Anesthesia-Related Perioperative Seizures: Pathophysiology, Predisposing Factors and Practical Recommendations

Epilepsy is one of the most prevalent neurological disorders both in the United States and worldwide. It is present in 0.5-1% of the population, with a 10% lifetime risk of experiencing a single seizure. Anesthesiologists are frequently faced with the management of seizures in epileptic and nonepileptic patients in the intraoperative, emergency, or intensive care unit settings. This review aims to provide an update on the pathophysiology, clinical presentation and treatment strategies of perioperative seizures and the pro- and anti-convulsant properties of anesthetic agents, focused on neurosurgical populations. Many aspects of anesthesia may affect seizure incidence in the perioperative setting, including changes in antiepileptic drug regimen causing sub therapeutic antiepileptic drug (AED) blood levels, nil per os (NPO) status, anxiety, sleep deprivation, and drug interactions. Several general anesthetics and drugs used during anesthesia possess pro-convulsant properties that may trigger clinical seizures at induction or emergence. Anesthetic-induced epilepsy has been described during anesthesia with sevoflurane, isoflurane, etomidate, local anesthetics, opioids, propofol, as well as other anesthetics and auxiliary drugs. In neurosurgical patients, perioperative seizure risk is highly relevant, especially in patients with brain tumors, subarachnoid hemorrhage (SAH) and traumatic brain injury (TBI). Although common in practice, routine antiepileptic prophylaxis in neurosurgical patients remains controversial.