Creutzfeldt-Jakob disease: updated diagnostic criteria, treatment algorithm, and the utility of brain biopsy

A systemic analysis of Creutzfeldt Jakob disease cases in Asia

Creutzfeldt Jakob Disease (CJD) is a rapidly progressive, fatal neurodegenerative disorder, also known as a subacute spongiform encephalopathy. There are three major subtypes of CJD i.e. Sporadic CJD, which occurs for reasons unbeknown to science (85% of known cases), Genetic or Familial CJD which is characterized by the presence of mutations in the human prion protein (PRNP) gene (10-15% cases) and Iatrogenic CJD that occurs via accidental transmission through medical and surgical procedures (1-2% cases). CJD cases occur globally with 1 case per one million population/year. Considerable data is available related to the incidence and prevalence of CJD in Europe and America. However, the global surveillance database is yet to include Asia even though several Asian countries have their own CJD monitoring units. sCJD is the highest among all CJD cases in Asia. China (1957) and Japan (1705) have reported more cases of sCJD than any Asian country and Hong Kong (1) has reported the least. On the other hand, gCJD is highest in Japan (370) and least in India (2). Our analysis establishes the presence of all variants of CJD across Asia. However, in most Asian countries in general and Southeast Asian countries in particular, CJD cases are misdiagnosed and often underreported. Since Asia is the most populated continent in the world, the actual global prevalence of CJD cannot be estimated until and unless these countries are accounted for. Concrete and reliable surveillance networks are needed across Asia to evaluate the prevalence and incidence of CJD in the region. [Figure: see text]The graphical abstract demonstrates the prevalence of CJD cases in the world and systematically analyses the incidence of CJD in Asian countries between the year 1986-2022. Highest number of cases were reported in Japan followed by China. The study emphasizes the need for assimilation of Asian data in global prevalence.

Creutzfeldt-Jakob disease presenting as psychiatric disorder: case presentation and systematic review

Creutzfeldt-Jakob disease (CJD) is a spongiform encephalopathy caused by misfolded human prion proteins (PrP)s. Due to variability in presentation, the diagnosis may be missed in lieu of various psychiatric disorders. Our study reports on a prototypical case and psychiatric mimic for CJD, and the workup used to establish the correct diagnosis. A 54-year-old male with a past medical history of traumatic brain injury and major depressive disorder presented with chest pain. During the hospital stay, he was found to be increasingly aggressive, and behaved out of character. Further review of clinical history revealed that the patient was diagnosed with cognitive impairment and depression one year prior. The patient was agitated, poorly redirectable, and had unstable gait on neurological examination. Magnetic resonance imaging (MRI) of the brain demonstrated restricted diffusion (DWI) along the parietooccipital and temporal regions (L > R) and in the subcortical structures, including the basal ganglia and thalami, with accompanying subtle fluid attenuation inversion recovery (FLAIR) hyperintense signal abnormality in these regions, deemed as artifactual at the time. Repeat MRI brain two months later demonstrated progression of the DWI signal with ADC correlate and FLAIR findings. Cerebrospinal fluid 14-3-3 and RT-QuIC samples were positive. Upon passing a few months later, brain autopsy and Western Blot confirmed the CJD diagnosis. Literature review was conducted on PubMed to identify CJD cases initially diagnosed as psychiatric disorder. Search terms included "CJD" or "Creutzfeldt-Jakob disease" with three common psychiatric diagnoses, "Depression," "Psychosis," and "Mania." Positive EEG, MRI, PET, and CSF (including protein 14-3-3 and tau) findings for CJD were found in 66.7, 81.1, 50, and 72.7% of cases, respectively. Overall, CJD can present as a psychiatric mimic. In suspicious cases, EEG, imaging, and CSF studies should be promptly utilized to arrive at the correct diagnosis. Repeated MRI imaging is often required to help in the diagnostic process. Brain biopsy should be considered in selected cases.

Comparison of Navigated and Frame-Based Stereotactic Biopsy-A Single-Center Cohort Study

Background and Objectives: As brain lesions present complex diagnostic challenges, accurate tissue sampling via biopsy is critical for effective treatment planning. Traditional frame-based stereotactic biopsy has been complemented by navigated biopsy techniques, leveraging advancements in imaging and navigation technology. This study aims to compare the navigated and frame-based stereotactic biopsy methods in a clinical setting, evaluating their efficacy, safety, and diagnostic outcomes to determine the optimal approach for precise brain lesion targeting. Materials and Methods: retrospective analysis was conducted on patients who underwent brain biopsies between January 2017 and August 2023 at an academic medical center. Data on patient demographics, clinical characteristics, biopsy technique (navigated vs. frame-based), and outcomes including accuracy, complications, and hospital stay duration were analyzed. Results: The cohort comprised 112 patients, with no significant age or gender differences between groups. Symptoms leading to biopsy were predominantly diminished muscle strength (42.0%), cognitive issues (28.6%), and aphasia (24.1%). Tumors were most common in the deep hemisphere (24.1%). The median hospital stay was 5 days, with a rehospitalization rate of 27.7%. Complications occurred in 4.47% of patients, showing no significant difference between biopsy methods. However, navigated biopsies resulted in fewer samples (p < 0.001) but with comparable diagnostic accuracy as frame-based biopsies. Conclusions: Navigated and frame-based stereotactic biopsies are both effective and safe, with comparable accuracy and complication rates. The choice of technique should consider lesion specifics, surgeon preference, and technological availability. The findings highlight the importance of advanced neurosurgical techniques in enhancing patient care and outcomes.

Amyloid-induced neurodegeneration: A comprehensive review through aggregomics perception of proteins in health and pathology

Amyloidosis of protein caused by fibrillation and aggregation are some of the most exciting new edges not only in protein sciences but also in molecular medicines. The present review discusses recent advancements in the field of neurodegenerative diseases and therapeutic applications with ongoing clinical trials, featuring new areas of protein misfolding resulting in aggregation. The endogenous accretion of protein fibrils having fibrillar morphology symbolizes the beginning of neuro-disorders. Prognostic amyloidosis is prominent in numerous degenerative infections such as Alzheimer's and Parkinson's disease, Amyotrophic lateral sclerosis (ALS), etc. However, the molecular basis determining the intracellular or extracellular evidence of aggregates, playing a significant role as a causative factor in neurodegeneration is still unclear. Structural conversions and protein self-assembly resulting in the formation of amyloid oligomers and fibrils are important events in the pathophysiology of the disease. This comprehensive review sheds light on the evolving landscape of potential treatment modalities, highlighting the ongoing clinical trials and the potential socio-economic impact of novel therapeutic interventions in the realm of neurodegenerative diseases. Furthermore, many drugs are undergoing different levels of clinical trials that would certainly help in treating these disorders and will surely improve the socio-impact of human life.

Euphoric Presentation in Creutzfeldt-Jakob Disease and Its Diagnostic Implications: A Case Report

Creutzfeldt-Jakob disease (CJD) constitutes an aggressively advancing, terminal neurodegenerative condition classified within the spectrum of transmissible spongiform encephalopathies. The difficulty in establishing a diagnosis before death arises from the condition's rarity and the resulting limited level of suspicion attributed to it. The polymorphic nature of CJD symptoms contributes to the challenge of early diagnostic recognition. Emotional and behavioral changes have been well documented, but the initial presentation of euphoria has not been documented. Here, we present the case of a female patient who was experiencing an unusual state of euphoria followed by intermittently altered mental status. She was ultimately diagnosed with sporadic CJD, discharged home on hospice, and died within six months of discharge.

Geographic Diversity in the Incidence of Human Prion Diseases - China, 2006-2019

Introduction

Human prion diseases (PrDs) are rare, fatal encephalopathies requiring comprehensive diagnostic analysis. This study examines hospital referral patterns to the Chinese National Surveillance for Creutzfeldt-Jakob Disease (CNS-CJD) from 2006 to 2019.

