Value of brain biopsy in neurodegenerative disease in childhood.

During the period 1968-1974, 45 children with suspected neurodegenerative syndromes underwent brain biopsy of the right frontal lobe. The histological examination was normal in 44% and nonspecifically abnormal in 43% of the specimens. In 13% a specific histological abnormality was found, namely 3 with spongy degeneration, 1 Alexander's leucodystrophy, 1 metachromatic leucodystrophy, and 1 pachygyria. Chemical analysis by thin-layer chromatography had little to offer in this series, being specifically abnormal only in the case of metachromatic leucodystrophy and nonspecifically abnormal in 6 cases. Postoperative generalized convulsions occurred in 3 children and a mild hemiparesis contralateral to the site of biopsy was noted in one patient. Comparing the outcome of the group having histologically normal biopsies with the group having nonspecifically abnormal ones it is concluded that frontal biopsy is not of such high prognostic value as has been claimed in previous reports. Some flexibility in the choice of the biopsy site is suggested. The specimens should be examined by chemical analysis as well as electron microscope in addition to the routine histological and histochemical methods. The neurodegenerative disorders of childhood which are at present identifiable in life only by brain biopsy are listed.