Brain Diffusion-Weighted and Diffusion Tensor Imaging Findings in an Infant with Biotinidase Deficiency

A previously healthy 7-week-old male infant was admitted because of clonic movements of the upper limbs. Findings of a neurologic exami-nationwere normal. His psychomotor developmentwas appropriate for his age.BrainMRimaging showedsupra- and infratentorialwhitematter signal-intensity abnormality, suggestive of edema, with frontal predom-inance and peripheral U-fiber involvement. Myelination was slightly di-minished in the posterior limbs of the internal capsules, also compatible with edema. The corpus callosum was spared. Deep gray matter struc-tures had a normal appearance. Nomalformationswere detected. Diffu-sion-weighted imaging (DWI, b 1000 s/mm2) and diffusion tensor imaging revealed symmetric moderately reduced diffusion with abnor-mally increased fractional anisotropy in the centra semiovalia and peri-rolandic white matter (Fig 1). MR spectroscopy (regions of interest po-sitioned at the left centrum semiovale and basal nuclei; TE 30 and 135 ms; not shown) showed a lactate doublet at 1.33 ppm