Methods

We assessed 1,970 PrD cases referred by various hospitals to CNS-CJD. Referral distributions were analyzed based on provincial-level administrative divisions (PLADs). Differences in referral numbers and confirmed cases between monitored and non-monitored PLADs were statistically evaluated.

Results

The study included cases from 344 hospitals across 29 Chinese PLADs. Hospital referrals increased over the surveillance years: from 28.2 hospitals annually during 2006-2010, to 64 in 2011-2015, and 107 in 2016-2019. Of these, 12.2% (42/344) of hospitals reported ≥10 PrD cases, accounting for 70.0% (1,379/1,970) of total cases. Referral numbers varied across PLADs, with the top 5 of Beijing (41), Henan (26), Shanghai (21), Guangdong (21), and Jiangsu (21) leading. Additionally, 12 CJD-surveillance PLADs had more referring hospitals and PrD cases than the other 17 non-surveillance PLADs.

Conclusions

Geographical variations in PrD recognition exist across Chinese PLADs, with certain regions and major cities reporting notably higher case numbers.

Creutzfeldt-Jakob Disease: A Rare Case of Dementia

Prion diseases are rare neurodegenerative diseases that have a rapid evolution. Creutzfeldt-Jakob disease (CJD) is the most common and its sporadic form the most frequent. Definitive diagnosis is only obtained through autopsy, and there are currently no available treatments. Here, we present a case of an 84-year-old woman presenting with resting tremor, abnormal gait, frequent falls, apraxia, visual hallucinations, and delirium. There were no signs of relevant metabolic, infectious, or nutritional alterations, and brain computed tomography (CT) scan and magnetic resonance imaging (MRI) had no significant findings. Two months later, the patient was completely immobile with mutism, seizures, and myoclonus. In the presence of a rapidly progressive dementia associated with myoclonus, it was hypothesized that the patient had CJD. The patient's clinical state deteriorated, she died, and autopsy confirmed sporadic CJD. The purpose of this case is to highlight a rare disease that can go undiagnosed because of low awareness and clinical suspicion and the importance of the differential diagnosis of dementia, a common disease at this age.

Creutzfeldt-Jakob disease presenting as Korsakoff syndrome caused by E196A mutation in PRNP gene: A case report

BACKGROUND

Prion diseases are a group of degenerative nerve diseases that are caused by infectious prion proteins or gene mutations. In humans, prion diseases result from mutations in the prion protein gene (PRNP). Only a limited number of cases involving a specific PRNP mutation at codon 196 (E196A) have been reported. The coexistence of Korsakoff syndrome in patients with Creutzfeldt-Jakob disease (CJD) caused by E196A mutation has not been documented in the existing literature.

CASE SUMMARY

A 61-year-old Chinese man initially presented with Korsakoff syndrome, followed by rapid-onset dementia, visual hallucinations, akinetic mutism, myoclonus, and hyperthermia. The patient had no significant personal or familial medical history. Magnetic resonance imaging of the brain revealed extensive hyperintense signals in the cortex, while positron emission tomography/computed tomography showed a diffuse reduction in cerebral cortex metabolism. Routine biochemical and microorganism testing of the cerebrospinal fluid (CSF) yielded normal results. Tests for thyroid function, human immunodeficiency virus, syphilis, vitamin B1 and B12 levels, and autoimmune rheumatic disorders were normal. Blood and CSF tests for autoimmune encephalitis and autoantibody-associated paraneoplastic syndrome yielded negative results. A test for 14-3-3 protein in the CSF yielded negative results. Whole-genome sequencing revealed a disease-causing mutation in PRNP. The patient succumbed to the illness 11 months after the initial symptom onset.

CONCLUSION

Korsakoff syndrome, typically associated with alcohol intoxication, also manifests in CJD patients. Individuals with CJD along with PRNP E196A mutation may present with Korsakoff syndrome.

Creutzfeldt-Jakob disease in a post-COVID-19 patient: did SARS-CoV-2 accelerate the neurodegeneration?

Background

Creutzfeldt-Jakob disease (CJD) is a rare, fatal neurodegenerative disorder, with few months as a usual duration from onset to death.

Case presentation

In this case report, a patient of Sporadic CJD (sCJD) who presented one month after severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. The diagnosis of this case was established after confirming findings from clinical, neurophysiology, radiological, and laboratory features of this disease.

Conclusion

Putting in mind all the updated data on the pathogenesis of CJD and the immune responses to SARS-CoV-2, we can suggest that COVID-19 can lead to accelerated pathogenesis and exaggerated manifestations of this fatal neurodegenerative disease.

Systematic review of pharmacological management in Creutzfeldt-Jakob disease: no options so far?

BACKGROUND

The Creutzfeldt-Jakob disease (CJD) is a spongiform encephalopathy that manifests as a rapidly progressive dementia syndrome. Currently, CJD has no cure, and many patients die within the first year, but some drugs are being studied as options for managing this condition.

OBJECTIVE

To evaluate the effectiveness of pharmacological treatments offered to patients with CJD as a means to increase survival and reduce cognitive deterioration.

METHODS

A systematic review of the literature was performed using 4 independent reviewers and 1 extra reviewer to resolve possible divergences in the search and analysis of papers indexed in MedLINE (PubMed), SciELO and Lilacs databases. The Medical Subject Heading (MeSH) terms used were: prion diseases, Creutzfeldt-Jakob disease, pharmacologic therapy, therapeutics, quinacrine, doxycycline, flupirtine, and pentosan polysulfate, with the Boolean operators AND and OR. This search included controlled clinical trials, uncontrolled clinical trials, and case series published from the year 2000 onwards, in the English language.

RESULTS

A total of 85 papers were found using the descriptors used. At the end of the selection analyses, 9 articles remained, which were analyzed fully and individually.

CONCLUSIONS

None of the drugs evaluated proved significantly effective in increasing survival in patients with CJD. Flupirtine appears to have a beneficial effect in reducing cognitive deterioration in patients with CJD. However, additional studies are needed to establish better evidence and therapeutic options for the management of patients with CJD.

Sporadic Creutzfeldt-Jakob Disease in a Patient With Multiple Sclerosis: A Case Report

Sporadic Creutzfeldt-Jakob disease (CJD) is a rare neurodegenerative condition and a human prion disease. Rapid progressive dementia, myoclonus, visual disturbances, cerebellar signs, and pyramidal/extrapyramidal symptoms are observed in such patients. However, these are non-specific symptoms and can manifest in a variety of other conditions. The occurrence of sporadic CJD in a patient with multiple sclerosis (MS) is rare. This is the case of a 54-year-old man on natazulimab for MS who developed rapid neurocognitive changes along with visual changes, imbalance issues, and mood changes. Diagnosis of sporadic CJD (sCJD) was confirmed through clinical features, physical examination and electroencephalogram findings, cerebral spinal fluid analysis, and later magnetic resonance imaging findings. sCJD with MS being a rare phenomenon, its recognition requires a high index of suspicion, careful chronological evaluation of the patient’s symptoms, and relevant investigations that can aid in reaching the diagnosis.

Degenerative dementias: A question of syndrome or disease?

BACKGROUND

Neurologists refer to numerous "syndromes,‿ consisting of specific combinations of clinical manifestations, following a specific progression pattern, and with the support of blood analysis (without genomic-proteomic parameters) and neuroimaging findings (MRI, CT, perfusion SPECT, or 18F-FDG-PET scans). Neurodegenerative "diseases,‿ on the other hand, are defined by specific combinations of clinical signs and histopathological findings; these must be confirmed by a clinical examination and a histology study or evidence of markers of a specific disorder for the diagnosis to be made. However, we currently know that most genetic and histopathological alterations can result in diverse syndromes. The genetic or histopathological aetiology of each syndrome is also heterogeneous, and we may encounter situations with pathophysiological alterations characterising more than one neurodegenerative disease. Sometimes, specific biomarkers are detected in the preclinical stage.

