Previous resting-state fMRI studies in dementia with Lewy bodies have described changes in functional connectivity in networks related to cognition, motor function, and attention as well as ...alterations in connectivity dynamics. However, whether these changes occur early in the course of the disease and are already evident at the stage of mild cognitive impairment is not clear. We studied resting-state fMRI data from 31 patients with mild cognitive impairment with Lewy bodies compared to 28 patients with mild cognitive impairment due to Alzheimer’s disease and 24 age-matched controls. We compared the groups with respect to within- and between-network functional connectivity. Additionally, we applied two different approaches to study dynamic functional connectivity (sliding-window analysis and leading eigenvector dynamic analysis). We did not find any significant changes in the mild cognitive impairment groups compared to controls and no differences between the two mild cognitive impairment groups, using static as well as dynamic connectivity measures. While patients with mild cognitive impairment with Lewy bodies already show clear functional abnormalities on EEG measures, the fMRI analyses presented here do not appear to be sensitive enough to detect such early and subtle changes in brain function in these patients.
Objective
To use arterial spin labelling to investigate differences in perfusion in mild cognitive impairment with Lewy bodies (MCI-LB) compared to Alzheimer type MCI (MCI-AD) and healthy controls.
...Methods
We obtained perfusion images on 32 MCI-LB, 30 MCI-AD and 28 healthy subjects of similar age. Perfusion relative to cerebellum was calculated, and we aimed to examine differences in relative perfusion between MCI-LB and the other groups. This included whole brain voxelwise comparisons, as well as using predefined region-of-interest ratios of medial occipital to medial temporal, and posterior cingulate to precuneus. Differences in occipital perfusion in eyes open vs eyes closed conditions were also examined.
Results
Compared to controls, the MCI-LB showed reduced perfusion in the precuneus, parietal, occipital and fusiform gyrus regions. In our predefined regions, the ratio of perfusion in occipital/medial temporal was significantly lower, and the posterior cingulate/precuneus ratio was significantly higher in MCI-LB compared to controls. Overall, the occipital perfusion was greater in the eyes open vs closed condition, but this did not differ between groups.
Conclusion
We found patterns of altered perfusion in MCI-LB which are similar to those seen in dementia with Lewy bodies, with reduction in posterior parietal and occipital regions, but relatively preserved posterior cingulate.
Objectives To investigate using quantitative EEG the (1) differences between patients with mild cognitive impairment with Lewy bodies (MCI-LB) and MCI with Alzheimer's disease (MCI-AD) and (2) its ...utility as a potential biomarker for early differential diagnosis. Methods We analyzed eyes-closed, resting-state, high-density EEG data from highly phenotyped participants (39 MCI-LB, 36 MCI-AD, and 31 healthy controls). EEG measures included spectral power in different frequency bands (delta, theta, pre-alpha, alpha, and beta), theta/alpha ratio, dominant frequency, and dominant frequency variability. Receiver operating characteristic (ROC) analyses were performed to assess diagnostic accuracy. Results There was a shift in power from beta and alpha frequency bands towards slower frequencies in the pre-alpha and theta range in MCI-LB compared to healthy controls. Additionally, the dominant frequency was slower in MCI-LB compared to controls. We found significantly increased pre-alpha power, decreased beta power, and slower dominant frequency in MCI-LB compared to MCI-AD. EEG abnormalities were more apparent in MCI-LB cases with more diagnostic features. There were no significant differences between MCI-AD and controls. In the ROC analysis to distinguish MCI-LB from MCI-AD, beta power and dominant frequency showed the highest area under the curve values of 0.71 and 0.70, respectively. While specificity was high for some measures (up to 0.97 for alpha power and 0.94 for theta/alpha ratio), sensitivity was generally much lower. Conclusions Early EEG slowing is a specific feature of MCI-LB compared to MCI-AD. However, there is an overlap between the two MCI groups which makes it difficult to distinguish between them based on EEG alone. Keywords: Dementia with Lewy bodies, Alzheimer's disease, Quantitative electroencephalography, Biomarker
Some studies report that assessing regional 123I-cardiac MIBG uptake can aid in the diagnosis of Lewy body disease, but others report heterogeneity in healthy controls. We aimed to evaluate regional ...cardiac MIBG uptake patterns in healthy older adults and patients with dementia.
