title: Verbal memory after temporal lobe epilepsy surgery in children: Do only mesial structures matter?
abstract: Previous findings have been mixed regarding verbal memory outcome after left temporal lobectomy in children, and there are few studies comparing verbal memory change after lateral versus mesial temporal lobe resections. We compared verbal memory outcome associated with sparing or including the mesial structures in children who underwent left or right temporal lobe resection. We also investigated predictors of postsurgical verbal memory change.
  
  
  
  We retrospectively assessed verbal memory change approximately 1 year after unilateral temporal lobe epilepsy surgery using a list learning task. Participants included 23 children who underwent temporal lobe surgery with sparing of the mesial structures (13 left), and 40 children who had a temporal lobectomy that included resection of mesial structures (22 left).
  
  
  
  Children who underwent resection from the left lateral and mesial temporal lobe were the only group to show decline in verbal memory. Furthermore, when we considered language representation in the left temporal resection group, patients with left language representation and spared mesial structures showed essentially no change in verbal memory from preoperative to follow-up, whereas those with left language representation and excised mesial structures showed a decline. Postoperative seizure status had no effect on verbal memory change in children after left temporal lobe surgery. Finally, we found that patients with intact preoperative verbal memory experienced a significant decline compared to those with below average preoperative verbal memory.
  
  
  
  Our findings provide evidence of significant risk factors for verbal memory decline in children, specific to left mesial temporal lobe epilepsy. Children who undergo left temporal lobe surgery that includes mesial structures may be most vulnerable for verbal memory decline, especially when language representation is localized to the left hemisphere and when preoperative verbal memory is intact.
authors.affiliation: Department of Psychology, University of Toronto, Toronto, Ontario, Canada.|Department of Psychology, Hospital for Sick Children, Toronto, Ontario, Canada.|Program in Neurosciences and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Nicole
authors.initials: N
authors.lastname: Law
authors.affiliation: Department of Neurosurgery, Hadassah Medical Center, Jerusalem, Israel.
authors.forename: Mony
authors.initials: M
authors.lastname: Benifla
authors.affiliation: Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: James
authors.initials: J
authors.lastname: Rutka
authors.affiliation: Department of Psychology, University of Toronto, Toronto, Ontario, Canada.|Department of Psychology, Hospital for Sick Children, Toronto, Ontario, Canada.|Program in Neurosciences and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Mary Lou
authors.initials: ML
authors.lastname: Smith
mesh_terms: D000293:Adolescent; D038481:Anterior Temporal Lobectomy / Q000009:adverse effects*; D002648:Child; D004833:Epilepsy, Temporal Lobe / Q000150:complications / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality; D006801:Humans; D007802:Language; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D011183:Postoperative Complications / Q000209:etiology*; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014706:Verbal Learning / Q000502:physiology*; D055815:Young Adult
keywords: Epilepsy; Hippocampus; Neuropsychology; Pediatric neurosurgery