Correlating DWI MRI With Pathologic and Other Features of Jakob-Creutzfeldt Disease

White matter abnormalities in healthy E200K carriers may serve as an early biomarker for genetic Creutzfeldt-Jakob disease (gCJD)

BACKGROUND

MRI is an important tool for disease diagnosis of Creutzfeldt-Jakob disease (CJD), yet its role in identifying preclinical stages of disease remains unclear. Here, we explored subtle white matter (WM) alterations in genetic CJD (gCJD) patients and in asymptomatic E200K mutation carriers using MRI, depending on total tau protein (t-tau) levels in CSF.

METHODS

Six symptomatic gCJD patients and N=60 healthy relatives of gCJD patients were included. Participants underwent genetic testing for the E200K mutation, MRI scans at 3T and a lumbar puncture (LP) for t-tau. Diffusion tensor imaging (DTI) metrics were calculated along WM tracts.

RESULTS

gCJD patients demonstrated higher mean diffusivity (MD), radial diffusivity (RD) and lower fractional anisotropy (FA) values compared with healthy relatives in several WM tracts (p<0.05). Out of the healthy relatives, 50% (N=30) were found to be carriers of the E200K mutation. T-tau levels in cerebrospinal fluid (CSF) were above the normal range (>290 pg/mL) in N=8 out of 23 carriers who underwent an LP. No significant differences in FA, MD, axial diffusivity (AD) and RD were detected between healthy mutation carriers (HMC) and healthy non-carriers within the WM tracts. Finally, significantly higher FA and lower MD, RD and AD along several WM tracts were found in HMC with elevated t-tau compared with HMC with normal t-tau (p<0.05).

CONCLUSIONS

DTI abnormalities along WM tracts were found in healthy E200K mutation carriers with elevated t-tau in CSF. Longer follow-up is required to determine whether these subtle WM alterations are predictive of future conversion to symptomatic gCJD.

TRIAL REGISTRATION NUMBER

NCT05746715.

Bright diffusion sign: A sensitive and specific radiologic biomarker for multinodular and vacuolating neuronal tumor

BACKGROUND AND PURPOSE

Accurate differentiation between multinodular and vacuolating neuronal tumor (MVNT) and dysembryoplastic neuroepithelial tumor (DNET) is important for treatment decision-making. We aimed to develop an accurate radiologic diagnostic model for differentiating MVNT from DNET using T2WI and diffusion-weighted imaging (DWI).

MATERIALS AND METHODS

A total of 56 patients (mean age, 47.48±17.78 years; 31 women) diagnosed with MVNT (n = 37) or DNET (n = 19) who underwent brain MRI, including T2WI and DWI, were included. Two board-certified neuroradiologists performed qualitative (bubble appearance, cortical involvement, bright diffusion sign, and bright apparent diffusion coefficient [ADC] sign) and quantitative (nDWI and nADC) assessments. A diagnostic tree model was developed with significant and reliable imaging findings using an exhaustive chi-squared Automatic Interaction Detector (CHAID) algorithm.

RESULTS

In visual assessment, the imaging features that showed high diagnostic accuracy and interobserver reliability were the bright diffusion sign and absence of cortical involvement (bright diffusion sign: accuracy, 94.64 %; sensitivity, 91.89 %; specificity, 100.00 %; interobserver agreement, 1.00; absence of cortical involvement: accuracy, 92.86 %; sensitivity, 89.19 %; specificity, 100.00 %; interobserver agreement, 1.00). In quantitative analysis, nDWI was significantly higher in MVNT than in DENT (1.52 ± 0.34 vs. 0.91 ± 0.27, p < 0.001), but the interobserver agreement was fair (intraclass correlation coefficient = 0.321). The overall diagnostic accuracy of the tree model with visual assessment parameters was 98.21 % (55/56).

CONCLUSION

The bright diffusion sign and absence of cortical involvement are accurate and reliable imaging findings for differentiating MVNT from DNET. By using simple, intuitive, and reliable imaging findings, such as the bright diffusion sign, MVNT can be accurately differentiated from DNET.

Development of statistical auto-segmentation method for diffusion restriction gray matter lesions in patients with newly diagnosed sporadic Creutzfeldt-Jakob disease

Quantification of diffusion restriction lesions in sporadic Creutzfeldt-Jakob disease (sCJD) may provide information of the disease burden. We aim to develop an automatic segmentation model for sCJD and to evaluate the volume of disease extent as a prognostic marker for overall survival. Fifty-six patients (mean age ± SD, 61.2 ± 9.9 years) were included from February 2000 to July 2020. A threshold-based segmentation was used to obtain abnormal signal intensity masks. Segmented volumes were compared with the visual grade. The Dice similarity coefficient was calculated to measure the similarity between the automatic vs. manual segmentation. Cox proportional hazards regression analysis was performed to evaluate the volume of disease extent as a prognostic marker. The automatic segmentation showed good correlation with the visual grading. The cortical lesion volumes significantly increased as the visual grade aggravated (extensive: 112.9 ± 73.2; moderate: 45.4 ± 30.4; minimal involvement: 29.6 ± 18.1 mm3) (P < 0.001). The deep gray matter lesion volumes were significantly higher for positive than for negative involvement of the deep gray matter (5.6 ± 4.6 mm3 vs. 1.0 ± 1.3 mm3, P < 0.001). The mean Dice similarity coefficients were 0.90 and 0.94 for cortical and deep gray matter lesions, respectively. However, the volume of disease extent was not associated with worse overall survival (cortical extent: P = 0.07; deep gray matter extent: P = 0.12).

PRNP expression predicts imaging findings in sporadic Creutzfeldt-Jakob disease

OBJECTIVE

We explored the relationship between regional PRNP expression from healthy brain tissue and patterns of increased and decreased diffusion and regional brain atrophy in patients with sporadic Creutzfeldt-Jakob disease (sCJD).

METHODS

We used PRNP microarray data from 6 healthy adult brains from Allen Brain Institute and T1-weighted and diffusion-weighted MRIs from 34 patients diagnosed with sCJD and 30 age- and sex-matched healthy controls to construct partial correlation matrices across brain regions for specific measures of interest: PRNP expression, mean diffusivity, volume, cortical thickness, and local gyrification index, a measure of cortical folding.

RESULTS

Regional patterns of PRNP expression in the healthy brain correlated with regional patterns of diffusion signal abnormalities and atrophy in sCJD. Among different measures of cortical morphology, regional patterns of local gyrification index in sCJD most strongly correlated with regional patterns of PRNP expression. At the vertex-wise level, different molecular subtypes of sCJD showed distinct regional correlations in local gyrification index across the cortex. Local gyrification index correlation patterns most closely matched patterns of PRNP expression in sCJD subtypes known to have greatest pathologic involvement of the cerebral cortex.

