Atrophy of the Corpus Callosum in Chronic Temporal Lobe Epilepsy.
Abstract number :
1.208
Submission category :
Year :
2001
Submission ID :
284
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
D. O[ssquote]Leary, Ph.D., Psychiatry, University of Iowa, Iowa City, IA; B.P. Hermann, Ph.D., Neurology, University of Wisconsin, Madison, WI; M. Seidenberg, Ph.D., Psychology, Chicago Medical School, North Chicago, IL; B. Bell, Ph.D., Neurology, Univers
RATIONALE: Quantitative MRI volumetric abnormalities in chronic temporal lobe epilepsy have been reported to extend into extratemporal regions, including volumetric abnormalities of cerebral white matter. The purpose of this investigation was to examine volumetric properties of the corpus callosum, identify predictors of volumetric abnormalities, and determine the neuropsychological correlates of volumetric abnormalities in the corpus callosum.
METHODS: Subjects were 38 individuals with temporal lobe epilepsy (TLE) and 25 healthy controls. Two research assistants were trained to trace the corpus callosum using BRAINS-2 software. A single mid-saggital slice (slice 127 on each individual[ssquote]s realigned and resampled image sets) was used for tracing. Technicians underwent formal training and independently traced 15 brains from another data set and reliability was assessed by comparing their traces to that of a third independent technician with previous experience and expertise in tracing the corpus callosum. The interclass correlation coefficient (ICC) was .91 for one tracer and .92 for the other. The technicians then traced the 63 brains of the TLE patients and controls while blinded to group membership. In addition to calculating the total volume of each corpus callosum, a computer program was used to divide each corpus callosum into seven areas using the Witelson technique. Patients underwent formal neuropsychological assessment and performance was related to corpus callosum volume in order to determine the clinical significance of any indentified volumetric anomalies.
RESULTS: The volume of the corpus callosum was significantly (p [lt] 0.05) smaller in temporal lobe epilepsy patients compared to healthy controls. The volumetric reduction was most evident in posterior corpus callosum (Witelson areas 5 through 7). Earlier age of onset of TLE was associated with significant (p [lt] 0.05) volumetric reduction of the corpus callosum. Reduction in corpus callosum volume was most closely associated with neuropsychological measures of speeded cognitive performance.
CONCLUSIONS: Temporal lobe epilepsy is associated with reduction in the volume of the corpus callosum, most affected in patients with early onset temporal lobe epilepsy. The identified volumetric reduction is of clinical significance as demonstrated by the relationship with measures of cognitive function.
Support: NIH RO1 37738