Low Frequency Stimulation and Seizure Induction in Pediatric and Young Adult Patients With Drug Resistant Epilepsy Undergoing Stereoelectroencephalography.

Abstract

Purpose: Describe the tolerability and outcome of direct brain stimulation for seizure induction in children and young adults undergoing intracranial electroencephalography.

Methods: Patients received low frequency stimulation (LFS) consisting of 30 seconds of 1 Hz bipolar, biphasic brain stimulation. A subset also received high frequency stimulation (HFS) for clinical purposes. Clinical data regarding epilepsy characteristics, stimulation, and outcomes were collected.

Results: Fifty-four patients (aged 1.8 to 23.4 years) with pediatric onset epilepsy were enrolled at Children's Hospital of Philadelphia and the Hospital of the University of Pennsylvania. Side effects during LFS included focal sensation (22%) and motor responses (41%). Non-seizure electrographic abnormalities were noted during stimulation in 87% of patients. During LFS, typical clinical seizures were seen in 24% of patients. During HFS (50 Hz), 58% of 36 patients had seizures (71% typical semiology). In 30% of patients, stimulated typical clinical seizures identified a contact not previously identified as part of the seizure onset zone. Of 43 patients who went on to have resection, ablation, or neuromodulation, 39 patients had ≥12 months of follow-up. Although 84% of 19 patients with stimulated typical clinical seizures had a good outcome, 60% of 20 patients with atypical or no clinical seizures during stimulation had good outcomes (P = 0.09).

Conclusions: LFS is well tolerated in pediatric and young adult DRE patients and in one fourth of cases identifies potential additional nodes of the seizure network. These data, consistent with adult studies, affirm that LFS has a role complementing HFS in evaluating pediatric DRE patients undergoing stereoelectroencephalography.