INTERPRETATION

These results suggest that the specific genetic and molecular environment in which the prion protein is expressed confer variable vulnerability to misfolding across different brain regions that is reflected in patterns of imaging findings in sCJD. Further work in larger samples will be needed to determine whether these regional imaging patterns can serve as reliable markers of distinct disease subtypes to improve diagnosis and treatment targeting.

Vacuoles related to tissue neuron-astrocyte ratio and infiltration of macrophages/monocytes contribute to hyperintense brain signals on diffusion-weighted magnetic resonance imaging in sporadic Creutzfeldt-Jakob disease

BACKGROUND

Radiological features in patients with sporadic Creutzfeldt-Jakob disease (sCJD) are hyperintensity of the cerebral cortex and the basal ganglia displayed by diffusion-weighted magnetic resonance imaging (DW-MRI). We performed a quantitative study on neuropathological and radiological findings.

METHODS

Patient 1 received a definite diagnosis of MM1-type sCJD, while patient 2 received a definite diagnosis of MM1 + 2-type sCJD. Two DW-MRI scans were performed on each patient. DW-MRI was either taken the day before or on the day of the patient's death, and several hyperintense or isointense areas were marked as a region of interest (ROI). Mean signal intensity of the ROI was measured. Pathological quantitative assessments of the vacuoles, astrocytosis, infiltration of monocytes/macrophages, and proliferation of microglia was performed. Vacuole load (% area vacuole), glial fibrillary acidic protein (GFAP), CD68, and Iba-1 load were calculated. We defined spongiform change index (SCI) to indicate vacuoles related to a tissue neuron-astrocyte ratio. We assessed the correlation of intensity of the last DW-MRI and the pathological findings as well as association of changes of the signal intensity on the sequential images and the pathological findings.

RESULT

We observed a strong positive correlation between SCI and DW-MRI intensity. In the analysis using serial DW-MRI and pathological findings, we found that CD68 load was significantly larger in areas where signal intensity decreased, as compared to those areas where hyperintensity remained unchanged.

CONCLUSION

DW-MRI intensity in sCJD is associated with the ratio of neuron to astrocyte in the vacuoles and the infiltration of macrophages and/or monocytes.

Improving Early Recognition of Creutzfeldt-Jakob Disease Mimics

Background and Objectives

Diagnostic criteria emphasize the use of sensitive and disease-specific tests to distinguish patients with rapidly progressive dementia (RPD) due to Creutzfeldt-Jakob disease (CJD) vs other causes (mimics). These tests are often performed in specialized centers, with results taking days to return. There is a need to leverage clinical features and rapidly reporting tests to distinguish patients with RPD due to CJD from those due to other causes (mimics) early in the symptomatic course.

Methods

In this case-control series, clinical features and the results of diagnostic tests were compared between mimics (n = 11) and patients with definite (pathologically proven, n = 33) or probable CJD (with positive real-time quaking-induced conversion [RT-QuIC], n = 60). Patients were assessed at Mayo Clinic Enterprise or Washington University from January 2014 to February 2021. Mimics were enrolled in prospective studies of RPD; mimics met the diagnostic criteria for probable CJD but did not have CJD.

Results

Mimics were ultimately diagnosed with autoimmune encephalitis (n = 6), neurosarcoidosis, frontotemporal lobar degeneration with motor neuron disease, dural arteriovenous fistula, cerebral amyloid angiopathy with related inflammation, and systemic lupus erythematous with polypharmacy. Age at symptom onset, sex, presenting features, and MRI and EEG findings were similar in CJD cases and mimics. Focal motor abnormalities (49/93, 11/11), CSF leukocytosis (4/92, 5/11), and protein >45 mg/dL (39/92, 10/11) were more common in mimics (p < 0.01). Positive RT-QuIC (77/80, 0/9) and total tau >1149 pg/mL (74/82, 2/10) were more common in CJD cases (all p < 0.01). Protein 14-3-3 was elevated in 64/89 CJD cases and 4/10 mimics (p = 0.067). Neural-specific autoantibodies associated with autoimmune encephalitis were detected within the serum (5/9) and CSF (5/10) of mimics; nonspecific antibodies were detected within the serum of 9/71 CJD cases.

Discussion

Immune-mediated, vascular, granulomatous, and neurodegenerative diseases may mimic CJD at presentation and should be considered in patients with early motor dysfunction and abnormal CSF studies. The detection of atypical features-particularly elevations in CSF leukocytes and protein-should prompt evaluation for mimics and consideration of empiric treatment while waiting for the results of more specific tests.

Case Report: Three Case Reports of Rapidly Progressive Dementias and Narrative Review

Rapidly progressive dementia (RPD) is a heterogeneous group of diseases characterized by cognitive impairment and other neurological disorders developed in a short span of fewer than 2 years. Currently viewed as new and infrequent entities, most medical personnel have little understanding of it. Nevertheless, they significantly compromise many patients' quality of life. Here, we drive 3 clinical cases that evolve as RPD with different etiologies.

Case 1

70-year-old woman presented to the emergency with neuropsychiatric syndrome for 18 days. The researchers identified inflammatory cerebrospinal fluid (CSF), protein 14-3-3-positive T-tau protein, MRI: T2 and FLAIR hyperintensities in bilateral caudate nuclei with diffusion restriction, EEG shows a generalized periodic pattern with triphasic wave morphology.

Case 2

29-year-old man with cognitive impairment and faciobrachial dystonia seizure. The diagnosis was confirmed by achieving elevated antibodies against voltage-gated potassium channels.

Case 3

A 49-year-old woman with encephalopathy and myoclonic seizures; EEG and MRI showed subtle changes. The patient also had a normal CSF but a positive CBA serologic NMDA-R antibody test. We described fundamental aspects of RPD to allow made differential diagnoses in patients with cognitive impairment and encephalopathy. Establishing an early and accurate diagnosis can benefit patients with RPD etiologies that are treatable and even reversible, decreasing in morbidity and mortality.

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.

