PULVINAR or HOCKEY STICK SIGN IN CJD

Creutzfeldt-Jakob Disease (CJD) is a rare transmissible spongiform encephalopathy caused by proteinecious infectious particle called PrP(prion).Among subtypes CJD most common is sporadic CJD(s CJD) and less common is variant CJD(v CJD).MRI is indispensable in making diagnosis and ruling out other conditions. Bilateral symmetrical abnormal high signal intensity in the posterior thalamus is the pulvinar sign and in dorsomedial thalamic nuclei pulvinar is the hockey-stick sign. In the appropriate clinical context the MRI identification of pulvinarhockey stick sign is a useful noninvasive test for the diagnosis of vCJD (upto 90sensitivity) and can avoid tonsillar biopsy.The pulvinar sign was originally defined simply as hyperintensity of the pulvinar. In young patients, the normal basal ganglia are relatively hyperintense compared to old and rarely in sCJD patients can have pulvinar sign and this could be mistaken for vCJD. Hence the pulvinar sign is redefined as hyperintensity of the pulvinar relative to the signal intensity of the anterior putamen. Hyperintensity of all deep grey-matter nuclei, with the pulvinar less bright than the anterior putamen and caudate is a feature of sCJD. Here we describe a case of sCJD with pulvinarhockey stick sign mimicking vCJD. Our patient had pulvinar hyperintensity less bright than putamen, cortical ribboning and age of onset in fifth decade which were typically suggestive of sCJD. So far vCJD has not been reported in our country.