[Laboratory and imaging studies for the diagnosis of prion disease].

We evaluated the diagnostic sensitivity of periodic synchronous discharge (PSD) in EEG, brain specific proteins in CSF such as neuron specific enolase (NSE), 14-3-3 protein, and tau protein, and imaging studies performed by T2-weighted MRI (T2I) and diffusion-weighted MRI (DWI). 36 patients with a mean age of 68.6 years were enrolled. Their diagnostic levels were as follows: seven were definite, 28 were possible, and one was probable who had a disease-specific point mutation of V180I. The diagnostic sensitivities of PSD, NSE, 14-3-3 protein, tau protein, DWI, and T2I were 50% (N = 36), 70% (N = 30), 80.8% (N = 26), 87.5% (N = 16), 92.3% (N = 26), and 42.3% (N = 26), respectively. DWI could revealed the CJD-related lesions earlier than the appearance of PSD. DWI revealed the lesions even in the patients who did not show PSD. For the diagnosis of CJD, DWI and either 14-3-3 protein or tau protein are useful. Using western blot, we detected the protease-resistant PrP in the urine of 11 of 15 CJD patients. We also detected it in three of 25 disease control patients. Differing from previous reports, the detection of a protease-resistant PrP was not specific to CJD patients. However, the sensitivity was 73.3% and the specificity was 88.9%.