Default Mode Network quantitative diffusion and resting-state functional magnetic resonance imaging correlates in sporadic Creutzfeldt-Jakob disease

Grey matter involvement is a well-known feature in sporadic Creutzfeldt-Jakob disease (sCJD), yet precise anatomy-based quantification of reduced diffusivity is still not fully understood. Default Mode Network (DMN) areas have been recently demonstrated as selectively involved in sCJD, and functional connectivity has never been investigated in prion diseases. We analyzed the grey matter involvement using a quantitatively multi-parametric MRI approach. Specifically, grey matter mean diffusivity of 37 subjects with sCJD was compared with that of 30 age-matched healthy controls with a group-wise approach. Differences in mean diffusivity were also examined between the cortical (MM(V)1, MM(V)2C, and VV1) and subcortical (VV2 and MV2K) subgroups of sCJD for those with autopsy data available (n = 27, 73%). We also assessed resting-state functional connectivity of both ventral and dorsal components of DMN in a subset of subject with a rs-fMRI dataset available (n = 17). Decreased diffusivity was predominantly present in posterior cortical regions of the DMN, but also outside of the DMN in temporal areas and in a few limbic and frontal areas, in addition to extensive deep nuclei involvement. Both subcortical and cortical sCJD subgroups showed decreased diffusivity subcortically, whereas only the cortical type expressed significantly decreased diffusivity cortically, mainly in parietal, occipital, and medial-inferior temporal cortices bilaterally. Interestingly, we found abnormally increased connectivity in both dorsal and ventral components of the DMN in sCJD subjects compared with healthy controls. The significance and possible utility of functional imaging as a biomarker for tracking disease progression in prion disease needs to be explored further.

Rapidly Progressive Dementia

PURPOSE OF REVIEW

This article presents a practical approach to the evaluation of patients with rapidly progressive dementia.

RECENT FINDINGS

The approach presented in this article builds upon the standard dementia evaluation, leveraging widely available tests and emergent specific markers of disease to narrow the differential diagnosis and determine the cause(s) of rapid progressive decline. The discovery of treatment-responsive causes of rapidly progressive dementia underscores the need to determine the cause early in the symptomatic course when treatments are most likely to halt or reverse cognitive decline.

SUMMARY

A pragmatic and organized approach to patients with rapidly progressive dementia is essential to mitigate diagnostic and therapeutic challenges and optimize patient outcomes.

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.

Biomarkers Analysis and Clinical Manifestations in Comorbid Creutzfeldt–Jakob Disease: A Retrospective Study in 215 Autopsy Cases

Creutzfeldt–Jakob disease (CJD), the most common human prion disorder, may occur as “pure” neurodegeneration with isolated prion deposits in the brain tissue; however, comorbid cases with different concomitant neurodegenerative diseases have been reported. This retrospective study examined correlations of clinical, neuropathological, molecular-genetic, immunological, and neuroimaging biomarkers in pure and comorbid CJD. A total of 215 patients have been diagnosed with CJD during the last ten years by the Czech National Center for Prion Disorder Surveillance. Data were collected from all patients with respect to diagnostic criteria for probable CJD, including clinical description, EEG, MRI, and CSF findings. A detailed neuropathological analysis uncovered that only 11.16% were “pure” CJD, while 62.79% had comorbid tauopathy, 20.47% had Alzheimer’s disease, 3.26% had frontotemporal lobar degeneration, and 2.33% had synucleinopathy. The comorbid subgroup analysis revealed that tauopathy was linked to putaminal hyperintensity on MRIs, and AD mainly impacted the age of onset, hippocampal atrophy on MRIs, and beta-amyloid levels in the CSF. The retrospective data analysis found a surprisingly high proportion of comorbid neuropathologies; only 11% of cases were verified as “pure” CJD, i.e., lacking hallmarks of other neurodegenerations. Comorbid neuropathologies can impact disease manifestation and can complicate the clinical diagnosis of CJD.

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.

Diffusion-Weighted Imaging is Key to Diagnosing Specific Diseases

This article reviews diseases for which persistent signal abnormalities on diffusion-weighted imaging are the key to their diagnosis. Specifically, updated knowledge regarding the neuroimaging patterns of the following diseases is summarized: sporadic Creutzfeldt-Jakob disease, neuronal intranuclear inclusion disease, and hereditary diffuse leukoencephalopathy with axonal spheroids-colony-stimulating factor receptors/adult-onset leukoencephalopathy with axonal spheroids and pigmented glia. In addition, their differential diagnoses; clinical manifestations; and pathologic, genetic, and imaging correlates are discussed.

Multimodal MRI staging for tracking progression and clinical-imaging correlation in sporadic Creutzfeldt-Jakob disease

Diffusion imaging is very useful for the diagnosis of sporadic Creutzfeldt-Jakob disease, but it has limitations in tracking disease progression as mean diffusivity changes non-linearly across the disease course. We previously showed that mean diffusivity changes across the disease course follow a quasi J-shaped curve, characterized by decreased values in earlier phases and increasing values later in the disease course. Understanding how MRI metrics change over-time, as well as their correlations with clinical deficits are crucial steps in developing radiological biomarkers for trials. Specifically, as mean diffusivity does not change linearly and atrophy mainly occurs in later stages, neither alone is likely to be a sufficient biomarker throughout the disease course. We therefore developed a model combining mean diffusivity and Volume loss (MRI Disease-Staging) to take into account mean diffusivity's non-linearity. We then assessed the associations between clinical outcomes and mean diffusivity alone, Volume alone and finally MRI Disease-Staging. In 37 sporadic Creutzfeldt-Jakob disease subjects and 30 age- and sex-matched healthy controls, high angular resolution diffusion and high-resolution T1 imaging was performed cross-sectionally to compute z-scores for mean diffusivity (MD) and Volume. Average MD and Volume were extracted from 41 GM volume of interest (VOI) per hemisphere, within the images registered to the Montreal Neurological Institute (MNI) space. Each subject's volume of interest was classified as either "involved" or "not involved" using a statistical threshold of ± 2 standard deviation (SD) for mean diffusivity changes and/or -2 SD for Volume. Volumes of interest were MRI Disease-Staged as: 0 = no abnormalities; 1 = decreased mean diffusivity only; 2 = decreased mean diffusivity and Volume; 3 = normal ("pseudo-normalized") mean diffusivity, reduced Volume; 4 = increased mean diffusivity, reduced Volume. We correlated Volume, MD and MRI Disease-Staging with several clinical outcomes (scales, score and symptoms) using 4 major regions of interest (Total, Cortical, Subcortical and Cerebellar gray matter) or smaller regions pre-specified based on known neuroanatomical correlates. Volume and MD z-scores correlated inversely with each other in all four major ROIs (cortical, subcortical, cerebellar and total) highlighting that ROIs with lower Volumes had higher MD and vice-versa. Regarding correlations with symptoms and scores, higher MD correlated with worse Mini-Mental State Examination and Barthel scores in cortical and cerebellar gray matter, but subjects with cortical sensory deficits showed lower MD in the primary sensory cortex. Volume loss correlated with lower Mini-Mental State Examination, Barthel scores and pyramidal signs. Interestingly, for both Volume and MD, changes within the cerebellar ROI showed strong correlations with both MMSE and Barthel. Supporting using a combination of MD and Volume to track sCJD progression, MRI Disease-Staging showed correlations with more clinical outcomes than Volume or MD alone, specifically with Mini-Mental State Examination, Barthel score, pyramidal signs, higher cortical sensory deficits, as well as executive and visual-spatial deficits. Additionally, when subjects in the cohort were subdivided into tertiles based on their Barthel scores and their percentile of disease duration/course ("Time-Ratio"), subjects in the lowest (most impaired) Barthel tertile showed a much greater proportion of more advanced MRI Disease-Stages than the those in the highest tertile. Similarly, subjects in the last Time-Ratio tertile (last tertile of disease) showed a much greater proportion of more advanced MRI Disease-Stages than the earliest tertile. Therefore, in later disease stages, as measured by time or Barthel, there is overall more Volume loss and increasing MD. A combined multiparametric quantitative MRI Disease-Staging is a useful tool to track sporadic Creutzfeldt-Jakob- disease progression radiologically.

