Neuronal depletion of cerebellum in late infantile metachromatic leukodystrophy.

The cerebellums of two children with late infantile metachromatic leukodystrophy were investigated by light and electron microscopy. These observations showed that the morphological abnormalities were comprised not only of severe demyelination and presence of metachromatic granules but also marked loss of Purkinje cells and granule cells. The depletion of Purkinje cells is considered to have resulted from demyelination of their myelinated axons. On the other hand, the reduction of granule cells is considered to be caused by the loss of Purkinje cells and presynaptic elements such as mossy fibers and glomerular collaterals of climbing fibers. The depletion of these neurons induced destruction of synaptic connection in the cerebellum.