Periodic focal epileptiform discharges.
OBJECTIVE: To report intraoperative periodic focal epileptiform discharges (PFEDs) during awake craniotomy using high-density electrocorticography (HD-ECoG).
METHODS: We retrospectively analyzed 81 patients undergoing awake craniotomy between 9/29/2016 and 7/5/2018. Intraoperative HD-ECoG was performed with direct electrocortical stimulation (DECS) for functional brain mapping. Real-time interpretation was performed and compared to scalp EEG when performed. Perioperative seizures, surgical complications, and characteristics of PFEDs were assessed.
RESULTS: 69/81 patients (mean age 48.5 years) underwent awake surgery; 55 operated for brain tumor, 11 for epilepsy and 3 for cavernomas. A focal abnormality on brain MRI was present in 63/69 (91.3%) patients. 43/69 (62.3%) patients had seizures preoperatively, 4/69 (5.7%) had seizures during DECS. PFEDs were identified in 11 patients (15.9%); 2 on depth recording and 9 during intraoperative HD-ECoG. 32 patients (46.3%) had preoperative EEG. HD-ECoG detected more epileptiform discharges (EDs) than standard EEG (32/43; 74.4% vs 9/32; 28.1%) (p =
CONCLUSIONS: Intraoperative PFEDs are novel, highly focal EDs approximating a single gyrus. In patients with brain tumors, PFEDs did not demonstrate a relationship to pre-operative seizures though has similarities to other common waveforms in patients with epilepsy.
SIGNIFICANCE: PFEDs expand our understanding of the interictal-ictal continuum and highlight improved temporo-spatial information obtained from increasing sensor density during intracranial EEG recording.
Published In/Presented At
Tatum, W. O., Feyissa, A. M., ReFaey, K., Grewal, S. S., Alvi, M. A., Castro-Apolo, R., Roth, G., Segura-Duran, I., Mahato, D., Ruiz-Garcia, H., Pamias-Portalatin, E., Yelvington, K., Chaichana, K., Bechtle, P., & Quinones-Hinojosa, A. (2019). Periodic focal epileptiform discharges. Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology, 130(8), 1320–1328. https://doi.org/10.1016/j.clinph.2019.04.718
Medicine and Health Sciences
Department of Medicine