The pulvinar sign on magnetic resonance imaging in variant Creutzfetdt-Jakob disease

Background There is a need for an accurate non-invasive diagnostic test for variant Creutzfeldt-Jakob disease (vCJD), We investigated the sensitivity and specificity of bilateral pulvinar high signal on magnetic resonance ima ging (MRI) for the diagnosis of vCJD. Methods MRI from patients with vCJD and controls (patients with suspected C JD) were analysed. Scans were reviewed on two separate occasions by two neu roradiologists and scored for the distribution of changes, and likely final diagnosis. Scans from vCJD cases were reassessed to reach a consensus on a ll abnormalities. Findings We analysed 36 patients and 57 controls. vCJD patients were correc tly identified based on bilateral pulvinar high signal in 29 of 36 and 32 o f 36 cases on the first assessment by the two radiologists, and 32 of 36 an d 31 of 36 on their second assessment. Bilateral increased pulvinar signal was identified in one of 57 and one of 57 controls on the first assessment and two of 57 and three of 57 controls on the second assessment. These repo rted changes in controls were graded as minimal/equivocal in six of seven p atients and moderate in one (<0.5% of all control assessments). 80% of the assessments in vCJD cases were graded as moderate or substantial. On consen sus review, 28 of 36 cases and none of 57 controls had prominent bilateral pulvinar signal-sensitivity 78% (95% CI 60-90%) and specificity 100% (95% C I 94-100%), Other common MRI features of vCJD were medial thalamic and peri aqueductal grey matter high signal, and the notable absence of cerebral atr ophy. Pulvinar high signal correlated with histological gliosis. Interpretation In the appropriate clinical context the MRI identification o f bilaterally increased pulvinar signal is a useful non-invasive test for t he diagnosis of vCJD.