Characterisation of RT-QuIC negative cases from the UK National CJD Research and Surveillance programme

INTRODUCTION

Incorporation of the real-time quaking-induced conversion (RT-QuIC) assays for diagnosis of sporadic Creutzfeldt-Jakob disease (CJD) has transformed diagnosis largely related to its extremely high specificity. However, the test has a c.10% false-negative result and we aim to characterize the clinical features, investigation profile, and molecular subtype in this cohort of patients.

METHODS

250 individuals diagnosed with definite sporadic CJD were identified from the UK National CJD Research and Surveillance Unit from 2012 to 2023. We compared the clinical features and investigation profile in those with a negative CSF RT-QuIC to those with a positive RT-QuIC.

RESULTS

27 individuals (10.8%) were CSF RT-QuIC negative. Median age of onset was younger (62 years vs 68 years, p = 0.002), median disease duration was longer (4.4 months vs 10.5 months, p < 0.001), and these individuals were less likely to present with gait difficulties (73% vs 93%, p = 0.003) or motor symptoms (62% vs 80%, p = 0.04). The sensitivity of electroencephalography and diffusion-weighted MRI were similar in both groups. In those who were RT-QuIC negative, there was an overrepresentation of the VV1 (32% vs 1%) and MM2 molecular subtypes (21% vs 3%). Co-occurring neurodegenerative disease was found in 33% (9/27) of those who were RT-QuIC negative.

CONCLUSIONS

Individuals with sporadic CJD and a negative CSF RT-QuIC present with younger age of onset, different clinical features and are over-represented with the VV1 and MM2 subtypes of sporadic CJD. Further work is required to better understand the biochemical properties contributing to RT-QuIC negative results in these cases.

Brain Organoids: A Game-Changer for Drug Testing

Neurological disorders are the second cause of death and the leading cause of disability worldwide. Unfortunately, no cure exists for these disorders, but the actual therapies are only able to ameliorate people's quality of life. Thus, there is an urgent need to test potential therapeutic approaches. Brain organoids are a possible valuable tool in the study of the brain, due to their ability to reproduce different brain regions and maturation stages; they can be used also as a tool for disease modelling and target identification of neurological disorders. Recently, brain organoids have been used in drug-screening processes, even if there are several limitations to overcome. This review focuses on the description of brain organoid development and drug-screening processes, discussing the advantages, challenges, and limitations of the use of organoids in modeling neurological diseases. We also highlighted the potential of testing novel therapeutic approaches. Finally, we examine the challenges and future directions to improve the drug-screening process.

IgLON5 autoimmunity in a patient with Creutzfeldt-Jakob disease: case report and review of literature

Objective

We present the case of a patient with clinical and imaging features of sporadic Creutzfeldt-Jakob disease (sCJD) and positive IgLON5 antibodies (Abs) in the serum and CSF.

Case report

A 66-year-old Chinese man presented to the hospital with a stroke-like episode, followed by rapidly progressive cognitive decline, mutism, and parkinsonism. The MRI results showed a cortical ribboning sign in diffusion-weighted MRI, periodic triphasic waves with a slow background in EEG, and positive protein 14-3-3 in CSF. There were matching IgLON5 Abs in the serum and CSF. A literature review showed positive autoimmune encephalitis Abs or autoimmune inflammatory disease between 0.5 and 8.6% among patients with clinical suspicion of CJD, most commonly anti-voltage-gated potassium channel (VGKC) complex and anti-N-methyl-D-aspartate receptor (NMDAR) Abs; however, IgLON5 autoimmunity in CJD has been rarely reported. This is an intriguing association as both conditions have been associated with brain deposits of phosphorylated tau protein.

Conclusion

IgLON5 Abs may be observed in patients with a diagnosis of CJD; it is unknown whether a synergistic effect of IgLON5 Abs with CJD exists, increasing neurodegenerative changes.

Prediction of clinical progression in nervous system diseases: plasma glial fibrillary acidic protein (GFAP)

Glial fibrillary acidic protein (GFAP), an intracellular type III intermediate filament protein, provides structural support and maintains the mechanical integrity of astrocytes. It is predominantly found in the astrocytes which are the most abundant subtypes of glial cells in the brain and spinal cord. As a marker protein of astrocytes, GFAP may exert a variety of physiological effects in neurological diseases. For example, previous published literatures showed that autoimmune GFAP astrocytopathy is an inflammatory disease of the central nervous system (CNS). Moreover, the studies of GFAP in brain tumors mainly focus on the predictive value of tumor volume. Furthermore, using biomarkers in the early setting will lead to a simplified and standardized way to estimate the poor outcome in traumatic brain injury (TBI) and ischemic stroke. Recently, observational studies revealed that cerebrospinal fluid (CSF) GFAP, as a valuable potential diagnostic biomarker for neurosyphilis, had a sensitivity of 76.60% and specificity of 85.56%. The reason plasma GFAP could serve as a promising biomarker for diagnosis and prediction of Alzheimer's disease (AD) is that it effectively distinguished AD dementia from multiple neurodegenerative diseases and predicted the individual risk of AD progression. In addition, GFAP can be helpful in differentiating relapsing-remitting multiple sclerosis (RRMS) versus progressive MS (PMS). This review article aims to provide an overview of GFAP in the prediction of clinical progression in neuroinflammation, brain tumors, TBI, ischemic stroke, genetic disorders, neurodegeneration and other diseases in the CNS and to explore the potential therapeutic methods.

Pooled analysis of patients with inherited prion disease caused by two- to twelve-octapeptide repeat insertions in the prion protein gene (PRNP)

Inherited prion diseases caused by two- to twelve-octapeptide repeat insertions (OPRIs) in the prion protein gene (PRNP) show significant clinical heterogeneity. This study describes a family with two new cases with a 4-OPRI mutation and two asymptomatic mutation carriers. The pooled analysis summarizes all cases reported in the literature to date and describes the relation between survival, age of onset, number of OPRI and codon 129 polymorphism. MEDLINE and Google Scholar were queried from database inception up to December 31, 2022. Age of onset was compared per number of OPRI and per codon 129 polymorphism using the Kruskal-Wallis and Wilcoxon-Mann-Whitney tests, respectively. Disease duration was modeled non-parametrically by a Kaplan-Meier model and semi-parametrically by a Cox model. This study comprised 164 patients. Lower number of OPRI and presence of valine (cis-V) versus methionine (cis-M) on codon 129 were associated with an older age of onset (P < 0.001 and P = 0.025, respectively) and shorter disease duration (P < 0.001 and P = 0.003, respectively). Within patients with 5- or more OPRI codon cis-V remained significantly associated with a shorter disease duration. Codon 129 homozygosity versus heterozygosity was not significantly associated with age of onset or disease duration (P = 0.076 and P = 0.409, respectively). This study summarized the largest cohort of patients with two- to twelve-OPRI to date. Lower number of OPRI and codon 129 cis-V is associated with an older age of onset and shorter disease duration, while homozygosity or heterozygosity on codon 129 was not.

MRI abnormalities in Creutzfeldt-Jakob disease and other rapidly progressive dementia

OBJECTIVE

To investigate brain MRI abnormalities in a cohort of patients with rapidly progressive dementia (RPD) with and without a diagnosis of Creutzfeldt-Jakob disease (CJD).