Correlating diffusion-weighted MRI intensity with type 2 pathology in mixed MM-type sporadic Creutzfeldt-Jakob disease

The existence of affected subjects with both abnormal prion protein (PrP^Sc) types has been reported, and their clinical features were somewhat similar to the dominant PrP^Sc type but varied in sporadic Creutzfeldt-Jakob disease (sCJD). Presently, the antemortem identification of both PrP^Sc types in sCJD is not possible. In this study, we attempted to clinically predict the concurrence of MM-type sCJD with another PrP^Sc type in the same individual. We retrospectively identified seven MM-type sCJD cases with both fine vacuole-type spongiform (FV) and large confluent vacuole-type spongiform change (LCV) among 49 sCJD cases. We reviewed clinical features, pathological findings, and radiological abnormalities in these seven cases. We also conducted a regional systemic study with five brains to associate the spongiform-change pattern with hyperintensity on magnetic resonance diffusion-weighted imaging (DWI) using the signal intensity index (SII). In the case series study, the one patient with dominant LCV showed longer disease duration, later onset of typical symptoms, no periodic sharp wave complexes in electroencephalography, and negative 14-3-3 protein findings compared to the six FV-dominant patients. LCV-dominant lesions tended to show higher intensity on DWI than did the FV-dominant lesions in respective patients. In the regional systemic study, LCV-dominant regions showed significantly higher SII on DWI than did the FV-dominant regions. In conclusion, mixed MM-type sCJD generally showed the clinical features of the phenotype that was dominant in pathological distribution. The SII may be clinically useful for investigating the concurrence of PrP^Sc type 2 in cases with the typical clinical course of MM1-type sCJD.

THK5351 and flortaucipir PET with pathological correlation in a Creutzfeldt-Jakob disease patient: a case report

Background

THK5351 and flortaucipir tau ligands have high affinity for paired helical filament tau, yet diverse off-target bindings have been reported. Recent data support the hypothesis that THK5351 binds to monoamine oxidase B (MAO-B) expressed from reactive astrocytes and that flortaucipir has an affinity toward MAO-A and B; however, pathological evidence is lacking. We performed a head-to-head comparison of the two tau ligands in a sporadic Creutzfeldt-Jakob disease (CJD) patient and performed an imaging-pathological correlation study.

Case presentation

A 67-year-old man visited our clinic a history of 6 months of rapidly progressive dementia, visual disturbance, and akinetic mutism. Diffusion-weighted imaging showed cortical diffusion restrictions in the left temporo-parieto-occipital regions. ¹⁸F-THK5351 PET, but not ¹⁸F-flortaucipir PET showed high uptake in the left temporo-parieto-occipital regions, largely overlapping with the diffusion restricted areas. Cerebrospinal fluid analysis was weakly positive for 14–3-3 protein and pathogenic prion protein was found. The patient showed rapid cognitive decline along with myoclonic seizures and died 13 months after his first visit. A post-mortem study revealed immunoreactivity for PrP^sc, no evidence of neurofibrillary tangles, and abundant astrocytosis which was reactive for MAO-B antibody.

Conclusions

Our findings add pathological evidence that increased THK5351 uptake in sporadic CJD patients might be caused by an off-target binding driven by its high affinity for MAO-B.

Electronic supplementary material

The online version of this article (10.1186/s12883-019-1434-z) contains supplementary material, which is available to authorized users.

The impact of self-replicating proteins on inflammation, autoimmunity and neurodegeneration-An untraveled path

The central nervous system (CNS) in neurodegenerative diseases is a battlefield in which microglia fight a highly atypical battle. During the inflammatory process microglia themselves become dysfunctional and even with all the available immune arsenal including cytokine or/and antibody production, the battle is eventually lost. A closer look into the picture will reveal the fact that this is mainly due to the atypical characteristics of the infectious agent. The supramolecular assemblies of misfolded proteins carry unique features not encountered in any of the common pathogens. Through misfolding, proteins undergo conformational changes which make them become immunogenic, neurotoxic and highly infective. The immunogenicity appears to be triggered by the exposure of previously hidden hydrophobic portions in proteins which act as damage-associated molecular patters (DAMPs) for the immune system. The neurotoxicity and infectivity are promoted by the small oligomeric forms of misfolded proteins/peptides. Oligomers adopt conformations such as tubular-like, beta-barrel-like, etc., that penetrate cell membranes through their hydrophobic surfaces, thus destabilizing ionic homeostasis. At the same time, oligomers act as a seed for protein misfolding through a prion/prion-like mechanism. Here, we propose the hypothesis that oligomers have catalytic surfaces and exercise their capacity to infect native proteins through specific characteristics such as hydrophobic, electrostatic and π-π stacking interactions as well as the specific surface area (SSA), surface curvature and surface chemistry of their nanoscale supramolecular assemblies. All these are the key elements for prion/prion-like mechanism of self-replication and disease spreading within the CNS. Thus, understanding the mechanism of prion's templating activity may help us in the prevention and development of novel therapeutic strategies for neurodegenerative diseases.

Quantitative Magnetic Resonance Abnormalities in Creutzfeldt-Jakob Disease and Fatal Insomnia

BACKGROUND

Quantitative neuroimaging might unveil abnormalities in prion diseases that are not perceivable at visual inspection. On the other hand, scarce studies have quantified volumetric changes in prion diseases.

OBJECTIVES

We aim to characterize volumetric and diffusion tensor imaging (DTI) changes in patients with prion diseases who presented with either Creutzfeldt-Jakob disease (CJD) or fatal insomnia (FI) phenotype.

METHODS

Twenty patients with prion diseases- 15 with CJD and 5 with fatal insomnia (FI)- and 40 healthy controls were examined with a 3-Tesla magnetic resonance imaging scanner. Images were segmented and normalized with SPM12. DTI maps were obtained with FMRIB Software Library. Whole-brain voxel-wise and region-of-interest analyses of volumetric and DTI changes were performed with SPM12. White matter (WM) changes were also analyzed with tract-based spatial statistics. Semiquantitive assessment of neuropathological parameters was compared with DTI metrics in thalamus from 11 patients.