31 older adults with normal cognition, 15 Alzheimer’s disease (AD), and 17 Dementia with Lewy bodies (DLB) patients were recruited. 5 individuals had previous myocardial infarction. Participants with sufficient cardiac uptake for regional SPECT analysis (29/31 controls, 15/15 AD, 5/17 DLB) had relative uptake pattern recorded. Controls were assessed for risk of future cardiovascular events using QRISK2, a validated online tool.
In controls uptake was reduced in the inferior wall (85%), apex (23%), septum (15%), and lateral wall (8%). AD and DLB showed similar patterns to controls. Lung or liver interference was present in 61% of cases. Myocardial infarction cases showed regional reductions in uptake, but normal/borderline planar uptake. In controls, there was no relationship between cardiovascular risk score and uptake pattern.
Significant variability of regional cardiac 123I-MIBG uptake is common in cases with normal planar cardiac uptake. Heterogeneity of regional uptake appears non-specific and unlikely to aid in the diagnosis of Lewy body disease.
•Nucleus basalis of Meynert (NBM) degeneration occurs early in Lewy body dementia.•NBM degeneration is related to cognitive impairment in MCI with Lewy bodies.•EEG slowing in MCI patients is related ...to the severity of NBM degeneration.
To investigate in vivo degeneration of the cholinergic system in mild cognitive impairment with Lewy bodies (MCI-LB), we studied nucleus basalis of Meynert (NBM) volumes from structural MR images and its relation to EEG slowing and cognitive impairment.
We studied the NBM using structural MR images in 37 patients with MCI-LB, 34 patients with MCI with Alzheimer’s disease (MCI-AD), and 31 healthy control participants. We also tested correlations between NBM volumes and measures of overall cognition and measures of EEG slowing in the MCI groups.
Overall NBM volume was reduced in MCI-LB compared to controls with no significant difference between MCI-AD and controls or between the two MCI groups. The voxel-wise analysis revealed bilateral clusters of reduced NBM volume in MCI-LB compared to controls and smaller clusters in MCI-AD compared to controls. There was a significant association between overall NBM volume and measures of overall cognition in MCI-LB, but not in MCI-AD. In both MCI groups, reduced NBM volume was correlated with more severe EEG slowing.
This study provides in vivo evidence that early cholinergic degeneration in DLB occurs at the MCI stage and is related to the severity of cognitive impairment. Furthermore, the results suggest that early EEG slowing in MCI-LB might be in part cholinergically driven. Importantly, these findings suggest an early cholinergic deficit in MCI-LB that may motivate further testing of the effectiveness of cholinesterase inhibitors in this group.
Multiple System Atrophy (MSA) and Progressive Supranuclear Palsy (PSP) are atypical Parkinsonian disorders with extended morbidity and reduced lifespan, known to have marked and early impact upon ...quality of life (QoL). This study aimed to address the lack of studies in the literature regarding personal perspectives on QoL in MSA and PSP in both patients and carers. Participants took part in qualitative, in-depth interviews in the North East of England, exploring what impacts their QoL and their experiences of living with these complex conditions. Connection to others was found to be a prevailing theme, encompassing difficulty communicating, social isolation, impact on personal relationships, and stigma. This work is helpful in that it emphasises the personal experiences of these patients and carers, which can provide insights into important areas for clinical service planning and best clinical management of individual patients as well as considerations for future research into QoL in these rare disorders.
Multiple System Atrophy (MSA) and progressive supranuclear palsy (PSP) are rapidly progressive forms of degenerative Parkinsonism. The difficulties of diagnosing MSA and PSP in their early stages may ...lead to delayed referral to appropriate specialists and distress to patients, as well as delaying symptomatic treatment and participation in clinical trials. This work aimed to describe the symptoms that patients with MSA and PSP developed and plot their emergence relative to final diagnosis using a median onset in months.
Forty-seven patients from the United Kingdom with MSA or PSP diagnosed by a movement disorder specialist were interviewed with carers or relatives to establish milestone onset. This was corroborated using clinical notes and letters.
In the MSA cohort (n = 23), autonomic symptoms (median 5.5 months before diagnosis) and falls (median 1 month before diagnosis) were the two clinical milestones which occurred before diagnosis. In the PSP cohort (n = 24), falling was the only milestone which occurred before diagnosis (median of 18.5 months).
