1,721,162 research outputs found
Unusual Clinical Presentations Challenging the Early Clinical Diagnosis of Creutzfeldt-Jakob Disease
No full textThe introduction of prion RT-QuIC, an ultrasensitive specific assay for the in vivo detection of the abnormal prion protein, has significantly increased the potential for an early and accurate clinical diagnosis of Creutzfeldt-Jakob disease (CJD). However, in the clinical setting, the early identification of patients with possible CJD is often challenging. Indeed, CJD patients may present with isolated symptoms that remain the only clinical manifestation for some time, or with neurological syndromes atypical for CJD. To enhance awareness of unusual disease presentations and promote earlier diagnosis, we reviewed the entire spectrum of atypical early manifestations of CJD, mainly reported to date as case descriptions or small case series. They included sensory either visual or auditory disturbances, seizures, isolated psychiatric manifestations, atypical parkinsonian syndromes (corticobasal syndrome, progressive supranuclear palsy-like), pseudobulbar syndrome, isolated involuntary movements (dystonia, myoclonus, chorea, blepharospasm), acute or subacute onsets mimicking a stroke, isolated aphasia, and neuropathy. Since CJD is a rare disease and its clinical course rapidly progressive, an in-depth understanding and awareness of early clinical features are mandatory to enhance the overall diagnostic accuracy in its very early stages and to recruit optimal candidates for future therapeutic trials
Rapidly Progressive Alzheimer’s Disease: Contributions to Clinical-Pathological Definition and Diagnosis
No full textRapidly progressive Alzheimer's disease (rpAD) has recently been recognized as a clinical disease subtype characterized by rapidly progressive cognitive decline and/or short disease duration, and the possible occurrence of early focal neurological signs. Consistently, rpAD represents a relatively frequent alternative diagnosis among cases referred as possible or probable Creutzfeldt-Jakob disease (CJD) to surveillance centers for prion disease worldwide. Indeed, the early clinical differential diagnosis between the two disorders can be challenging given the partial overlap in clinical features and cerebrospinal fluid (CSF) levels of the protein surrogate markers 14-3-3 and total-tau. Although typical AD and rpAD seem to share the neuropathological core features, recent evidence suggests that a distinctive molecular signature involving the structure of amyloid-β aggregates and the proteomic landscape of amyloid plaques may distinguish rpAD from typical AD. Here we review clinical, neuropathological, and molecular features and diagnostic findings, including CSF biomarker data, reported to date in rpAD. Furthermore, we summarize the main clinical, pathological and laboratory features of 27 autopsy confirmed cases of rpAD referred to our center. The results of this retrospective analysis, while largely confirming previously published genetic, clinical, and neuropathological data, suggest a higher prevalence of moderate to severe cerebral amyloid angiopathy in rpAD compared to typical AD, a finding to explore further and validate in a larger patient group
Human prion disease: molecular pathogenesis, and possible therapeutic targets and strategies
Full text linkIntroduction: Human prion diseases are heterogeneous, and often rapidly progressive, transmissible neurodegenerative disorders associated with misfolded prion protein (PrP) aggregation and self-propagation. Despite their rarity, prion diseases comprise a broad spectrum of phenotypic variants determined at the molecular level by different conformers of misfolded PrP and host genotype variability. Moreover, they uniquely occur in idiopathic, genetically determined, and acquired forms with distinct etiologies.Area covered: This review provides an up-to-date overview of potential therapeutic targets in prion diseases and the main results obtained in cell and animal models and human trials. The open issues and challenges associated with developing effective therapies and informative clinical trials are also discussed.Expert opinion: Currently tested therapeutic strategies target the cellular PrP to prevent the formation of misfolded PrP or to favor its elimination. Among them, passive immunization and gene therapy with antisense oligonucleotides against prion protein mRNA are the most promising. However, the disease's rarity, heterogeneity, and rapid progression profoundly frustrate the successful undertaking of well-powered therapeutic trials and patient identification in the asymptomatic or early stage before the development of significant brain damage. Thus, the most promising therapeutic goal to date is preventing or delaying phenoconversion in carriers of pathogenic mutations by lowering prion protein expression
Diagnostic Accuracy of a Combined Analysis of Cerebrospinal Fluid t-PrP, t-tau, p-tau, and Aβ42 in the Differential Diagnosis of Creutzfeldt-Jakob Disease from Alzheimer's Disease with Emphasis on Atypical Disease Variants
