Sporadic Creutzfeldt-Jakob disease: phenotypic variability

Prion disease are characterized by cerebral deposition of an abnormal protease-resistant isoform of a membrane-bound glycoprotein called prion protein. Sporadic Creutzfeldt-Jakob disease (CJDs) is the most frequent, accounting for approximately 85% of all human prion disease. The identification of a new variant of Creutzfeldt-Jakob disease has reinforced the need for a detailed analysis of phenotypic variability of CJDs. CJDs is typically characterized by rapidly progressive dementia, myoclonus, periodic sharp-wave electroencephalographic activity, and wide-spread spongiform degeneration. However, variations in clinical presentation, disease duration, as well as type and distribution of lesion have been consistently observed. The physicochemical properties of PrPsc in conjunction with the PRNP codon 129 genotype largely determine this phenotypic variability. Continued attention to clinically atypical cases is required to monitor the real incidence of CJDs. To reach this goal neuropathological examination, including the search for PrPsc, and molecular genetic analysis of human prion protein gene (PRNP) should be increasingly applied to atypical neurodegenerative diseases.     

Diffusion-weighted MRI in sporadic Creutzfeldt-Jakob disease

Conventional MRI with T1, T2 and FLAIR sequences has an important role for the diagnosis of Creutzfeldt-Jakob disease, but the usual examination does not exclude the disease. The objective of this study is to report on the role of diffusion-weighted imaging (DWI) in the diagnostic strategy. From 2002 to 2006, four patients with a suspected diagnosis of sporadic Creutzfeldt-Jakob disease, which was retrospectively confirmed, underwent DWI. In all patients, MRI demonstrated high-signal intensities on FLAIR sequences and on spin-echo T2-weighted MRI, with restricted diffusion of caudate and lenticular nuclei. In one patient, DWI revealed cortical high-signal intensities that were not visualized on either FLAIR or T2-weighted MRI. In two other patients, MRI showed restricted thalamic diffusion, which is a classic sign of the new variant of the disease. Thus, thalamic involvement can be found in the sporadic form of the disease. It can be revealed on DWI and by apparent diffusion coefficient (ADC) mapping or detected only by ADC measurement.     

散发型克-雅病的临床特点分析

目的探讨散发型克-雅病(sporadic Creutzfeldt-Jakob disease,s CJD)的临床特点,以期更好地指导临床医师早期发现该病。方法纳入s CJD患者17例,分析其临床特点、早期症状、辅助检查结果以及生存期等。结果男女比例为1:1.83,平均发病年龄为(60±8.8)岁,首发症状以行走不稳(82.4%)、记忆力减退(64.7%)为主,其中,肌阵挛、磁共振"绸带征"、基底节异常信号、脑电图三相波、脑脊液14-3-3蛋白的阳性率分别为82.4%、76.5%、58.8%、82.4%、70%。随访过程中,12例患者已死亡,平均生存期为(12±7.7)个月。结论本研究中,s CJD患者多数中老年发病,首发症状无特异性,磁共振"绸带征"及脑电图三相波阳性出现的几率较高。     

Classification of sporadic Creutzfeldt-Jakob disease based on molecular and phenotypic analysis of 300 subjects.

Phenotypic heterogeneity in sporadic Creutzfeldt-Jakob disease (sCJD) is well documented, but there is not yet a systematic classification of the disease variants. In a previous study, we showed that the polymorphic codon 129 of the prion protein gene (PRNP), and two types of protease-resistant prion protein (PrP(Sc)) with distinct physicochemical properties, are major determinants of these variants. To define the full spectrum of variants, we have examined a series of 300 sCJD patients. Clinical features, PRNP genotype, and PrP(Sc) properties were determined in all subjects. In 187, we also studied neuropathological features and immunohistochemical pattern of PrP(Sc) deposition. Seventy percent of subjects showed the classic CJD phenotype, PrP(Sc) type 1, and at least one methionine allele at codon 129; 25% of cases displayed the ataxic and kuru-plaque variants, associated to PrP(Sc) type 2, and valine homozygosity or heterozygosity at codon 129, respectively. Two additional variants, which included a thalamic form of CJD and a phenotype characterized by prominent dementia and cortical pathology, were linked to PrP(Sc) type 2 and methionine homozygosity. Finally, a rare phenotype characterized by progressive dementia was linked to PrP(Sc) type 1 and valine homozygosity. The present data demonstrate the existence of six phenotypic variants of sCJD. The physicochemical properties of PrP(Sc) in conjunction with the PRNP codon 129 genotype largely determine this phenotypic variability, and allow a molecular classification of the disease variants.     

