control births for the same 2-year period. Of 46 pre- and perinatal events considered, eight were found to have occurred with significantly increased frequency for mothers with epilepsy. The offspring of these women were 2.8 times more likely to have low birth weight for their gestational age and 2.5 to 3.7 times more likely to have low Apgar scores or asphyxia. The excess risk of these adverse outcomes could not be explained by maternal race, parity, age, previous fetal loss, or socioeconomic status. These findings suggest that increased vigilance for complications of pregnancy and childbirth is warranted for epileptic women.

Effects of pregnancy on antiepileptic drug utilization

Pregnancy is associated with characteristic changes in the disposition of antiepileptic drugs; recent findings on this aspect of drug utilization are presented. In one study involving 48 pregnancies, the mean level-dose ratio of phenytoin decreased by 34%. In another study of 111 patients, phenytoin clearance increased gradually over the first 32 weeks of pregnancy and reached twice the preconception value. In two studies with phenobarbital, levels tended to decrease, although this effect was less pronounced than for phenytoin. Similarly for primidone, pregnancy had little effect on steady-state levels; however, levels of phenobarbital formed from primidone exhibited large decreases during pregnancy followed by increases after delivery. This effect was quite consistent. Carbamazepine clearance tended to increase to a relatively small extent. Limited data indicate that valproate levels decrease by 30 to 40% during pregnancy. The mechanisms responsible for these effects have not been elucidated and possibly include decreased bioavailability or compliance, increased metabolic clearance, or decreased plasma protein binding. Since the patient at risk of an increase in seizure frequency cannot be identified prior to conception, therapeutic monitoring is imperative during and after pregnancy.

Epileptic seizure disorders. Developments in diagnosis and therapy

There has been considerable progress in various segments of epileptology over the past two to three decades. The diagnostic sector has benefited from more advanced and sophisticated EEG-related techniques. The advent of computerized tomography has expedited the clinical evaluation of epileptic patients and new high-technology methods have been introduced. A new type of diagnostic subdivision (based on age-determined epileptic conditions and certain epileptic syndromes) is of great practical significance because of its prognostic implications (distinction of basically benign and severe forms of epileptic seizure disorders). The therapeutic sector has been stimulated by the introduction of new antiepileptic medications and particularly by profound insights into metabolic and pharmacokinetic characteristics of anticonvulsants; this has resulted in the introduction of techniques for serum level determinations. There have been new developments in the field of neurosurgical treatment of epileptic seizure disorders.

Fetal drug exposure-behavioral teratogenesis

This paper reviews the neurobehavioral and developmental effects of fetal drug exposure. The drugs most commonly associated with adverse developmental outcome include alcohol, anticonvulsants (particularly phenytoin and trimethadione), narcotics, and some environmental toxins. Major limitations of studies examining the consequences of prenatal drug exposure on development include inadequate control of other confounding factors, uncertain accuracy of drug histories, and outcome criteria that provide insufficient delineation of subtle developmental delays.

Practical aspects in the treatment of epilepsy

The different forms of epilepsy require different treatment, and drug choice depends on certain pharmacological and pharmacokinetic principles. Optimal treatment is based on single drug therapy, if possible, and monitoring of plasma antiepileptic drug levels. Such treatment, together with clinical observations and the cooperation of a well-informed patient, will achieve the best seizure control. Nevertheless, seizure recurrence or increased seizure frequency is a possibility. When withdrawal of treatment is indicated, it must be done according to certain principles. The possibility of pregnancy must be considered when choosing antiepileptic drugs for fertile women. Drug kinetics are different during pregnancy, and frequent monitoring and adjustment of the regimen are essential. Special care is necessary during delivery because of a higher risk of complications and apparently increased perinatal mortality. Plasma half-life of antiepileptic drugs may be increased or decreased in newborns. Slow elimination of diazepam contributes a special risk. Breast feeding is safe in most cases, but phenobarbital and diazepam may cause sedation of the infant.