No full textAccording to recent studies, the determination of cerebrospinal fluid (CSF) total tau (t-tau)/phosphorylated tau (p-tau) ratio and total prion protein (t-PrP) levels significantly improves the accuracy of the diagnosis of Alzheimer's disease (AD) in atypical cases with clinical or laboratory features mimicking Creutzfeldt-Jakob disease (CJD). However, this has neither been validated nor tested in series including atypical CJD variants. Furthermore, the added diagnostic value of amyloid-β (Aβ)42 remains unclear. To address these issues, we measured t-PrP, 14-3-3, t-tau, p-tau, and Aβ42 CSF levels in 45 typical and 44 atypical/rapidly progressive AD patients, 54 typical and 54 atypical CJD patients, and 33 controls. CJD patients showed significantly lower CSF t-PrP levels than controls and AD patients. Furthermore, atypical CJD was associated with lower t-PrP levels in comparison to typical CJD. T-tau, 14-3-3, or t-PrP alone yielded, respectively, 80.6, 63.0, and 73.0 sensitivity and 75.3, 92.1, and 75 specificity in distinguishing AD from CJD. On receiver operating characteristic (ROC) curve analyses of biomarker combinations, the (t-tau×Aβ42)/(p-tau×t-PrP) ratio achieved the best accuracy, with 98.1 sensitivity and 97.7 specificity overall, and 96.2 sensitivity and 95.5 specificity for the "atypical" disease groups. Our results show that the combined analysis of CSF t-PrP, t-tau, p-tau, and Aβ42 is clinically useful in the differential diagnosis between CJD and AD. Furthermore, the finding of reduced CSF t-PrP levels in CJD patients suggest that, likewise Aβ42 in AD, CSF t-PrP levels reflect the extent of PrPc conversion into abnormal PrP (PrPSc) and the burden of PrPSc deposition in CJD
Revisiting the Heidenhain Variant of Creutzfeldt-Jakob Disease: Evidence for Prion Type Variability Influencing Clinical Course and Laboratory Findings
Full text linkThe Heidenhain variant defines a peculiar clinical presentation of sporadic Creutzfeldt-Jakob disease (sCJD) characterized by isolated visual disturbances at disease onset and reflecting the early targeting of prions to the occipital cortex. Molecular and histopathological typing, thus far performed in 23 cases, has linked the Heidenhain variant to the MM1 sCJD type. To contribute a comprehensive characterization of cases with the Heidenhain variant, we reviewed a series of 370 definite sCJD cases. Eighteen patients (4.9%) fulfilled the selection criteria. Fourteen of them belonging to sCJD types MM1 or MM1+2C had a short duration of isolated visual symptoms and overall clinical disease, a high prevalence of periodic sharp-wave complexes in EEG, and a marked increase of cerebrospinal fluid proteins t-tau and 14-3-3 levels. In contrast, three cases of the MM 2C or MM 2+1C types showed a longer duration of isolated visual symptoms and overall clinical disease, non-specific EEG findings, and cerebrospinal fluid concentration below threshold for the diagnosis of "probable" CJD of both 14-3-3 and t-tau. However, a brain DWI-MRI disclosed an occipital cortical hyperintensity in the majority of examined cases of both groups. While confirming the strong linkage with the methionine genotype at the polymorphic codon 129 of the prion protein gene, our results definitely establish that the Heidenhain variant can also be associated with the MM 2C sCJD type in addition to the more common MM1 type. Likewise, our results highlight the significant differences in clinical evolution and laboratory findings between cases according to the dominant PrPSc type (type 1 versus type 2)
Genomic, transcriptomic and RNA editing analysis of human MM1 and VV2 sporadic Creutzfeldt-Jakob disease
Full text linkCreutzfeldt-Jakob disease (CJD) is characterized by a broad phenotypic spectrum regarding symptoms, progression, and molecular features. Current sporadic CJD (sCJD) classification recognizes six main clinical-pathological phenotypes. This work investigates the molecular basis of the phenotypic heterogeneity of prion diseases through a multi-omics analysis of the two most common sCJD subtypes: MM1 and VV2. We performed DNA target sequencing on 118 genes on a cohort of 48 CJD patients and full exome RNA sequencing on post-mortem frontal cortex tissue on a subset of this cohort. DNA target sequencing identified multiple potential genetic contributors to the disease onset and phenotype, both in terms of coding, damaging-predicted variants, and enriched groups of SNPs in the whole cohort and the two subtypes. The results highlight a different functional impairment, with VV2 associated with higher impairment of the pathways related to dopamine secretion, regulation of calcium release and GABA signaling, showing some similarities with Parkinson’s disease both on a genomic and a transcriptomic level. MM1 showed a gene expression profile with several traits shared with different neurodegenerative, without an apparent distinctive characteristic or similarities with a specific disease. In addition, integrating genomic and transcriptomic data led to the discovery of several sites of ADAR-mediated RNA editing events, confirming and expanding previous findings in animal models. On the transcriptomic level, this work represents the first application of RNA sequencing on CJD human brain samples. Here, a good clusterization of the transcriptomic profiles of the two subtypes was achieved, together with the finding of several differently impaired pathways between the two subtypes. The results add to the understanding of the molecular features associated with sporadic CJD and its most common subtypes, revealing strain-specific genetic signatures and functional similarities between VV2 and Parkinson’s disease and providing preliminary evidence of RNA editing modifications in human sCJD. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40478-022-01483-9
