Several molecular subtypes of sporadic Creutzfeldt–Jakob disease have been identified and electroencephalogram and cerebrospinal fluid biomarkers have been reported to support clinical diagnosis but with variable utility according to subtype. In recent years, a series of publications have demonstrated a potentially important role for magnetic resonance imaging in the pre-mortem diagnosis of sporadic Creutzfeldt–Jakob disease. Magnetic resonance imaging signal alterations correlate with distinct sporadic Creutzfeldt–Jakob disease molecular subtypes and thus might contribute to the earlier identification of the whole spectrum of sporadic Creutzfeldt–Jakob disease cases. This multi-centre international study aimed to provide a rationale for the amendment of the clinical diagnostic criteria for sporadic Creutzfeldt–Jakob disease. Patients with sporadic Creutzfeldt–Jakob disease and fluid attenuated inversion recovery or diffusion-weight imaging were recruited from 12 countries. Patients referred as ‘suspected sporadic Creutzfeldt–Jakob disease’ but with an alternative diagnosis after thorough follow up, were analysed as controls. All magnetic resonance imaging scans were assessed for signal changes according to a standard protocol encompassing seven cortical regions, basal ganglia, thalamus and cerebellum. Magnetic resonance imaging scans were evaluated in 436 sporadic Creutzfeldt–Jakob disease patients and 141 controls. The pattern of high signal intensity with the best sensitivity and specificity in the differential diagnosis of sporadic Creutzfeldt–Jakob disease was identified. The optimum diagnostic accuracy in the differential diagnosis of rapid progressive dementia was obtained when either at least two cortical regions (temporal, parietal or occipital) or both caudate nucleus and putamen displayed a high signal in fluid attenuated inversion recovery or diffusion-weight imaging magnetic resonance imaging. Based on our analyses, magnetic resonance imaging was positive in 83% of cases. In all definite cases, the amended criteria would cover the vast majority of suspected cases, being positive in 98%. Cerebral cortical signal increase and high signal in caudate nucleus and putamen on fluid attenuated inversion recovery or diffusion-weight imaging magnetic resonance imaging are useful in the diagnosis of sporadic Creutzfeldt–Jakob disease. We propose an amendment to the clinical diagnostic criteria for sporadic Creutzfeldt–Jakob disease to include findings from magnetic resonance imaging scans.

Creutzfeldt-Jakob disease (CJD) is a rare and fatal neurodegenerative disorder with a worldwide incidence of 1-1.5 per million. As in other countries, a CJD surveillance unit with a clinical and neuropathological approach was established in Goettingen (Germany) in 1993. Here we report the epidemiological data from a prospective 12-year surveillance. Since 1993, there has been an increasing incidence of CJD, from 0.7 in 1993 to 1.6 in 2005 with a quite stable level since 1998. During this period, the proportion of patients with MV and VV codon 129 genotype rose, possibly because of better identification of atypical subtypes. Six percent of all patients had a PRNP mutation, mainly D178N-129M (FFI), E200K and V210I. Iatrogenic CJD was a rare phenomenon. No patient infected by cadaveric growth hormone extracts was reported. Furthermore, no variant CJD patient has yet been identified in Germany. Differential diagnoses revealed a variety of neurodegenerative diseases, with Alzheimer's disease in the lead. One-third of the non-CJD patients included in this study suffered from a potentially treatable disorder such as metabolic or inflammatory diseases. The incidence and mortality rates in Germany are similar to those in other European countries. In contrast, however, acquired forms, such as iatrogenic and variant CJD are still rare in Germany or have not yet been identified.