NMDA receptor autoantibodies in sporadic Creutzfeldt-Jakob disease

Journal of Neurology -     

散发性克-雅病PrP基因129密码子基因型与临床表型14例研究

目的：探讨散发性克－雅病（Creutzfeldt-Jakob disease,CJD)PrP基因129位点密码子基因型与临床表型的关系。方法：对14例散发性CJD患者进行PrP基因129例密码子的检测，并与临床表现进行了分析。结果：（1）根据诊断标准，14例散发性CJD中8例诊断为肯定CJD，6例诊断为很可能CJD。（2）8例诊断肯定CJD组中，PrP基因129例位点密码子为甲硫氨酸纯合型6例，甲充氨酸／缬氨酸2例，6例诊断很可能CJD组的PrP基因129密码子均为甲硫氨酸纯合型。（3）12例PrP基因129位点为甲硫氨酸纯合型的患者以认知障碍起病8例，共济失调1例；视觉障碍2例；肌阵挛1例，病程最长20个月，最短2．5个月，病程中有癫痫5例，肌阵挛6周，视觉障碍6例。7例有典型周期性同步放电（PSD）脑电改变。（4）2例甲硫氨酸／缬氨型患者均以共济失调起病。2个月后才出现痴呆，病理程分析为16个月和20个月，均无典型的PSD。（2）本组散发性CJDPrP基因129位点密码子甲硫氨酸／甲硫氨酸，甲硫氨酸／缬氨酸，分布比例与日本相同，但与西方不同，而且没有缬氨酸纯合型。     

散发性Creutzfeldt-Jakob病头部磁共振表现

目的 探讨散发性Creutzfeldt-Jakob病(sCJD)头部磁共振的表现及其与临床的关系。方法 对10例sCJD于病后第2—12个月进行头部磁共振扫描，其中脑活检证实6例，14-3-3蛋白检测8例，脑电特异性改变8例及朊蛋白基因分析8例。结果5例双侧尾状核、壳核于T2，加权像或Flair像呈对称性高信号，苍白球与丘脑正常，T1加权像无改变；2例脑萎缩，1例少许脑腔隙梗死，另有2例正常。结论 (1)4例甲硫氨酸纯合型(129Met／Met)底节T2异常信号发现时间平均2．5个月，存活时间平均10．5个月；1例甲硫氨酸杂合型(129Met／Val)底节异常信号发现时间为12个月，存活时间为16个月；(2)底节T2异常信号者平均病程为12．2个月，长于底节无异常信号者(平均5．5个月)；(3)双侧尾核、壳核T2加权像对称性高信号是sCJD重要影像学改变，在特定的临床背景下为sCJD临床诊断依据之一。     

A novel phenotype of sporadic Creutzfeldt-Jakob disease

An atypical case of sporadic Creutzfeldt-Jakob disease (CJD) is described in a 78-year-old woman homozygous for methionine at codon 129 of the prion protein (PrP) gene. The neuropathological signature was the presence of PrP immunoreactive plaque-like deposits in the cerebral cortex, striatum and thalamus. Western blot analysis showed a profile of the pathological form of PrP (PrP(Sc)) previously unrecognised in sporadic CJD, marked by the absence of diglycosylated protease resistant species. These features define a novel neuropathological and molecular CJD phenotype.     

Supranuclear vertical gaze abnormalities in sporadic Creutzfeldt-Jakob disease

Supranuclear gaze palsies are an uncommon feature of Creutzfeldt-Jakob disease (CJD). Most reported cases of CJD with features of supranuclear gaze palsy are familial. We report 2 patients with supranuclear vertical gaze abnormalities associated with spongiform changes in the midbrain. Both patients were found to have sporadic CJD after genetic testing. Distinguishing familial from sporadic CJD in this setting has important genetic and epidemiological implications.     

Cerebral gene expression profiles in sporadic Creutzfeldt-Jakob disease

The pathomechanism of sporadic Creutzfeldt-Jakob disease (sCJD) in the central nervous system is insufficiently understood. The aims of this study were to identify differentially regulated genes in the frontal cortex of sCJD and to profile the gene expression patterns in sCJD by using Affymetrix HGU133A microarrays (Affymetrix, Santa Clara, CA). The microarray data were generated by dChip and analyzed by Significance Analysis of Microarray (SAM) software. A comparison between control and sCJD samples identified 79 upregulated and 275 downregulated genes, which showed at least 1.5- and 2-fold changes, respectively, in sCJD frontal cortex, with an estimated false discovery rate of 5% or less. The major alterations in sCJD brains included upregulation of the genes encoding immune and stress-response factors and elements involved in cell death and cell cycle, as well as prominent downregulation of genes encoding synaptic proteins. A comparison of the molecular subtypes of sCJD showed various expression patterns associated with particular subtypes. The range of the upregulated genes and the degree of the increased expression appeared to be correlated with the degree of the neuropathological alterations in particular subtypes. Conspicuously, sCJD brains showed a great similarity with ageing human brains, both in the global expression patterns and in the identified differentially expressed genes.     

Prion deposition in olfactory biopsy of sporadic Creutzfeldt-Jakob disease

Currently, definite peripheral markers for the in vivo diagnosis of sporadic Creutzfeldt-Jakob disease (CJD) are not available. Here, we report the presence of pathological prion protein in the olfactory mucosa of a case with sporadic Creutzfeldt-Jakob disease. Prion protein immunoreactivity was detected in an olfactory biopsy performed 45 days after the disease onset, suggesting that the involvement of olfactory epithelium is an early event in sporadic Creutzfeldt-Jakob disease.