Analysis of conformational stability of abnormal prion protein aggregates across the spectrum of Creutzfeldt-Jakob disease prions
Full text linkThe wide phenotypic variability of prion diseases is thought to depend on the interaction of a host genotype with prion strains that have self-perpetuating biological properties enciphered in distinct conformations of the misfolded prion protein, PrP(Sc) The latter concept is largely based on indirect approaches studying the effect of proteases or denaturing agents on the physicochemical properties of PrP(Sc) aggregates. Furthermore, most data come from studies on rodent-adapted prion strains, making current understanding of the molecular basis of strains and phenotypic variability in naturally occurring diseases, especially in humans, more limited. To fill this gap, we studied the effect of guanidine hydrochloride (GdnHCl) and heating on PrP(Sc) aggregates extracted from 60 sporadic CJD and 6 variant CJD brains. While denaturation curves obtained after exposure of PrP(Sc) to increasing GndHCl concentrations showed a similar profile among the 7 CJD types analysed, PrP(Sc) exposure to increasing temperature revealed significantly different and type-specific responses. In particular, MM1 and VV2, the most prevalent and faster replicating CJD types, showed stable and highly resistant PrP(Sc) aggregates, whereas VV1, a rare and slow propagating type, revealed unstable aggregates that easily dissolved at low temperature. Taken together our results indicate that the molecular interactions mediating the aggregation state of PrP(Sc), possibly enciphering strain diversity, are differently targeted by GdnHCl, temperature and proteases. Furthermore, the detected positive correlation between thermo-stability of PrP(Sc) aggregates and disease transmission efficiency makes inconsistent the proposed hypothesis that a decrease in conformational stability of prions results in an increase in their replication efficiency.IMPORTANCE: Prion strains are defined as infectious isolates propagating distinctive phenotypic traits after transmission to syngenic hosts. Although the molecular basis of prion strains is not fully understood, it is largely accepted that variations in prion protein conformation drive the molecular changes leading to the different phenotypes. In this study, we exposed abnormal prion protein aggregates, encompassing the spectrum of human prion strains, to both guanidine hydrochloride and thermal unfolding. Remarkably, while exposure to increasing temperature revealed significant strain-specific differences in the denaturation profile of the protein, treatment with guanidine hydrochloride did not. The findings suggest that thermal and chemical denaturation perturb the structure of prion protein aggregates differently. Moreover, since the most thermo-stable prion protein types were those associated with the most prevalent phenotypes and most rapidly and efficiently transmitting strains, the results suggest a direct correlation between the strain replication efficiency and the thermo-stability of prion protein aggregates.</p
Behçet disease presenting with movement disorders and antibasal ganglia antibodies
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Unsuccessful transmissions of atypical genetic Creutzfeldt-Jakob disease (PRNP p.T183A-129M) in transgenic mice
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Pharmacodynamics of a low subacute levodopa dose helps distinguish between multiple system atrophy with predominant Parkinsonism and Parkinson’s disease
No full textThe differential diagnosis between multiple system atrophy with predominant parkinsonism (MSA-P) and Parkinson's disease (PD) may be challenging at disease onset. Levodopa responsiveness helps distinguish the two groups, but studies evaluating this issue using objective standardized tests are scanty. We retrospectively examined the extent of levodopa response by an objective kinetic-dynamic test in a series of patients prospectively followed up for a parkinsonian syndrome and eventually diagnosed as MSA-P or PD. Sixteen MSA-P and 31 PD patients under chronic levodopa therapy received a first morning fasting dose of levodopa/benserazide (100/25 mg) or levodopa/carbidopa (125/12.5 or 100/25 mg) and underwent simultaneous serial assessments of plasma levodopa concentration and alternate finger tapping frequency up to 3 h post dosing. The main levodopa pharmacodynamic variables were the maximum percentage increase in tapping frequency over baseline values (ΔTapmax %) and the area under the tapping effect-time curve (AUCTap). Levodopa pharmacokinetics did not show significant differences between MSA-P and PD, whereas both the magnitude and overall extent of levodopa tapping effect were markedly reduced in the MSA-P group (p < 0.001). The combined use of specific cut-off values for both the main pharmacodynamic variables, ΔTapmax % <20 % and AUCTap <1900 [(tapping/min)·min], correctly discriminated 15 out of 16 MSA-P patients from PD patients. A combined estimation of these pharmacodynamic variables after a subacute low levodopa dose may be a simple and practical clinical tool to aid the differential diagnosis between MSA-P and PD
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