Antiepileptic Drug Withdrawal in Patients with Temporal Lobe Epilepsy Undergoing Presurgical Video‐EEG Monitoring

Abstract

Summary: Purpose: To investigate antiepileptic drug (AED) withdrawal during video‐EEG monitoring in adult patients with temporal lobe epilepsy (TLE). Methods: Between 1995 and 1997, 102 consecutive patients with refractory TLE were admitted to the epilepsy monitoring unit for presurgical evaluation. Patients were monitored with ongoing AEDs being rapidly decreased and discontinued in 4–6 days. The monitoring was continued until sufficient numbers of seizures were recorded. Serum AED levels were checked at admission and after the first complex partial seizure (CPS). Results: In all, 89 patients had 429 CPSs (mean, 4.8 per patient), including 156 (36.4%) secondarily generalized. A mean of 153.8 h (16–451 h) was required for completing the monitoring in each patient. Forty‐three (48.3%) patients experienced seizure clusters, and eight (9.0%) had generalized seizures that had never occurred or had been absent for years. However, none evolved to status epilepticus. Carbamazepine was the most commonly used AED in 71.9% of patients, followed by valproate and phenytoin. When the first CPS occurred, mean 77.2 h since the beginning of the monitoring, serum levels of these three AEDs were mostly subtherapeutic rather than minimal. Conclusions: Acute AED withdrawal effectively provoked seizures in TLE patients undergoing presurgical video‐EEG monitoring. However, nearly 50% of patients had seizure clusters or secondarily generalized seizures. Serum AED levels were mostly subtherapeutic when the first CPS occurred.

Safety and Yield of Early Cessation of AEDs in Video-EEG Telemetry and Outcomes

“…This increases the risk of provoked secondary generalized seizures with an early peak that for some medications could be a rebound phenomenon in addition to loss of therapeutic effect 9 . Generalized tonic clonic seizures in acute withdrawal may occasionally end in refractory status epilepticus 10 . Therefore, continuous supervision of patients, and the ability to respond rapidly to a seizure are essential for patient safety 1 .…”

The Effects of Slow Withdrawal of Antiepileptic Drugs During Long-Term Video-EEG Monitoring on Seizure Clusters and Status Epilepticus

“…Yen ve ark.nın [4] yaptığı çalışmada hızlı antiepileptik ilaç kesilmesiyle birlikte status ve küme nöbet görülme sıklığının arttığı gösterilmiştir. Ancak hızlı ilaç kesilmesi status epileptikus ve küme nöbet riskini arttırmasına rağmen, antiepileptik ilaçların yavaş kesilmesi durumunda ise hastanede kalış süresi uzayacaktır.…”

“…Literatürdeki çalışmalarda ise bu süre 3.2-6 gün arasında değişmektedir. [3,4,8,9] Uzun süreli video-EEG monitorizasyonu süresince ortaya çıkan küme nöbetler sırasında izlenen nöbetler tamamen birbirinden bağımsız odaklardan kaynaklanabileceği gibi belirli bir odaktan da kaynaklanabilir. Bu nedenle yazarlara göre monitorizasyon süresince izlenen küme nöbetler predominan epileptik odağın tanımlanmasını zorlaştırır.…”

“…Yen ve ark. [4] temporal lop epilepsili hastalarda karbamazepin monoterapisi alanlarda serum ilaç düzeyinin düşmesiyle kompleks parsiyel nöbetlerin görül-me eğiliminin olduğunu bildirmişlerdir. Başka bir çalışmada ise okskarbazepinin akut kesilmesini takiben iki gün içinde jeneralize tonik klonik nöbet görülme sıklığının arttığı bildirilmiştir.…”

“…Antiepileptik ilaçların kesilmesini takiben akut dönemde ortaya çıkan jeneralize tonik klonik nöbet ya da nöbetlerin dirençli status epileptikusla sonlandığı bildirilmiştir. [4] Bu nedenle uzun süreli video-EEG monitorizasyonu süresince gelişebilecek status epileptikus ya da küme nöbetler için hazır-lıklı biçimde hastaların yakından izlenmeleri önerilmektedir.…”