Diffusion Tensor Imaging in Temporal Lobe Epilepsy: Clinical and Neuropsychological Correlates.
Abstract number :
1.248
Submission category :
Year :
2001
Submission ID :
285
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
K. Arfanakis, Ph.D., Medical Physics, University of Wisconsin, Madison, WI; B. Meyerand, Ph.D., Medical Physics, University of Wisconsin, Madison, WI; B. Hermann, Ph.D., Neurology, University of Wisconsin, Madison, WI; M. Seidenberg, Ph.D., Psychology, Un
RATIONALE: Previous quantitative MRI volumetric investigations of patients with focal temporal lobe epilepsy have revealed atrophy in extratemporal regions including cerebral white matter, with a pattern of generalized cognitive inefficiency consistent with the widespread nature of the volumetric abnormalities. These volumetric and cognitive abnormalities are particularly evident in early onset temporal lobe epilepsy. Volumetric abnormalities were also evident when distinct white matter tracts were manually traced (e.g., corpus callosum). The possibility exists that while white matter volumes are reduced, these tissues may have normal physiological properties. We here report diffusion tensor imaging (DTI) of discrete white matter fiber tracts in patients with temporal lobe epilepsy and healthy controls. The aim of this investigation was to compare DTI in epilepsy patients versus controls, determine the relationship with clinical seizure characteristics and examine the clinical significance of DTI measurements via their association with neuropsychological status.
METHODS: 13 patients with temporal lobe epilepsy and 11 healthy controls were investigated. Regions of interest included the anterior and posterior corpus callosum (CC), arcuate fasciculus, and anterior and posterior limbs of the internal capsule. Specific DTI indices investigated included fractional anisotrophy (FA) and lattice index. Patients also underwent neuropsychological assessment and WAIS-III IQ scores (verbal, Performance and Full Scale IQ) were related to DTI measurements.
RESULTS: Compared to healthy controls, patients with temporal lobe epilepsy exhibited significant abnormalities limited to the corpus callosum including FA and lattice in posterior corpus callosum and lattice in anterior corpus callosum. Earlier age of recurrent seizure onset was significantly (p [lt] 0.05) associated with FA and lattice abnormalities in posterior corpus callosum and arcuate fasciculus with similar trends (p [lt] 0.10) in the anterior corpus callosum and anterior limb of the internal capsule. Significant correlations were evident between lattice and Performance IQ in anterior and posterior corpus callosum.
CONCLUSIONS: DTI abnormalities exist in normal appearing white matter tracts in patients with temporal lobe epilepsy. These abnormalities are especially evident in the corpus callosum, associated with early age of recurrent seizure onset, and are of clinical significance as demonstrated by association with cognitive measures.
Support: NIH RO1 37738