Rabies: spongiform lesions in the brain.

Striped skunks (Mephitis mephitis) experimentally infected with street rabies virus developed spongiform lesions that light- and electron-microscopically were indistinguishable from those found in the transmissible spongiform encephalopathies of man and animals. These previously unreported lesions were also detected in naturally occurring cases of rabies. The spongiform lesions consisted of round or oval vacuoles in the neuropil, rarely in neuronal perikarya. The most severely affected areas were the thalamus and cerebral cortex. The implications of this finding include similarities in the pathogenetic mechanisms of rabies and the traditional spongiform encephalopathies and the possibility of lesion variation due to differences in rabies viral strains. The spongiform lesions of rabies will require consideration in differential diagnosis.