Risk of Developing Seizure After Percutaneous Endoscopic Lumbar Discectomy

Study Design: A retrospective analysis in patients who underwent percutaneous endoscopic lumbar discectomy (PELD) and developed seizures during the procedure; and to identify the risk of developing seizure during PELD by measuring cervical epidural pressure. Objective: To evaluate clinical significance, characteristics, and risk factors for developing seizure and neck pain in patients undergoing PELD. Summary and Background Data: Increased epidural pressure during PELD has been reported earlier. Risk of developing intraoperative seizure has not been investigated till date. We experienced some unexpected complication such as, seizures during PELD, and, therefore, we correlated it with the prodromal symptom and the strategies to avoid such complications during PELD. Methods: Four of the total 16,725 patients who underwent PELD between 2000 and 2008 developed intraoperative seizures. A review of their medical records and radiologic files were correlated with the complication. Factors evaluated were the type of seizures, prodromal symptoms, comorbidities and clinical outcome. To postulate a pathophysiologic cause of seizure, we designed a study to monitor the intraoperative cervical epidural pressure in 33 patients undergoing PELD. Results: A striking feature of the 4 patients in this series was that they all complained of neck pain before the seizure event. There was no identifiable pattern of seizure observed. The duration of the procedure in these patients was longer than uninvolved cases. None of the patients developed any type of sequel subsequent to seizure. The outcome of surgery has been similar with the patients that did not have any type of complications after PELD. In the subsequent study of cervical epidural pressure, no patients developed seizure. However, there was occurrence of neck pain in the group with increased cervical epidural pressure. Conclusions: Although rare (0.02%), seizure can occur in patients undergoing PELD, occurrence of neck pain is correlated with increase in cervical epidural pressure, which should be considered as prodromal sign and alert the surgeon. Duration of procedure and speed of infusion are associated risk factor.