February 1996

Accuracy and Reliability of Periodic Sharp Wave Complexes in Creutzfeldt-Jakob Disease

Author Affiliations

From the Departments of Clinical Neurophysiology (Drs Steinhoff and Herrendorf), Neurology (Drs Räcker, Poser, and Weber, Mr Grosche, and Ms Zerr), and Neuropathology (Dr Kretzschmar), Georg-August University, Göttingen, Germany.

Arch Neurol. 1996;53(2):162-166. doi:10.1001/archneur.1996.00550020074017

Objective:  To assess the sensitivity, specificity, and interobserver reliability of periodic sharp wave complexes in the electroencephalograms of patients with Creutzfeldt-Jakob disease.

Design:  Sixty-eight electroencephalograms in 29 patients who had been suspected of having Creutzfeldt-Jakob disease were reanalyzed by an investigator who was unaware of the clinical data. The incidence of periodic sharp wave complexes in neuropathologically confirmed Creutzfeldt-Jakob disease vs progressive dementia other than Creutzfeldt-Jakob disease was assessed. Blinded electroencephalogram analysis was performed by a second investigator. The interobserver reliability was assessed by the k value.

Setting:  University hospital, base of the German National Creutzfeldt-Jakob Disease Surveillance Study.

Patients:  Fifteen patients with neuropathologically confirmed Creutzfeldt-Jakob disease and 14 patients who had been suspected of having Creutzfeldt-Jakob disease because of rapidly progressive dementia but in whom other dementias were diagnosed by unblinded investigators based on clinical and electroencephalographic criteria.

Main Outcome Measure:  Sensitivity and specifity of periodic sharp wave complexes assessed by their incidence in Creutzfeldt-Jakob disease vs other dementias. Interobserver reliability of periodic sharp wave complexes was expressed by the k value.

Results:  For periodic sharp wave complexes, blinded electroencephalographic analysis resulted in a sensitivity and a specificity of 67% and 86%, respectively. Interobserver reliability was excellent (k=0.95).

Conclusion:  This blinded electroencephalographic study in Creutzfeldt-Jakob disease confirms the high diagnostic value of electroencephalography, as previously reported by open studies.