Memory outcomes following hemispherectomy in children

Tamara P Tavares; Elizabeth N Kerr; Mary Lou Smith

doi:10.1016/j.yebeh.2020.107360

Memory outcomes following hemispherectomy in children

Epilepsy Behav. 2020 Nov:112:107360. doi: 10.1016/j.yebeh.2020.107360. Epub 2020 Aug 31.

Authors

Tamara P Tavares¹, Elizabeth N Kerr², Mary Lou Smith³

Affiliations

¹ Department of Psychology, The Hospital for Sick Children, Toronto, ON, Canada; Neurosciences and Mental Health Program, The Hospital for Sick Children, Toronto, ON, Canada. Electronic address: tamara.tavares@sickkids.ca.
² Department of Psychology, The Hospital for Sick Children, Toronto, ON, Canada; Department of Paediatrics, University of Toronto, Toronto, ON, Canada.
³ Department of Psychology, The Hospital for Sick Children, Toronto, ON, Canada; Department of Paediatrics, University of Toronto, Toronto, ON, Canada; Department of Psychology, University of Toronto, Toronto, ON, Canada; Neurosciences and Mental Health Program, The Hospital for Sick Children, Toronto, ON, Canada. Electronic address: marylou.smith@utoronto.ca.

PMID: 32882625
DOI: 10.1016/j.yebeh.2020.107360

Abstract

Objective: A vast proportion of children with epilepsy exhibit memory impairments. Although numerous studies have examined memory performance following pediatric resective epilepsy surgery, little is known about the memory outcomes following hemispherectomy. The few studies that report on memory performance typically include restricted measures, consist of case reports, or do not report on preoperative performance. Given the current limitations, the aim of this study was to delineate pre- and postoperative memory functioning in youth who underwent a hemispherectomy.

Method: Participants included patients who had undergone a hemispherectomy at the Hospital for Sick Children, between 1999 and 2016. Standardized neuropsychological assessments of verbal (digit span, word list recall, word pair recall, stories) and visual (faces, dot locations) memory abilities prior to and after surgery were reviewed. A Wilcoxon signed rank test and effect sizes was completed to compare patients' memory performance to population norms and to assess pre- to postoperative difference scores.

Results: Thirteen participants were included in the study: five patients completed preoperative assessments only and eight patients completed pre- and postoperative assessments. Preoperatively, patients performed substantially worse relative to population norms as indicated by large effect sizes (r: 0.5-0.9). Postoperatively, effect sizes were large for the majority of the memory tests, demonstrating considerable differences in patients' memory scores over time. When clinically meaningful changes were examined, stable performance was evident on 63% of the memory tasks.

Conclusion: Overall, the results highlight that youth who are eligible for hemispherectomy demonstrate profound memory deficits prior to surgery. In addition, undergoing hemispherectomy was not necessarily associated with declined memory performance, with the majority of patients showing stable scores.

Keywords: Epilepsy surgery; Hemispherectomy; Memory; Pediatric epilepsy.

MeSH terms

Adolescent
Child
Epilepsy* / surgery
Hemispherectomy* / adverse effects
Humans
Memory
Memory Disorders / etiology
Neuropsychological Tests
Treatment Outcome