RESULTS

Patients with CJD and FI presented significant atrophy in thalamus and cerebellum. In CJD, mean diffusivity (MD) was decreased in striatum and increased in subcortical WM, while both increased and decreased values were observed across different thalamic nuclei. In FI, MD was increased in thalamus and cerebellum. Spongiform change and PrPSc deposition were more intense in thalamus in CJD than in FI, although no significant correlations arose with MD values in the nuclei studied.

CONCLUSION

Volumetric and DTI abnormalities suggest a central common role of the thalamus in prion diseases. We report, for the first time, quantitative MRI changes in FI, and provide further evidence of WM involvement in prion diseases.

Diffusion tensor imaging and functional MRI

The advances in diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and functional magnetic resonance imaging (fMRI) over the last 20 years have vastly contributed to improving the understanding of the brain structure and function in patients with many diseases of the central nervous system (CNS). DWI is commonly used, for instance, in the diagnostic workup of stroke, CNS neoplasia, and rapidly progressive dementia cases. The new DTI methods provide more specific information about the most destructive aspects of tumors, neurodegenerative dementia, and multiple sclerosis pathology and give a more complete picture of the complex pathologic mechanisms of these conditions. More recently, fMRI has provided insight to the mechanisms of brain adaptation and plasticity to damage related to many neurologic conditions and has further extended our ability to understand the functional significance of pathologic changes in these diseases. Although at present fMRI does not have a role in the diagnosis, routine assessment, and monitoring of neurologic diseases, significant efforts are under way in order to achieve harmonization of both acquisition and postprocessing procedures, which are likely to contribute to a significant change of the clinical scenario.

Diffusion-weighted MRI findings and clinical correlations in sporadic Creutzfeldt-Jakob disease

The objective of this study is to investigate the hyperintense lesions on diffusion-weighted magnetic resonance imaging (DWI) and its clinical correlation in sporadic Creutzfeldt-Jakob disease (sCJD). Patients who suffered from sCJD and followed up at the Department of Neurology at the General Hospital of the People's Liberation Army during the period of June 1, 2007 to July 1, 2014 were reviewed. The location of the hyperintense lesions on DWI, apparent diffusion coefficient (ADC) values of the hyperintense lesions were correlated with symptoms and clinical course. A total of 58 sCJD patients and ten healthy controls were included. Hyperintense lesions on DWI were observed in all the patients. The patients with basal ganglia (BG) hyperintense lesions on DWI had shorter disease duration and higher incidence of myoclonus (92 versus 44 %) than those without BG hyperintense lesions. The patients with occipital cortex hyperintense lesions on DWI had shorter disease duration between symptom onset and akinetic mutism than those without these lesions. The lower of the BG ADC value the faster presence of akinetic mutism and the shorter disease duration the patients will have. The presence of BG and occipital cortex hyperintense lesions on DWI and BG ADC values is correlated with the clinical course and clinical symptoms.

Clinical Overlap between Jakob-Creutzfeldt Disease and Lewy Body Disease

Objective:

Sporadic Jakob-Creutzfeldt disease (sCJD) and dementia with Lewy bodies (DLB) have overlapping clinical symptoms that can lead to their misdiagnosis. We delineated the clinical overlap between sCJD and DLB, and assessed the value of magnetic resonance imaging (MRI) to differentiate between them.

Methods:

Medical records, MRI, electroencephalogram (EEG) and cerebrospinal fluid (CSF) were reviewed from 56 sCJD and 30 DLB subjects.

Results:

46% of sCJD subjects met probable DLB criteria and 40% of DLB subjects met probable CJD criteria. A greater proportion of sCJD subjects had cerebellar signs (66% vs. 10%, p<0.001), myoclonus (64% vs. 30%, p=0.002), and visual symptoms (other than hallucinations) (61% vs. 7%, p<0.001), whereas more DLB subjects had hallucinations (70% vs. 39%, p=0.007) and fluctuations (57% vs. 23%, p=0.002). Cortical and/or basal ganglia MRI diffusion weighted imaging hyperintensities consistent with sCJD were seen in 96% of sCJD subjects but in none with DLB. Logistic regression in sCJD revealed that those meeting probable DLB criteria were more likely to have occipital lobe involvement on MRI (OR 1.4, p=0.058, model p=0.022). Parietal lobe involvement on MRI was a predictor of “Other Focal Cortical signs” (OR 1.9, p=0.021). EEG and CSF assessments lacked sensitivity for sCJD as 48% of sCJD patients had a negative EEG; 67% of the 36 sCJD patents with a CSF evaluation had a negative or inconclusive 14-3-3 result. Too few DLB patients had EEG or CSF to assess their utility.

Conclusion:

Sporadic CJD and DLB have significant symptom overlap. MRI helps differentiate these diseases and is related to the signs/symptoms observed in sCJD.

Mathematical models for the diffusion magnetic resonance signal abnormality in patients with prion diseases

In clinical practice signal hyperintensity in the cortex and/or in the striatum on magnetic resonance (MR) diffusion-weighted images (DWIs) is a marker of sporadic Creutzfeldt–Jakob Disease (sCJD). MR diagnostic accuracy is greater than 90%, but the biophysical mechanisms underpinning the signal abnormality are unknown. The aim of this prospective study is to combine an advanced DWI protocol with new mathematical models of the microstructural changes occurring in prion disease patients to investigate the cause of MR signal alterations. This underpins the later development of more sensitive and specific image-based biomarkers. DWI data with a wide a range of echo times and diffusion weightings were acquired in 15 patients with suspected diagnosis of prion disease and in 4 healthy age-matched subjects. Clinical diagnosis of sCJD was made in nine patients, genetic CJD in one, rapidly progressive encephalopathy in three, and Gerstmann–Sträussler–Scheinker syndrome in two. Data were analysed with two bi-compartment models that represent different hypotheses about the histopathological alterations responsible for the DWI signal hyperintensity. A ROI-based analysis was performed in 13 grey matter areas located in affected and apparently unaffected regions from patients and healthy subjects. We provide for the first time non-invasive estimate of the restricted compartment radius, designed to reflect vacuole size, which is a key discriminator of sCJD subtypes. The estimated vacuole size in DWI hyperintense cortex was in the range between 3 and 10 µm that is compatible with neuropathology measurements. In DWI hyperintense grey matter of sCJD patients the two bi-compartment models outperform the classic mono-exponential ADC model. Both new models show that T₂ relaxation times significantly increase, fast and slow diffusivities reduce, and the fraction of the compartment with slow/restricted diffusion increases compared to unaffected grey matter of patients and healthy subjects. Analysis of the raw DWI signal allows us to suggest the following acquisition parameters for optimized detection of CJD lesions: b = 3000 s/mm² and TE = 103 ms. In conclusion, these results provide the first in vivo estimate of mean vacuole size, new insight on the mechanisms of DWI signal changes in prionopathies and open the way to designing an optimized acquisition protocol to improve early clinical diagnosis and subtyping of sCJD.