DEVELOPMENT

We performed a literature review to identify patients whose histopathological or genetic disorder was discordant with that expected for the clinical syndrome observed, as well as patients presenting multiple neurodegenerative diseases, confirming the heterogeneity and overlap between syndromes and diseases. We also observed that the treatments currently prescribed to patients with neurodegenerative diseases are symptomatic.

CONCLUSIONS

Our findings show that the search for disease biomarkers should be restricted to research centres, given the lack of disease-modifying drugs or treatments improving survival. Moreover, syndromes and specific molecular or histopathological alterations should be managed independently of one another, and new "diseases‿ should be defined and adapted to current knowledge and practice.

The Role of Transposable Elements of the Human Genome in Neuronal Function and Pathology

Transposable elements (TEs) have been extensively studied for decades. In recent years, the introduction of whole-genome and whole-transcriptome approaches, as well as single-cell resolution techniques, provided a breakthrough that uncovered TE involvement in host gene expression regulation underlying multiple normal and pathological processes. Of particular interest is increased TE activity in neuronal tissue, and specifically in the hippocampus, that was repeatedly demonstrated in multiple experiments. On the other hand, numerous neuropathologies are associated with TE dysregulation. Here, we provide a comprehensive review of literature about the role of TEs in neurons published over the last three decades. The first chapter of the present review describes known mechanisms of TE interaction with host genomes in general, with the focus on mammalian and human TEs; the second chapter provides examples of TE exaptation in normal neuronal tissue, including TE involvement in neuronal differentiation and plasticity; and the last chapter lists TE-related neuropathologies. We sought to provide specific molecular mechanisms of TE involvement in neuron-specific processes whenever possible; however, in many cases, only phenomenological reports were available. This underscores the importance of further studies in this area.

Atypical Case of VV1 Creutzfeldt–Jakob Disease Subtype: Case Report

Creutzfeldt–Jakob disease (CJD) is a rare form of rapidly progressive, neurodegenerative disease that results from the misfolding and accumulation of an aberrant, disease-associated prion protein (PrPD). CJD affects 1–1.5 cases per million per year with the sporadic-type accounting for an estimated 85% of these cases. Sporadic CJD (sCJD) is further subdivided into five subtypes based on genetic polymorphisms; the rarest subtype, sCJDVV1, occurs at a rate of 1 case per one-hundredth million population per year. Clinical characteristics of the sCJDVV1 subtype have been reported to show, early age of onset (44 years), average disease duration of 21 months, absent PSWCs on electroencephalography (EEG), and MRI hyperintensities in the cerebral cortex with usual negative signal in the basal ganglia or thalamus. We present a case of the sCJDVV1 subtype with uncommon features. Contrary to current data on sCJDVV1, our patient presented with an unusual age at onset (61 years) and longer disease duration (32 months). The highly sensitive and specific real-time quaking-induced conversion (RT-QuIC) assay was negative. Presenting clinical symptoms included paranoid thoughts and agitation, rapidly progressive memory decline, prosopagnosia, and late development of myoclonus and mutism. Other findings showed positive antithyroid peroxidase antibodies (anti-TPO), and absent PSWCs on EEG. High-dose steroid therapy treatment was administered based on positive anti-TPO findings, which failed to elicit any improvement and the patient continued to decline. To our knowledge, only four cases with the sCJDVV1 subtype, including our patient, have been reported to have a negative result on RT-QuIC. This may suggest varied sensitivity across sCJD subtypes. However, given the rarity of our patient's subtype, and the relatively novel RT-QuIC, current data are based on a small number of cases and larger cohorts of confirmed VV1 cases with RT-QuIC testing need to be reported.

An autopsy case of MV2K-type sporadic Creutzfeldt-Jakob disease presenting with characteristic clinical, radiological, and neuropathological findings

In Japan, because MV2-type sporadic Creutzfeldt-Jakob disease (CJD) is rare, little is known about its clinical and neuropathological characteristics. An autopsy case of MV2K-type sporadic CJD is presented, and the characteristic clinical, radiological, and neuropathological findings are discussed. The patient was a Japanese woman who died at the age of 72 years. Her initial symptom was rapidly progressive dementia. She then developed truncal ataxia and delusions. Approximately nine months after onset, she exhibited akinetic mutism. The total clinical course was 11 months. Magnetic resonance imaging revealed hyperintensity areas in the basal ganglia, thalamus, and hippocampus on diffusion-weighted images. In the cerebral cortex, this finding was slight and inconspicuous. Electroencephalography revealed no periodic sharp wave complexes. Prion protein (PrP) gene analysis revealed no mutations, and polymorphic codon 129 exhibited methionine and valine heterozygosity. In the cerebrospinal fluid, levels of both total tau and 14-3-3 proteins were elevated. Grossly, the brain weighed 1050 g before fixation and exhibited diffuse cortical atrophy. On histopathological examination, extensive fine vacuole-type spongiform degeneration was noted in the cerebral cortex. Numerous kuru plaques were observed in the cerebellum. PrP immunohistochemistry revealed extensive diffuse synaptic- and perineuronal-type PrP deposits in the cerebral cortex. Kuru plaques were strongly immunoreactive for PrP. Western blot analysis of brain tissue samples revealed mixed type 2 and intermediate type. Systematic and comprehensive investigations of both clinical and neuropathological aspects are required for accurate diagnosis.

Creutzfeldt-Jakob Disease: Alterations of Gut Microbiota

Introduction

Human gut dysbiosis has been implicated with the onset of many neurodegenerative disorders. However, the current data focused on the gut microbiota of patients with Creutzfeldt-Jakob disease (CJD) are still lacking. In our study, we explored the gut microbiota alteration in patients with CJD.

Method

We performed 16S ribosomal RNA MiSeq sequencing in stool samples of patients with CJD and controls. Functional analysis of the gut microbiota between these two groups was based on Kyoto Encyclopedia of Genes and Genomes and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2. Clinical rating scales were used to evaluate the association between cognitive impairment and gut microbiota alteration.

Result

We identified a significant alteration in both the structure and the richness of the CJD group. Function analysis revealed that the gut microbiota of patients with CJD enriched in immune signaling molecule interactions and xenobiotics biodegradation. MoCA and survival times were found to be associated with gut microbiota in patients with CJD.

Conclusion

We demonstrated an altered gut microbiota in patients with CJD, which was associated with the cognitive impairment and the survival time of these patients.

The clinical approach to the identification of higher-order visual dysfunction in neurodegenerative disease

PURPOSE OF REVIEW

This review is intended to assist the reader in gaining the knowledge and skills necessary for the recognition and assessment of higher-order visual dysfunction due to neurodegenerative diseases including Alzheimer's disease, dementia with Lewy bodies, Parkinson's dementia, corticobasal degeneration, Creutzfeldt-Jakob disease, and the posterior cortical atrophy syndrome. Clinical problem-solving and pattern recognition must be developed and practiced to accurately diagnosis disturbances of higher-order visual function, and knowledge of higher-order visual brain regions and their visual syndromes forms the foundation for deciphering symptoms presented by patients and/or their care partners. Tests of higher-order visual dysfunction must be assembled by the clinician and assessment can take time and effort. The use of screening tests, follow-up visits, and formal neuropsychological referrals are critical components for accurate diagnosis and these principles are reviewed here.

RECENT FINDINGS

A recent survey of neuro-ophthalmologists revealed that over half of the respondents report that 5-10% of their new patient referrals carry a diagnosis of neurodegenerative disease and many patients were referred for visual symptoms of unknown cause. Despite over a century of discovery related to higher-order visual functions of the human brain, translation of discovery to the clinical assessment of patients has been slow or absent. As with the approach to translational medicine in general, to see meaningful progress, an interdisciplinary approach is indispensable. The first step involves the application of discoveries from the field visual neuroscience by clinicians from the fields of ophthalmology, neurology, and neuropsychology, and from the disciplines of neuro-ophthalmology and behavioral neurology. The unmet need for recognition, assessment, and management of higher-order visual dysfunction in neurodegeneration is evident and clinicians can contribute to closing the gap by using the approach and the tools outlined in the review.

