Tract-based spatial statistics of diffusion tensor imaging after corpus callosotomy in relation to seizure recurrence.

Abstract

PURPOSE: To delineate microstructural changes in transected white matter tracts

after corpus callosotomy in relation to seizure recurrence using tract-based

spatial statistics of diffusion tensor imaging (DTI-TBSS). METHODS: We

retrospectively included 12 total corpus callosotomy patients who had undergone

serial pre- and postoperative DTI studies. The first postoperative DTI was

performed within 6 months after callosotomy. The second postoperative DTI was

performed in five patients with seizure recurrence (symptomatic group) and in

seven patients without seizure recurrence (asymptomatic group) after 1 year

following surgery. Group comparisons of fractional anisotropy (FA) with age- and

sex-matched controls were performed in a whole brain voxel-wise manner using

DTI-TBSS. RESULTS: The first postoperative DTI-TBSS showed a significant FA

decrease in the entire corpus callosum in all patients. The second postoperative

DTI-TBSS showed that a significant FA decrease remained in the entire corpus

callosum in the asymptomatic group. However, in the symptomatic group, no

significant decrease of FA was observed in some parts of the posterior body and

splenium of the corpus callosum, although there was still a significant FA

decrease in the genu of the corpus callosum. CONCLUSIONS: Using DTI-TBSS

analysis, we characterized and visualized microstructural white matter changes

over time in relation to seizure recurrence in callosotomy patients, suggesting

that reorganization of some transected white matter tracts may be related to

seizure recurrence. DTI-TBSS analysis can provide reliable and useful information

about the state of white matter bundles affected by corpus callosotomy in a

noninvasive manner.