METHODS

One hundred and seven patients with diagnosis of prion disease (60 with definite sCJD, 33 with probable sCJD and 14 with genetic prion disease) and 40 non-prion related RPD patients (npRPD) underwent brain MRI including DWI and FLAIR. MRIs were evaluated with a semiquantitative rating score, which separately considered abnormal signal extent and intensity in 22 brain regions. Clinical findings at onset, disease duration, cerebrospinal-fluid 14-3-3 and t-tau protein levels, and EEG data were recorded.

RESULTS

Among patients with definite/probable diagnosis of CJD or genetic prion disease, 2/107 had normal DWI-MRI: in one patient a 2-months follow-up DWI-MRI showed CJD-related changes while the other had autopsy-proven CJD despite no DWI abnormalities 282 days after clinical onset. CJD-related cortical changes were detected in all lobes and involvement of thalamus was common. In the npRPD groups, 6/40 patients showed DWI alterations that clustered in three different patterns: (1) minimal/doubtful signal alterations (limbic encephalitis, dementia with Lewy bodies); (2) clearly suggestive of alternative diagnoses (status epilepticus, Wernicke or metabolic encephalopathy); (3) highly suggestive of CJD (mitochondrial disease), though cortical swelling let exclude CJD.

CONCLUSIONS

In the diagnostic work-up of RPD, negative/doubtful DWI makes CJD diagnosis rather unlikely, while specific DWI patterns help differentiating CJD from alternative diagnoses. The pulvinar sign is not exclusive of the variant form.

Gut microbiota and metabolome in sporadic Creutzfeldt-Jakob disease

BACKGROUND

Gut dysbiosis and the resulting changes in the metabolites have been associated with neurological diseases. However, the relationship between the gut microbiota and sporadic Creutzfeldt-Jakob disease (sCJD) need to be clarified. The aim of this study was to evaluate the changes in the composition of gut microbiota and metabolome accompanying sCJD, and determine their correlation with disease severity.

METHODS

Fecal samples were collected from 25 sCJD patients and 23 healthy controls. The composition of the fecal microbiota and metabolites was respectively analyzed by 16S ribosomal RNA sequencing and untargeted metabolomics. The correlation of gut microbiota and metabolites with MMSE, MoCA and MRC scores was analyzed.

RESULTS

The sCJD patients showed significant differences in the composition of gut microbiota and metabolites relative to the healthy controls. Several bacteria taxa in sCJD patients were increased at genus level, such as Turicibacter, norank_f_Christensenellaceae, Eisenbergiella, Bilophila and Holdemania. A total of 547 differential metabolites were identified between these two groups (VIP > 1, FDR p < 0.05). As per KEGG analysis, the metabolites related to the biosynthesis of phenylpropanoids, especially biochanin A, showed the most obvious decrease in the sCJD group. In addition, most metabolites involved in the pathways related to linoleic acid metabolism and steroid hormone biosynthesis were associated with MRC scale.

CONCLUSION

Our findings provide new insights into the relationship between gut microbiota and metabolites and sCJD. Some compounds, especially those related to the biosynthesis of phenylpropanoids were significantly altered in patients with sCJD, and those related to linoleic acid metabolism and steroid hormone biosynthesis might be biomarkers of evaluating disease severity.

Magnetic resonance imaging arterial spin labeling hypoperfusion with diffusion-weighted image hyperintensity is useful for diagnostic imaging of Creutzfeldt-Jakob disease

Background and objectives

Magnetic resonance imaging with arterial spin labeling (ASL) perfusion imaging is a noninvasive method for quantifying cerebral blood flow (CBF). We aimed to evaluate the clinical utility of ASL perfusion imaging to aid in the diagnosis of Creutzfeldt-Jakob disease (CJD).

Methods

This retrospective study enrolled 10 clinically diagnosed with probable sporadic CJD (sCJD) based on the National CJD Research & Surveillance Unit and EuroCJD criteria and 18 healthy controls (HCs). Diffusion-weighted images (DWIs), CBF images obtained from ASL, N-isopropyl-(123I)-p-iodoamphetamine (123IMP)-single-photon emission computed tomography (SPECT) images, and 18F-fluorodeoxyglucose (18FDG)-positron emission tomography (PET) images were analyzed. First, the cortical values obtained using volume-of-interest (VOI) analysis were normalized using the global mean in each modality. The cortical regions were classified into DWI-High (≥ +1 SD) and DWI-Normal (< +1 SD) regions according to the DWI-intensity values. The normalized cortical values were compared between the two regions for each modality. Second, each modality value was defined as ASL hypoperfusion (< -1 SD), SPECT hypoperfusion (< -1 SD), and PET low accumulation (< -1 SD). The overall agreement rate of DWIs with ASL-CBF, SPECT, and PET was calculated. Third, regression analyses between the normalized ASL-CBF values and normalized SPECT or PET values derived from the VOIs were performed using a scatter plot.

Results

The mean values of ASL-CBF (N = 10), 123IMP-SPECT (N = 8), and 18FDG-PET (N = 3) in DWI-High regions were significantly lower than those in the DWI-Normal regions (p < 0.001 for all); however, HCs (N = 18) showed no significant differences in ASL-CBF between the two regions. The overall agreement rate of DWI (high or normal) with ASL-CBF (hypoperfusion or normal) (81.8%) was similar to that of SPECT (85.2%) and PET (78.5%) in CJD. The regression analysis showed that the normalized ASL-CBF values significantly correlated with the normalized SPECT (r = 0.44, p < 0.001) and PET values (r = 0.46, p < 0.001) in CJD.

Discussion

Patients with CJD showed ASL hypoperfusion in lesions with DWI hyperintensity, suggesting that ASL-CBF could be beneficial for the diagnostic aid of CJD.

Potential Therapeutic Use of Stem Cells for Prion Diseases

Prion diseases are neurodegenerative disorders that are progressive, incurable, and deadly. The prion consists of PrPSc, the misfolded pathogenic isoform of the cellular prion protein (PrPC). PrPC is involved in a variety of physiological functions, including cellular proliferation, adhesion, differentiation, and neural development. Prion protein is expressed on the membrane surface of a variety of stem cells (SCs), where it plays an important role in the pluripotency and self-renewal matrix, as well as in SC differentiation. SCs have been found to multiply the pathogenic form of the prion protein, implying their potential as an in vitro model for prion diseases. Furthermore, due to their capability to self-renew, differentiate, immunomodulate, and regenerate tissue, SCs are prospective cell treatments in many neurodegenerative conditions, including prion diseases. Regenerative medicine has become a new revolution in disease treatment in recent years, particularly with the introduction of SC therapy. Here, we review the data demonstrating prion diseases' biology and molecular mechanism. SC biology, therapeutic potential, and its role in understanding prion disease mechanisms are highlighted. Moreover, we summarize preclinical studies that use SCs in prion diseases.

Metabolic Brain Changes Can Predict the Underlying Pathology in Neurodegenerative Brain Disorders: A Case Report of Sporadic Creutzfeldt-Jakob Disease with Concomitant Parkinson's Disease

The co-occurrence of multiple proteinopathies is being increasingly recognized in neurodegenerative disorders and poses a challenge in differential diagnosis and patient selection for clinical trials. Changes in brain metabolism captured by positron emission tomography (PET) with 18 F-fluorodeoxyglucose (FDG) allow us to differentiate between different neurodegenerative disorders either by visual exploration or by studying disease-specific metabolic networks in individual patients. However, the impact of multiple proteinopathies on brain metabolism and metabolic networks remains unknown due to the absence of pathological studies. In this case study, we present a 67-year-old patient with rapidly progressing dementia clinically diagnosed with probable sporadic Creutzfeldt-Jakob disease (sCJD). However, in addition to the expected pronounced cortical and subcortical hypometabolism characteristic of sCJD, the brain FDG PET revealed an intriguing finding of unexpected relative hypermetabolism in the bilateral putamina, raising suspicions of coexisting Parkinson's disease (PD). Additional investigation of disease-specific metabolic brain networks revealed elevated expression of both CJD-related pattern (CJDRP) and PD-related pattern (PDRP) networks. The patient eventually developed akinetic mutism and passed away seven weeks after symptom onset. Neuropathological examination confirmed neuropathological changes consistent with sCJD and the presence of Lewy bodies confirming PD pathology. Additionally, hyperphosphorylated tau and TDP-43 pathology were observed, a combination of four proteinopathies that had not been previously reported. Overall, this case provides valuable insights into the complex interplay of neurodegenerative pathologies and their impact on metabolic brain changes, emphasizing the role of metabolic brain imaging in evaluating potential presence of multiple proteinopathies.

