Diagnosis of new variant Creutzfeldt-Jakob disease

As of December 31, 1998, 35 deaths had been attributed to new variant Creut zfeldt-Jakob disease (nvCJD) in the United Kingdom, of which 33 cases had b een neuropathologically confirmed and 2 classified as probable nvCJD. Fifte en cases were male and 20 female. The median illness duration was 14 months (range, 8-38 months) and the median age at death was 23 years (range, 18-5 3 years). The clinical features were consistent with previous descriptions. In nearly all cases, there were early psychiatric symptoms after a median period of 6 months ataxia developed, followed by involuntary movements and cognitive impairment. Electroencephalograms did not show the "typical" appe arances found in sporadic CJD, about half the cases tested had a positive 1 4-3-3 immunoassay, and over 70% of cases had bilateral pulvinar high signal on magnetic resonance brain scanning. Prion protein gene analysis showed t hat all cases were homozygous for methionine at codon 129. Diagnostic crite ria for nvCJD have been formulated, which have a high sensitivity and speci ficity.