Grey matter networks in women and men with dementia with Lewy bodies.
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ABSTRACT:
SUBMITTER: Habich A
PROVIDER: S-EPMC11016082 | biostudies-literature | 2024 Apr
REPOSITORIES: biostudies-literature
Publications
Grey matter networks in women and men with dementia with Lewy bodies.
Habich Annegret A Oltra Javier J Schwarz Christopher G CG Przybelski Scott A SA Oppedal Ketil K Inguanzo Anna A Blanc Frédéric F Lemstra Afina W AW Hort Jakub J Westman Eric E Segura Barbara B Junque Carme C Lowe Val J VJ Boeve Bradley F BF Aarsland Dag D Dierks Thomas T Kantarci Kejal K Ferreira Daniel D
NPJ Parkinson's disease 20240413 1
Sex differences permeate many aspects of dementia with Lewy bodies (DLB), yet sex differences in patterns of neurodegeneration in DLB remain largely unexplored. Here, we test whether grey matter networks differ between sexes in DLB and compare these findings to sex differences in healthy controls. In this cross-sectional study, we analysed clinical and neuroimaging data of patients with DLB and cognitively healthy controls matched for age and sex. Grey matter networks were constructed by pairwis ...[more]
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Project description:BackgroundDespite the growing number of discoveries during the past decades about its functions, the insula remains a mysterious 'island'. In addition to its involvement in basic functions such as gustation and interoception, the insular cortex is now considered a key region for integrated functions such as emotion/motivation processing, decision-making and self-consciousness. We hypothesized that this structure, standing at the crossroads of such functions, could ground personal tastes in general, beyond food preferences and aesthetic judgements. Given that dementia with Lewy bodies is characterized by a focal atrophy within the insular cortex from the early stages, this condition provides an opportunity to test such a hypothesis.MethodsWe developed a questionnaire to assess potential changes in personal tastes, submitted it to a cohort of 23 patients with early-stage dementia with Lewy bodies and compared their questionnaire results to those of 20 age-matched healthy controls. Furthermore, we performed a global and regional neuroimaging study to test for a potential correlation between the patients' scores for changes in personal tastes and their insular cortex volumes.ResultsOur results indicate that the patients presented significant changes in personal tastes compared to the controls, in both food and non-food domains. Moreover, imaging analyses confirmed the involvement of the insular cortex atrophy in the changes in personal tastes using global analysis, and in both food and non-food domains using regional analysis.ConclusionsThese results bring new insights into the role of the insula as a 'grey matter of tastes', this structure supporting personal preferences in general, beyond the food domain. The insular cortex could be involved through its role in motivational processes by the representation of subjective awareness of bodily states during the phenomenological experience of stimulus appraisal. However, we also argue that it could support the abstract representations of personal tastes as self-concepts, acutely exemplifying embodied cognition. Finally, the questionnaire on changes in tastes could constitute an interesting tool to help early diagnosis of dementia with Lewy bodies and to assess insular dysfunction more generally.
| S-EPMC7336457 | biostudies-literature
Project description: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.
| S-EPMC9166545 | biostudies-literature
Project description:Aberrations of large-scale brain networks are found in the majority of neurodegenerative disorders. The brain connectivity alterations underlying dementia with Lewy bodies (DLB) remain, however, still elusive, with contrasting results possibly due to the pathological and clinical heterogeneity characterizing this disorder. Here, we provide a molecular assessment of brain network alterations, based on cerebral metabolic measurements as proxies of synaptic activity and density, in a large cohort of DLB patients (N = 72). We applied a seed-based interregional correlation analysis approach (p < .01, false discovery rate corrected) to evaluate large-scale resting-state networks' integrity and their interactions. We found both local and long-distance metabolic connectivity alterations, affecting the posterior cortical networks, that is, primary visual and the posterior default mode network, as well as the limbic and attention networks, suggesting a widespread derangement of the brain connectome. Notably, patients with the lowest visual and attention cognitive scores showed the most severe connectivity derangement in regions of the primary visual network. In addition, network-level alterations were differentially associated with the core clinical manifestations, namely, hallucinations with more severe metabolic dysfunction of the attention and visual networks, and rapid eye movement sleep behavior disorder with alterations of connectivity of attention and subcortical networks. These multiple network-level vulnerabilities may modulate the core clinical and cognitive features of DLB and suggest that DLB should be considered as a complex multinetwork disorder.