The advances in the early and accurate diagnosis of Creutzfeldt-Jakob disease and other prion diseases: where are we today?

INTRODUCTION

Before the introduction of MRI diffusion-weighted images (DWI), the diagnosis of Creutzfeldt-Jakob disease (CJD) relied upon nonspecific findings including clinical symptoms, EEG abnormalities, and elevated levels of cerebrospinal fluid 14-3-3 protein. Subsequently, the use of DWI has improved diagnostic accuracy, but it sometimes remains difficult to differentiate CJD from encephalitis, epilepsy, and other dementing disorders. The revised diagnostic criteria include real-time quaking-induced conversion (RT-QuIC), detecting small amounts of CJD-specific prion protein, and clinically sensitive DWI. Combining these techniques has further improved diagnostic accuracy, enabling earlier diagnosis.

AREAS COVERED

Herein, the authors review the recent advances in diagnostic methods and revised diagnostic criteria for sporadic CJD. They also discuss other prion diseases, such as variant CJD and chronic wasting disease, where the emergence of new types is a concern.

EXPERT OPINION

Despite improvements in diagnostic methods and criteria, some subtypes of prion disease are still difficult to diagnose, and even the diagnosis using the most innovative RT-QuIC test remains a challenge in terms of accuracy and standardization. However, these revised criteria can be adapted to the emergence of new types of prion diseases. It is essential to continue careful surveillance and update information on the latest prion disease phenotypes.

Clinical and Genetic Characteristics of the Heidenhain Variant of Creutzfeldt-Jakob Disease

BACKGROUND

The Heidenhain variant of Creutzfeldt-Jakob disease (HvCJD), as a rare phenotype of CJD, has been under-recognized. We aim to elucidate the clinical and genetic features of HvCJD and investigate the differences of clinical features between genetic and sporadic HvCJD to improve our understanding of this rare subtype.

METHOD

HvCJD patients admitted to the Xuanwu Hospital from February 2012 to September 2022 were identified, and published reports on genetic HvCJD cases were also reviewed. The clinical and genetic features of HvCJD were summarized, and the clinical features between genetic and sporadic HvCJD were compared.

RESULTS

A total of 18 (7.9%) HvCJD patients were identified from 229 CJD cases. Blurred vision was the most common visual disturbance at the disease's onset, and the median duration of isolated visual symptoms was 30.0 (14.8-40.0) days. DWI hyperintensities could appear in the early stage, which might help with early diagnosis. Combined with previous studies, nine genetic HvCJD cases were identified. The most common mutation was V210I (4/9), and all patients (9/9) had methionine homozygosity (MM) at codon 129. Only 25% of cases had a family history of the disease. Compared to sporadic HvCJD, genetic HvCJD cases were more likely to present with non-blurred vision visual symptoms at onset and develop cortical blindness during the progression of the disease.

CONCLUSIONS

HvCJD not only could be sporadic, but also, it could be caused by different PRNP mutations. Sporadic HvCJD was more likely to present with blurred vision visual symptoms at onset, and genetic HvCJD was more likely to develop cortical blindness with the disease's progression.

Human prion diseases: An overview

Prion diseases are a group of neurodegenerative diseases. The disease-causing agent is a protein (PrP), that is normally produced in the nervous system, aggregated in an abnormal form. The abnormal protein, known as prion (PrP^Sc), is capable of self-propagation promoting the misfolding of the normal protein (PrP). These conditions can be acquired sporadically, genetically, or infectiously either by eating meat contaminated with prions or from iatrogenic exposure. The diagnosis of these diseases is often challenging. The use of highly sensitive and specific diagnostic tools, such as MRI and RT-QuIC, may aid in the diagnosis. Neuropathological examination of brain tissue ensures a definite diagnosis. At present, no treatment significantly improves the course of prion diseases; however, an early diagnosis is of paramount importance for patient care decision planning, infection control purposes, and genetic counseling.

Application of real-time quaking-induced conversion in Creutzfeldt-Jakob disease surveillance

BACKGROUND

Evaluation of the application of CSF real-time quaking-induced conversion in Creutzfeldt-Jakob disease surveillance to investigate test accuracy, influencing factors, and associations with disease incidence.

METHODS

In a prospective surveillance study, CSF real-time quaking-induced conversion was performed in patients with clinical suspicion of prion disease (2014-2022). Clinically or histochemically characterized patients with sporadic Creutzfeldt-Jakob disease (n = 888) and patients with final diagnosis of non-prion disease (n = 371) were included for accuracy and association studies.

RESULTS

The overall test sensitivity for sporadic Creutzfeldt-Jakob disease was 90% and the specificity 99%. Lower sensitivity was associated with early disease stage (p = 0.029) and longer survival (p < 0.001). The frequency of false positives was significantly higher in patients with inflammatory CNS diseases (3.7%) than in other diagnoses (0.4%, p = 0.027). The incidence increased from 1.7 per million person-years (2006-2017) to 2.0 after the test was added to diagnostic the criteria (2018-2021).

CONCLUSION

We validated high diagnostic accuracy of CSF real-time quaking-induced conversion but identified inflammatory brain disease as a potential source of (rare) false-positive results, indicating thorough consideration of this condition in the differential diagnosis of Creutzfeldt-Jakob disease. The surveillance improved after amendment of the diagnostic criteria, whereas the incidence showed no suggestive alterations during the COVID-19 pandemic.

The allure and pitfalls of the prion-like aggregation in neurodegeneration

Prion diseases are fatal neurodegenerative disorders where the formation of amyloids is thought to be infectious by templating their conformation on to natively-folded counterparts. Postulated nearly four decades ago, the search for the mechanism behind the conformational templating has proceeded to no avail. Here, we extend the thermodynamic hypothesis of protein folding (Anfinsen's dogma) to the amyloid phenomenon and illustrate that the amyloid conformation (cross-β) is one of two conformational states that are thermodynamically accessible to any protein sequence depending on concentration. A protein spontaneously assumes its native conformation below supersaturation and the amyloid cross-β conformation above supersaturation. The information to adopt the native conformation and the amyloid conformation is present in the primary sequence and the backbone of the protein, respectively, and does not require templating. The rate-limiting step for proteins to adopt the cross-β conformation of amyloid is termed nucleation, which can be catalyzed by surfaces (heterogeneous nucleation) or preformed amyloid fragments (seeding). Irrespective of the nucleation pathway, once triggered, amyloid formation proceeds spontaneously in fractal-like fashion, where the surfaces of the growing fibrils act as heterogeneous nucleation catalysts for new fibrils, a phenomenon known as secondary nucleation. This pattern is in contrast to the linear growth assumptions that the prion hypothesis necessitates for faithful prion strain replication. Additionally, the cross-β conformation buries the majority of the protein side chain inside the fibrils, making the fibrils inert, generic, and extremely stable. As such, the source of toxicity in prion disorders may come to a greater extent from the loss of proteins in their normal, soluble, and therefore functional state rather than from their transformation into stable, insoluble, nonfunctioning amyloids.

Corrigendum: PMCA-based detection of prions in the olfactory mucosa of patients with sporadic Creutzfeldt-Jakob disease

[This corrects the article DOI: 10.3389/fnagi.2022.848991.].

Human prion diseases and the prion protein - what is the current state of knowledge?

Prion diseases and the prion protein are only partially understood so far in many aspects. This explains the continued research on this topic, calling for an overview on the current state of knowledge. The main objective of the present review article is to provide a comprehensive up-to-date presentation of all major features of human prion diseases bridging the gap between basic research and clinical aspects. Starting with the prion protein, current insights concerning its physiological functions and the process of pathological conversion will be highlighted. Diagnostic, molecular, and clinical aspects of all human prion diseases will be discussed, including information concerning rare diseases like prion-associated amyloidoses and Huntington disease-like 1, as well as the question about a potential human threat due to the transmission of prions from prion diseases of other species such as chronic wasting disease. Finally, recent attempts to develop future therapeutic strategies will be addressed.

Amino Acid Substitution within Seven-Octapeptide Repeat Insertions in the Prion Protein Gene Associated with Short-Term Course

The majority of seven-octapeptide repeat insertion (7-OPRI) carriers exhibit relatively early onset and a slowly progressive course. We have presented three cases of 7-OPRI, including two that are rapidly progressing, and compared the clinical and ancillary characteristics of the short-term and long-term disease course, as well as factors that influence disease course. The clinical and ancillary features of three new 7-OPRI patients in a Chinese pedigree were analyzed. Global data on 7-OPRI cases were then collected by reviewing the literature, and the cases were grouped according to clinical duration as per the WHO sCJD criteria, with a two-year cut-off. A Chinese pedigree has a glycine-to-glutamate substitution within the 7-OPRI insertion, which enhances the hydrophilicity of the prion protein. Two cases in this pedigree had a short disease course (consistent with the typical clinical and ancillary features of sCJD). In addition, the members of this pedigree had a later onset (p < 0.001) and shorter disease course (p < 0.001) compared to previously reported 7-OPRI cases with 129 cis-M and a similar age of onset and disease course to that of cases with 129 cis-V. The 7-OPRI cases with a shorter clinical course (n = 4) had a later onset (p = 0.021), higher rate of hyperintensity on MRI (p = 0.029) and higher frequency of 129 cis-V (p = 0.066) compared to those with a longer clinical course (n = 13). The clinical presentation of 7-OPRI is significantly heterogeneous. Codon 129 cis-V and amino acid substitution within repeat insertions are possible contributors to the short-term disease course of 7-OPRI.

Creutzfeldt-Jakob Disease with Stroke-Like Symptoms: Case report

Creutzfeldt-Jakob disease (CJD) is a rare, progressive, and fatal prion disease. Often the first sign of CJD is rapidly progressive dementia, leading to memory loss, personality changes, and hallucinations. Myoclonus typically occurs in 90% of cases, but often may not be an initial symptom. Other frequently occurring psychiatric symptoms include depression, anxiety, paranoia, obsessive-compulsive symptoms, and psychosis. Speech disorder, loss of balance and coordination may also accompany. We present a case of CJD with sudden onset of right hemiparesis.

Thalamic-insomnia phenotype in E200K Creutzfeldt-Jakob disease: A PET/MRI study

•

gCJD with PRNP E200K mutations frequently manifested as a thalamic-insomnia phenotype.

•

Some features of the E200K phenotype are somewhere in between typical CJD and FFI.

•

PET is a sensitive approach to help identify the functional changes in prion disease.

Background

Insomnia and thalamic involvement were frequently reported in patients with genetic Creutzfeldt-Jakob disease (gCJD) with E200K mutations, suggesting E200K might have discrepancy with typical sporadic CJD (sCJD). The study aimed to explore the clinical and neuroimage characteristics of genetic E200K CJD patients by comprehensive neuroimage analysis.

Methods

Six patients with gCJD carried E200K mutation on Prion Protein (PRNP) gene, 13 patients with sporadic CJD, and 22 age- and sex-matched normal controls were enrolled in the study. All participants completed a hybrid positron emission tomography/magnetic resonance imaging (PET/MRI) examination. Signal intensity on diffusion-weighted imaging (DWI) and metabolism on PET were visually rating analyzed, statistical parameter mapping analysis was performed on PET and 3D-T1 images. Clinical and imaging characteristics were compared between the E200K, sCJD, and control groups.

Results

There was no group difference in age or gender among the E200K, sCJD, and control groups. Insomnia was a primary complaint in patients with E200K gCJD (4/2 versus 1/12, p = 0.007). Hyperintensity on DWI and hypometabolism on PET of the thalamus were observed during visual rating analysis of images in patients with E200K gCJD. Gray matter atrophy (uncorrected p < 0.001) and hypometabolism (uncorrected p < 0.001) of the thalamus were more pronounced in patients with E200K gCJD.

Conclusion

The clinical and imaging characteristics of patients with gCJD with PRNP E200K mutations manifested as a thalamic-insomnia phenotype. PET is a sensitive approach to help identify the functional changes in the thalamus in prion disease.

[A case of Creutzfeldt-Jakob disease presenting with nonconvulsive status epilepticus in the early stages]

A 64-year-old Japanese woman presented with 1 week of recurrent convulsive seizures. At the time of admission, she was in a coma and did not present with convulsions. Intravenous diazepam administration improved her consciousness, although severe psychomotor excitement developed. Brain MRI demonstrated diffusion restriction in the cerebral cortex of the right hemisphere. Electroencephalography (EEG) showed periodic discharges centered around the parietal regions with right-sided dominance. Nonconvulsive status epilepticus (NCSE) was suspected, and the patient was actively treated with anti-epileptic drugs. She developed akinetic mutism and generalized myoclonus 1 month after admission. Follow-up EEG studies disclosed periodic synchronous discharges. Abnormal prion protein in the cerebral fluid was detected using a real-time quaking-induced conversion assay. The clinical diagnosis in the present case was sporadic Creutzfeldt-Jakob disease (CJD). Seizures as an initial symptom in patients with CJD are relatively rare. Our case suggests that CJD should be considered as a differential diagnosis when a patient presents with refractory NCSE.

[A case of genetic Creutzfeldt-Jakob disease that required differential diagnosis of acute encephalopathy associated with Sjogren's syndrome]

An 86-year-old female was admitted to our hospital with acute progressive gait disturbance and cognitive impairment. Brain MR diffusion weighted imaging revealed abnormal high signal intensities in the bilateral hemispheres, dominantly in the frontal lobe. We first suspected acute encephalopathy due to Creutzfeldt-Jakob disease (CJD) from her clinical information. At the same time, we could not negate the possibility of Sjögren's syndrome (SjS) -related encephalopathy based on the abnormal findings on brain MRI and positive anti-SS-A antibody in the serum. After consulting with an otorhinolaryngologist and a pathologist, biopsy of the salivary gland was performed with a strict precaution against infection of prion virus. Pathological examination of the biopsy specimen showed accumulation of many lymphocytes around the gland, which satisfied grade 4 in the Greenspan classification. A definite diagnosis of SjS was made based on the pathological findings, and intravenous high dose methylprednisolone followed by oral prednisolone were administered for suspected SjS-related encephalopathy. However, the neurological symptoms did not improve and we judged that SjS-related encephalopathy was unlikely. The poor response to steroid therapy and the presence of tau protein, strongly positive 14-3-3 protein and a codon 180: Val/Ile mutation in the cerebrospinal fluid finally led to a clinical diagnosis of genetic CJD. In-hospital cooperation in terms of infection prevention is important when performing invasive procedure in the case of suspected CJD to distinguish treatable encephalopathy.

