Hemispherectomy seizure outcomes in relationship to pre-operative and post-operative EEGfindings
Abstract number :
373
Submission category :
9. Surgery / 9B. Pediatrics
Year :
2020
Submission ID :
2422718
Source :
www.aesnet.org
Presentation date :
12/6/2020 12:00:00 PM
Published date :
Nov 21, 2020, 02:24 AM
Authors :
Pi-Yi Ko, Mary Bridge Hospital; Ahmad Marashly - Seattle Children's Hospital/University of Washington;
Rationale:
Seizure outcomes following hemispherectomy are generally good, with reported 50-80% of patients achieving seizure freedom post-operatively. Studies have shown that pre-operative and post-operative interictal discharges provide poor and uncertain prognosticative value, respectively. In this study, we aim to characterize the prognostic value of the evolution from pre-operative to post-operative seizures in functional hemispherectomy.
Method:
We retrospectively reviewed 22 patients who underwent hemispherectomy at our institution (2010-2020) who had both pre-operative and post-operative EEGs available for review. All EEGs were reviewed for ictal and interictal findings, and categorized as ipsilateral to the lesion, independently arising from the contralateral side, and/or generalized. Seizure outcomes were classified according to the Engel Surgical Outcome Scale.
Results:
Of 22 patients, 18 (82%) became seizure free (Engel Class IA), with a mean clinical follow up of 4.1 years (range 0.3-9.5 years) after surgery. Of pre-operative EEGs, 41% had seizures, 100% had ipsilateral interictal discharges, and 36% had contralateral interictal discharges. Of post-operative EEGs, obtained on average 1.6 years (range 5 days-7.9 years) after surgery, 14% had seizures, 73% had ipsilateral interictal discharges, and 23% had contralateral interictal discharges. Of the 14% who had seizures on post-operative EEG, all were free of clinical seizures. On paired EEG review, 13 patients (59%) demonstrated resolution of either ictal or interictal discharges, 2 (9%) demonstrated an emergence of contralateral interictal discharges, and 7 (32%) demonstrated no change. Of the 4 patients in this cohort who did not achieve Engel Class IA seizure freedom, 3 were Engel Class IB and 1 was Engel Class IIB. Their EEGs were not predictive of their outcomes, with 3 having no seizures on either pre- or post-operative EEG, and 1 having resolution of pre-operative seizures. All patients who had persistent postoperative seizures achieved Engel IA.
Conclusion:
Seizure outcomes after hemispherectomy are generally excellent, with 82% in our cohort achieving seizure freedom and 100% achieving Engel Class I or II. The presence of ictal or interictal findings on pre- and post-operative EEGs independently, as well as the evolution of EEG findings over time was not predictive of outcomes
Funding:
:None
Surgery