Birthe Pedersen

On the Association Between Valproate and Polycystic Ovary Syndrome

Summary: 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.

Heart rate variability analysis indicates preictal parasympathetic overdrive preceding seizure‐induced cardiac dysrhythmias leading to sudden unexpected death in a patient with epilepsy

Evidence for seizure‐induced cardiac dysrhythmia leading to sudden unexpected death in epilepsy (SUDEP) has been elusive. We present a patient with focal cortical dysplasia who has had epilepsy for 19 years and was undergoing presurgical evaluation. The patient did not have any cardiologic antecedents. During long‐term video–electroencephalography (EEG) monitoring, following a cluster of secondarily generalized tonic–clonic seizures (GTCS), the patient had prolonged postictal generalized EEG suppression, asystole, followed by arrhythmia, and the patient died despite cardiopulmonary resuscitation. Analysis of heart rate variability showed a marked increase in the parasympathetic activity during the period preceding the fatal seizures, compared with values measured 1 day and 7 months before, and also higher than the preictal values in a group of 10 patients with GTCS without SUDEP. The duration of the QTc interval was short (335–358 msec). This unfortunate case documented during video‐EEG monitoring indicates that autonomic imbalance and seizure‐induced cardiac dysrhythmias contribute to the pathomechanisms leading to SUDEP in patients at risk (short QT interval).

The Provision of Epilepsy Care across Europe

Summary:  Purpose: To assess the needs and resources available in the provision of basic epilepsy care across Europe.

Source localization of rhythmic ictal EEG activity: A study of diagnostic accuracy following STARD criteria

Although precise identification of the seizure‐onset zone is an essential element of presurgical evaluation, source localization of ictal electroencephalography (EEG) signals has received little attention. The aim of our study was to estimate the accuracy of source localization of rhythmic ictal EEG activity using a distributed source model.

Inhibition of photosensitive seizures in man by the β-carboline, ZK 95962, a selective benzodiazepine receptor agonist

A single-dose study of the beta-carboline, ZK 95962, on photosensitive generalized paroxysmal activity in the EEG was conducted in 6 patients with primary generalized epilepsy. Four of the patients were newly diagnosed and did not receive any antiepileptic drug or other medication during the study. Two were receiving current therapy with carbamazepine. A double-blind cross-over study with 2 injections of ZK 95962 (20 micrograms/kg body weight repeated 10 min after 1st injection) and 2 placebo injections were carried out in a randomized order, with 4 h intervals between the injections with active drug and placebo. On the day before the trial, the sensitivity range (standardized photosensitivity range, SPR) was determined hourly using flash frequencies of 2, 6, 8, 10, 15, 20, 30 and 40 Hz for 4 sec in ascending and descending order until generalized spikes or spike waves occurred. A significant reduction in photosensitivity was observed 2-12 min after injection of ZK 95962 in all patients, lasting 2-3 h. No change in the SPR was observed after placebo injections. The feelings of uneasiness and myoclonic jerks, provoked by photostimulation, were also abolished by ZK 95962, but not by placebo injections. Side effects, including sedation were not observed. The results suggest that benzodiazepine receptor ligands such as ZK 95962 may be potent antiepileptic drugs.

Elderly Patients with Epilepsy: Specific Requirements

Summary: Epilepsy is the third most common neurologic disorder in the elderly and, combined with the progressive aging of the population, this high incidence will lead to an increasing number of elderly patients who require epilepsy care. Treatment of epilepsy in elderly patients is often complicated by the physiologic changes that occur in old age, e.g., reduced absorption, slower metabolism, and deterioration of liver and renal function. Another consideration is that elderly patients are most likely to be suffering from other diseases, necessitating multiple therapies. The potential for drug interactions is therefore high. Because of these factors, traditional antiepileptic drug (AED) therapies are associated with a higher incidence of adverse effects in elderly patients than in younger patients. Tiagabine (TGB) is one of a family of new AEDs recently developed. The newer AEDs tend to have a comparable antiepileptic efficacy and a lower potential for toxicity compared with the traditional AEDs. Clinical studies have shown that age appears to have no effect on the pharmacokinetics of TGB and that there is little difference in the incidence of adverse events between elderly and young patients. Although clinical experience with TGB in the elderly is still limited, TGB shows promise for treatment of epilepsy in the elderly population.

O15: Source localisation of rhythmic ictal activity: a study of diagnostic accuracy following STARD criteria

G. Waterstraat1,2, M. Burghoff2,3, T. Fedele1,2,3, H.J. Scheer3, G. Curio1,2,4 1Charite-University Medicine Berlin, Neurophysics Group, Department of Neurology, Campus Benjamin Franklin, Berlin, Germany; 2Bernstein Focus: Neurotechnology Berlin, Berlin, Germany; 3Physikalisch-Technische Bundesanstalt, Institute Berlin, Berlin, Germany; 4Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany