Dementia characterized by neuronal loss and status spongiosus (DNLS) is a non-Alzheimer degenerative process which is characterized by Pick-like lobar atrophy with neuronal depletion and gliosis of the cerebral cortex, corpus striatum, medial thalamus, and substantia nigra and the absence of neuronal inclusions. To further investigate the cause and pathogenesis of DNLS, we probed cerebral homogenates from three cases of DNLS for protease-resistant prion protein to determine if DNLS could be a variant of a human prion disease. Limited proteolysis of prion proteins and guanidine thiocyanate treatment of cortical homogenates was used to enrich potential abnormal prion protein immunoreactivity. Although protease-resistant prion protein was detected in a case of sporadic Creutzfeldt-Jakob disease no abnormal prion protein was found in the cases of DNLS. We conclude that DNLS is not a human prion disease and remains an important dementia of uncertain etiology.