Posterior Quadrant Disconnection for Childhood Onset Sub-Hemispheric Posterior Head Region Epilepsy: Indications in an Indian Cohort and Outcome

Abstract

Background: Posterior quadrant disconnection (PQD) is an under-utilized surgical technique in the management of refractory epilepsy. There is a dearth of data pertinent to post-PQD seizure outcomes. Methods: This retrospective study analyzed patients with drug-resistant childhood-onset epilepsy who underwent PQD at our center from 2009 to 2018. The clinical, imaging, and electrophysiological data were reviewed. The seizure outcome was noted from the latest follow-up in all patients. Results: Fifteen patients underwent PQD, with a mean age at onset of epilepsy of 3.3 ± 4.6 years. All patients had seizure onset in childhood with focal onset of seizures, and in addition, 5 had multiple seizure types. All cases underwent presurgical workup with MRI, video-EEG, psychometry, while PET/MEG was done if required. Engel Ia and ILAE I outcomes were considered to be favorable. The histology of the specimen showed 9 patients (60%) had gliosis, 4 (26.7%) had focal cortical dysplasia (FCD), while 1 patient had nodular heterotopia and another had polymicrogyria-pachygyria complex. Postoperative follow-up was available in 14 cases. One patient was lost to follow-up. Mean follow-up duration for the cohort was 45 + 24 months. At last, follow-up (n = 14), 66.7% (10 cases) had favorable outcome (Engel Ia). At the end of 1-year follow-up, up to 73% (n = 11) of the patients were seizure-free. Four patients developed transient hemiparesis after surgery which improved completely by 3–6 months. Conclusions: Gliosis was more common etiology requiring PQD in our series than Western series, where FCD was more common. PQD is a safe and effective surgical modality in childhood-onset epilepsy with posterior head region epileptogenic focus.