Spongy degeneration of the nervous system associated with propionic acidemia.

The pathologic changes in the brain of a five and a half month old male child who died of propionic acidemia are presented. Although previous pathologic reports of this disorder describe either no involvement of the central nervous system or focal myelin sheath vacuolization, the present case exhibited different pathology, namely, spongy degeneration of the white matter of Van Bogaert and Bertrand's type. Thus this case illustrates that the pathologic changes in the brain in propionic acidemia are variable. In addition, the cerebellum in this patient showed marked diffuse atrophy and early loss of the external granular layer, two changes that have not been emphasized by previous authors.