Abstracts

Rationale: GLUT1 deficiency syndrome (GLUT1-DS) leads to early-onset epilepsy associated with mental impairment and complex motor disorders. Although neuroimaging is considered uninformative in GLUT1-DS, delayed myelination has been reported in patients with GLUT1-DS. We performed diffusion tensor imaging (DTI) to assess white matter abnormalities in patients with GLUT1-DS. Images were analyzed with tract-based spatial statistics (TBSS).Methods: We studied 3 patients with GLUT1-DS. Age at the scan was from 6 to 14 years (mean 10.6 years). Conventional cranial MRI did not show abnormalities. DTI was acquired using 3T MRI (3.0T Trio, Siemens) and fractional anisotropy (FA) images were constructed. The FA images of patients were compared with those of 21 controls whose age at the scan was from 5 to 16 years (mean 10.6 years). Statistical analysis of FA images was carried out using TBSS implemented in FSL (The Oxford FMRIB Software Library). TBSS projects all subjects FA data onto a mean FA tract skeleton, before applying voxelwise cross-subject statistics. Individual FA data were then projected onto the skeleton, and then correction for multiple comparisons was performed. Regions with significant differences were identified with threshold: p<0.05.Results: The patients with GLUT1-DS, as compared to controls, widespread areas of significantly decreased FA in the cerebral white matters, brain stem, and cerebellar white matters. On the other hand, no areas of increased FA were observed in patients.Conclusions: Decreased FA on TBSS may reflect delayed myelination or white matter damages caused by reduced glucose entry into the brain. TBSS is useful to detect latent white matter abnormalities in GLUT1-DS.