[Malformations in the offspring of pregnant women with epilepsy. Presentation of an international registry of antiepileptic drugs and pregnancy (EURAP)]

The interaction between epilepsy and pregnancy has been studied for many years; nonetheless the risk associated with individual antiepileptic drug has not been adequately characterized up to date. Moreover, virtually nothing is known about the possible human teratogenicity of the newer antiepileptic drugs. Because of the complexity of the mechanisms involved, the crucial evidence needed can only come from very large population based studies, and a collaborative European multicentre investigation has been set up to this purpose. Specific objectives include the evaluation of the risk of major foetal malformations and of delay in prenatal growth following exposure to antiepileptic drugs, assessment of the pattern of congenital abnormalities associated with older and newer antiepileptic drugs and their combinations, and identification of possible relationships with dosage and with a variety of other risk factors. All women exposed to antiepileptic drugs at the time of conception are eligible for entry. The protocol is purely observational and does not entail any change in prescribing pattern or management policies, which are left to the discretion of the treating physician. Data obtained during prospective monitoring for up to 1 year after birth are regularly collected in especially designed forms and entered into Regional Registries prior to transfer to a Central European Registry of Antiepileptic Drugs and Pregnancy (EURAP). Evaluations of incidence and prevalence of teratogenic endpoints will be based exclusively on cases enrolled before foetal outcome is known and in any case not after the 16th week of pregnancy. Cases enrolled after birth, after the 16th week of pregnancy or after prenatal diagnosis will only be reported descriptively. The study is being implemented gradually in 19 countries in Western and Eastern Europe. Wide participation from interested physicians is essential for the achievement of the study objectives, which are expected to lead to important advances in pre pregnancy counselling and overall clinical management of women with epilepsy.

Single-Dose Pharmacokinetics of Lamotrigine in Children: Influence of Age and Antiepileptic Comedication

To evaluate the influence of pediatric age and antiepileptic comedication on the single-dose pharmacokinetics of lamotrigine, 19 patients with epilepsy (10 comedicated with enzyme inducers and 9 comedicated with valproic acid) aged 8 months to 30 years received a single oral dose of lamotrigine (0.6 to 2.2 mg/kg) after an overnight fast. Blood samples were collected for at least 36 hours and plasma lamotrigine concentrations were determined by high-performance liquid chromatography. Pharmacokinetic parameters were calculated by noncompartmental analysis. Lamotrigine half-life (T1/2) and oral clearance (Cl/F) values were significantly lower and significantly higher, respectively, in patients comedicated with enzyme inducers than in those receiving valproic acid (T1/2 = 8.1 vs. 41.7 hours respectively, P < 0.001; Cl/F = 0.11 vs. 0.04 L/h per kg respectively, P < 0.005, geometric means), whereas Cmax and Tmax values were comparable in the two groups. The differences in pharmacokinetic parameters persisted when comparisons were made within subgroups stratified according to age. Within groups of patients homogeneous for type of comedication, Cmax and AUC values tended to be lower in children aged less than 12 years than in older patients. There was no significant relationship between half-life values and age. The authors conclude that both age and type of comedication influence lamotrigine pharmacokinetics. The reduction in lamotrigine concentrations caused by enzyme inducers and the elevation caused by valproic acid can be explained by stimulation and inhibition, respectively, of lamotrigine glucuronidation. On the other hand, the lower plasma lamotrigine levels in children than in adolescents and older patients may not be explainable solely by differences in metabolic rate.

Malformations in offspring of women with epilepsy: a prospective study

PURPOSE

The incidence of malformations among infants of mothers with epilepsy treated with antiepileptic drugs (AEDs) during pregnancy is higher than that found in the general population. The aim of this study was to contribute to providing a definition of the rate of congenital anomalies in the offspring of mothers with epilepsy and to detect possible risk factors.

METHODS

Since 1977, 517 pregnancies were followed up at the San Paolo Hospital in Milan by a team of epileptologists and obstetricians. The patients received monthly obstetric and neurologic examinations, and the blood levels of AEDs were tested monthly. During pregnancy the patients underwent ultrasound investigations to evaluate fetal morphology and development. At the time of delivery, the infants were submitted to a standardized examination by a pediatrician, and a more detailed clinical examination was performed on day 5. Malformations were classified as (a) genetic and chromosomic, (b) severe and mild malformations, and (c) deformities.