The risk of Creutzfeldt-Jakob disease infection in cadaveric surgical training

The usefulness of cadaver surgical training in the clinical field is already well known. In Japan, the number of universities introducing cadaver surgical training is increasing. In addition to formalin fixation, various fixation methods are used, such as the Thiel method, saturated salt solution method, N-vinyl-2-pyrrolidone method, and fresh-frozen cadavers. Although protection against infections during fixation and cadaver surgical training has been implemented in most universities, it is currently inadequate. Furthermore, the possibility of undiagnosed infectious diseases in donors cannot be excluded. Prion diseases, such as Creutzfeldt-Jakob disease, are relatively rare, but they are fatal, with no effective treatment. The abnormal prion protein that causes prion diseases is resistant to formaldehyde and cannot be inactivated by all methods of cadaver fixation presently in use. Recently developed real-time quaking-induced conversion has been reported to be a useful screening method for prion infection. In addition, this article aims to raise awareness of prion diseases in cadaver surgical training by reviewing the current understanding of prion diseases in cadavers and their screening methods.

Three cases of Creutzfeldt-Jakob disease presenting with a predominant dysexecutive syndrome

Creutzfeldt-Jakob disease (CJD) is a rare, uniformly fatal prion disease. Although CJD commonly presents with rapidly progressive dementia, ataxia, and myoclonus, substantial clinicopathological heterogeneity is observed in clinical practice. Unusual and predominantly cognitive clinical manifestations of CJD mimicking common dementia syndromes are known to pose as an obstacle to early diagnosis and prognosis. We report a series of three patients with probable or definite CJD (one male and two females, ages 52, 58 and 68) who presented to our tertiary behavioral neurology clinic at Mayo Clinic Rochester that met criteria for a newly defined progressive dysexecutive syndrome. Glucose hypometabolism patterns assessed by ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) strongly resembled those of dysexecutive variant of Alzheimer's disease (dAD). However, magnetic resonance imaging (MRI) demonstrated restricted diffusion in neocortical areas and deep nuclei, while cerebrospinal fluid biomarkers indicated abnormal levels of 14-3-3, total-tau, and prion seeding activity (RT-QuIC), establishing the diagnosis of CJD. Electroencephalogram (EEG) additionally revealed features previously documented in atypical cases of CJD. This series of clinical cases demonstrates that CJD can present with a predominantly dysexecutive syndrome and FDG-PET hypometabolism typically seen in dAD. This prompts for the need to integrate information on clinical course with multimodal imaging and fluid biomarkers to provide a precise etiology for dementia syndromes. This has important clinical implications for the diagnosis and prognosis of CJD in the context of emerging clinical characterization of progressive dysexecutive syndromes in neurodegenerative diseases like dAD.

Body-first Parkinson's disease and variant Creutzfeldt-Jakob disease - similar or different?

In several neurodegenerative disorders, proteins that typically exhibit an α-helical structure misfold into an amyloid conformation rich in β-sheet content. Through a self-templating mechanism, these amyloids are able to induce additional protein misfolding, facilitating their propagation throughout the central nervous system. This disease mechanism was originally identified for the prion protein (PrP), which misfolds into PrP^Sc in a number of disorders, including variant Creutzfeldt-Jakob disease (vCJD) and bovine spongiform encephalopathy (BSE). More recently, the prion mechanism of disease was expanded to include other proteins that rely on this self-templating mechanism to cause progressive degeneration, including α-synuclein misfolding in Parkinson's disease (PD). Several studies now suggest that PD patients can be subcategorized based on where in the body misfolded α-synuclein originates, either the brain or the gut, similar to patients developing sporadic CJD or vCJD. In this review, we discuss the human and animal model data indicating that α-synuclein and PrP^Sc misfolding originates in the gut in body-first PD and vCJD, and summarize the data identifying the role of the autonomic nervous system in the gut-brain axis of both diseases.

PMCA-Based Detection of Prions in the Olfactory Mucosa of Patients With Sporadic Creutzfeldt-Jakob Disease

Sporadic Creutzfeldt-Jakob disease (sCJD) is a rare neurodegenerative disorder caused by the conformational conversion of the prion protein (PrP^C) into an abnormally folded form, named prion (or PrP^Sc). The combination of the polymorphism at codon 129 of the PrP gene (coding either methionine or valine) with the biochemical feature of the proteinase-K resistant PrP (generating either PrP^Sc type 1 or 2) gives rise to different PrP^Sc strains, which cause variable phenotypes of sCJD. The definitive diagnosis of sCJD and its classification can be achieved only post-mortem after PrP^Sc identification and characterization in the brain. By exploiting the Real-Time Quaking-Induced Conversion (RT-QuIC) assay, traces of PrP^Sc were found in the olfactory mucosa (OM) of sCJD patients, thus demonstrating that PrP^Sc is not confined to the brain. Here, we have optimized another technique, named protein misfolding cyclic amplification (PMCA) for detecting PrP^Sc in OM samples of sCJD patients. OM samples were collected from 27 sCJD and 2 genetic CJD patients (E200K). Samples from 34 patients with other neurodegenerative disorders were included as controls. Brains were collected from 26 sCJD patients and 16 of them underwent OM collection. Brain and OM samples were subjected to PMCA using the brains of transgenic mice expressing human PrP^C with methionine at codon 129 as reaction substrates. The amplified products were analyzed by Western blot after proteinase K digestion. Quantitative PMCA was performed to estimate PrP^Sc concentration in OM. PMCA enabled the detection of prions in OM samples with 79.3% sensitivity and 100% specificity. Except for a few cases, a predominant type 1 PrP^Sc was generated, regardless of the tissues analyzed. Notably, all amplified PrP^Sc were less resistant to PK compared to the original strain. In conclusion, although the optimized PMCA did not consent to recognize sCJD subtypes from the analysis of OM collected from living patients, it enabled us to estimate for the first time the amount of prions accumulating in this biological tissue. Further assay optimizations are needed to faithfully amplify peripheral prions whose recognition could lead to a better diagnosis and selection of patients for future clinical trials.

Parkinson's disease with a typical clinical course of 17 years overlapped by Creutzfeldt-Jakob disease: an autopsy case report

BACKGROUND

Late-stage Parkinson's disease (PD) often presents with neuropsychiatric symptoms such as dementia, psychosis, excessive daytime sleepiness, apathy, depression, and anxiety. However, neuropsychiatric symptoms are the cardinal features of Creutzfeldt-Jakob disease (CJD), raising the possibility that CJD may be an overlooked condition when it accompanies late-stage PD.

CASE PRESENTATION

We describe a female autopsy case of PD with a typical clinical course of 17 years, in which CJD overlapped with PD during the final year of the patient's life. The patient died aged 85 years. Neuropathological features included widespread Lewy body-related α-synucleinopathy predominantly in the brainstem and limbic system, as well as the typical pathology of methionine/methionine type 1 CJD in the brain.

