title: Medically resistant pediatric insular-opercular/perisylvian epilepsy. Part 2: outcome following resective surgery.
abstract: OBJECTIVE Seizure onset in the insular cortex as a cause of refractory epilepsy is underrepresented in the pediatric population, possibly due to difficulties localizing seizure onset in deep anatomical structures and limited surgical access to the insula, a complex anatomical structure with a rich overlying vascular network. Insular seizure semiology may mimic frontal, temporal, or parietal lobe semiology, resulting in false localization, incomplete resection, and poor outcome. METHODS The authors retrospectively reviewed the records of all pediatric patients who underwent insular cortical resections for intractable epilepsy at Miami Children's Hospital from 2009 to 2015. Presurgical evaluation included video electroencephalography monitoring and anatomical/functional neuroimaging. All patients underwent excisional procedures utilizing intraoperative electrocorticography or extraoperative subdural/depth electrode recording. RESULTS Thirteen children (age range 6 months-16 years) with intractable focal epilepsy underwent insular-opercular resection. Seven children described symptoms that were suggestive of insular seizure origin. Discharges on scalp EEG revealed wide fields. Four patients were MRI negative (i.e., there were no insular or brain abnormalities on MRI), 4 demonstrated insular signal abnormalities, and 5 had extrainsular abnormalities. Ten patients had insular involvement on PET/SPECT. All patients underwent invasive investigation with insular sampling; in 2 patients resection was based on intraoperative electrocorticography, whereas 11 underwent surgery after invasive EEG monitoring with extraoperative monitoring. Four patients required an extended insular resection after a failed initial surgery. Postoperatively, 2 patients had transient hemiplegia. No patients had new permanent neurological deficits. At the most recent follow-up (mean 43.8 months), 9 (69%) children were seizure free and 1 had greater than 90% seizure reduction. CONCLUSIONS Primary insular seizure origin should be considered in children with treatment-resistant focal seizures that are believed to arise within the perisylvian region based on semiology, widespread electrical field on scalp EEG, or insular abnormality on anatomical/functional neuroimaging. There is a reasonable chance of seizure freedom in this group of patients, and the surgical risks are low.
authors.affiliation: Pediatric Neurosurgery, Miami (Nicklaus) Children's Hospital, Miami, Florida.
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Weil
authors.affiliation: Departments of 1 Pediatric Neurology and.
authors.forename: Ngoc Minh D
authors.initials: NM
authors.lastname: Le
authors.affiliation: Departments of 1 Pediatric Neurology and.
authors.forename: Prasanna
authors.initials: P
authors.lastname: Jayakar
authors.affiliation: Departments of 1 Pediatric Neurology and.
authors.forename: Trevor
authors.initials: T
authors.lastname: Resnick
authors.affiliation: Departments of 1 Pediatric Neurology and.
authors.forename: Ian
authors.initials: I
authors.lastname: Miller
authors.affiliation: Pediatric Neurosurgery, Miami (Nicklaus) Children's Hospital, Miami, Florida.
authors.forename: Aria
authors.initials: A
authors.lastname: Fallah
authors.affiliation: Departments of 1 Pediatric Neurology and.
authors.forename: Michael
authors.initials: M
authors.lastname: Duchowny
authors.affiliation: Pediatric Neurosurgery, Miami (Nicklaus) Children's Hospital, Miami, Florida.
authors.forename: Sanjiv
authors.initials: S
authors.lastname: Bhatia
mesh_terms: D000293:Adolescent; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D000069279:Drug Resistant Epilepsy / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000639:trends; D017034:Epilepsy, Frontal Lobe / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D007223:Infant; D064795:Intraoperative Neurophysiological Monitoring / Q000379:methods / Q000639:trends*; D008297:Male; D019635:Neurosurgical Procedures / Q000639:trends*; D011446:Prospective Studies; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: AED = antiepileptic drug; ECoG = electrocorticography; EEG = electroencephalography; FCD = focal cortical dysplasia; MCA = middle cerebral artery; TSC = tuberous sclerosis complex; TTE = time-to-event; epilepsy surgery; insula; insular epilepsy; opercula; pediatric; perisylvian; refractory epilepsy; seizure