[An infant autopsy case of severe multicystic leukoencephalopathy]

A boy aged 4 years and 2 months died of an unknown neurological disease, which had insidiously occurred around the age of one year. The case slowly developed sleeping tendency, spastic tetraplegia, optic nerve atrophy and flexion contracture but no epileptic seizures. There was neither consanguinity nor familial history of neurological disorders. The proband had intrauterine exposure to X-ray at the seventh fetal month. Laboratory examinations including antiviral antibodies and lysosomal enzymes provided no evidence for known brain disorders. Neuropathological examination revealed widespread multicystic destruction predominantly in the centrum semiovale. The subcortical arcuate fibers were spared. The commissural fibers as well as long tract fibers were also symmetrically affected. There was neither inflammatory reaction, calcification, Rosenthal fibers nor globoid cells. Axons were comparatively preserved. Tissue debris was not metachromatic in acid cresyl violet stain. Chemical analysis demonstrated no changes in fatty acid profiles. These clinicopathological features partly mimic leukoencephalopathy with vanishing white matter (van der Knaap), except for the lack of familial history and cerebellar signs, and the more extensive neuropathological lesions. Although the influence of intrauterine X-ray irradiation could not be neglected completely, reports of several similar cases in the literature suggests that this case had a new variant of child-onset multicystic leukoencephalopathy or leukodystrophy.