CONCLUSIONS

Our case demonstrates the clinicopathological co-occurrence of PD and CJD in a sporadic patient. The possibility of mixed pathology, including prion pathology, should be taken into account when neuropsychiatric symptoms are noted during the disease course of PD.

Nutrigenomic Studies on the Ameliorative Effect of Enzyme-Digested Phycocyanin in Alzheimer's Disease Model Mice

Alzheimer’s disease (AD) is the most common form of dementia, and the cognitive impairments associated with this degenerative disease seriously affect daily life. Nutraceuticals for the prevention or delay of AD are urgently needed. It has been increasingly observed that phycocyanin (PC) exerts neuroprotective effects. AD model mice intracerebroventricularly injected with amyloid beta-peptide 25–35 (Aβ_25–35) at 10 nmol/head displayed significant cognitive impairment in the spontaneous alternation test. Cognitive impairment was significantly ameliorated in mice treated with 750 mg/kg of enzyme-digested (ED) PC by daily oral administration for 22 consecutive days. Application of DNA microarray data on hippocampal gene expression to nutrigenomics studies revealed that oral EDPC counteracted the aberrant expression of 35 genes, including Prnp, Cct4, Vegfd (Figf), Map9 (Mtap9), Pik3cg, Zfand5, Endog, and Hbq1a. These results suggest that oral administration of EDPC ameliorated cognitive impairment in AD model mice by maintaining and/or restoring normal gene expression patterns in the hippocampus.

Differential Accumulation of Misfolded Prion Strains in Natural Hosts of Prion Diseases

Prion diseases, also known as transmissible spongiform encephalopathies (TSEs), are a group of neurodegenerative protein misfolding diseases that invariably cause death. TSEs occur when the endogenous cellular prion protein (PrP^C) misfolds to form the pathological prion protein (PrP^Sc), which templates further conversion of PrP^C to PrP^Sc, accumulates, and initiates a cascade of pathologic processes in cells and tissues. Different strains of prion disease within a species are thought to arise from the differential misfolding of the prion protein and have different clinical phenotypes. Different strains of prion disease may also result in differential accumulation of PrP^Sc in brain regions and tissues of natural hosts. Here, we review differential accumulation that occurs in the retinal ganglion cells, cerebellar cortex and white matter, and plexuses of the enteric nervous system in cattle with bovine spongiform encephalopathy, sheep and goats with scrapie, cervids with chronic wasting disease, and humans with prion diseases. By characterizing TSEs in their natural host, we can better understand the pathogenesis of different prion strains. This information is valuable in the pursuit of evaluating and discovering potential biomarkers and therapeutics for prion diseases.

COVID-19-associated encephalitis or Creutzfeldt-Jakob disease: a case report

Background: Accurate diagnosis and management of patients with rapidly progressive dementia may be challenging during the COVID-19 pandemic, which has negatively influenced the diagnostic performances, medical resource allocation and routine care for all non-COVID-19 diseases. Case Presentation: We herein present a case of a 57‐year‐old male with rapidly progressive cognitive decline, headache, diplopia, myalgia, unsteady gait, aggression, depression, insomnia, hallucinations and delusions of persecution. COVID-19-associated encephalitis was briefly considered as a differential diagnosis. However, this hypothesis was rejected upon further investigation. A final diagnosis of sporadic Creutzfeldt–Jakob disease was made. Conclusion: A timely and accurate diagnosis of Creutzfeldt–Jakob disease gives patients and their families the chance to receive a good standard of healthcare and avoid extensive evaluations for other conditions.

Clinical and Radiological Deterioration in a Case of Creutzfeldt-Jakob Disease following SARS-CoV-2 Infection: Hints to Accelerated Age-Dependent Neurodegeneration

Systemic inflammation and the host immune responses associated with certain viral infections may accelerate the rate of neurodegeneration in patients with Creutzfeldt–Jakob disease (CJD), a rare, transmissible neurodegenerative disease. However, the effects of the newly emerged SARS-CoV-2 infection on the pathogenesis of CJD are unknown. In this study, we describe the case of an elderly female patient with sporadic CJD that exhibited clinical deterioration with the emergence of seizures and radiological neurodegenerative progression following an infection with SARS-CoV-2 and severe COVID-19. Despite efforts to control the progression of the disease, a dismal outcome ensued. This report further evidences the age-dependent neurological effects of SARS-CoV-2 infection and proposes a vulnerability to CJD and increased CJD progression following COVID-19.

Case Report: Extremely Early Detection of Preclinical Magnetic Resonance Imaging Abnormality in Creutzfeldt-Jakob Disease With the V180I Mutation

The diagnosis of presymptomatic Creutzfeldt–Jakob disease (CJD) is challenging. The levels of total tau protein, 14-3-3 protein, and protease-resistant isoform of prion protein (PrP^res) in the cerebrospinal fluid; periodic sharp wave complexes on electroencephalography; and diffusion-weighted imaging (DWI) of brain magnetic resonance imaging (MRI) have all been used to diagnose symptomatic CJD, but none of these markers have been established in the diagnosis of presymptomatic CJD. Here, we report a case of genetic CJD with the V180I mutation in which a small punctate cortical hyperintensity was detected on DWI 6 months before symptom onset and 9 months before diagnosis. Presymptomatic CJD is currently impossible to diagnose because of the lack of established early diagnostic markers. However, since MRI is increasingly used in daily clinical practice, the chance detection of such DWI abnormalities would have important implications in terms of providing a clue to examine a highly specific early diagnostic marker to be developed in the future for CJD. This will allow presymptomatic intervention by disease-modifying therapy in the near future.

The First Sporadic Creutzfeldt-Jakob Disease Case with a Rare Molecular Subtype VV1 and 1-Octapeptide Repeat Deletion in PRNP

In the present manuscript, we report the clinical presentation and challenging diagnostic work-up of a sporadic Creutzfeldt–Jakob disease patient with confirmed VV1 subtype and heterozygous 1-octapeptide repeat deletion in the prion protein gene. The described patient was a 58-year-old woman. Interestingly, most of the reported patients with the VV1 subtype to date are men with an average age of 44 years at disease onset. The patient was observed clinically from symptoms onset until her death 22 months later. This report describes the patient’s insidious clinical evolution and the paraclinical examinations and pathology reports gathered at different time points of disease progression. Unfortunately, the absence of typical clinical and paraclinical features of classic sporadic Creutzfeldt–Jakob disease made the brain biopsy surgery necessary. This case report illustrates the diagnostic difficulties posed by the phenotypic heterogeneity of sporadic Creutzfeldt–Jakob disease and urges clinicians to consider this diagnosis even in patients who do not fulfil the typical clinical disease criteria. Furthermore, it highlights the need for real-time quaking-induced conversion method adaptation for detection of rare sporadic Creutzfeldt–Jakob disease subtypes with certain prion protein gene variants.

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.