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An advanced DWI acquisition scheme was applied to 15 patients with suspected sCJD.

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Data fitting with two bi-compartment models outperformed the classic ADC model.

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In affected GM T₂ values were increased, diffusion was more hindered or restricted.

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For the first time an estimate of the restricted compartment radius was provided.

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The radius may reflect vacuole size, which is a key discriminator of sCJD subtypes.

White matter involvement in sporadic Creutzfeldt-Jakob disease

Sporadic Creutzfeldt-Jakob disease is considered primarily a disease of grey matter, although the extent of white matter involvement has not been well described. We used diffusion tensor imaging to study the white matter in sporadic Creutzfeldt-Jakob disease compared to healthy control subjects and to correlated magnetic resonance imaging findings with histopathology. Twenty-six patients with sporadic Creutzfeldt-Jakob disease and nine age- and gender-matched healthy control subjects underwent volumetric T₁-weighted and diffusion tensor imaging. Six patients had post-mortem brain analysis available for assessment of neuropathological findings associated with prion disease. Parcellation of the subcortical white matter was performed on 3D T₁-weighted volumes using Freesurfer. Diffusion tensor imaging maps were calculated and transformed to the 3D-T₁ space; the average value for each diffusion metric was calculated in the total white matter and in regional volumes of interest. Tract-based spatial statistics analysis was also performed to investigate the deeper white matter tracts. There was a significant reduction of mean (P = 0.002), axial (P = 0.0003) and radial (P = 0.0134) diffusivities in the total white matter in sporadic Creutzfeldt-Jakob disease. Mean diffusivity was significantly lower in most white matter volumes of interest (P < 0.05, corrected for multiple comparisons), with a generally symmetric pattern of involvement in sporadic Creutzfeldt-Jakob disease. Mean diffusivity reduction reflected concomitant decrease of both axial and radial diffusivity, without appreciable changes in white matter anisotropy. Tract-based spatial statistics analysis showed significant reductions of mean diffusivity within the white matter of patients with sporadic Creutzfeldt-Jakob disease, mainly in the left hemisphere, with a strong trend (P = 0.06) towards reduced mean diffusivity in most of the white matter bilaterally. In contrast, by visual assessment there was no white matter abnormality either on T₂-weighted or diffusion-weighted images. Widespread reduction in white matter mean diffusivity, however, was apparent visibly on the quantitative attenuation coefficient maps compared to healthy control subjects. Neuropathological analysis showed diffuse astrocytic gliosis and activated microglia in the white matter, rare prion deposition and subtle subcortical microvacuolization, and patchy foci of demyelination with no evident white matter axonal degeneration. Decreased mean diffusivity on attenuation coefficient maps might be associated with astrocytic gliosis. We show for the first time significant global reduced mean diffusivity within the white matter in sporadic Creutzfeldt-Jakob disease, suggesting possible primary involvement of the white matter, rather than changes secondary to neuronal degeneration/loss.

Sporadic Creutzfeldt-Jakob disease (sCJD) is considered primarily a disease of grey matter. However, Caverzasi et al. now show a global decrease in mean diffusivity in white matter. The changes appear to be associated with reactive astrocytic gliosis and activated microglia, and suggest primary involvement of the white matter in sCJD.

Application of quantitative DTI metrics in sporadic CJD

Diffusion Weighted Imaging is extremely important for the diagnosis of probable sporadic Jakob-Creutzfeldt disease, the most common human prion disease. Although visual assessment of DWI MRI is critical diagnostically, a more objective, quantifiable approach might more precisely identify the precise pattern of brain involvement. Furthermore, a quantitative, systematic tracking of MRI changes occurring over time might provide insights regarding the underlying histopathological mechanisms of human prion disease and provide information useful for clinical trials. The purposes of this study were: 1) to describe quantitatively the average cross-sectional pattern of reduced mean diffusivity, fractional anisotropy, atrophy and T1 relaxation in the gray matter (GM) in sporadic Jakob-Creutzfeldt disease, 2) to study changes in mean diffusivity and atrophy over time and 3) to explore their relationship with clinical scales. Twenty-six sporadic Jakob-Creutzfeldt disease and nine control subjects had MRIs on the same scanner; seven sCJD subjects had a second scan after approximately two months. Cortical and subcortical gray matter regions were parcellated with Freesurfer. Average cortical thickness (or subcortical volume), T1-relaxiation and mean diffusivity from co-registered diffusion maps were calculated in each region for each subject. Quantitatively on cross-sectional analysis, certain brain regions were preferentially affected by reduced mean diffusivity (parietal, temporal lobes, posterior cingulate, thalamus and deep nuclei), but with relative sparing of the frontal and occipital lobes. Serial imaging, surprisingly showed that mean diffusivity did not have a linear or unidirectional reduction over time, but tended to decrease initially and then reverse and increase towards normalization. Furthermore, there was a strong correlation between worsening of patient clinical function (based on modified Barthel score) and increasing mean diffusivity.

Genetic CJD with a novel E200G mutation in the prion protein gene and comparison with E200K mutation cases

A novel point mutation resulting in a glutamate-to-glycine substitution in PRNP at codon 200, E200G with codon 129 MV polymorphism (cis valine) and type 2 PrP^Sc was identified in a patient with a prolonged disease course leading to pathology-proven Jakob-Creutzfeldt disease. Despite the same codon as the most common genetic form of human PRNP mutation, E200K, this novel mutation (E200G) presented with a different clinical and pathological phenotype, including prolonged duration, large vacuoles, no vacuolation in the hippocampus, severe neuronal loss in the thalamus, mild cerebellar involvement, and abundant punctate linear and curvilinear deposition of PrP^Sc in synaptic boutons and axonal terminals along the dendrites.

"Dazed and diffused": making sense of diffusion abnormalities in neurologic pathologies

To review diffusion abnormalities seen in diffusion-weighted MRI in neurological pathologies. We examine the clinical significance of the abnormalities in a broad spectrum of neurological diseases and highlight our current understanding of their causes. Diffusion abnormalities seen on diffusion-weighted MRI can play an important role in the diagnosis and follow-up of a broad spectrum of neurological diseases. A thorough understanding of the appearance and significance of these abnormalities is critical in patient management.

