title: Different effects of anterior temporal lobectomy and selective amygdalohippocampectomy on verbal memory performance of patients with epilepsy.
abstract: The advantage of selective amygdalohippocampectomy (SAH) over anterior temporal lobectomy (ATL) for the treatment of temporal lobe epilepsy (TLE) remains controversial. Because ATL is more extensive and involves the lateral and medial parts of the temporal lobe, it may be predicted that its impact on memory is more important than SAH, which involves resection of medial temporal structures only. However, several studies do not support this assumption. Possible explanations include task-specific factors such as the extent of semantic and syntactic information to be memorized and failure to control for main confounders. We compared preoperative vs. postoperative memory performance in 13 patients with SAH with 26 patients who underwent ATL matched on side of surgery, IQ, age at seizure onset, and age at surgery. Memory function was assessed using the Logical Memory subtest from the Wechsler Memory Scales - 3rd edition (LM-WMS), the Rey Auditory Verbal Learning Test (RAVLT), the Digit Span subtest from the Wechsler Adult Intelligence Scale, and the Rey-Osterrieth Complex Figure Test. Repeated measures analyses of variance revealed opposite effects of SAH and ATL on the two verbal learning memory tests. On the immediate recall trial of the LM-WMS, performance deteriorated after ATL in comparison with that after SAH. By contrast, on the delayed recognition trial of the RAVLT, performance deteriorated after SAH compared with that after ATL. However, additional analyses revealed that the latter finding was only observed when surgery was conducted in the right hemisphere. No interaction effects were found on other memory outcomes. The results are congruent with the view that tasks involving rich semantic content and syntactical structure are more sensitive to the effects of lateral temporal cortex resection as compared with mesiotemporal resection. The findings highlight the importance of task selection in the assessment of memory in patients undergoing TLE surgery.
authors.affiliation: Centre de recherche en neuropsychologie et cognition (CERNEC), Département de Psychologie, Université de Montréal, Canada.
authors.forename: Olivier
authors.initials: O
authors.lastname: Boucher
authors.affiliation: Département de Psychologie, Université du Québec à Montréal, Canada.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Dagenais
authors.affiliation: Centre hospitalier de l'Université de Montréal - Hôpital Notre-Dame, Canada.
authors.forename: Alain
authors.initials: A
authors.lastname: Bouthillier
authors.affiliation: Centre hospitalier de l'Université de Montréal - Hôpital Notre-Dame, Canada.
authors.forename: Dang Khoa
authors.initials: DK
authors.lastname: Nguyen
authors.affiliation: Département de Psychologie, Université du Québec à Montréal, Canada; Centre hospitalier de l'Université de Montréal - Hôpital Notre-Dame, Canada. Electronic address: rouleau.isabelle@uqam.ca.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Rouleau
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000679:Amygdala / Q000601:surgery*; D038481:Anterior Temporal Lobectomy; D002648:Child; D000069279:Drug Resistant Epilepsy / Q000523:psychology* / Q000601:surgery*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006624:Hippocampus / Q000601:surgery*; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D008568:Memory; D019635:Neurosurgical Procedures / Q000379:methods*; D011183:Postoperative Complications / Q000523:psychology; D011597:Psychomotor Performance; D012640:Seizures / Q000601:surgery; D016896:Treatment Outcome; D014706:Verbal Learning; D014888:Wechsler Scales; D055815:Young Adult
keywords: Anterior temporal lobectomy; Epilepsy; Memory; Mesiotemporal surgery; Neurosurgery; Selective amygdalohippocampectomy