Comparison of cerebrospinal fluid tau, ptau(181), synuclein, and 14-3-3 for the detection of Creutzfeldt-Jakob disease in clinical practice

Creutzfeldt-Jakob disease (CJD) is the leading human prion disease and is a major public health concern, with the risk of secondary iatrogenic transmission. Screening for CJD is often based on the detection of 14-3-3 protein in cerebrospinal fluid (CSF) through western blot assay and, in a second step, on a more specific method such as RT-QuIC (Real-Time Quaking-Induced Conversion). Alternatives to the detection of 14-3-3 in CSF have recently been proposed, specifically CSF tau proteins, tau/p-tau(181) ratio, and alpha-synuclein. In the present work, we compare the diagnostic performance of these biomarkers with that of 14-3-3 protein in a cohort of suspected CJD patients. Our results indicate that tau detection is the most effective and suitable approach for routine disease detection in a clinical setting. Combination with other biomarkers does not improve overall performance, while the tau/p-tau(181) ratio remains useful for differentiating Alzheimer's from CJD. In the end, the performance of tau protein detection in CSF reached 78% sensitivity and 80% specificity for the detection of CJD. It is interesting to note that the use of an automated method with a high concentration range allows for rapid and accurate results, which is very useful in clinical practice and allows for confirmatory testing such as RT-QuIC without delay.

Using Catchment Population to Estimate Sporadic Creutzfeldt-Jakob Disease Incidence

INTRODUCTION

Catchment populations have several uses. A method using catchment population to estimate the incidence of sporadic Creutzfeldt-Jakob disease (sCJD) is described.

MATERIALS AND METHODS

A cohort of nine consecutive patients diagnosed with sCJD, symptom onset spanning 26 months, were observed at a rural tertiary university medical center that has approximately 40,000 hospital discharges annually. An effective catchment population was determined using surrounding county utilization frequency that captured all nine sCJD patients and accounted for over 87% of discharges.

RESULTS

The effective sCJD hospital catchment population was 1.266 million, implying an annual sCJD incidence rate of 3.39 per million (95% CIs, 1.55-6.43), assuming a Poisson distribution for sCJD occurrence.

CONCLUSIONS

This annual incidence rate suggests that many sCJD patients are unrecognized and unreported. An advantage of this catchment population method is independence from death certificate accuracy, important in rare diseases that are both rapidly and invariably fatal. The relative absence of significant healthcare systems competition in this rural population enhances the reliability of this finding. The most likely explanation for the high sCJD incidence rate suggested by this study is enhanced clinical suspicion and improved diagnostic accuracy.

The role of microglia in prion diseases and possible therapeutic targets: a literature review

Creutzfeldt-Jakob disease (CJD) is a rare and fatal condition that leads to progressive neurodegeneration due to gliosis, vacuolation of central nervous system tissue, and loss of neurons. Microglia play a crucial role in maintaining Central Nervous System (CNS) homoeostasis, both in health and disease, through phagocytosis and cytokine production. In the context of CJD, the immunomodulatory function of microglia turns it into a cell of particular interest. Microglia would be activated by infectious prion proteins, initially acquiring a phagocytic and anti-inflammatory profile (M2), and producing cytokines such as IL-4, IL-10, and TGF-β. Therefore, microglia are seen as a key target for the development of new treatment approaches, with many emerging strategies to guide it towards a beneficial role upon neuroinflammation, by manipulating its metabolic pathways. In such a setting, many cellular targets in microglia that can be involved in phenotype modulation, such as membrane receptors, have been identified and pointed out as possible targets for further experiments and therapeutic approaches. In this article, we review the major findings about the role of microglia in CJD, including its relationship to some risk factors associated with the development of the disease. Furthermore, considering its central role in neural immunity, we explore microglial connection with other elements of the immune system and cell signalling, such as inflammasomes, the complement and purinergic systems, and the latest finding strategies to guide these cells from harmful to beneficial roles.

Prognostic value of diffusion-weighted imaging in patients with newly diagnosed sporadic Creutzfeldt-Jakob disease

OBJECTIVES

To evaluate clinico-radiologic markers that predict poor overall survival (OS) in sporadic Creutzfeldt-Jakob disease (sCJD) and to develop a prognostic model.

MATERIALS AND METHODS

Patients with newly diagnosed sCJD were included who underwent diffusion-weighted imaging (DWI) from February 2000 to July 2020. The impact of 9 clinico-radiologic features on OS was analyzed using univariable and multivariable Cox proportional hazards regression model. The DWI prognostic score model was generated. The weighted kappa was calculated for interobserver agreement.

RESULTS

Sixty patients (mean age ± SD, 61.0 ± 9.7 years, 32 women) were included. Univariable analysis showed positive associations between poor OS and patient age (p = 0.003), extent of involved cortical lobes (p = 0.11), involvement of caudate nucleus (p = 0.07), and putamen (p = 0.04). Multivariable analysis demonstrated two independent prognostic factors: age ≥ 60 (HR 2.65, 95% CI, 1.41-4.98), and diffusion restriction in caudate nucleus and putamen (HR 2.24, 95% CI, 1.15-4.37). Based on these features, the DWI prognostic score model was generated: low-risk (0-1 point), intermediate-risk (2-3 points), and high-risk (4-5 points) groups. Median OS in high-risk group was 1.7 months, which was significantly shorter than those in the intermediate-risk (14.2 months) and low-risk (26.5 months) groups (p < 0.001). Interobserver agreements were excellent (κ = 0.91-0.92).

CONCLUSIONS

Our study demonstrated that age and diffusion restriction in caudate nucleus and putamen were the independent prognostic factors of poor overall survival in sporadic Creutzfeldt-Jakob disease. Our DWI prognostic score model may be useful in clinical settings for disease stratification.

KEY POINTS

• Age ≥ 60, and diffusion restriction in caudate nucleus and putamen were the independent prognostic factors of poor overall survival in sCJD. • Based on our DWI prognostic score model, median overall survival in high-risk group was 1.7 months, which was significantly shorter than those in the intermediate-risk group (14.2 months) and low-risk group (26.5 months) (p < 0.001). • The proposed DWI prognostic score model may be useful in clinical settings for disease stratification.

The First Meta-Analysis of the M129V Single-Nucleotide Polymorphism (SNP) of the Prion Protein Gene (PRNP) with Sporadic Creutzfeldt-Jakob Disease

Prion diseases are fatal, chronic, and incurable neurodegenerative diseases caused by pathogenic forms of prion protein (PrP^Sc) derived from endogenous forms of prion protein (PrP^C). Several case–control and genome-wide association studies have reported that the M129V polymorphism of the human prion protein gene (PRNP) is significantly associated with susceptibility to sporadic Creutzfeldt–Jakob disease (CJD). However, since some case–control studies have not shown these associations, the results remain controversial. We collected data that contain the genotype and allele frequencies of the M129V single-nucleotide polymorphism (SNP) of the PRNP gene and information on ethnic backgrounds from sporadic CJD patients. We performed a meta-analysis by collecting data from eligible studies to evaluate the association between the M129V SNP of the PRNP gene and susceptibility to sporadic CJD. We found a very strong association between the M129V SNP of the PRNP gene and susceptibility to sporadic CJD using a meta-analysis for the first time. We validated the eligibility of existing reports and found severe heterogeneity in some previous studies. We also found that the MM homozygote is a potent risk factor for sporadic CJD compared to the MV heterozygote in the heterozygote comparison model (MM vs. MV, odds ratio = 4.9611, 95% confidence interval: 3.4785; 7.0758, p < 1 × 10⁻¹⁰). To the best of our knowledge, this was the first meta-analysis assessment of the relationship between the M129V SNP of the PRNP gene and susceptibility to sporadic CJD.