Diagnosing sporadic creutzfeldt-jakob disease in a patient with a suspected status epilepticus in the intensive care unit

Objective. Several tests are available in the diagnostics of sporadic Creutzfeldt-Jakob disease (sCJD); however, none of these is conclusive. We review the values of these tests, from an intensive care unit (ICU) perspective. Methods. Case report and review of the literature. Results. A 53-year-old woman initially presenting with psychiatric symptoms developed myoclonus and was admitted 1 month later to the ICU with a suspected nonconvulsive status epilepticus and respiratory insufficiency, probably due to extensive antiepileptic drug therapy. Typical MRI and EEG findings and a positive 14-3-3 protein led to the diagnosis of sCJD. All treatments were terminated, and autopsy confirmed sCJD. Conclusions. Clinical signs combined with MRI, EEG, and 14-3-3 and/or tau protein determination might be sufficient to diagnose or exclude sCJD and may therefore prevent the application of unnecessary diagnostic tests.

Rapidly progressive dementia: prion diseases and other rapid dementias

Dementias that occur over weeks to months require a different differential than the slowly progressive dementias that occur over years. Because of the rapidity of decline in cognition, the evaluation of the patient is usually urgent and requires an extensive workup with multiple tests running in parallel. Creutzfeldt-Jakob disease, perhaps the prototypic rapidly progressive dementia (RPD), is often the first diagnosis many neurologists consider when faced with a patient with rapid cognitive decline. Many conditions other than prion disease, however, can present with RPD. Other etiologies include autoimmune conditions, cancers, uncommon presentations of other more common neurodegenerative dementias, and others. This chapter discusses some of the major etiologies for RPDs and offers an algorithm for diagnosis. Some topics, such as other neurodegenerative dementias and autoimmune dementias, are covered in other chapters in this issue, and will be mentioned here only briefly.

Role of magnetic resonance imaging, cerebrospinal fluid, and electroencephalogram in diagnosis of sporadic Creutzfeldt-Jakob disease

Sporadic Creutzfeldt-Jakob disease (sCJD) is a rapidly progressive dementia (RPD) that can be difficult to identify antemortem, with definitive diagnosis requiring tissue confirmation. We describe the clinical, magnetic resonance imaging (MRI), cerebrospinal fluid (CSF), and electroencephalogram (EEG) measures of a small cohort of 30 patients evaluated for RPD. Clinical and diagnostic measures were cross-sectionally obtained from 17 sCJD patients (15 definite, two probable), 13 non-prion rapidly progressive dementia patients (npRPD), and 18 unimpaired controls. In a subset of patients (nine sCJD and nine npRPD) diffusion tensor imaging (DTI) measures [fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD)] were also obtained for the caudate, corpus callosum, posterior limb of the internal capsule, pulvinar, precuneus, and frontal lobe. Differences among groups were assessed by an analysis of variance. Compared to npRPD individuals, sCJD patients had cerebellar dysfunction, significantly higher CSF tau, "positive" CSF 14-3-3, and hyperintensities on diffusion-weighted imaging (DWI) that met previously established imaging criteria for sCJD. EEG changes were similar for the two groups. In addition, sCJD patients had significant decreases in DTI measures (MD, AD, RD but not FA) within the caudate and pulvinar compared to either npRPD patients or unimpaired controls. Our results confirm that CSF abnormalities and MRI (especially DWI) can assist in distinguishing sCJD patients from npRPD patients. Future longitudinal studies using multiple measures (including CSF and MRI) are needed for evaluating pathological changes seen in sCJD patients.

Cerebral white matter disruption in Creutzfeldt-Jakob disease

BACKGROUND AND PURPOSE

Human prion diseases are known to cause gray matter degeneration in specific cerebral structures, but evidence for white matter involvement is scarce. We used DTI to test the hypothesis that white matter integrity is disrupted in human CJD during the early stages of the disease.

MATERIALS AND METHODS

Twenty-one patients with the E200K variant of CJD and 19 controls participated in DTI studies conducted on a 1.5T MR imaging scanner. The data were quantitatively analyzed and mapped with a voxelwise TBSS method.

RESULTS

We found significant reductions of FA in patients with CJD in distinct and functionally relevant white matter pathways, including the corticospinal tract, internal capsule, external capsule, fornix, and posterior thalamic radiation. Moreover, these FA deficits increased with disease duration, and were mainly determined by increase of radial diffusivity, suggesting elevated permeability of axonal membranes.

CONCLUSIONS

The findings suggest that some of the symptoms of CJD may be caused by a functional dysconnection syndrome, and that the leukoencephalopathy is progressive and detectable fairly early in the course of the disease.

Glucose metabolism in sporadic Creutzfeldt-Jakob disease: a statistical parametric mapping analysis of (18) F-FDG PET

BACKGROUND AND PURPOSE

Reports describing functional neuroimaging techniques, such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT), in sporadic Creutzfeldt-Jakob disease (sCJD) have consistently suggested that these tools are sensitive for the identification of areas of hypoperfusion or hypometabolism, even in the early stages of sCJD. However, there are few reports on the use of [18F]fluoro-2-deoxy-D-glucose (FDG) PET in sCJD, and most of them are single case reports. Only two small cohort studies based on visual inspection or a region of interest method have been published to date. Using a statistical parametric mapping (SPM) analysis of (18) F-FDG PET, we investigated whether there are brain regions preferentially affected in sCJD.

METHODS

After controlling for age and gender, using SPM 2, we compared the glucose metabolism between (i) 11 patients with sCJD and 35 controls and (ii) the subset of five patients with the Heidenhain variant of sCJD and 35 controls.

RESULTS

The patients with sCJD showed decreased glucose metabolism in bilateral parietal, frontal and occipital cortices. The Heidenhain variant of sCJD showed glucose hypometabolism mainly in bilateral occipital areas.

CONCLUSIONS

Glucose hypometabolism in sCJD was detected in extensive cortical regions; however, it was not found in the basal ganglia or thalamus, which are frequently reported to be affected on diffusion-weighted images. The medial temporal area, which is possibly resistant to the prion deposits, was also less involved in sCJD.

The evaluation of rapidly progressive dementia

BACKGROUND

Rapidly progressive dementia (RPD) is a unique set of disorders resulting in cognitive, behavioral, and motor decline within 2 years. A variety of etiologies may contribute to RPD including neurodegenerative, inflammatory, infectious, and toxic-metabolic conditions. Jakob-Creutzfeldt disease (CJD) is frequently the most concerning diagnosis on the differential. The challenge for the neurologist is distinguishing prion disease from reversible processes that result in dementia.

