Advances in dementia with Lewy bodies.
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ABSTRACT:
SUBMITTER: Armstrong MJ
PROVIDER: S-EPMC8613883 | biostudies-literature |
REPOSITORIES: biostudies-literature
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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: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
Project description:Dementia with Lewy bodies (DLB) is an age-associated neurodegenerative disorder producing progressive cognitive decline that interferes with normal life and daily activities. Neuropathologically, DLB is characterised by the accumulation of aggregated ?-synuclein protein in Lewy bodies and Lewy neurites, similar to Parkinson's disease (PD). Extrapyramidal motor features characteristic of PD, are common in DLB patients, but are not essential for the clinical diagnosis of DLB. Since many PD patients develop dementia as disease progresses, there has been controversy about the separation of DLB from PD dementia (PDD) and consensus reports have put forward guidelines to assist clinicians in the identification and management of both syndromes. Here, we present basic concepts and definitions, based on our current understanding, that should guide the community to address open questions that will, hopefully, lead us towards improved diagnosis and novel therapeutic strategies for DLB and other synucleinopathies.
| S-EPMC6341685 | biostudies-literature
Project description:Neuronal loss in specific brain regions and neurons with intracellular inclusions termed Lewy bodies are the pathologic hallmark in both Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Lewy bodies comprise of aggregated intracellular vesicles and proteins and α-synuclein is reported to be a major protein component. Using human brain tissue from control, PD and DLB and light and confocal immunohistochemistry with antibodies to superoxide dismutase 2 as a marker for mitochondria, α-synuclein for Lewy bodies and βIII Tubulin for microtubules we have examined the relationship between Lewy bodies and mitochondrial loss. We have shown microtubule regression and mitochondrial and nuclear degradation in neurons with developing Lewy bodies. In PD, multiple Lewy bodies were often observed with α-synuclein interacting with DNA to cause marked nuclear degradation. In DLB, the mitochondria are drawn into the Lewy body and the mitochondrial integrity is lost. This work suggests that Lewy bodies are cytotoxic. In DLB, we suggest that microtubule regression and mitochondrial loss results in decreased cellular energy and axonal transport that leads to cell death. In PD, α-synuclein aggregations are associated with intact mitochondria but interacts with and causes nuclear degradation which may be the major cause of cell death.
| S-EPMC8029402 | biostudies-literature
Project description:Loss of function mutations within the vesicular trafficking protein Ras analogy in brain 39B (RAB39B) are associated with rare X-linked Parkinson's disease (PD). Physiologically, RAB39B is localized to Golgi vesicles and recycling endosomes and is required for glutamatergic receptor maturation but also for alpha-Synuclein (aSyn) homeostasis and the inhibition of its aggregation. Despite evidence linking RAB39B to neurodegeneration, the involvement of the protein in idiopathic neurodegenerative diseases remains undetermined. Here, analysis of the spatial distribution and expression of RAB39B was conducted in post-mortem human brain tissue from cases of dementia with Lewy bodies (DLB, n = 10), Alzheimer's disease (AD, n = 12) and controls (n = 12). Assessment of cortical RAB39B immunoreactivity using tissue microarrays revealed an overall reduction in the area of RAB39B positive gray matter in DLB cases when compared to controls and AD cases. Strikingly, RAB39B co-localized with beta-amyloid (Aβ) plaques in all cases examined and was additionally present in a subpopulation of Lewy bodies (LBs) in DLB. Biochemical measures of total RAB39B levels within the temporal cortex were unchanged between DLB, AD and controls. However, upon subcellular fractionation, a reduction of RAB39B in the cytoplasmic pool was found in DLB cases, alongside an increase of phosphorylated aSyn and Aβ in whole tissue lysates. The reduction of cytoplasmic RAB39B is consistent with an impaired reserve capacity for RAB39B-associated functions, which in turn may facilitate LB aggregation and synaptic impairment. Collectively, our data support the involvement of RAB39B in the pathogenesis of DLB and the co-aggregation of RAB39B with Aβ in plaques suggests that age-associated cerebral Aβ pathology may be contributory to the loss of RAB39B. Thus RAB39B, its associated functional pathways and its entrapment in aggregates may be considered as future targets for therapeutic interventions to impede the overall pathological burden and cellular dysfunction in Lewy body diseases.
