Prion diseases

18F-FP-CIT PET/CT in a case of probable sporadic Creutzfeldt-Jakob disease with parkinsonism as initial symptom

Creutzfeldt-Jakob disease (CJD) is a low-prevalence, fatal neurodegenerative disease. Parkinsonism as first symptom of CJD is rare. We present a case manifesting difficulty falling asleep as unspecific prodromal symptom and parkinsonism as initial symptom. The patient received positron emission tomography/computed tomography (PET/CT) of dopamine transporter (DAT) using 18 F-FP-CIT. The DAT-scan demonstrated presynaptic dopaminergic deficit in bilateral posterior putamen, which supports the hypothesis of nigrostriatal pathway dysfunction in CJD.

Pathophysiology of Traumatic Brain Injury, Chronic Traumatic Encephalopathy, and Neuropsychiatric Clinical Expression

This article focuses on neuropsychiatric clinical expression and neuropathology associated with chronic traumatic encephalopathy (CTE), which is thought to develop years after traumatic brain injury. The incidence, prevalence, additional risk factors, and pathophysiology remain largely unknown. CTE is considered a tauopathy because the endogenous brain protein tau, in its hyperphosphorylated state (p-tau), defines the predominant neuropathological findings and may underlie aspects of cell toxicity, synapse and circuit dysfunction, and clinical signs and symptoms. We discuss pathophysiological mechanisms possibly affecting p-tau accumulation. Finally, we interweave how clinical features and neuroanatomical sites associated with CTE potentially intersect with posttraumatic stress disorder.

Analysis of Chinese patients with sporadic Creutzfeldt-Jakob disease

Sporadic Creutzfeldt-Jakob disease (sCJD) is a rare, incurable, and fatal neurodegenerative disorder. The objective of this study was to describe the clinical features and survival time of Chinese sCJD patients, and to explore the associations between clinical data and survival. In this study, we analysed the clinical data of 21 sCJD patients in a tertiary care hospital and used all Chinese case material available from 152 patients with sCJD in literatures between 2008 and 2018. The mean age of onset of all 173 deceased patients was 61.44 year-olds (y), with the highest incidence in the population of 60 to 69 y. The most common manifestation at disease onset was progressive dementia. With the progression of the disease, the four main clinical symptoms and signs were developed, including myoclonus, visual or cerebella disturbance, pyramidal or extrapyramidal dysfunction, and akinetic mutism. Extrapyramidal symptoms were more frequently observed. The mean survival time was 7.34 months, and 82.10% of cases died within 1 year after disease onset. The follow-up showed that the survival time was longer and the myoclonus sign was more frequently presented in younger-onset sCJD patients. Patients with abnormalities only in cortical regions had a higher frequency of pyramidal dysfunction than patients having lesions in both cortex and basal ganglia. The findings of this study might provide some insight into the clinical characteristics of sCJD patients in China, but further studies could examine the presences of clinical features and survival time in patients with early age of onset in a prospective manner.

Case series of Creutzfeldt-Jakob disease in a third-level hospital in Quito

BACKGROUND

Creutzfeldt-Jakob disease is a rare and fatal neurodegenerative disorder that affects mammals and humans. The prevalence of this disease in the United States is 0.5 to 1 per million inhabitants. So far in Ecuador, we do not know what the prevalence or incidence is, and only one case report has been written.

CASE PRESENTATION

We present a case series of Creutzfeldt-Jakob disease in a third-level hospital in Quito. The average age of symptom onset in our patients was 58.8 years. The male to female ratio was 1:1. Two patients began with cognitive/behavioral symptoms, while 4 patients began with focal neurological signs; 1 case with ataxia, 2 with gait disorders and 1 with vertigo and headache. All of the patients had the clinical features established by the World Health Organization. In addition, the entire cohort was positive for the 14-3-3 protein in cerebrospinal fluid, and had high signal abnormalities in caudate and putamen nucleus in DWI and FLAIR IRM. Only in one case, did we reach a definitive diagnosis through a pathological study. All other cases had a probable diagnosis. In this series of cases, 6 out of 6 patients died. The average time from the onset of the symptoms to death in this cohort was 13 months.

CONCLUSION

This is the first report of a series of cases of Creutzfeldt-Jakob disease in Quito. Although definitive diagnosis must be histopathological, there are ancillary tests currently available that have allowed us to obtain a diagnosis of the disease.

Rapid cognitive and functional decline: Creutzfeldt-Jakob disease

The emergence of "mad cow disease" has sparked interest in prion diseases, including Creutzfeldt-Jakob disease, a spongiform encephalopathy that can mimic other rapidly progressive dementias. A systematic approach to evaluation and diagnostic testing can help rule out other causes.

CSF concentrations of cAMP and cGMP are lower in patients with Creutzfeldt-Jakob disease but not Parkinson's disease and amyotrophic lateral sclerosis

Background

The cyclic nucleotides cyclic adenosine-3′,5′-monophosphate (cAMP) and cyclic guanosine-3′,5′-monophosphate (cGMP) are important second messengers and are potential biomarkers for Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and Creutzfeldt-Jakob disease (CJD).

