Neuroanatomical correlates of cognitive phenotypes in temporal lobe epilepsy.
OBJECTIVE
Previous research characterized three cognitive phenotypes in temporal lobe epilepsy, each associated with a different profile of clinical seizure and demographic characteristics, total cerebral (gray, white, cerebrospinal fluid) and hippocampal volumes, and prospective cognitive trajectories. The objective of this investigation was to characterize in detail the specific neuroanatomical abnormalities associated with each cognitive phenotype.


METHODS
High-resolution MRI scans of healthy controls (n=53) and patients with temporal lobe epilepsy (n=55), grouped by cognitive phenotype (minimally impaired; memory impaired; memory, executive function, and speed impaired), were examined with respect to patterns of gray matter thickness throughout the cortical mantle, as well as volumes of subcortical structures, corpus callosum, and regions of the cerebellum.


RESULTS
Increasing abnormalities in temporal and extratemporal cortical thickness, volumes of subcortical structures (hippocampus, thalamus, basal ganglia), all regions of the corpus callosum, and bilateral cerebellar gray matter distinguish the cognitive phenotypes in a generally stepwise fashion. The most intact anatomy is observed in the minimally impaired epilepsy group and the most abnormal anatomy is evident in the epilepsy group with impairments in memory, executive function, and speed.


CONCLUSIONS
Empirically derived cognitive phenotypes are associated with the presence, severity, and distribution of anatomic abnormalities in widely distributed cortical, subcortical, callosal, and cerebellar networks.
Dabbs
Kevin
K
Department of Neurology, University of Wisconsin School of Medicine and Public Health, 600 North Highland, Madison, WI 53792, USA.
Jones
Jana
J
Seidenberg
Michael
M
Hermann
Bruce
B
D000328:Adult; D001921:Brain / Q000473:pathology*; D002531:Cerebellum / Q000473:pathology; D002540:Cerebral Cortex / Q000473:pathology; D003071:Cognition / Q000502:physiology*; D003337:Corpus Callosum / Q000473:pathology; D004833:Epilepsy, Temporal Lobe / Q000473:pathology* / Q000523:psychology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010641:Phenotype; D011597:Psychomotor Performance / Q000502:physiology