To detect a possible correlation between the neurology and duration of Creutzfeldt-Jakob disease (CJD) and cerebral pathology, we studied 22 autopsy cases by histological and immunohistochemical methods. The duration of disease ranged between 1 and 15 months with an average of 5.2 months. Only in 11 cases was the EEG typical for CJD. Morphologically the changes varied from minimal spongy changes to severe neuronal loss and brain atrophy. For the three cortical regions examined semiquantitatively, there was no correlation between the severity of spongiform changes and the duration of disease or the pattern of neurological symptoms. The study shows that more extensive sampling for the detection of regional heterogeneity of changes is mandatory in spongiform encephalopathies, and that complicating changes such as intermittent infections may play a role for the survival time as well. Moreover, genetic determinants, prion protein polymorphisms and the mode of exposure have to be considered as possible modulating factors.