title: Reduced neocortical thickness and complexity mapped in mesial temporal lobe epilepsy with hippocampal sclerosis.
abstract: We mapped the profile of neocortical thickness and complexity in patients with mesial temporal lobe epilepsy (MTLE) and hippocampal sclerosis. Thirty preoperative high-resolution magnetic resonance imaging scans were acquired from 15 right (mean age: 31.9 +/- 9.7 standard deviation [SD] years) and 15 left (mean age: 30.8 +/- 8.4 SD years) MTLE patients who were seizure-free for 2 years after anteriomesial temporal resection. Nineteen healthy controls were also scanned (mean age: 24.8 +/- 3.9 SD years). A cortical pattern matching technique mapped thickness across the entire neocortex. Mesial temporal structures were not included in this analysis. Cortical models were remeshed in frequency space to compute their fractal dimension (surface complexity). Both MTLE groups showed up to 30% bilateral decrease in cortical thickness, in the frontal poles, frontal operculum, orbitofrontal, lateral temporal, and occipital regions. In both groups, cortical complexity was decreased in multiple lobar regions. Significant linkages were found relating longer duration of epilepsy to greater cortical thickness reduction in the superior frontal and parahippocampal gyrus ipsilateral to the side of seizure onset. The pervasive extrahippocampal structural deficits may result from chronic seizure propagation or may reflect other causes such as initial precipitating factors leading to MTLE.
authors.affiliation: Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA. linjj@uci.edu
authors.forename: Jack J
authors.initials: JJ
authors.lastname: Lin
authors.forename: Noriko
authors.initials: N
authors.lastname: Salamon
authors.forename: Agatha D
authors.initials: AD
authors.lastname: Lee
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Dutton
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Geaga
authors.forename: Kiralee M
authors.initials: KM
authors.lastname: Hayashi
authors.forename: Eileen
authors.initials: E
authors.lastname: Luders
authors.forename: Arthur W
authors.initials: AW
authors.lastname: Toga
authors.forename: Jerome
authors.initials: J
authors.lastname: Engel
authors.forename: Paul M
authors.initials: PM
authors.lastname: Thompson
mesh_terms: D000328:Adult; D000465:Algorithms; D001931:Brain Mapping; D004833:Epilepsy, Temporal Lobe / Q000473:pathology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019579:Neocortex / Q000473:pathology*; D012598:Sclerosis; D012640:Seizures / Q000473:pathology / Q000503:physiopathology