title: A critical evaluation of the lateralizing significance of material-specific memory deficits in patients with mesial temporal lobe epilepsy with hippocampal sclerosis.
abstract: To critically assess the value of material-specific memory deficits in lateralizing temporal lobe dysfunction preoperatively, we compared the neuropsychological data of 50 consecutive patients with unilateral mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS; right: 31, left: 19) with those of 50 age- and education-matched healthy control subjects. On case-control comparison, both the subcohorts with left and right MTLE-HS performed poorly on intelligence tests, in addition to individual memory tests. However, comparison of the verbal and visual memory functions between subcohorts with right and left MTLE-HS revealed that learning trials and delayed word list recall were the only tests that hypothesized left temporal lobe dysfunction. We conclude that material-specific memory deficits are largely test driven, but there is a lateralizing role for task-specific deficits in left MTLE-HS. Although neuropsychological data help to define baseline neuropsychological impairment, caution should be exercised in interpreting the lateralizing value of material-specific memory deficits prior to surgery.
authors.affiliation: R. Madhavan Nayar Center for Comprehensive Epilepsy Care, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India.
authors.forename: Malcolm K
authors.initials: MK
authors.lastname: Jeyaraj
authors.forename: Ramshekhar N
authors.initials: RN
authors.lastname: Menon
authors.forename: Sunitha
authors.initials: S
authors.lastname: Justus
authors.forename: Aley
authors.initials: A
authors.lastname: Alexander
authors.forename: P Sankara
authors.initials: PS
authors.lastname: Sarma
authors.forename: Kurupath
authors.initials: K
authors.lastname: Radhakrishnan
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000150:complications* / Q000473:pathology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis* / Q000209:etiology*; D009483:Neuropsychological Tests; D012372:ROC Curve; D012016:Reference Values; D012598:Sclerosis / Q000209:etiology; D014706:Verbal Learning; D055815:Young Adult
keywords: Hippocampal sclerosis; Material-specific memory; Neuropsychological dysfunction; Temporal lobe epilepsy; Verbal memory; Visual memory