Hypothermia for refractory status epilepticus

Abstract

Introduction: Status epilepticus (SE) can be refractory to conventional anticonvulsants, requiring anesthetic doses of medications to suppress seizures. This approach carries significant morbidity, is associated with a high fatality rate, and may not always control SE. Hypothermia has been shown to suppress epileptiform activity experimentally, but has not previously been used as a primary modality to control SE in humans.

Methods: Four patients with SE refractory to benzodiazepine and/or barbiturate infusions were treated with hypothermia (target temperature: 31-35 degrees C) using an endovascular cooling system. All received continuous EEG monitoring, three were on midazolam infusions and one had recurrent seizures on weaning from pentobarbital.

Results: Therapeutic hypothermia was successful in aborting seizure activity in all four patients, allowing midazolam infusions to be discontinued; three achieved a burst-suppression pattern on EEG. After controlled rewarming, two patients remained seizure-free, and all four demonstrated a marked reduction in seizure frequency. Adverse events included shivering, coagulopathy without bleeding, and venous thromboembolism. Two death occurred, neither directly related to hypothermia; however, immunosuppression related to the use of barbiturates and hypothermia may have contributed to an episode of fatal sepsis in one patient.

Conclusions: Hypothermia was able to suppress seizure activity in patients with SE refractory to traditional therapies with minimal morbidity. It appears promising as an alternative or an adjunct to anesthetic doses of other agents, but requires further study to better evaluate its safety and efficacy.