Clinical applications of diffusion-weighted sequence in brain imaging: beyond stroke

Diffusion-weighted imaging (DWI) is a well-established MRI sequence for diagnosing early stroke and provides therapeutic implications. However, DWI yields pertinent information in various other brain pathologies and helps establish a specific diagnosis and management of other central nervous system disorders. Some of these conditions can present with acute changes in neurological status and mimic stroke. This review will focus briefly on diffusion imaging techniques, followed by a more comprehensive description of the utility of DWI in common neurological entities beyond stroke.

Human Prion Disorders: Review of the Current Literature and a Twenty-Year Experience of the National Surveillance Center in the Czech Republic

Human prion disorders (transmissible spongiform encephalopathies, TSEs) are unique, progressive, and fatal neurodegenerative diseases caused by aggregation of misfolded prion protein in neuronal tissue. Due to the potential transmission, human TSEs are under active surveillance in a majority of countries; in the Czech Republic data are centralized at the National surveillance center (NRL) which has a clinical and a neuropathological subdivision. The aim of our article is to review current knowledge about human TSEs and summarize the experience of active surveillance of human prion diseases in the Czech Republic during the last 20 years. Possible or probable TSEs undergo a mandatory autopsy using a standardized protocol. From 2001 to 2020, 305 cases of sporadic and genetic TSEs including 8 rare cases of Gerstmann-Sträussler-Scheinker syndrome (GSS) were confirmed. Additionally, in the Czech Republic, brain samples from all corneal donors have been tested by the NRL immunology laboratory to increase the safety of corneal transplants since January 2007. All tested 6590 corneal donor brain tissue samples were negative for prion protein deposits. Moreover, the routine use of diagnostic criteria including biomarkers are robust enough, and not even the COVID-19 pandemic has negatively impacted TSEs surveillance in the Czech Republic.

Construction of immune/Creutzfeldt-Jakob disease-related gene coexpression network to predict biomarkers

BACKGROUND AND PURPOSE

Creutzfeldt-Jakob disease (CJD) is a transmissible spongiform encephalopathy characterized by rapid onset and high mortality. Despite considerable progress in the treatment and diagnosis of CJD, patient prognosis remains poor. Many studies have found that the immune response is associated with the pathophysiology of CJD. However, few studies have reported coexpression correlations between genes associated with CJD and the immune response. This study was undertaken to construct a network of coexpressed immune- and CJD-related genes that may reveal new biomarkers and therapeutic targets for CJD.

METHODS

Gene expression data from 11 CJD patients and 10 nonneurological controls were obtained from the Gene Expression Omnibus database. High-confidence protein-protein interaction (PPI) data were downloaded from the Human Protein Reference Database, and gene expression data of immune- and CJD-associated genes were downloaded from the AmiGo16 and DisGeNET databases, respectively. An immune/CJD-related expression network was constructed based on Pearson correlation coefficients and PPI networks, and a CJD-directed neighbour coexpression network was extracted, in which we compared the gene expression patterns and correlations between different groups. The samples were classified using CJD-specific modules, and differentially expressed genes (DEGs) between the CJD and nonneurological controls groups were identified within the CJD-specific modules. Further functional analysis was performed using Kyoto Encyclopaedia of Genes and Genomes (KEGG) enrichment analysis of genes in each CJD-specific module.

RESULTS

We constructed an immune/CJD-related coexpression gene network comprising 2007 nodes and 5268 edges, with immune-associated genes occupying important positions in the network. In the CJD-directed neighbour coexpression network, immune-associated genes exhibited the highest coexpression level with their interacting genes. Results from Pearson correlation analysis showed that most of the CJD-associated genes were positively correlated with immune-associated genes. Screening for CJD-specific modules identified MAPK1, CASP3, APP, MAPT, SNCA, and YWHAH, indicating a close connection between CJD and the immune response. Analyses of coexpression status and expression level of CJD-specific genes revealed a very high coexpression pattern for any two genes, with most genes being DEGs. Finally, KEGG enrichment analyses of all CJD-specific genes showed that the pathophysiology of CJD is closely related to infection and the immune response.

CONCLUSIONS

Our coexpression network analysis revealed a close connection between CJD- and immune-associated genes, and we identified six CJD-specific modules. Biological function analysis of CJD-specific module genes revealed that immune responses are associated with CJD pathophysiology and may provide novel diagnostic and therapeutic biomarkers for this disease.

Sporadic Creutzfeldt-Jakob Syndrome Misdiagnosed as Recurrent Stroke: A Case Report

While sporadic Creutzfeldt-Jakob disease (sCJD) typically presents with neurological symptoms such as cognitive impairment, ataxia, and myoclonus, its clinical manifestations can be diverse. We report a 70-year-old woman with sCJD who was misdiagnosed with recurrent stroke. She initially showed hemiplegia and high-intensity signals on brain diffusion-weighted magnetic resonance imaging (DWI), which corresponded to the symptoms of a stroke. She was diagnosed with recurrent stroke as her muscle weakness showed stepwise deterioration, with the appearance of additional high-intensity signals on brain DWI. Several days later, she developed Broca’s aphasia, cognitive impairment, and myoclonus in the right upper and left lower extremities. Brain DWI showed high-intensity signals in the cortex, caudate nucleus, and putamen. Therefore, sCJD was suspected; she subsequently underwent further evaluation and was diagnosed with sCJD. The findings of this case indicate that sCJD can have a clinical course similar to that of recurrent stroke.

Diagnostic value of diffusion-weighted brain magnetic resonance imaging in patients with sporadic Creutzfeldt-Jakob disease: a systematic review and meta-analysis

OBJECTIVE

To evaluate the diagnostic yield and performance of DWI in patients with sporadic CJD (sCJD).

METHODS

A systematic literature search of the MEDLINE and EMBASE databases was performed, since their inception up to July 28, 2020. Pooled diagnostic yield of diffusion-weighted imaging was calculated using DerSimonian-Laird random-effects model. Pooled diagnostic performance of DWI (sensitivity, specificity, and area under the curve) in diagnosing sCJD among patients with rapidly progressive dementia was calculated using a bivariate random-effects model. Subgroup analysis and meta-regression were performed.

RESULTS

Fifteen original articles with a total of 1144 patients with sCJD were included. The pooled diagnostic yield was 91% (95% confidence interval [CI], 86 to 94%); summary sensitivity, 91% (95% CI, 84 to 95%); and specificity, 97% (95% CI, 94 to 99%). The area under the hierarchical summary receiver operating characteristic curve was 0.99 (95% CI, 0.97-0.99). Simultaneous involvement of the neocortex and striatum was the most common finding, and the neocortex was the most common site to be involved on DWI followed by striatum, thalamus, and cerebellum. Subgroup analysis and meta-regression demonstrated significant heterogeneity among the studies associated with the reference standards used for diagnosis of sCJD.

CONCLUSIONS

DWI showed excellent diagnostic value in diagnosis of sporadic Creutzfeldt-Jakob disease among patients with rapidly progressive dementia. Simultaneous involvement of the neocortex and striatum was the most common finding, and the neocortex was the most common site to be involved on diffusion-weighted imaging followed by striatum, thalamus, and cerebellum.

KEY POINTS

• The pooled diagnostic yield of diffusion-weighted imaging in sporadic Creutzfeldt-Jakob disease was 91%. • The diagnostic performance of diffusion-weighted imaging for predicting sporadic Creutzfeldt-Jakob disease among patients with rapidly progressive dementia was excellent, with pooled sensitivity, 91%, and specificity, 97%. • Simultaneous involvement in the neocortex and striatum was most commonly seen on diffusion-weighted imaging (60%), followed by the neocortex without striatum (30%), thalamus (21%), cerebellum (8%), and striatum without neocortex (7%).