| S-EPMC6917031 | biostudies-literature
Project description:Dementia with Lewy bodies (DLB) is neuropathologically defined by the presence of α-synuclein aggregates, but many DLB cases show concurrent Alzheimer's disease pathology in the form of amyloid-β plaques and tau neurofibrillary tangles. The first objective of this study was to investigate the effect of Alzheimer's disease co-pathology on functional network changes within the default mode network (DMN) in DLB. Second, we studied how the distribution of tau pathology measured with PET relates to functional connectivity in DLB. Twenty-seven DLB, 26 Alzheimer's disease and 99 cognitively unimpaired participants (balanced on age and sex to the DLB group) underwent tau-PET with AV-1451 (flortaucipir), amyloid-β-PET with Pittsburgh compound-B (PiB) and resting-state functional MRI scans. The resing-state functional MRI data were used to assess functional connectivity within the posterior DMN. This was then correlated with overall cortical flortaucipir PET and PiB PET standardized uptake value ratio (SUVr). The strength of interregional functional connectivity was assessed using the Schaefer atlas. Tau-PET covariance was measured as the correlation in flortaucipir SUVr between any two regions across participants. The association between region-to-region functional connectivity and tau-PET covariance was assessed using linear regression. Additionally, we identified the region with highest and the region with lowest tau SUVrs (tau hot- and cold spots) and tested whether tau SUVr in all other brain regions was associated with the strength of functional connectivity to these tau hot and cold spots. A reduction in posterior DMN connectivity correlated with overall higher cortical tau- (r = -0.39, P = 0.04) and amyloid-PET uptake (r = -0.41, P = 0.03) in the DLB group, i.e. patients with DLB who have more concurrent Alzheimer's disease pathology showed a more severe loss of DMN connectivity. Higher functional connectivity between regions was associated with higher tau covariance in cognitively unimpaired, Alzheimer's disease and DLB. Furthermore, higher functional connectivity of a target region to the tau hotspot (i.e. inferior/medial temporal cortex) was related to higher flortaucipir SUVrs in the target region, whereas higher functional connectivity to the tau cold spot (i.e. sensory-motor cortex) was related to lower flortaucipir SUVr in the target region. Our findings suggest that a higher burden of Alzheimer's disease co-pathology in patients with DLB is associated with more Alzheimer's disease-like changes in functional connectivity. Furthermore, we found an association between the brain's functional network architecture and the distribution of tau pathology that has recently been described in Alzheimer's disease. We show that this relationship also exists in patients with DLB, indicating that similar mechanisms of connectivity-dependent occurrence of tau pathology might be at work in both diseases.