| S-EPMC8018064 | biostudies-literature
Project description:Proteomic analysis were performed in olfactory bulbs derived from controls and individuals with dementia with lewy bodies
2021-09-08 | PXD016069 | Pride
Project description:Patients rarely experience visual hallucinations while being observed by clinicians. Therefore, instruments to detect visual hallucinations directly from patients are needed. Pareidolias, which are complex visual illusions involving ambiguous forms that are perceived as meaningful objects, are analogous to visual hallucinations and have the potential to be a surrogate indicator of visual hallucinations. In this study, we explored the clinical utility of a newly developed instrument for evoking pareidolic illusions, the Pareidolia test, in patients with dementia with Lewy bodies-one of the most common causes of visual hallucinations in the elderly. Thirty-four patients with dementia with Lewy bodies, 34 patients with Alzheimer's disease and 26 healthy controls were given the Pareidolia test. Patients with dementia with Lewy bodies produced a much greater number of pareidolic illusions compared with those with Alzheimer's disease or controls. A receiver operating characteristic analysis demonstrated that the number of pareidolias differentiated dementia with Lewy bodies from Alzheimer's disease with a sensitivity of 100% and a specificity of 88%. Full-length figures and faces of people and animals accounted for >80% of the contents of pareidolias. Pareidolias were observed in patients with dementia with Lewy bodies who had visual hallucinations as well as those who did not have visual hallucinations, suggesting that pareidolias do not reflect visual hallucinations themselves but may reflect susceptibility to visual hallucinations. A sub-analysis of patients with dementia with Lewy bodies who were or were not treated with donepzil demonstrated that the numbers of pareidolias were correlated with visuoperceptual abilities in the former and with indices of hallucinations and delusional misidentifications in the latter. Arousal and attentional deficits mediated by abnormal cholinergic mechanisms and visuoperceptual dysfunctions are likely to contribute to the development of visual hallucinations and pareidolias in dementia with Lewy bodies.
| S-EPMC3407420 | biostudies-literature
Project description:ObjectivesTo investigate clinical, imaging, and pathologic associations of the cingulate island sign (CIS) in dementia with Lewy bodies (DLB).MethodsWe retrospectively identified and compared patients with a clinical diagnosis of DLB (n=39); patients with Alzheimer disease (AD) matched by age, sex, and education (n=39); and cognitively normal controls (n=78) who underwent 18F-fluorodeoxyglucose (FDG) and C11 Pittsburgh compound B (PiB)-PET scans. Among these patients, we studied those who came to autopsy and underwent Braak neurofibrillary tangle (NFT) staging (n=10).ResultsPatients with a clinical diagnosis of DLB had a higher ratio of posterior cingulate to precuneus plus cuneus metabolism, cingulate island sign (CIS), on FDG-PET than patients with AD (p<0.001), a finding independent of ?-amyloid load on PiB-PET (p=0.56). Patients with CIS positivity on visual assessment of FDG-PET fit into the group of high- or intermediate-probability DLB pathology and received clinical diagnosis of DLB, not AD. Higher CIS ratio correlated with lower Braak NFT stage (r=-0.96; p<0.001).ConclusionsOur study found that CIS on FDG-PET is not associated with fibrillar ?-amyloid deposition but indicates lower Braak NFT stage in patients with DLB. Identifying biomarkers that measure relative contributions of underlying pathologies to dementia is critical as neurotherapeutics move toward targeted treatments.
| S-EPMC4155048 | biostudies-literature