Methodology/Principal Findings

Here, we investigated by liquid chromatography/tandem mass spectrometry (LC-MS/MS) the cerebrospinal fluid (CSF) concentrations of cAMP and cGMP of 82 patients and evaluated their diagnostic potency as biomarkers. For comparison with a well-accepted biomarker, we measured tau concentrations in CSF of CJD and control patients. CJD patients (n = 15) had lower cAMP (−70%) and cGMP (−55%) concentrations in CSF compared with controls (n = 11). There was no difference in PD, PD dementia (PDD) and ALS cases. Receiver operating characteristic (ROC) curve analyses confirmed cAMP and cGMP as valuable diagnostic markers for CJD indicated by the area under the curve (AUC) of 0.86 (cAMP) and 0.85 (cGMP). We calculated a sensitivity of 100% and specificity of 64% for cAMP and a sensitivity of 67% and specificity of 100% for cGMP. The combination of both nucleotides increased the sensitivity to 80% and specificity to 91% for the term cAMPxcGMP (AUC 0.92) and to 93% and 100% for the ratio tau/cAMP (AUC 0.99).

Conclusions/Significance

We conclude that the CSF determination of cAMP and cGMP may easily be included in the diagnosis of CJD and could be helpful in monitoring disease progression as well as in therapy control.

Protein structure along the order-disorder continuum

Thermal fluctuations cause proteins to adopt an ensemble of conformations wherein the relative stability of the different ensemble members is determined by the topography of the underlying energy landscape. “Folded” proteins have relatively homogeneous ensembles, while “unfolded” proteins have heterogeneous ensembles. Hence, the labels “folded” and “unfolded” represent attempts to provide a qualitative characterization of the extent of structural heterogeneity within the underlying ensemble. In this work, we introduce an information-theoretic order parameter to quantify this conformational heterogeneity. We demonstrate that this order parameter can be estimated in a straightforward manner from an ensemble and is applicable to both unfolded and folded proteins. In addition, a simple formula for approximating the order parameter directly from crystallographic B factors is presented. By applying these metrics to a large sample of proteins, we show that proteins span the full range of the order–disorder axis.

Retroviral display in gene therapy, protein engineering, and vaccine development

The display and analysis of proteins expressed on biological surfaces has become an attractive tool for the study of molecular interactions in enzymology, protein engineering, and high-throughput screening. Among the growing number of established display systems, retroviruses offer a unique and fully mammalian platform for the expression of correctly folded and post-translationally modified proteins in the context of cell plasma membrane-derived particles. This is of special interest for therapeutic applications such as gene therapy and vaccine development and also offers advantages for the engineering of mammalian proteins toward customized binding affinities and catalytic activities. This review critically summarizes the basic concepts and applications of retroviral display and analyses its benefits in comparison to other display techniques.

Dementia screening, biomarkers and protein misfolding: Implications for public health and diagnosis

Misfolded proteins are at the core of many neurodegenerative diseases, nearly all of them associated with cognitive impairment. For example Creutzfeldt-Jacob disease is associated with aggregation of prion protein, Lewy body dementia and Parkinson disease with α-synuclein and forms of frontotemporal dementia with tau, TDP 43 and host of other proteins, Alzheimer disease (AD), the most common cause of dementia, and its prodromal syndrome mild cognitive impairment (MCI) are an increasing public health problem and a diagnostic challenge to may clinicians. AD is characterized pathologically by the accumulation of amyloid β protein (Aβ) as senile plaques and in the walls of blood vessels as amyloid angiopathy. Additionally, there are accumulations of tau-protein as neurofibrillary tangles and dystrophic neurites. Biological markers of AD and MCI can serve as in vivo diagnostic indicators of underlying pathology, particularly when clinical symptoms are mild and are likely present years before the onset of clinical symptoms. Research to discover and refine fluid and imaging biomarkers of protein aggregation has undergone a rapid evolution and combined analysis of different modalities may further increase diagnostic sensitivity and specificity. Multi-center trials are now investigating whether imaging and/or cerebrospinal fluid (CSF) biomarker candidates can be used as outcome measures for use in phase III clinical trials for AD.

Influence of aging and neurodegeneration on dendritic spine morphology

In neuronal circuits, excitatory synaptic transmission predominantly occurs at postsynaptic protrusions called dendritic spines. Spines are highly plastic structures capable of formation, enlargement, shrinkage, and elimination over time. Individual spine morphology is widely variable, and evidence suggests these differences in morphology are relevant to spine function. Recent reports provide evidence that spine structural plasticity underlies functional synaptic changes, including those seen in animal models of learning and memory plasticity. Conversely, impairments in cognitive functions, such as those commonly seen in aging, have recently been linked to and correlated with alterations in spine density and morphology. In addition, dendritic spine density and morphology also appear to be altered in various transgenic animal models of neurodegenerative diseases. Ultimately, an understanding of the synaptic basis of age- and disease-related cognitive impairments may lead to the development of drug treatments that can restore or protect synaptic profiles in neural circuits that mediate cognition.