Genetic Prion Disease: Insight from the Features and Experience of China National Surveillance for Creutzfeldt-Jakob Disease

Human genetic prion diseases (gPrDs) are directly associated with mutations and insertions in the PRNP (Prion Protein) gene. We collected and analyzed the data of 218 Chinese gPrD patients identified between Jan 2006 and June 2020. Nineteen different subtypes were identified and gPrDs accounted for 10.9% of all diagnosed PrDs within the same period. Some subtypes of gPrDs showed a degree of geographic association. The age at onset of Chinese gPrDs peaked in the 50-59 year group. Gerstmann-Sträussler-Scheinker syndrome (GSS) and fatal familial insomnia (FFI) cases usually displayed clinical symptoms earlier than genetic Creutzfeldt-Jakob disease (gCJD) patients with point mutations. A family history was more frequently recalled in P105L GSS and D178N FFI patients than T188K and E200K patients. None of the E196A gCJD patients reported a family history. The gCJD cases with point mutations always developed clinical manifestations typical of sporadic CJD (sCJD). EEG examination was not sensitive for gPrDs. sCJD-associated abnormalities on MRI were found in high proportions of GSS and gCJD patients. CSF 14-3-3 positivity was frequently detected in gCJD patients. Increased CSF tau was found in more than half of FFI and T188K gCJD cases, and an even higher proportion of E196A and E200K gCJD patients. 63.6% of P105L GSS cases showed a positive reaction in cerebrospinal fluid RT-QuIC. GSS and FFI cases had longer durations than most subtypes of gCJD. This is one of the largest studies of gPrDs in East Asians, and the illness profile of Chinese gPrDs is clearly distinct. Extremely high proportions of T188K and E196A occur among Chinese gPrDs; these mutations are rarely reported in Caucasians and Japanese.

Case Report: Paraneoplastic Hashimoto's Encephalopathy Associated With Lymphomatosis Cerebri With Periodic Synchronous Discharges Resembling Creutzfeldt-Jakob Disease

Hashimoto's encephalopathy (HE) is an autoimmune encephalopathy that presents with various clinical symptoms, including cognitive deterioration, convulsive seizures, and personality changes. HE is associated with thyroid autoimmunity; however, few cases have been reported to develop as paraneoplastic syndrome. Herein, we report the case of a 73-year-old woman with onset of rapidly progressive dementia. Brain magnetic resonance imaging showed diffuse T2 hyperintensity areas involving the bilateral cerebral white matter, right midbrain tegmental area, left cerebral peduncle, and right middle cerebellar peduncle without clear diffusion hyperintensities and gadolinium enhancement. Her neurological symptoms worsened rapidly, and she presented with the apallic syndrome. Electroencephalogram showed periodic synchronous discharge, suggestive of Creutzfeldt–Jakob disease. However, a brain biopsy revealed infiltration of atypical lymphoid cells expressing CD20, and the anti-NH2 terminal of the α-enolase antibody was detected, diagnosing the complication with lymphomatosis cerebri and HE. High-dose intravenous methylprednisolone therapy and oral prednisolone with whole cranial irradiation enabled her to have simple conversations and consume food orally; however, severe cognitive impairment persisted. Although HE is a rare complication of malignant lymphoma, clinicians should be aware that it could be strongly suspected if the clinical symptoms worsen in the absence of imaging changes.

Propagation of CJD Prions in Primary Murine Glia Cells Expressing Human PrPc

There are various existing cell models for the propagation of animal prions. However, in vitro propagation of human prions has been a long-standing challenge. This study presents the establishment of a long-term primary murine glia culture expressing the human prion protein homozygous for methionine at codon 129, which allows in vitro propagation of Creutzfeldt-Jakob disease (CJD) prions (variant CJD (vCJD) and sporadic CJD (sCJD) type MM2). Prion propagation could be detected by Western blotting of pathological proteinase K-resistant prion protein (PrPSc) from 120 days post exposure. The accumulation of PrPSc could be intensified by adding a cationic lipid mixture to the infectious brain homogenate at the time of infection. Stable propagation of human prions in a long-term murine glia cell culture represents a new tool for future drug development and for mechanistic studies in the field of human prion biology. In addition, our cell model can reduce the need for bioassays with human prions and thereby contributes to further implementation of the 3R principles aiming at replacement, reduction and refinement of animal experiments.

Creutzfeldt-Jakob disease in pregnancy: the use of modified RT-QuIC to determine infectivity in placental tissues

Sporadic Creutzfeldt–Jakob Disease (sCJD) rarely affects women of childbearing age. There is currently no evidence of vertical transmission. Given the biosafety implications of performing Caesarean sections (C-section) in these patients, we used sensitive real-time quaking-induced conversion (RT-QuIC) assays to test for the infectious prion protein (PrP^Sc) in products of gestation. A 35-year-old woman with sCJD presented in her 10^th gestational week with an eight month history of progressive cognitive impairment. During C-section, amniotic fluid, cord blood and placental tissue were collected and analysed using RT-QuIC protocols adapted for use with these tissues. The patient’s diagnosis of sCJD, MM2 subtype, was confirmed at autopsy. There were borderline positive results in one sampled area of the placenta, but otherwise the cord blood and amniotic fluid were negative on our RT-QuIC assays. A healthy baby was delivered via C-section at 36 weeks and 3 days gestational age, with no evidence of neurological disease to date. We conclude that precautions should be taken with products of gestation, but the level of PrP^Sc is extremely low.

White Matter Integrity Involvement in the Preclinical Stage of Familial Creutzfeldt-Jakob Disease: A Diffusion Tensor Imaging Study

Objective

The objective of the study was to explore patterns of white matter (WM) alteration in preclinical stage familial Creutzfeldt–Jakob disease (fCJD) using diffusion tensor imaging (DTI).

Methods

Seven asymptomatic carriers of the PRNP G114V mutation and six non-carriers were recruited from the same fCJD kindred and follow-up obtained from all asymptomatic carriers and two non-carriers 2 years later. Overlapping WM patterns were also explored in asymptomatic carriers and symptomatic CJD patients. All participants underwent clinical and neuropsychological assessments and DTI at baseline and follow-up. DTI data were subjected to whole-brain voxel-wise analysis of fractional anisotropy (FA) and mean diffusivity (MD) in WM using tract-based spatial statistics. Three comparisons were conducted: baseline carriers against non-carriers (baseline analysis), changes after 2 years in carriers (follow-up analysis), and differences between patients with symptomatic CJD and healthy controls (CJD patient analysis).

Results

Neither carriers nor non-carriers developed any neurological symptoms during 2 years of follow-up. Baseline analysis showed no differences between the carrier and non-carrier groups in MD and FA. Follow-up analysis showed significantly increased MD in multiple WM tracts, among which increased MD in the bilateral superior longitudinal fasciculus, bilateral anterior thalamic radiation, bilateral cingulate gyrus, and left uncinate fasciculus overlapped the patterns observed in patients with symptomatic CJD.

Conclusion

Changes in integrity within multiple WM tracts can be detected during the preclinical stage of fCJD.

[Inherited Creutzfeldt-Jakob disease with four-octapeptide repeat insertional mutation in the prion gene]

We report a case of a 60-year-old man who presented with symptoms of memory loss, gait disorder, and sluggish movement. We considered both Parkinson's disease and multiple system atrophy as possible diagnoses and consequently hospitalized the patient owing to the worsening symptoms and the development of consciousness disorder. During the course of the disease, dementia, loss of consciousness, and movement disorders worsened rapidly within one year after admission, and the patient eventually developed mutism. The significant clinical characteristics of our case included no myoclonus and involuntary tremors in the extremities. There was no periodic synchronous discharge on electro-encephalography and cranial MRI with diffusion-weighted images showed no high-intensity findings in cortex. Prion protein genetic analysis identified four repeated insertional mutations in the octapeptide repeat (OPR) region, and the patient was diagnosed with inherited Creutzfeldt-Jakob disease. Cases of OPR insertional mutations are a few in Japan and occur in about 10% of population in Europe. Creutzfeldt-Jakob disease with OPR insertional mutation shows various clinical manifestations and atypical findings on electroencephalography and cranial MRI. Diagnosing for Creutzfeldt-Jakob disease with OPR insertional mutation is important in Prion protein genetic analysis.