The Three Glycotypes in the London Classification System of Sporadic Creutzfeldt-Jakob Disease Differ in Disease Duration

Sporadic Creutzfeldt-Jakob disease (sCJD) is the most common form of CJD and is believed to be caused by the misfolding and aggregation of endogenous prion protein. Several classification systems have been developed to correlate the molecular characteristics of these misfolded prions (PrP^Sc) to the heterogeneous clinical presentations of sCJD. A central component of these systems is glycotyping, which involves the interpretation of the results of western immunoblotting of the protease-resistant fragment of the misfolded prion protein (PrP^res). The two main classification systems differ in their recognition of a unique banding pattern on electrophoretic gels correlating to a putative clinical subtype. The perpetuation of both classification systems within scientific literature is, in part, due to a paucity of high-level evidence that conclusively addresses the merit of recognising each unique banding pattern. Here, 110 post-mortem confirmed cases of sCJD collected at the Australian Creutzfeldt-Jakob Disease Registry (ANCJDR) between 1993 and 2018 were analysed and classified as per the London classification system. The data presented here demonstrated that sCJD cases with 'type 1' and 'type 2' PrP^Sc as defined by the London classification system differ in their disease duration. No other differences in clinical phenotype or biological characteristics were found to be statistically significant. These findings highlight the importance of sample size and replicability in analyses of this rare disease process. Recognising these glycotypes as phenotypically distinct may represent 'best practice' in the collection and processing of sCJD samples within international registries for research purposes.

Evaluation of a New Criterion for Detecting Prion Disease With Diffusion Magnetic Resonance Imaging

Importance

Early diagnosis is a requirement for future treatment of prion diseases. Magnetic resonance imaging (MRI) with diffusion-weighted images and improved real-time quaking-induced conversion (RT-QuIC) in cerebrospinal fluid (CSF) have emerged as reliable tests.

Objectives

To assess the sensitivity and specificity of diffusion MRI for the diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD) with a new criterion (index test) of at least 1 positive brain region among the cortex of the frontal, parietal, temporal, and occipital lobes; the caudate; the putamen; and the thalamus.

Design, Setting, and Participants

This diagnostic study with a prospective and a retrospective arm was performed from January 1, 2003, to October 31, 2018. MRIs were collected from 1387 patients with suspected sCJD consecutively referred to the National Prion Disease Pathology Surveillance Center as part of a consultation service.

Intervention

Magnetic resonance imaging. Four neuroradiologists blinded to the diagnosis scored the MRIs of 200 randomly selected patients. One neuroradiologist scored the MRIs of all patients.

Main Outcomes and Measures

Sensitivity and specificity of the index test compared with currently used criteria and CSF diagnostic (improved RT-QuIC, 14-3-3, and tau CSF tests).

Results

A total of 872 patients matched the inclusion criteria (diffusion MRI and autopsy-confirmed diagnosis), with 619 having sCJD, 102 having other prion diseases, and 151 having nonprion disease. The primary analysis included 200 patients (mean [SD] age, 63.6 [12.9] years; 100 [50.0%] male). Sensitivity of the index test of 4 neuroradiologists was 90% to 95% and superior to sensitivity of current MRI criteria (69%-76%), whereas specificity was 90% to 100% and unchanged. Interrater reliability of the 4 neuroradiologists was high (κ = 0.81), and individual intrarater reliability was excellent (κ ≥0.87). The sensitivity of the index test of 1 neuroradiologist for 770 patients was 92.1% (95% CI, 89.7%-94.1%) and the specificity was 97.4% (95% CI, 93.4%-99.3%) compared with a sensitivity of 69.8% (95% CI, 66.0%-73.4%; P < .001) and a specificity of 98.0% (95% CI, 94.3%-99.6%; P > .99) according to the current criteria. For 88 patients, index test sensitivity (94.9%; 95% CI, 87.5%-98.6%) and specificity (100%; 95% CI, 66.4%-100%) were similar to those of improved RT-QuIC (86.1% [95% CI, 76.5%-92.8%] and 100% [95% CI, 66.4%-100%], respectively). Lower specificities were found for 14-3-3 and tau CSF tests in 452 patients.

Conclusions and Relevance

In this study, the diagnostic performance of diffusion MRI with the new criterion was superior to that of current standard criteria and similar to that of improved RT-QuIC. These results may have important clinical implications because MRI is noninvasive and typically prescribed at disease presentation.

Machine Learning Driven Profiling of Cerebrospinal Fluid Core Biomarkers in Alzheimer's Disease and Other Neurological Disorders

Amyloid-beta (Aβ) 42/40 ratio, tau phosphorylated at threonine-181 (p-tau), and total-tau (t-tau) are considered core biomarkers for the diagnosis of Alzheimer’s disease (AD). The use of fully automated biomarker assays has been shown to reduce the intra- and inter-laboratory variability, which is a critical factor when defining cut-off values. The calculation of cut-off values is often influenced by the composition of AD and control groups. Indeed, the clinically defined AD group may include patients affected by other forms of dementia, while the control group is often very heterogeneous due to the inclusion of subjects diagnosed with other neurological diseases (OND). In this context, unsupervised machine learning approaches may overcome these issues providing unbiased cut-off values and data-driven patient stratification according to the sole distribution of biomarkers. In this work, we took advantage of the reproducibility of automated determination of the CSF core AD biomarkers to compare two large cohorts of patients diagnosed with different neurological disorders and enrolled in two centers with established expertise in AD biomarkers. We applied an unsupervised Gaussian mixture model clustering algorithm and found that our large series of patients could be classified in six clusters according to their CSF biomarker profile, some presenting a typical AD-like profile and some a non-AD profile. By considering the frequencies of clinically defined OND and AD subjects in clusters, we subsequently computed cluster-based cut-off values for Aβ42/Aβ40, p-tau, and t-tau. This approach promises to be useful for large-scale biomarker studies aimed at providing efficient biochemical phenotyping of neurological diseases.

Subtype Diagnosis of Sporadic Creutzfeldt-Jakob Disease with Diffusion Magnetic Resonance Imaging

OBJECTIVE

Sporadic Creutzfeldt-Jakob disease (sCJD) comprises several subtypes as defined by genetic and prion protein characteristics, which are associated with distinct clinical and pathological phenotypes. To date, no clinical test can reliably diagnose the subtype. We established two procedures for the antemortem diagnosis of sCJD subtype using diffusion magnetic resonance imaging (MRI).

METHODS

MRI of 1,458 patients referred to the National Prion Disease Pathology Surveillance Center were collected through its consultation service. One neuroradiologist blind to the diagnosis scored 12 brain regions and generated a lesion profile for each MRI scan. We selected 487 patients with autopsy-confirmed diagnosis of "pure" sCJD subtype and at least one positive diffusion MRI examination. We designed and tested two data-driven procedures for subtype diagnosis: the first procedure-prion subtype classification algorithm with MRI (PriSCA_MRI)-uses only MRI examinations; the second-PriSCA_MRI + Gen-includes knowledge of the prion protein codon 129 genotype, a major determinant of sCJD subtypes. Both procedures were tested on the first MRI and the last MRI follow-up.

RESULTS

PriSCA_MRI classified the 3 most prevalent subtypes with 82% accuracy. PriSCA_MRI + Gen raised the accuracy to 89% and identified all subtypes. Individually, the 2 most prevalent sCJD subtypes, MM1 and VV2, were diagnosed with sensitivities up to 95 and 97%, respectively. The performances of both procedures did not change in 168 patients with longitudinal MRI studies when the last examination was used.

INTERPRETATION

This study provides the first practical algorithms for antemortem diagnosis of sCJD subtypes. MRI diagnosis of subtype is likely to be attainable at early disease stages to prognosticate clinical course and design future therapeutic trials. ANN NEUROL 2021;89:560-572.