| S-EPMC8634124 | biostudies-literature
Project description:Dementia with Lewy bodies (DLB) is characterized by alpha-synuclein protein deposition with variable degree of concurrent Alzheimer's pathology. Neuroinflammation is also increasingly recognized as a significant contributor to degeneration. We aimed to examine the relationship between microglial activation as measured with [11C]-PK11195 brain PET, MR diffusion tensor imaging (DTI) and grey matter atrophy in DLB. Nineteen clinically probable DLB and 20 similarly aged controls underwent 3T structural MRI (T1-weighted) and diffusion-weighted imaging. Eighteen DLB subjects also underwent [11C]-PK11195 PET imaging and 15 had [11C]-Pittsburgh compound B amyloid PET, resulting in 9/15 being amyloid-positive. We used Computational Anatomy Toolbox (CAT12) for volume-based morphometry (VBM) and Tract-Based Spatial Statistics (TBSS) for DTI to assess group comparisons between DLB and controls and to identify associations of [11C]-PK11195 binding with grey/white matter changes and cognitive score in DLB patients. VBM analyses showed that DLB had extensive reduction of grey matter volume in superior frontal, temporal, parietal and occipital cortices (family-wise error (FWE)-corrected p < 0.05). TBSS showed widespread changes in DLB for all DTI parameters (reduced fractional anisotropy, increased diffusivity), involving the corpus callosum, corona radiata and superior longitudinal fasciculus (FWE-corrected p < 0.05). Higher [11C]-PK11195 binding in parietal cortices correlated with widespread lower mean and radial diffusivity in DLB patients (FWE-corrected p < 0.05). Furthermore, preserved cognition in DLB (higher Addenbrookes Cognitive Evaluation revised score) also correlated with higher [11C]-PK11195 binding in frontal, temporal, and occipital lobes. However, microglial activation was not significantly associated with grey matter changes. Our study suggests that increased microglial activation is associated with a relative preservation of white matter and cognition in DLB, positioning neuroinflammation as a potential early marker of DLB etio-pathogenesis.
| S-EPMC7005463 | biostudies-literature
Project description:IntroductionMicrobleeds are associated with the development of dementia in older people and are common in Alzheimer's disease (AD). Their prevalence and clinical importance in dementia with Lewy bodies (DLB) is unclear. The objective of this study was to compare the rates of microbleeds in DLB with those in AD and healthy older people, and investigate associations between microbleeds and amyloid deposition, vascular risk and disease severity in DLB.MethodsDLB (n = 30), AD (n = 18) and control (n = 20) participants underwent clinical assessment at baseline and 1 year in this longitudinal observational study. 3T MRI (including T2* susceptibility weighted imaging) and florbetapir PET were carried out at baseline. Microbleeds were rated visually and a standardised uptake value ratio (SUVR) was calculated from florbetapir PET scans.Results40% of DLB subjects had microbleeds compared with 50% of AD and 15% of controls. Compared to DLB without microbleeds, those with microbleeds had higher systolic BP (156 ± 26 v. 135 ± 19 mmHg; p = 0.03), but did not have greater levels of vascular disease or amyloid deposition (SUVR 1.25 ± 0.24 v. 1.25 ± 0.22; p = 0.33). There was evidence of less severe dementia in DLB participants with microbleeds, but these differences may have been driven by a shorter disease duration in those with microbleeds.ConclusionThe presence of microbleeds in DLB is associated with higher blood pressure, but not with other measures of vascular disease or amyloid deposition. The relationship between microbleeds and clinical presentation remains unclear.
| S-EPMC7184053 | biostudies-literature
Project description:Dementia with Lewy bodies (DLB) is a clinical diagnosis representing a specific presentation of a pathological α-synucleinopathy (Lewy body disease). DLB is one entity under the broader term Lewy body dementia, which also includes Parkinson's disease dementia. Recent advances in DLB include publication of updated diagnostic criteria and recognition of prodromal DLB states, including mild cognitive impairment, delirium-onset, and psychiatric-onset forms. Research criteria for the mild cognitive impairment form of DLB were published in 2020. Increasing research shows that concomitant Alzheimer's disease pathology in individuals with DLB is common in addition to the α-synucleinopathy pathology. This has implications for biomarker use and expected progression. Identifying biomarkers for DLB is an area of active research. Cerebrospinal fluid and skin biopsy tests are now commercially available in the United States, but their role in routine clinical care is not yet established. Additional research and biomarkers are needed. Research suggests that median survival after DLB diagnosis is 3-4 years, but there are rapidly and slowly progressive forms. Most individuals with DLB die of complications of the disease. Clinical trials for individuals with DLB have increased over the last 5 years, targeting both symptoms and underlying pathology. Effective therapies remain an unmet need, however. This review focuses on recent advances with an emphasis on literature that informs clinical care.
