Stereo-EEG for Epileptogenic Focus Localization in Schizencephaly: A Single-center Experience in Four Patients

World Neurosurg. 2023 Apr:172:e319-e325. doi: 10.1016/j.wneu.2023.01.019. Epub 2023 Jan 9.

Abstract

Objective: Schizencephaly is a congenital cerebral malformation characterized by clefts in the hemispheres of the brain, where variations in semiology often make it difficult to localize epileptogenic focus. Here, we report on a series of patients who underwent stereo-encephalography (SEEG) for epileptogenic focus localization and subsequent SEEG-guided surgical intervention.

Methods: Four patients (ages 27, 33, 27, 25 years) with a mean seizure history of 16 years (range 8-22 years) were analyzed. Data pertaining to semiology, video encephalography (EEG), magnetic resonance imaging, positron emission tomography, and invasive EEG studies, surgical intervention and post-surgery outcome were collected and analyzed.

Results: All seizure onset zones were within the extent of schizencephaly; however, the limbic system (including the hippocampus, amygdala, cingulate gyrus, or insula) was involved in early spreading. Two patients underwent SEEG-guided radiofrequency thermo-ablation (RFTA) in the seizure onset zone, 1 patient underwent lesionectomy via craniotomy, and 1 underwent neither RFTA nor lesionectomy. At 2 years post-surgery, the outcomes were as follows: Engel grade Ia (n = 2), Ib (n = 1), and III (n = 1).

Conclusions: This article reports on a precise approach to treating patients with schizencephaly dependent of seizure onset zone and functional cortex mapping. Subsequent SEEG-guided surgical interventions (radiofrequency thermo-ablation and lesionectomy) were shown to reduce seizure frequency, while preserving the neurologic functions in drug-resistant epilepsy patients with schizencephaly.

Keywords: Epilepsy surgery; Radiofrequency thermoablation; Schizencephaly; Stereo-encephalography.

Publication types

  • Case Reports

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Drug Resistant Epilepsy* / diagnostic imaging
  • Drug Resistant Epilepsy* / surgery
  • Electroencephalography / methods
  • Humans
  • Magnetic Resonance Imaging / methods
  • Retrospective Studies
  • Schizencephaly* / complications
  • Schizencephaly* / diagnostic imaging
  • Schizencephaly* / surgery
  • Seizures / surgery
  • Stereotaxic Techniques
  • Tomography, X-Ray Computed
  • Treatment Outcome
  • Young Adult