Reliability of EEG in the diagnosis of Creutzfeldt-Jakob disease.

Although EEG is generally considered a useful tool for the diagnosis of Creutzfeldt-Jakob disease (CJD), some cases have been reported where the EEG was non-specific. We reviewed a series of 15 CJD patients, observed in our institute in the period 1975-91. In 12 cases the diagnosis was confirmed on post-mortem examination. The prominent aspect of the present series was the homogeneity of clinical, neurophysiological and neuropathological data. All patients showed the presence of periodic sharp wave complexes (PSWC) and EEG reactivity to external stimuli or drugs was uniform. The EEG can give essential information for the diagnosis of CJD if 2 basic conditions are satisfied: (1) serial recordings are performed in relation to the different stages of the disease, and (2) not only the presence of PSWC is considered, but also the reactivity of EEG to dynamic events such as the response to external stimuli and drugs, and the level of consciousness.