Adult onset thalamocerebellar degeneration in dogs associated to neuronal storage of ceroid lipopigment.

Late onset of hereditary cerebellar cortical abiotrophy has been described in a large variety of canine breeds. In some reported conditions, the cerebellar lesion is combined with degeneration of other systems. Here we describe a new hereditary cerebellar cortical degeneration in eight adult American Staffordshire and Pit Bull Terriers. The neuronal degeneration in these animals not only affects Purkinje cells of the cerebellum but also certain thalamic nuclei. In addition, nerve cell loss appears to be associated with a lysosomal storage disease, which is restricted to the affected cell populations. The stored material was histologically and ultrastructurally identified as fluorescent lipopigment. Since animals were euthanized at various stages of the disease, it could be shown that lysosomal storage preceded neuronal loss. Selective involvement of restricted neuronal populations is highly unusual in ceroid lipofuscinoses. It remains to be determined if the present neurodegenerative disease is caused by a primary or secondary neuronal ceroid lipofuscinosis.