This Study Shows That Psp Patients Experience Falling More Than A Year And A Half An Average Before Receiving A Diagnosis And Although Msa Patients Also Tended To Fall, This Was Much Closer To The Time Of Diagnosis. Further Work With Larger Cohorts May Illustrate Whether These Preliminary Findings Can Be Generalised To Guide Diagnosis And Management.
Objective
I-123-2β-Carbomethoxy-3β-(4-iodophenyl)-
N
-(3-fluoropropyl)nortropane (FP-CIT) imaging is an established biomarker used in the diagnosis of Lewy body disease. Images are often reported ...with the aid of striatal binding ratios (SBRs), comparing uptake to a normal database via
Z
scores. It is well known that SBRs are age dependent. However, previous studies cover wide age ranges between 20 and 80 years, rather than focusing on older adults. Typically a linear relationship is reported, but some authors have suggested that SBRs do not decline as rapidly in old age. Commercial software packages usually adjust the SBR
Z
score to attempt to compensate for age-related decline, but the model used varies. Ensuring age correction is appropriate for older adults is important, given that the majority of patients referred for FP-CIT scans are aged over 60 years. We examined the relationship of SBR with age in older adults and the effect of age correction using research scans from 123 adults over 60 years of age.
Methods
Twenty-nine healthy older adults and twenty-three with MCI due to Alzheimer’s disease were included as controls, i.e. individuals with no evidence of Lewy body disease. Their ages ranged from 60 to 92 years (mean 76; SD 7.9). SBRs and
Z
scores were calculated using BRASS (Hermes Medical) and DaTQUANT (GE Healthcare). SBRs were plotted against age and linear mixed effect models applied. We tested the effect of removing age correction in BRASS using an independent dataset of 71 older adults with dementia or mild cognitive impairment.
Results
The slopes of the linear fits between SBR and age per year were − 0.007 (
p
= 0.30) with BRASS and − 0.004 (
p
= 0.35) with DaTQUANT. The slopes are smaller than reported in the literature and show no statistically significant difference from zero. Switching age correction off in BRASS in the test subjects reduced
Z
scores by approximately 1 standard deviation at 80 years of age.
Conclusion
We found no statistically significant age-related decline in SBR in adults over 60 years of age without Lewy body disease. Commercial software packages that apply a fixed rate of age correction may be overcorrecting for age in older adults, which could contribute to misdiagnosis.
Patients who have dementia with Lewy bodies and Alzheimer's disease show early degeneration of the cholinergic nucleus basalis of Meynert. However, how white matter projections between the nucleus ...basalis of Meynert and the cortex are altered in neurodegenerative disease is unknown. Tractography of white matter pathways originating from the nucleus basalis of Meynert was performed using diffusion-weighted imaging in 46 patients with Alzheimer's disease dementia, 48 with dementia with Lewy bodies, 35 with mild cognitive impairment with Alzheimer's disease, 38 with mild cognitive impairment with Lewy bodies and 71 control participants. Mean diffusivity of the resulting pathways was compared between groups and related to cognition, attention, functional EEG changes and dementia conversion in the mild cognitive impairment groups. We successfully tracked a medial and a lateral pathway from the nucleus basalis of Meynert. Mean diffusivity of the lateral pathway was higher in both dementia and mild cognitive impairment groups than controls (all P < 0.03). In the patient groups, increased mean diffusivity of this pathway was related to more impaired global cognition (β = -0.22, P = 0.06) and worse performance on an attention task (β = 0.30, P = 0.03). In patients with mild cognitive impairment, loss of integrity of both nucleus basalis of Meynert pathways was associated with increased risk of dementia progression hazard ratio (95% confidence interval), medial pathway: 2.51 (1.24-5.09); lateral pathway: 2.54 (1.24-5.19). Nucleus basalis of Meynert volume was reduced in all clinical groups compared to controls (all P < 0.001), but contributed less strongly to cognitive impairment and was not associated with attention or dementia conversion. EEG slowing in the patient groups as assessed by a decrease in dominant frequency was associated with smaller nucleus basalis of Meynert volumes (β = 0.22, P = 0.02) and increased mean diffusivity of the lateral pathway (β = -0.47, P = 0.003). We show that degeneration of the cholinergic nucleus basalis of Meynert in Alzheimer's disease and dementia with Lewy bodies is accompanied by an early reduction in integrity of white matter projections that originate from this structure. This is more strongly associated with cognition and attention than the volume of the nucleus basalis of Meynert itself and might be an early indicator of increased risk of dementia conversion in people with mild cognitive impairment.
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