[Later onset metachromatic leukodystrophy diagnosed by nerve biopsy].

Three cases of later onset metachromatic leukodystrophy in one family were reported. The brother is 32 years old, younger sister is 35 years old and the elder sister is 39 years old, who were normal as child without any family history of neurological disease. The three cases began their illness at about the age of 30 years old with dysarthria, progressive dementia, motor disturbance and numbness in the extremities. CT scan showed low density in the white matter of frontal, parietal lobes and around the ventricle. The written reports of CT scan were lacunar infarction in brother, multiple lacunar infarction in younger sister and Binswanger's disease in elder sister. Nerve biopsy showed myelinated fibers were decreased in number. Metachromatical materials were seen in and around the Schwann cell cytoplasm. Metachromatical materials were lamillar inclusions in granular matrix by electromicroscopic examination. So nerve biopsy is easy, safe and effective method to diagnose the uncertain pathogenic leukoence-phalopathy.