DTI in Leukoencephalopathy with Brainstem and Spinal Cord Involvement and Elevated Lactate (LBSL): Local Strongly Increased FA and Reduced Diffusivity as Well as Globally Reduced FA and Increased Diffusivity.

Marjan Steenweg¹, Marjo van der Knaap, Frederik Barkhof², Petra Pouwels³

LBSL is an inherited white matter (WM) disorder without known pathological basis. To gain insight into tissue microstructure, this study used high-resolution DTI (1.45x1.45x2mm) at 1.5T. Performing TBSS, a general increase in MD and decrease in FA was seen in the central cerebral WM, not always coinciding with signal abnormalities on conventional images. Strikingly, ROI-analysis showed small areas with an extremely low MD, together with low axial and radial diffusivity, and very high FA. Restricted diffusion has been described in leukoencephalopathies caused by myelin vacuolation, raising the question whether this also plays a role in LBSL.