A case of leukoencephalopathy with vanishing white matter

A 6-year old Turkish boy with a recently defined entity: "leukoencephalopat hy with vanishing white matter" is described. He was born to consanguinous parents. His psychomotor development was normal till he first presented wit h fever and generalized tonic-clonic seizures at the age of 2.5, followed b y rapid motor and mental deterioration. Decerebrate posture and marked spas ticity subsequently developed. The initial MRI examination showed diffuse i nvolvement of white matter, including subcortical U-fibers, with signal int ensity parallel to CSF on all sequences. The white matter appeared swollen. The ventricles were slightly enlarged and there was cavum septi pellucidi et vergae. The posterior crus of the internal capsule, external and extreme capsules were affected. Cerebellar hemispheres and vermis showed atrophy. The involvement pattern of brainstem was noteworthy in that pontine tegment um and cruri cerebri were affected. Follow-up MRI obtained after three year s did not show any interval change. Brain biopsy showed thinned cortex with relatively preserved cortical layering and neuronal structure. There was r arefaction of the white matter with cystic degeneration. Fibrillary gliosis and increased number of oligodendroglial cells were observed within the ce rebral white matter.