Vaporized Hydrogen Peroxide and Ozone Gas Synergistically Reduce Prion Infectivity on Stainless Steel Wire

Prions are infectious agents causing prion diseases, which include Creutzfeldt–Jakob disease (CJD) in humans. Several cases have been reported to be transmitted through medical instruments that were used for preclinical CJD patients, raising public health concerns on iatrogenic transmissions of the disease. Since preclinical CJD patients are currently difficult to identify, medical instruments need to be adequately sterilized so as not to transmit the disease. In this study, we investigated the sterilizing activity of two oxidizing agents, ozone gas and vaporized hydrogen peroxide, against prions fixed on stainless steel wires using a mouse bioassay. Mice intracerebrally implanted with prion-contaminated stainless steel wires treated with ozone gas or vaporized hydrogen peroxide developed prion disease later than those implanted with control prion-contaminated stainless steel wires, indicating that ozone gas and vaporized hydrogen peroxide could reduce prion infectivity on wires. Incubation times were further elongated in mice implanted with prion-contaminated stainless steel wires treated with ozone gas-mixed vaporized hydrogen peroxide, indicating that ozone gas mixed with vaporized hydrogen peroxide reduces prions on these wires more potently than ozone gas or vaporized hydrogen peroxide. These results suggest that ozone gas mixed with vaporized hydrogen peroxide might be more useful for prion sterilization than ozone gas or vaporized hydrogen peroxide alone.

Extracellular Protein Aggregates Colocalization and Neuronal Dystrophy in Comorbid Alzheimer's and Creutzfeldt-Jakob Disease: A Micromorphological Pilot Study on 20 Brains

Alzheimer’s disease (AD) and sporadic Creutzfeldt–Jakob disease (sCJD) are both characterized by extracellular pathologically conformed aggregates of amyloid proteins—amyloid β-protein (Aβ) and prion protein (PrP^Sc), respectively. To investigate the potential morphological colocalization of Aβ and PrP^Sc aggregates, we examined the hippocampal regions (archicortex and neocortex) of 20 subjects with confirmed comorbid AD and sCJD using neurohistopathological analyses, immunohistochemical methods, and confocal fluorescent microscopy. Our data showed that extracellular Aβ and PrP^Sc aggregates tended to be, in most cases, located separately, and “compound” plaques were relatively rare. We observed PrP^Sc plaque-like structures in the periphery of the non-compact parts of Aβ plaques, as well as in tau protein-positive dystrophic structures. The AD ABC score according to the NIA-Alzheimer’s association guidelines, and prion protein subtype with codon 129 methionine–valine (M/V) polymorphisms in sCJD, while representing key characteristics of these diseases, did not correlate with the morphology of the Aβ/PrP^Sc co-aggregates. However, our data showed that PrP^Sc aggregation could dominate during co-aggregation with non-compact Aβ in the periphery of Aβ plaques.

Not All Cases of Visual Snows are Benign: Mimics of Visual Snow Syndrome

Visual snow syndrome (VSS) is a clinical disorder characterized by pan-field visual disturbance. It is a diagnosis of exclusion since its pathophysiology remains unknown. Excluding other mimics is of great significance since some serious pathologies can have secondary visual snow (VS) as an initial presentation. Delayed or incorrect diagnosis of these VSS mimics may lead to permanent vision loss or even death. The purpose of this review is to help physicians distinguish VSS mimics promptly to avoid bad outcomes. The authors performed a PubMed literature search of articles, case reports, and reviews describing VS symptoms in patients with underlying diseases other than VSS. The red flags of secondary VS symptoms were highlighted, such as new-onset or intermittent VS, unilateral or quadrant VS, and accompanied ocular or neurological deficits. There are four main categories of VSS mimics, ie, including neurological disorders, ocular pathologies, drug-related VS, and other systemic diseases. The physicians could largely exclude most etiologies based on history taking, ophthalmologic and neurologic examinations, and neuroimaging. Further research in VS should carefully define and unify the inclusion and exclusion criteria of this disorder and investigate these secondary VS conditions and their pathogenesis.

Regional Differences in Neuroinflammation-Associated Gene Expression in the Brain of Sporadic Creutzfeldt-Jakob Disease Patients

Neuroinflammation is an essential part of neurodegeneration. Yet, the current understanding of neuroinflammation-associated molecular events in distinct brain regions of prion disease patients is insufficient to lay the ground for effective treatment strategies targeting this complex neuropathological process. To address this problem, we analyzed the expression of 800 neuroinflammation-associated genes to create a profile of biological processes taking place in the frontal cortex and cerebellum of patients who suffered from sporadic Creutzfeldt-Jakob disease. The analysis was performed using NanoString nCounter technology with human neuroinflammation panel+. The observed gene expression patterns were regionally and sub-regionally distinct, suggesting a variable neuroinflammatory response. Interestingly, the observed differences could not be explained by the molecular subtypes of sporadic Creutzfeldt-Jakob disease. Furthermore, analyses of canonical pathways and upstream regulators based on differentially expressed genes indicated an overlap between biological processes taking place in different brain regions. This suggests that even smaller-scale spatial data reflecting subtle changes in brain cells' functional heterogeneity and their immediate pathologic microenvironments are needed to explain the observed differential gene expression in a greater detail.

Extracellular Amyloid Deposits in Alzheimer's and Creutzfeldt-Jakob Disease: Similar Behavior of Different Proteins?

Neurodegenerative diseases are characterized by the deposition of specific protein aggregates, both intracellularly and/or extracellularly, depending on the type of disease. The extracellular occurrence of tridimensional structures formed by amyloidogenic proteins defines Alzheimer's disease, in which plaques are composed of amyloid β-protein, while in prionoses, the same term "amyloid" refers to the amyloid prion protein. In this review, we focused on providing a detailed didactic description and differentiation of diffuse, neuritic, and burnt-out plaques found in Alzheimer's disease and kuru-like, florid, multicentric, and neuritic plaques in human transmissible spongiform encephalopathies, followed by a systematic classification of the morphological similarities and differences between the extracellular amyloid deposits in these disorders. Both conditions are accompanied by the extracellular deposits that share certain signs, including neuritic degeneration, suggesting a particular role for amyloid protein toxicity.

A cold water, ultrasonically activated stream efficiently removes proteins and prion-associated amyloid from surgical stainless steel

Background

Sterile service department decontamination procedures for surgical instruments struggle to demonstrate efficient removal of the hardiest infectious contaminants, such as prion proteins. A recently designed novel system, which uses a low pressure ultrasonically activated, cold water stream, has previously demonstrated efficient hard surface cleaning of several biological contaminants.

Aim

To test the efficacy of an ultrasonically activated stream for the removal of tissue proteins, including prion-associated amyloid, from surgical stainless steel surfaces.

Methods

Test surfaces were contaminated with 22L, ME7 or 263K prion-infected brain homogenates. The surfaces were treated with the ultrasonically activated water stream for contact times of 5 and 10 s. Residual proteinaceous and amyloid contamination were quantified using sensitive microscopic analysis, and immunoblotting was used to characterize the eluted prion residues before and after treatment with the ultrasonically activated stream.

Findings

Efficient removal of the different prion strains from the surgical stainless steel surfaces was observed, and reduced levels of protease-susceptible and -resistant prion protein was detected in recovered supernatant.

Conclusion

This study demonstrated that an ultrasonically activated stream has the potential to be a cost-effective solution to improve current decontamination practices and has the potential to reduce hospital-acquired infections.