Neurodegenerative Proteinopathies in the Proteoform Spectrum-Tools and Challenges

Proteinopathy refers to a group of disorders defined by depositions of amyloids within living tissue. Neurodegenerative proteinopathies, including Alzheimer's disease, Parkinson's disease, Creutzfeldt-Jakob disease, and others, constitute a large fraction of these disorders. Amyloids are highly insoluble, ordered, stable, beta-sheet rich proteins. The emerging theory about the pathophysiology of neurodegenerative proteinopathies suggests that the primary amyloid-forming proteins, also known as the prion-like proteins, may exist as multiple proteoforms that contribute differentially towards the disease prognosis. It is therefore necessary to resolve these disorders on the level of proteoforms rather than the proteome. The transient and hydrophobic nature of amyloid-forming proteins and the minor post-translational alterations that lead to the formation of proteoforms require the use of highly sensitive and specialized techniques. Several conventional techniques, like gel electrophoresis and conventional mass spectrometry, have been modified to accommodate the proteoform theory and prion-like proteins. Several new ones, like imaging mass spectrometry, have also emerged. This review aims to discuss the proteoform theory of neurodegenerative disorders along with the utility of these proteomic techniques for the study of highly insoluble proteins and their associated proteoforms.

How common are seizures in the heidenhain variant of creutzfeldt-jakob disease? A case report and systematic review

The Heidenhain variant of Creutzfeld-Jakob disease (HvCJD) is a relentlessly progressive and fatal neurodegenerative disorder characterised by prominent visual features early in its clinical course. However, seizures are uncommonly reported in HvCJD. The case history of a patient admitted to our institution with HvCJD and seizures is described followed by a systematic review of the association between HvCJD and seizures. A systematic search of the databases Medline, PubMed, and PsycInfo was conducted, from inception to November 2019, using keywords relating to 'Creutzfeldt-Jakob disease' and 'Heidenhain variant', to ascertain the frequency of seizures in HvCJD, as well as, seizure semiology and electrographic features. The Preferred Items Reporting for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed in the construction of this systematic review. All studies, including case reports of patients who met the diagnostic criteria for HvCJD where details pertaining to clinical presentation, imaging, biochemical and EEG findings were available were included. There were 46 articles reporting on a total of 73 patients. Seizures occurred in only four out of 73 cases (5.5%). The semiology of these seizures were focal motor seizures with or without secondary generalisation and occipital lobe seizures. Imaging and electrographic findings were most commonly abnormal in the posterior cerebral cortices (in particular the occipital and occipito-parietal regions). This systematic review suggests that seizures are uncommon in HvCJD despite the frequency of imaging and electrographic abnormalities in the posterior cerebral regions. A key limitation of this systematic review is the variability of publications in terms of incomplete reporting of clinical data, in particular potential under-reporting of seizures, as well as follow up, which may have contributed to the lower frequency of seizures reported in patients with HvCJD.

A patient with sporadic Creutzfeldt-Jakob disease: challenges of rare diseases in the COVID-19 era

We describe a patient who presented to hospital during the coronavirus disease 2019 (COVID-19) pandemic with sporadic Creutzfeldt–Jakob disease (sCJD). The case demonstrates the typical clinical, radiological and laboratory features of this condition. It also highlights some of the challenges associated with diagnosis and care of patients with rare diseases such as sCJD, and how these have been intensified by COVID-19.

Extracellular vesicles - propagators of neuropathology and sources of potential biomarkers and therapeutics for neurodegenerative diseases

Neurodegenerative diseases are characterised by the irreversible degeneration of neurons in the central or peripheral nervous systems. These include amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), Parkinson's disease (PD) and prion diseases. Small extracellular vesicles (sEVs), a type of EV involved in cellular communication, have been well documented as propagating neurodegenerative diseases. These sEVs carry cargo, such as proteins and RNA, to recipient cells but are also capable of promoting protein misfolding, thus actively contributing to the progression of these diseases. sEV secretion is also a compensatory process for lysosomal dysfunction in the affected cells, despite inadvertently propagating disease to recipient cells. Despite this, sEV miRNAs have biomarker potential for the early diagnosis of these diseases, while stem cell-derived sEVs and those generated through exogenous assistance demonstrate the greatest therapeutic potential. This Review will highlight novel advancements in the involvement of sEVs as propagators of neuropathology, biomarkers and potential therapeutics in neurodegenerative diseases.

Creutzfeldt-Jakob Disease With Atypical Magnetic Resonance Imaging Features

Creutzfeld-Jakob disease (CJD) is a rare neurodegenerative condition characterized by rapid progression and fatal outcomes. Patients with progressive dementia and associated atypical features should be investigated, especially with the MRI brain for CJD. Cortical ribboning on diffusion-weighted MRI images is a very crucial diagnostic sign for CJD. Here we present a case of a 52-year-old woman admitted to the hospital after a seizure episode and two-month history of altered mental status. She presented with a 40-minute episode of status epilepticus, necessitating admission to the intensive care unit. Head CT showed no acute intracranial abnormalities, and MRI showed generalized brain atrophy. Electroencephalography (EEG) demonstrated an intermittent slowing of the left hemisphere. Two weeks after admission, she got discharged. Four days later, she presented to the hospital after being found disoriented in a park. MRI showed ventricular dilation and a questionable focus of restricted diffusion in the left thalamus posteriorly. CJD protein panel was collected. Three days after discharge, she was brought to the hospital, and CJD protein testing revealed the presence of 14-3-3 protein, elevated T-tau, and negative real-time quaking-induced conversion (RT-QuIC). The National Prion Disease Surveillance Center reviewed her case, and the CJD diagnosis was confirmed.

Challenges and Advances in Antemortem Diagnosis of Human Transmissible Spongiform Encephalopathies

Transmissible spongiform encephalopathies (TSEs), also known as prion diseases, arise from the structural conversion of the monomeric, cellular prion protein (PrPC) into its multimeric scrapie form (PrPSc). These pathologies comprise a group of intractable, rapidly evolving neurodegenerative diseases. Currently, a definitive diagnosis of TSE relies on the detection of PrPSc and/or the identification of pathognomonic histological features in brain tissue samples, which are usually obtained postmortem or, in rare cases, by brain biopsy (antemortem). Over the past two decades, several paraclinical tests for antemortem diagnosis have been developed to preclude the need for brain samples. Some of these alternative methods have been validated and can provide a probable diagnosis when combined with clinical evaluation. Paraclinical tests include in vitro cell-free conversion techniques, such as the real-time quaking-induced conversion (RT-QuIC), as well as immunoassays, electroencephalography (EEG), and brain bioimaging methods, such as magnetic resonance imaging (MRI), whose importance has increased over the years. PrPSc is the main biomarker in TSEs, and the RT-QuIC assay stands out for its ability to detect PrPSc in cerebrospinal fluid (CSF), olfactory mucosa, and dermatome skin samples with high sensitivity and specificity. Other biochemical biomarkers are the proteins 14-3-3, tau, neuron-specific enolase (NSE), astroglial protein S100B, α-synuclein, and neurofilament light chain protein (NFL), but they are not specific for TSEs. This paper reviews the techniques employed for definite diagnosis, as well as the clinical and paraclinical methods for possible and probable diagnosis, both those in use currently and those no longer employed. We also discuss current criteria, challenges, and perspectives for TSE diagnosis. An early and accurate diagnosis may allow earlier implementation of strategies to delay or stop disease progression.

Corticobasal manifestations of Creutzfeldt-Jakob disease with D178N-homozygous 129M genotype

Creutzfeldt-Jakob disease (CJD) is a prion disease, usually presented with memory loss, ataxia, dementia, myoclonus, involuntary movements and psychiatric problems. D178N-homozygous 129M genotype has been recognized in the diagnosis of fatal familial insomnia (FFI) globally. Here we report a patient presented with progressive left upper limb stiffness, bradykinesia, hypomimia and weight loss (10 kg) initially. She progressed to dementia, dysphasia, dysphonia and be bedridden quickly but did not present insomnia. She was diagnosed with CJD corticobasal subtype carrying a classic D178N-129M mutation of PRNP in FFI. Remarkably, she has a strong family history of neurological degeneration diseases but the other members of this pedigree who do not carry D178N-homozygous 129M mutation in PRNP do not present any CJD or FFI symptoms. We conclude that this patient carrying D178N-homozygous 129M mutation in PRNP should be diagnosed as CJD. Thus, the clinicopathology should be considered as a crucial evidence in diagnosing some cases, but FFI could be evaluated as a differential diagnosis with a unique clinical profile.