Real-time quaking-induced conversion (RT-QuIC) allows the amplification of miniscule amounts of scrapie prion protein (PrPSc). Recent studies applied the RT-QuIC methodology to cerebrospinal fluid (CSF) for diagnosing human prion diseases. However, to date, there has not been a formal multi-centre assessment of the reproducibility, validity and stability of RT-QuIC in this context, an indispensable step for establishment as a diagnostic test in clinical practice. In the present study, we analysed CSF from 110 prion disease patients and 400 control patients using the RT-QuIC method under various conditions. In addition, “blinded” ring trials between different participating sites were performed to estimate reproducibility. Using the previously established cut-off of 10,000 relative fluorescence units (rfu), we obtained a sensitivity of 85 % and a specificity of 99 %. The multi-centre inter-laboratory reproducibility of RT-QuIC revealed a Fleiss’ kappa value of 0.83 (95 % CI: 0.40–1.00) indicating an almost perfect agreement. Moreover, we investigated the impact of short-term CSF storage at different temperatures, long-term storage, repeated freezing and thawing cycles and the contamination of CSF with blood on the RT-QuIC seeding response. Our data indicated that the PrPSc seed in CSF is stable to any type of storage condition but sensitive to contaminations with blood (>1250 erythrocytes/μL), which results in a false negative RT-QuIC response. Fresh blood-contaminated samples (3 days) can be rescued by removal of erythrocytes. The present study underlines the reproducibility and high stability of RT-QuIC across various CSF storage conditions with a remarkable sensitivity and specificity, suggesting RT-QuIC as an innovative and robust diagnostic method.Electronic supplementary materialThe online version of this article (doi:10.1007/s12035-015-9133-2) contains supplementary material, which is available to authorized users.

Atypical clinical course and low sensitivity of established diagnostic tests are the main diagnostic problems in the MV2 subtype of sporadic Creutzfeldt-Jakob disease (sCJD). Clinical symptoms and signs, MRI, EEG and biochemical CSF markers were studied in 26 patients. Histological findings were semiquantitatively evaluated. Compared with typical sCJD, the disease duration was prolonged (median 12 months). Dementia, ataxia and psychiatric symptoms were present in all patients. Extrapyramidal signs were observed in 88%. T2-weighted MRI showed basal ganglia hyperintensities in 90%. Increased thalamic signal intensity was detected in 88% on diffusion-weighted MRI. Increased CSF tau-protein was found in 83%, and the 14-3-3 test was positive in 76%. The EEG revealed periodic sharp wave complexes in only two patients. Kuru plaques, severe thalamic and basal ganglia gliosis and spongiform changes, and neuronal loss in the pulvinar were the prominent histological features. At least one of the three diagnostic tests (MRI, tau- and 14-3-3 protein) supported the clinical diagnosis in all patients. MRI was the most sensitive of the diagnostic tests applied. Thalamic hyperintensities were observed unusually frequently. Prolonged disease duration, early and prominent psychiatric symptoms, absence of typical EEG, thalamic hyperintensities on MRI and relatively low 14-3-3 protein sensitivity may be suspicious for variant CJD. However, distinct sensory symptoms and young age at onset, which are often found in the latter, are not common in the MV2 subtype, and the pulvinar sign was observed in only one case.

The development of in vitro amplification systems allows detecting femtomolar amounts of prion protein scrapie (PrPSc) in human cerebrospinal fluid (CSF). We performed a CSF study to determine the effects of prion disease type, codon 129 genotype, PrPSc type, and other disease-related factors on the real-time quaking-induced conversion (RT-QuIC) response. We analyzed times to 10,000 relative fluorescence units, areas under the curve and the signal maximum of RT-QuIC response as seeding parameters of interest. Interestingly, type of prion disease (sporadic vs. genetic) and the PRNP mutation (E200K vs. V210I and FFI), codon 129 genotype, and PrPSc type affected RT-QuIC response. In genetic forms, type of mutation showed the strongest effect on the observed outcome variables. In sporadic CJD, MM1 patients displayed a higher RT-QuIC signal maximum compared to MV1 and VV1. Age and gender were not associated with RT-QuIC signal, but patients with a short disease course showed a higher seeding efficiency of the RT-QuIC response. This study demonstrated that PrPSc characteristics in the CSF of human prion disease patients are associated with disease subtypes and rate of decline as defined by disease duration.Electronic supplementary materialThe online version of this article (doi:10.1007/s12035-014-8709-6) contains supplementary material, which is available to authorized users.