REVIEW SUMMARY

This review discusses the clinical aspects and the diagnostic workup of RPD. Particular focus is given to both CJD and the potentially treatable inflammatory conditions that may cause a similar presentation. Furthermore, a standardized stepwise approach is outlined for patients presenting with RPD.

CONCLUSIONS

Neurologists should adopt a standardized approach to the rapidly presenting disease processes that may mimic CJD in their clinical and radiologic features.

Diffusion-weighted MRI hyperintensity patterns differentiate CJD from other rapid dementias

BACKGROUND

Diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) MRI have high sensitivity and specificity for Creutzfeldt-Jakob disease (CJD). No studies, however, have demonstrated how MRI can distinguish CJD from nonprion causes of rapidly progressive dementia (npRPD). We sought to determine the diagnostic accuracy of MRI for CJD compared to a cohort of npRPD subjects.

METHODS

Two neuroradiologists blinded to diagnosis assessed DWI and FLAIR images in 90 patients with npRPD (n = 29) or prion disease (sporadic CJD [sCJD], n = 48, or genetic prion disease [familial CJD, n = 6, and Gerstmann-Sträussler-Scheinker, n = 7]). Thirty-one gray matter regions per hemisphere were assessed for abnormal hyperintensities. The likelihood of CJD was assessed using our previously published criteria.

RESULTS

Gray matter hyperintensities (DWI > FLAIR) were found in all sCJD cases, with certain regions preferentially involved, but never only in limbic regions, and rarely in the precentral gyrus. In all sCJD cases with basal ganglia or thalamic DWI hyperintensities, there was associated restricted diffusion (apparent diffusion coefficient [ADC] map). This restricted diffusion, however, was not seen in any npRPD cases, in whom isolated limbic hyperintensities (FLAIR > DWI) were common. One reader's sensitivity and specificity for sCJD was 94% and 100%, respectively, the other's was 92% and 72%. After consensus review, the readers' combined MRI sensitivity and specificity for sCJD was 96% and 93%, respectively. Familial CJD had overlapping MRI features with sCJD.

CONCLUSIONS

The pattern of FLAIR/DWI hyperintensity and restricted diffusion can differentiate sCJD from other RPDs with a high sensitivity and specificity. MRI with DWI and ADC should be included in sCJD diagnostic criteria. New sCJD MRI criteria are proposed.

[Sporadic Creutzfeldt-Jakob disease: two cases in intensive care]

Prion diseases or spongiform encephalopathies are a family of rare neurodegenerative diseases characterized by long incubation periods associated with slow, irreversible and invariably fatal evolution. In humans, they are classified as sporadic, acquired and hereditary or genetic. Diagnosing sporadic "Creutzfeldt-Jakob Disease" (sCJD) is a real challenge for the intensive care physician, given the variability in its clinical presentation and its low incidence. The cases of two patients admitted to the Intensive Care Unit are presented. After ruling out other diseases, they were diagnosed with sCJD with a likelihood level according to the World Health Organization Classification. Clinical and laboratory diagnostic aspects of the disease were analyzed, highlighting the utility of 14-3-3 protein identification in the cerebrospinal fluid.

Putaminal volume and diffusion in early familial Creutzfeldt-Jakob disease

BACKGROUND

The putamen is centrally implicated in the pathophysiology of Creutzfeldt-Jakob Disease (CJD). To our knowledge, its volume has never been measured in this disease. We investigated whether gross putaminal atrophy can be detected by MRI in early stages, when the diffusion is already reduced.

METHODS

Twelve familial CJD patients with the E200K mutation and 22 healthy controls underwent structural and diffusion MRI scans. The putamen was identified in anatomical scans by two methods: manual tracing by a blinded investigator, and automatic parcellation by a computerized segmentation procedure (FSL FIRST). For each method, volume and mean Apparent Diffusion Coefficient (ADC) were calculated.

RESULTS

ADC was significantly lower in CJD patients (697+/-64 microm(2)/s vs. 750+/-31 microm(2)/s, p<0.005), as expected, but the volume was not reduced. The computerized FIRST delineation yielded comparable ADC values to the manual method, but computerized volumes were smaller than manual tracing values.

CONCLUSIONS

We conclude that significant diffusion reduction in the putamen can be detected by delineating the structure manually or with a computerized algorithm. Our findings confirm and extend previous voxel-based and observational studies. Putaminal volume was not reduced in our early-stage patients, thus confirming that diffusion abnormalities precede detectible atrophy in this structure.

Updated clinical diagnostic criteria for sporadic Creutzfeldt-Jakob disease

Several molecular subtypes of sporadic Creutzfeldt–Jakob disease have been identified and electroencephalogram and cerebrospinal fluid biomarkers have been reported to support clinical diagnosis but with variable utility according to subtype. In recent years, a series of publications have demonstrated a potentially important role for magnetic resonance imaging in the pre-mortem diagnosis of sporadic Creutzfeldt–Jakob disease. Magnetic resonance imaging signal alterations correlate with distinct sporadic Creutzfeldt–Jakob disease molecular subtypes and thus might contribute to the earlier identification of the whole spectrum of sporadic Creutzfeldt–Jakob disease cases. This multi-centre international study aimed to provide a rationale for the amendment of the clinical diagnostic criteria for sporadic Creutzfeldt–Jakob disease. Patients with sporadic Creutzfeldt–Jakob disease and fluid attenuated inversion recovery or diffusion-weight imaging were recruited from 12 countries. Patients referred as ‘suspected sporadic Creutzfeldt–Jakob disease’ but with an alternative diagnosis after thorough follow up, were analysed as controls. All magnetic resonance imaging scans were assessed for signal changes according to a standard protocol encompassing seven cortical regions, basal ganglia, thalamus and cerebellum. Magnetic resonance imaging scans were evaluated in 436 sporadic Creutzfeldt–Jakob disease patients and 141 controls. The pattern of high signal intensity with the best sensitivity and specificity in the differential diagnosis of sporadic Creutzfeldt–Jakob disease was identified. The optimum diagnostic accuracy in the differential diagnosis of rapid progressive dementia was obtained when either at least two cortical regions (temporal, parietal or occipital) or both caudate nucleus and putamen displayed a high signal in fluid attenuated inversion recovery or diffusion-weight imaging magnetic resonance imaging. Based on our analyses, magnetic resonance imaging was positive in 83% of cases. In all definite cases, the amended criteria would cover the vast majority of suspected cases, being positive in 98%. Cerebral cortical signal increase and high signal in caudate nucleus and putamen on fluid attenuated inversion recovery or diffusion-weight imaging magnetic resonance imaging are useful in the diagnosis of sporadic Creutzfeldt–Jakob disease. We propose an amendment to the clinical diagnostic criteria for sporadic Creutzfeldt–Jakob disease to include findings from magnetic resonance imaging scans.