The only positive finding of diagnostic value in vCJD from these tests is the pulvinar sign on MRI, which is not entirely specific for vCJD and can be absent in up to 9% of cases, even after multiple MRIs (14).
The pulvinar sign, which is relatively sensitive and specific for vCJD (14), did not exclude other disorders that rarely have similar features, including Wernicke's encephalopathy and inflammatory limbic encephalitis (27-29).
The pulvinar sign was present on the T2-weighted images in 5 of the 10 cases.
The pulvinar sign has diagnostic value for vCJD, but studies have also reported it in sCJD cases where it was accompanied by signal changes in other regions of the brain (13,14).
One patient had florid plaques and a pulvinar sign
on magnetic resonance imaging, mimicking vCJD (5).
Patients with vCJD can be distinguished from patients with the more common sporadic CJD by their younger median age at death (28 years and 68 years, respectively), predominantly psychiatric manifestations at illness onset, delayed appearance of frank neurologic signs, absence of a diagnostic electroencephalographic pattern, presence of the pulvinar sign
on MRI, and a longer median illness duration (<6 and 14 months, respectively) (3,8).