Prodrome to Seizure in Transforaminal Endoscopic Surgery: A Series of 9 Cases

Abstract

Objective: Percutaneous transforaminal endoscopic lumbar discectomy (PTELD) is safe and ef- fective. Perioperative or postoperative seizures are a rare complication that can be prevented by promptly identifying prodromal symptoms and signs. This study aimed to identify prodromal symptoms and risk factors of avoidable seizures in patients undergoing PTELD and to quantify irrigation fluid ingression into the epidural space on immediate postoperative magnetic reso- nance imaging (MRI).Methods: This retrospective analysis included patients who underwent PTELD under local anes- thesia from February 2018 to June 2022. Surgical records were reviewed to identify patients who developed prodromal symptoms, and immediate postoperative MRI was evaluated for ra- diological correlations.Results: Nine patients developed prodromal symptoms of neck pain (n = 6), upper dorsal pain (n = 7), headache (n = 2), confusion (n = 2), visual disturbance (n = 1) and hemodynamic alter- ations (n = 4). No patients had seizures. Calcified lumbar disc herniation-associated posterior apophyseal ring fracture, central lumbar disc herniation, obesity, double-level surgery, use of an automated pump, and a large working channel endoscope were associated with an increased fluid flow rate for epidural work and duration of surgery. MRI showed significant epidural fluid collection cranial to the operative level, reaching the thoracolumbar junction, in patients with prodrome, suggesting increased intracranial pressure due to thecal sac compression. Conclusion: Prodromal symptoms should be considered a red flag for avoidable seizures. The duration of surgery and infusion fluid flow rate are controllable risk factors during surgery. Risk factors should be kept in mind. The judicious use of automated pumps and larger channel work- ing endoscopes is recommended.