List of abbreviations

AD: Alzheimer disease; ADL: Activities of Daily Living; CBD Cortical basal degeneration; CBS: Corticobasal syndrome; CJD: Creutzfeldt-Jakob disease; DWI: Diffusion-weighted image; EEG: Electroencephalograph, fCJD: familial Creutzfeld-Jakob disease; FFI: Fatal familial insomnia; FLAIR: Fluid-attenuated inversion recovery; MMSE: Mini-mental state examination; MoCA: Montreal Cognitive Assessment; MRI: Magnetic resonance imaging; PD: Parkinson disease; PrP: Prion protein; PSWC: Periodic sharp wave complexes; SWI: Susceptibility-weighted imaging

Focal sharp waves are a specific early-stage marker of the MM2-cortical form of sporadic Creutzfeldt-Jakob disease

Periodic sharp wave complexes (PSWCs), identified using electroencephalography, are observed in less than half of patients with the methionine homozygosity type 2 cortical (MM2c) form of sporadic Creutzfeldt-Jakob disease (sCJD), and only at a later stage of the disease. In this study, we identified early and specific markers on the electroencephalograms (EEGs) of patients with MM2c-sCJD. We retrospectively investigated the clinical records, EEGs, and magnetic resonance imaging (MRI) scans of patients diagnosed with sCJD and compared the EEG findings of MM2c-sCJD and MM1/classic sCJD groups. The records of six patients with MM2c-sCJD and eight with MM1/classic sCJD were included. The median ages of onset in the MM2c- and MM1/classic sCJD groups were 75.0 (range, 60–83) and 72.5 (range, 51–74) years, respectively, and the average durations between disease onset and the first EEG were 9.17 (range, 4–15) and 1.88 (range, 1–4) months, respectively. Focal sharp waves and/or focal spike-and-wave complexes in the brain regions corresponding with cortical hyperintensities on MRI scans were identified on the EEGs of patients with MM2c-sCJD in the early stages of disease progression. In contrast, EEGs of patients in the early stages of MM1/classic sCJD showed lateralized or generalized diffuse sharp waves and spike-and-wave complexes, which were not limited to cortical hyperintensities identified with MRI scans. Our findings indicate that focal sharp waves and/or focal spike-and-wave complexes on the EEGs of patients in the early phase of MM2c-sCJD are characteristic of the disease, suggesting the possible usefulness of this characteristic for early diagnosis.

Different Clinical Contexts of Use of Blood Neurofilament Light Chain Protein in the Spectrum of Neurodegenerative Diseases

One of the most pressing challenges in the clinical research of neurodegenerative diseases (NDDs) is the validation and standardization of pathophysiological biomarkers for different contexts of use (CoUs), such as early detection, diagnosis, prognosis, and prediction of treatment response. Neurofilament light chain (NFL) concentration is a particularly promising candidate, an indicator of axonal degeneration, which can be analyzed in peripheral blood with advanced ultrasensitive methods. Serum/plasma NFL concentration is closely correlated with cerebrospinal fluid NFL and directly reflects neurodegeneration within the central nervous system. Here, we provide an update on the feasible CoU of blood NFL in NDDs and translate recent findings to potentially valuable clinical practice applications. As NFL is not a disease-specific biomarker, however, blood NFL is an easily accessible biomarker with promising different clinical applications for several NDDs: (1) early detection and diagnosis (i.e., amyotrophic lateral sclerosis, Creutzfeldt-Jakob disease, atypical parkinsonisms, sporadic late-onset ataxias), (2) prognosis (Huntington's disease and Parkinson's disease), and (3) prediction of time to symptom onset (presymptomatic mutation carriers in genetic Alzheimer's disease and spinocerebellar ataxia type 3).

Second-Generation RT-QuIC Assay for the Diagnosis of Creutzfeldt-Jakob Disease Patients in Brazil

The recent development of IQ-CSF, the second generation of real-time quaking-induced conversion (RT-QuIC) using cerebrospinal fluid (CSF), for the diagnosis of Creutzfeldt-Jakob Disease (CJD) represents a major diagnostic advance in the field. Highly accurate results have been reported with encouraging reproducibility among different centers. However, availability is still insufficient, and only a few research centers have access to the method in developing countries. In Brazil, we have had 603 suspected cases of CJD since 2005, when surveillance started. Of these, 404 were undiagnosed. This lack of diagnosis is due, among other factors, to the lack of a reference center for the diagnosis of these diseases in Brazil, resulting in some of these samples being sent abroad for analysis. The aim of this research study is to report the pilot use of IQ-CSF in a small cohort of Brazilian patients with possible or probable CJD, implementing a reference center in the country. We stored CSF samples from patients with possible, probable or genetic CJD (one case) during the time frame of December 2016 through June 2018. All CSF samples were processed according to standardized protocols without access to the clinical data. Eight patients presented to our team with rapidly progressive dementia and typical neurological signs of CJD. We used CSF samples from seven patients with other neurological conditions as negative controls. Five out of seven suspected cases had positive tests; two cases showed inconclusive results. Among controls, there was one false-positive (a CSF sample from a 5-year-old child with leukemia under treatment). The occurrence of a false positive in one of the negative control samples raises the possibility of the presence of interfering components in the CSF sample from patients with non-neurodegenerative pathologies. Our pilot results illustrate the feasibility of having CJD CSF samples tested in Brazilian centers and highlight the importance of interinstitutional collaboration to pursue a higher diagnostic accuracy in CJD in Brazil and Latin America.

The Insomnia Plague in Fictional Macondo

Disease and medicine are found throughout Gabriel García Márquez's work. This article examines the insomnia plague described in the novel One Hundred Years of Solitude and performs a differential diagnosis exercise with conditions that affect both sleep and memory. The main finding is that the insomnia plague narrated by García Márquez, with its clinical manifestations, the sequence of symptoms, and its resolution, cannot be associated with any specific diagnosis. However, similarities to and differences from several clinical conditions are discussed, as well as the relation between the neurophysiologic phenomena of sleep and memory.

Identification of Prion Disease-Related Somatic Mutations in the Prion Protein Gene (PRNP) in Cancer Patients

Prion diseases are caused by misfolded prion protein (PrP^Sc) and are accompanied by spongiform vacuolation of brain lesions. Approximately three centuries have passed since prion diseases were first discovered around the world; however, the exact role of certain factors affecting the causative agent of prion diseases is still debatable. In recent studies, somatic mutations were assumed to be cause of several diseases. Thus, we postulated that genetically unstable cancer tissue may cause somatic mutations in the prion protein gene (PRNP), which could trigger the onset of prion diseases. To identify somatic mutations in the PRNP gene in cancer tissues, we analyzed somatic mutations in the PRNP gene in cancer patients using the Cancer Genome Atlas (TCGA) database. In addition, to evaluate whether the somatic mutations in the PRNP gene in cancer patients had a damaging effect, we performed in silico analysis using PolyPhen-2, PANTHER, PROVEAN, and AMYCO. We identified a total of 48 somatic mutations in the PRNP gene, including 8 somatic mutations that are known pathogenic mutations of prion diseases. We identified significantly different distributions among the types of cancer, the mutation counts, and the ages of diagnosis between the total cancer patient population and cancer patients carrying somatic mutations in the PRNP gene. Strikingly, although invasive breast carcinoma and glioblastoma accounted for a high percentage of the total cancer patient population (9.9% and 5.4%, respectively), somatic mutations in the PRNP gene have not been identified in these two cancer types. We suggested the possibility that somatic mutations of the PRNP gene in glioblastoma can be masked by a diagnosis of prion disease. In addition, we found four aggregation-prone somatic mutations, these being L125F, E146Q, R151C, and K204N. To the best of our knowledge, this is the first specific analysis of the somatic mutations in the PRNP gene in cancer patients.