Clinical range and MRI in Creutzfeldt-Jakob disease with heterozygosity atcodon 129 and prion protein type 2

A 68 year old woman with sporadic Creutzfeldt-Jakob disease is described, w ho neither showed characteristic EEG abnormalities nor a positive test of t he neuronal protein 14-3-3 or neuron specific enolase (NSE) in CSF, despite a clinical presentation with ataxia of cerebellar type, rapidly progressiv e dementia, myoclonus, and marked hyperintense signal abnormalities in the deep cortical layers and the basal ganglia on T2 and diffusion weighted MRI . Moreover she showed atypical clinical features with a syndrome of inappro priate antidiuretic hormone (ADH) secretion (SIADH) and a peripheral sensor imotor polyneuropathy. Whether these disturbances are independent of Creutz feldt-Jakob disease or a feature of it is discussed. It has recently been s hown that in Creutzfeldt-Jakob disease different clinical and pathological phenotypes correlate with the polymorphism at codon 129 of the prion protei n gene (PRNP) and the type of the protease resistant fragment that accumula tes in the brain. According to the new classification at least six sporadic variants of Creutzfeldt-Jakob disease exist. The molecular genetic analysi s showed heterozygosity of PRNP at codon 129 for methionine and valine and the presence of PrPCJD type 2 in the brain of this patient. As a new featur e of changes on MRI, striking cortical changes of hyperintense signals are described in diffusion weighted as well as T2 weighted MRT that directly co rrelate with the histomorphological spongy degeneration of the brain in thi s region. In cases of rapidly progressive dementia, Creutzfeldt-Jakob disea se always needs to be considered even if unusual features are present and c urrent diagnostic criteria are not in favour of this disease.