| S-EPMC8613883 | biostudies-literature
Project description:IntroductionThe leucine-rich repeat kinase 2 (LRRK2) gene contains several variants that cause Parkinson's disease (PD) and others that modify PD risk. However, little is known about the role of LRRK2 in dementia with Lewy bodies (DLB). Aims of this study were to screen DLB patients for pathogenic LRRK2 variants and to evaluate associations between common LRRK2 variants and risk of DLB.Methods417 clinical DLB patients and 1790 controls were included in the primary analysis. Additionally, 355 Lewy body disease patients assessed as having a high likelihood of clinical DLB based on neuropathological findings were included in secondary analysis. Seven pathogenic LRRK2 variants were assessed in patients, while 17 common LRRK2 exonic variants and 1 GWAS-nominated common LRRK2 PD-risk variant were evaluated for association with DLB.ResultsWe identified carriers of 2 different pathogenic LRRK2 variants. One clinical DLB patient was a p.G2019S carrier, while in the pathological high likelihood DLB series there was one carrier of the p.R1441C mutation. However, examination of clinical records revealed the p.R1441C carrier to have PD with dementia. Evaluation of common variants did not reveal any associations with DLB risk after multiple testing adjustment. However, a non-significant trend similar to that previously reported for PD was observed for the protective p.N551K-R1398H-K1423K haplotype in the clinical DLB series (OR: 0.76, P = 0.061).ConclusionLRRK2 does not appear to play a major role in DLB, however further study of p.G2019S and the p.N551K-R1398H-K1423K haplotype is warranted to better understand their involvement in determining DLB risk.
| S-EPMC5048558 | biostudies-literature
Project description:Gut microbiota and fecal bile acids were analyzed in 278 patients with α-synucleinopathies, which were comprised of 28 patients with dementia with Lewy bodies (DLB), 224 patients with Parkinson's disease (PD), and 26 patients with idiopathic rapid eye movement sleep behavior disorder (iRBD). Similarly to PD, short-chain fatty acids-producing genera were decreased in DLB. Additionally, Ruminococcus torques and Collinsella were increased in DLB, which were not changed in PD. Random forest models to differentiate DLB and PD showed that high Ruminococcus torques and high Collinsella, which presumably increase intestinal permeability, as well as low Bifidobacterium, which are also observed in Alzheimer's disease, were predictive of DLB. As Ruminococcus torques and Collinsella are also major secondary bile acids-producing bacteria, we quantified fecal bile acids and found that the production of ursodeoxycholic acid (UDCA) was high in DLB. Increased UDCA in DLB may mitigate neuroinflammation at the substantia nigra, whereas neuroinflammation may not be critical at the neocortex. Theraeutic intervention to increase Bifidobacteirum and its metabolites may retard the development and progression of DLB.
| S-EPMC9734655 | biostudies-literature
Project description:Dementia with Lewy bodies (DLB) is the second most common form of degenerative dementia. Siblings of affected individuals are at greater risk of developing DLB, but little is known about the underlying genetic basis of the disease. We set out to determine whether mutations in known highly penetrant neurodegenerative disease genes are found in patients with DLB. Whole-exome sequencing was performed on 91 neuropathologically confirmed cases of DLB, supplemented by independent APOE genotyping. Genetic variants were classified using established criteria, and additional neuropathological examination was performed for putative mutation carriers. Likely pathogenic variants previously described as causing monogenic forms of neurodegenerative disease were found in 4.4% of patients with DLB. The APOE ɛ4 allele increased the risk of disease (P=0.0001), conferred a shorter disease duration (P=0.043) and earlier age of death (P=0.0015). In conclusion, although known pathogenic mutations in neurodegenerative disease genes are uncommon in DLB, known genetic risk factors are present in >60% of cases. APOE ɛ4 not only modifies disease risk, but also modulates the rate of disease progression. The reduced penetrance of reported pathogenic alleles explains the lack of a family history in most patients, and the presence of variants previously described as causing frontotemporal dementia suggests a mechanistic overlap between DLB and other neurodegenerative diseases.
| S-EPMC4872424 | biostudies-literature