A new leukoencephalopathy with vanishing white matter.

We identified nine children with a leukoencephalopathy of similar type according to clinical and MRI findings. The patients included three affected sibling pairs. The age range was 3 to 19 years. The onset of the disease was in childhood; the course was both chronic-progressive and episodic. There were episodes of deterioration following infections and minor head traumas, and these could results in unexplained coma. In eight patients with advanced disease, MRI revealed a diffuse cerebral hemispheric leukoencephalopathy, in which increasing areas of the abnormal white matter had a signal intensity close to that of CSF on all pulse sequences. In one patient in the early stages of disease, initial MRI showed diffusely abnormal cerebral white matter, which only reached the signal characteristics of CSF at a later stage. In the patients in whom the disease was advanced, magnetic resonance spectroscopy (MRS) of the white matter showed an almost complete disappearance of all normal signals and the presence of glucose and lactate, compatible with the presence of mainly CSF and little brain tissue. Spectra of the cortex were much better preserved. However, in addition to the normal resonances, there were signals representing lactate and glucose. MRS of the white matter in the patient whose disease was at an early stage was much less abnormal. Autopsy in one patient confirmed the presence of extensive cystic degeneration of the cerebral white matter with reactive change and a preserved cortex. Typical involvement of pontine tegmental white matter was suggested by MRI and confirmed by autopsy. The disease probably has an autosomal recessive mode of inheritance, but the basic metabolic defect is not known.