[An adult patient with Krabbe's disease--the first case reported in Japan].

A 31-year-old woman, a child of consanguineous parents, who had shown mental retardation and slowness in running ability since childhood, complained of progressive spastic gait for one and a half years prior to admission. On admission, neurological examination revealed severe spastic paraplegia, mental retardation, visual disturbance, cerebellar ataxia, disturbance of deep sensation, sphincter disturbance, pes cavus and pes equinovarus. Protein content in the cerebrospinal fluid was increased to 86.1 mg/dl. Markedly reduced activity of galactosylceramidase in the leukocytes and the cultured fibroblasts confirmed the diagnosis of Krabbe's disease. T2-weighted MR images disclosed high signal areas in the deep white matter of the bilateral parieto-occipital lobes. There were also abnormal high signal bands along the bilateral pyramidal tracts from the corona radiata to the cerebral peduncle and the posterior part of the corpus callosum. The nerve conduction studies showed markedly decreased motor and sensory conduction velocities with decreased amplitudes. Visual evoked potentials showed prolongation of the right P100 latency. Auditory brainstem responses showed prolonged interpeak latencies between I-V peaks. Somatosensory evoked potentials showed prolongation of the N20 latencies. The morphometric histopathological analysis of the sural nerve revealed a decrease in the density of myelinated fibers and the presence of myelinated fibers with thin myelin sheath relative to the size of transverse area of axon. There were linear inclusion bodies in the cytoplasm of Schwann cells on electron microscopic examination. This is the first report in Japan of a patient with Krabbe's disease who survived after adolescence.