Publications by authors named "Juan S Bottan"

2 Publications

  • Page 1 of 1

Seizure Freedom in Temporal Plus Epilepsy Surgery Following Stereo-Electroencephalography.

Can J Neurol Sci 2020 05;47(3):374-381

Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada.

Background: "Temporal plus" epilepsy (TPE) is a term that is used when the epileptogenic zone (EZ) extends beyond the boundaries of the temporal lobe. Stereotactic electroencephalography (SEEG) has been essential to identify additional EZs in adjacent structures that might be part of the temporal lobe/limbic network.

Objective: We present a small case series of temporal plus cases successfully identified by SEEG who were seizure-free after resective surgery.

Methods: We conducted a retrospective analysis of 156 patients who underwent SEEG in 5 years. Six cases had TPE and underwent anterior temporal lobectomy (ATL) with additional extra-temporal resections.

Results: Five cases had a focus on the right hemisphere and one on the left. Three cases were non-lesional and three were lesional. Mean follow-up time since surgery was 2.9 years (SD ± 1.8). Three patients had subdural electrodes investigation prior or in addition to SEEG. All patients underwent standard ATL and additional extra-temporal resections during the same procedure or at a later date. All patients were seizure-free at their last follow-up appointment (Engel Ia = 3; Engel Ib = 2; Engel Ic = 1). Pathology was nonspecific/gliosis for all six cases.

Conclusion: TPE might explain some of the failures in temporal lobe epilepsy surgery. We present a small case series of six patients in whom SEEG successfully identified this phenomenon and surgery proved effective.
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May 2020

Robot-Assisted Insular Depth Electrode Implantation Through Oblique Trajectories: 3-Dimensional Anatomical Nuances, Technique, Accuracy, and Safety.

Oper Neurosurg (Hagerstown) 2020 03;18(3):278-283

Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Canada.

Background: The insula is a deep cortical structure that has renewed interest in epilepsy investigation. Invasive EEG recordings of this region have been challenging. Robot-assisted stereotactic electroencephalography has improved feasibility and safety of such procedures.

Objective: To describe technical nuances of three-dimensional (3D) oblique trajectories for insular robot-assisted depth electrode implantation.

Methods: Fifty patients who underwent robot-assisted depth electrode implantation between June 2017 and December 2018 were retrospectively analyzed. Insular electrodes were implanted through oblique, orthogonal, or parasagittal trajectories. Type of trajectories, accuracy, number of contacts within insular cortex, imaging, and complication rates were analyzed. Cadaveric and computerized tomography/magnetic resonance imaging 3D reconstructions were used to visualize insular anatomy and the technical implications of oblique trajectories.

Results: Forty-one patients (98 insular electrodes) were included. Thirty (73.2%) patients had unilateral insular coverage. Average insular electrodes per patient was 2.4. The mean number of contacts was 7.1 (SD ± 2.91) for all trajectories and 8.3 (SD ± 1.51) for oblique insular trajectories. The most frequently used was the oblique trajectory (85 electrodes). Mean entry point error was 1.5 mm (0.2-2.8) and target error was 2.4 mm (0.8-4.0), 2.0 mm (1.1-2.9) for anterior oblique and 2.8 mm (0.8-4.9) for posterior oblique trajectories. There were no complications related to insular electrodes.

Conclusion: Oblique trajectories are the preferred method for insular investigation at our institution, maximizing the number of contacts within insular cortex without traversing through sulci or major CSF fissures. Robot-assisted procedures are safe and efficient. 3D understanding of the insula's unique anatomical features can help the surgeon to improve targeting of this structure.
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March 2020