Leukoencephalopathy with patchy lesions, temporal cystic degeneration, and normal head size.

A 5 yr old girl is reported with patchy white matter lesions, cystic degeneration of the temporal tips, normal cortex, and normal cerebellum, documented by FLAIR, and diffusion-weighted MRI. This condition differed from the entity megalencephalic leukoencephalopathy with cysts by lack of diffuse involvement of the white matter and cortical thinning, by presence of a normal head size, and existence of a non-progressive, severe clinical condition. Occurrence of cystic degeneration in the temporal tips distinguished the condition from other leukoencephalopathies. This leukoencephalopathy appears to be a new distinct entity.