Abstracts

Rationale: Recently, diffusion tensor imaging (DTI) and tractography have been applied to the study of epilepsy and have demonstrated white matter abnormalities in patients with epilepsy. In this study, we performed DTI in patients with cryptogenic West syndrome and examined the correlation between DTI findings and the developmental prognosis.Methods: We studied eight patients referred to our hospital who developed cryptogenic West syndrome between June 2006 and September 2008 and eight age-matched controls who underwent 3-Tesla magnetic resonance imaging (3T-MRI) for screening of central nervous system (CNS) illness and were ultimately diagnosed as neurologically normal. The patients underwent 3T-MRI before receiving adrenocorticotropic hormone (ACTH) therapy and at the age of 1 year. We visualized the corticospinal tract (CST) and inferior longitudinal fasciculus (ILF) bilaterally and commissural fibers passing through the corpus callosum (CF) using tractography. We set regions of interest (ROIs) on these fibers and calculated the fractional anisotropy (FA) for each ROI. We classified the patients into two groups: Group MR+ included two patients whose developmental quotients (DQs) were under 70 at the age of 1 year, and Group MR included six patients whose DQs were 70 or higher. We compared the FA values of each fiber among these two groups and control patients. Diffusion tensor imaging was carried out with a 3.0 T magnetic resonance scanner (Trio, Siemens, Germany). A motion-probing gradient (MPG) was applied in 12 orientations after the acquisition of b = 0 images. The echo time corresponding to the respective b-factor was 84 ms for 1,000 s/mm2. The DQ was evaluated using the Tsumori-Inage Developmental Quotient Test at 1 year of age.Results: The FA values in all fibers before ACTH therapy were similar among the three groups. At the age of 1 year, for all of the fibers except the left CST, the FA values were lower in Group MR+ than those of Group MR and controls. The FA values were similar in Group MR and controls at the age of 1 year.Conclusions: The FA values of white matter tracts were similar at the onset of cryptogenic West syndrome, independent of the developmental prognosis. At the age of 1 year, however, all of the FA values were lower in the patients with poor developmental prognoses, except for the left CST. The FA values at the age of 1 year may correlate with developmental status. These findings may reflect delayed myelination or white matter microstructural abnormalities in cryptogenic West syndrome.