Axo-dendritic abnormalities in a case of juvenile neuronal storage disease.

Axonal enlargements (meganeurites) and dendritic degeneration were found in the pyramidal neurons from the frontal cortex of a patient with juvenile neuronal storage disease studied with the aid of ultrastructural and Golgi methods. Meganeurites appeared as enlargements at the axon hillock-initial segment area and were similar to those described in other neuronal diseases; dendritic degeneration was heavy and appeared throughout the cell domain. These neuropile changes can be related to the precocious mental abnormalities observed in this group of diseases which depend on a storage phenomenon due to a lysosomal enzyme deficiency.