Intraoperative ECoG in bottom-of-the-sulcus syndrome using a novel flexible strip electrode

Niccolò Biagioli; Sofia Morandi; Anna Elisabetta Vaudano; Matteo Pugnaghi; Elisa Moriconi; Giacomo Pavesi; Vincenzo Tramontano; Stefano Meletti

doi:10.1002/epd2.20211

Intraoperative ECoG in bottom-of-the-sulcus syndrome using a novel flexible strip electrode

Epileptic Disord. 2024 Feb 29. doi: 10.1002/epd2.20211. Online ahead of print.

Authors

Niccolò Biagioli^{1

2}, Sofia Morandi³, Anna Elisabetta Vaudano^{1

2

3}, Matteo Pugnaghi^{2

3}, Elisa Moriconi⁴, Giacomo Pavesi⁴, Vincenzo Tramontano³, Stefano Meletti^{1

2

3}

Affiliations

¹ Department of Biomedical Metabolic Sciences and Neurosciences, University of Modena and Reggio Emilia, Modena, Italy.
² Neurology Unit, Head and Neck Neuroscience Department, AOU, Modena, Italy.
³ Clinical Neurophysiology Unit, Head and Neck Neuroscience Department, AOU, Modena, Italy.
⁴ Neurosurgery Unit, Head and Neck Neuroscience Department, AOU, Modena, Italy.

PMID: 38420724
DOI: 10.1002/epd2.20211

Abstract

The recording of epileptiform discharges from bottom-of-sulcus focal cortical dysplasia (BOSD) is often difficult during intraoperative electrocorticography (ECoG) due to the deep localization. We describe the use in this scenario of a new-generation electrode strip with high flexibility, easily adapted to cortical gyri and sulci. A right-handed 20-year-old male with drug-resistant focal epilepsy due to BOSD of the inferior frontal gyrus and daily focal aware seizures was evaluated for epilepsy surgery. Based on electroclinical and neuroimaging results, a focal cortectomy guided by ECoG was proposed. ECoG recordings were performed with new-generation cortical strips (Wise Cortical Strip; WCS®) and standard cortical strips. ECoG, performed on the convexity of the frontal cortical surface, recorded only sporadic spikes with both types of strips. Then, after microsurgical trans-sulcal dissection, WCS was molded along the sulcal surface of the suspected BOSD based on 3D-imaging reconstruction, showing continuous/subcontinuous 3-4-Hz rhythmic spike activity from the deepest electrode. Registration after resection of the BOSD did not show any epileptiform activity. Pathology showed dysmorphic neurons and gliosis. No surgical complications occurred. The patient is seizure-free after 12 months. This single case experience shows that highly flexible electrode strips with adaptability to cortical gyrations can identify IEDs originating from deep location and could therefore be useful in cases of bottom of the sulcus dysplasia.

Keywords: Etiology: focal cortical dysplasia (Type II); Localization: central (right); Phenomenology: tonic posture; Syndrome: focal non-idiopathic frontal (FLE); bottom of the sulcus dysplasia; electrocorticography; epilepsy surgery; focal cortical dysplasia; intraoperative monitoring.