RESULTS

The overall rate of malformations was 9.7%: of these, 5.3% were structurally severe, 2.2% were mild, 0.4% were chromosomic-genetic, and 1.8% were deformities. No malformation was detected in the 25 untreated patients.

CONCLUSIONS

The risks of teratogenicity have been regarded as multifactorial, involving such factors as genetic predisposition, although most prospective studies show that AED-related factors are the primary risk factors for an increased incidence of congenital malformations.

Intrauterine growth in the offspring of epileptic women: a prospective multicenter study

The aim of the present study was to evaluate the risk of intrauterine growth delay in the offspring of epileptic mothers and to quantify the risks of intrauterine exposure to antiepileptic drugs (AEDs). Data concerning 870 newborns, prospectively collected in Canada, Japan and Italy, using the same study design, were pooled and analyzed. The overall proportion of newborns whose body weight (7.8%) or head circumference (11.1%) at birth were below the 10th percentile was not increased. However, logistic regression analysis showed that the risk of small head circumference was significantly higher in Italian than in Japanese (RR 4.2; 95% CI: 2.2-8.0) or Canadian children (RR 2.6; 95% CI: 1.1-6.5), and in children exposed to polytherapy (RR 2.7; 95% CI: 1.2-6.3), phenobarbital (PB) (RR 3.6; 95% CI: 1.4-9.4) and primidone (PRM) (RR 4.5; 95% CI: 1.5-13.8). Country was also the only factor affecting low body weight, with Italian children having a higher risk than Japanese (RR 5.2; 95% CI: 2.6-10.4) or Canadian (RR 8.8; 95% CI: 2.0-38.1) children. Due to the small categories, the influence of AED doses and plasma concentrations was studied for each individual AED, without adjustment for the other potential confounding factors. A clear dose-dependent effect was found for PB and PRM in terms of both small head circumference and low body weight, and a concentration-dependent effect for PB in terms of small head circumferences. The size of the difference between the Italian and the other two populations, which is only partially explained by differences in therapeutic regimens, suggests that genetic, environmental and ethnic factors also need to be taken into account when considering possible explanations.

Serum antibodies to Purkinje cells and dorsal root ganglia neurons in sensory neuronopathy without malignancy

Anti-Purkinje cell antibodies (APCA), believed to be markers of paraneoplastic cerebellar degeneration in females, have been identified in the serum of 3 men with subacute sensory neuronopathies and no evidence of tumors 5 years after the onset of the neurological signs. By indirect immunohistochemistry on sections of rat cerebellum and dorsal root ganglia, the patients' IgG bound to the cytoplasms of both Purkinje cells and dorsal root ganglia neurons. By western blot analysis on whole human cerebellum and whole human dorsal root ganglia homogenates, the IgG from 2 patients bound to a 62-kd protein in both homogenates and the IgG from 1 patient bound to a 110-kd protein in the cerebellum homogenate only. Yo autoantibody test was negative in all patients. Our study provides evidence that non-anti-Yo APCA may be associated with subacute sensory neuronopathies and are not necessarily markers of an underlying tumor. The previously described anti-Yo APCA has only occurred in females with cancer.

Acute presentation of Tangier polyneuropathy: a clinical and morphological study

We describe a patient with Tangier disease and a peripheral neuropathy with an unusual acute onset. The morphological studies of sural nerve biopsy revealed both axonal degeneration and demyelination, and the fiber loss was preferentially restricted to two of ten nerve fascicles. The cytoplasm of Schwann cells, fibroblasts, macrophages and pericytes were vacuolated because of the presence of numerous lipid droplets. The clinical and morphological findings are consistent with the possibility that ischemia plays a major role in causing this neuropathy.

Antibodies to sulfatide and to chondroitin sulfate C in patients with chronic sensory neuropathy

Sera from eight of 25 patients with chronic sensory neuropathy had high titers of antibodies to sulfatide and chondroitin sulfate C or both. Preclearing of patients' sera with either sulfatide or chondroitin sulfate C revealed that in four patients the antisulfatide antibodies crossreacted with chondroitin sulfate C. By indirect immunohistochemistry sera reactive to sulfatide only had a different staining pattern from those reactive to both sulfatide and chondroitin sulfate C. By direct immunohistochemistry we found immunoglobulins bound to nerve fibers only in patients with serum antibodies against both sulfatide and chondroitin sulfate C. Our study provides evidence that antibodies to sulfatide and to chondroitin sulfate C differ in their fine specificity and are present in 30% of patients with chronic sensory neuropathy.