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.

Comparative study of neck pain in relation to increase of cervical epidural pressure during percutaneous endoscopic lumbar discectomy.

STUDY DESIGN: A prospective study. OBJECTIVE: By monitoring cervical epidural pressure (EP) changes throughout the procedure, we intend to discover the effect of percutaneous endoscopic lumbar discectomy (PELD) on cervical epidural pressure and whether there is a correlation between posterior neck pain and increased cervical EP, which is known to have a linear correlation with intracranial pressure (ICP). SUMMARY OF BACKGROUND DATA: Patients sometimes complain of posterior neck pain during PELD. Due to the massive irrigation fluid used during the procedure, the possibility of increased ICP as the cause is quite strong. METHODS: Twenty-eight patients undergoing PELD with ASA physical status 1 or 2 were enrolled in this study. In all patients, a cervical epidural catheter was placed at the C6-C7 level before the procedure and was connected to a pressure transducer. Cervical EPs were monitored continuously throughout the procedure. Initial stabilized EP (EP), EP at the time of neck pain, maximal EP during the procedure, and EP at the end of the procedure were checked. Neck pain onset time from the beginning of irrigation and total irrigation time were also checked. RESULTS: Of 28 patients, 8 patients complained of neck pain. Neck pain onset time from the beginning of irrigation was 35.6 +/- 11.3 (mean +/- SD) minutes. The EP at the time of neck pain (52.9 +/- 9.2 mm Hg) was significantly higher than the maximal EP in patients without neck pain (34.8 +/- 14.7 mm Hg). In all patients who complained of neck pain, the cervical EP at the time of neck pain showed pressures above 37 mm Hg. The maximal EP in those with neck pain (73.6 +/- 25.8 mm Hg) was also significantly higher than the EP in those without neck pain (34.8 +/- 14.7 mm Hg). In a correlation study, patients with higher maximal EPs had higher probabilities of having neck pain. In 6 of 8 patients, an abrupt increase in EP was observed after the onset of neck pain, while in the other 2 patients, the procedure ended just after neck pain appeared. CONCLUSION: Neck pain occurring during PELD is associated with a highly increased cervical EP generated by continuous infusion.