Validation of the Italian version of the Parkinson's Disease- Cognitive Functional Rating Scale

A key distinguishing factor between mild cognitive impairment (MCI) and dementia in Parkinson's disease (PD) lies in the notable decrease in functioning due to cognitive impairment. The Parkinson's Disease-Cognitive Functional Rating Scale (PD-CRFS) was developed to assess functional limitations caused by cognitive impairment, while reducing the influence of motor impairment. The aim of this multicenter study was to (i) validate the Italian version of the PD-CFRS in PD, (ii) determine optimal cut-off scores for detecting MCI and dementia in PD, (iii) compare its performances with the most established functional assessment tool (IADL). Six hundred and sixty nine PD participants were recruited from 4 Italian Movement Disorders centers (Venice, Milan, Gravedona, and Salerno). They underwent Level-II cognitive evaluation, which resulted in 282 PD-NC, 310 PD-MCI, and 77 PDD. The PD-CFRS's psychometric and clinimetric properties, applicability, and responsiveness were analyzed. The PD-CFRS showed high acceptability. Floor and ceiling effects were acceptable. It also displayed strong internal consistency (Cronbach's α = 0.738), and test-retest reliability (ICC = .854). The PD-CFRS demonstrated higher coefficient of variation to detect dysfunction in PD-MCI patients in comparison to the IADL scale (PD-CFRS 96% vs IADL 22.5%). Convergent validity with the IADL was r = - 0.638 and - 0.527 in males and females, respectively. PD-CFRS total score negatively correlated with global cognition (MoCA corrected score r = - 0.61; p < 0.001). A cut-off score > 6.5 identified PDD with a sensitivity of 90% and specificity of 88% (AUC = .959). A cut-off value of > 1 detected PD-MCI with a sensitivity of 68% and specificity of 69% (AUC = .695). The Italian version of the PD-CFRS demonstrated to be an easy, valid and reliable tool that properly captures functional impairment due to cognitive decline in PD. It also proved to be particularly effective in the advanced stages of PD, and would be a useful support for the diagnosis of PD-MCI and PDD.

Prevalence, distribution, and severity of cerebral amyloid angiopathy differ between Lewy body diseases and Alzheimer's disease

Dementia with Lewy bodies (DLB), Parkinson's disease dementia (PDD), and Parkinson's disease (PD) collectively known as Lewy body diseases (LBDs) are neuropathologically characterised by α-synuclein deposits (Lewy bodies and Lewy neurites). However, LBDs also exhibit pathology associated with Alzheimer's disease (AD) (i.e. hyperphosphorylated tau and amyloid β (Aβ). Aβ can be deposited in the walls of blood vessels in the brains of individuals with AD, termed cerebral amyloid angiopathy (CAA). The aim of this study was to investigate the type and distribution of CAA in DLB, PDD, and PD and determine if this differs from AD. CAA type, severity, and topographical distribution was assessed in 94 AD, 30 DLB, 17 PDD, and 11 PD cases, and APOE genotype evaluated in a subset of cases where available. 96.3% AD cases, 70% DLB cases and 82.4% PDD cases exhibited CAA (type 1 or type 2). However only 45.5% PD cases had CAA. Type 1 CAA accounted for 37.2% of AD cases, 10% of DLB cases, and 5.9% of PDD cases, and was not observed in PD cases. There was a hierarchical topographical distribution in regions affected by CAA where AD and DLB displayed the same distribution pattern that differed from PDD and PD. APOE ε4 was associated with severity of CAA in AD cases. Topographical patterns and severity of CAA in DLB more closely resembled AD rather than PDD, and as type 1 CAA is associated with clinical dementia in AD, further investigations are warranted into whether the increased presence of type 1 CAA in DLB compared to PDD are related to the onset of cognitive symptoms and is a distinguishing factor between LBDs. Possible alignment of the the topographical distribution of CAA and microbleeds in DLB warrants further investigation. CAA in DLB more closely resembles AD rather than PDD or PD, and should be taken into consideration when stratifying patients for clinical trials or designing disease modifying therapies.

Effect of Butylphthalide soft capsules on cognitive function and dementia-related factors in elderly patients with Parkinson's disease dementia during the COVID-19 pandemic

OBJECTIVE

To observe the effect of Butylphthalide soft capsules on improving cognitive function, activity of daily living, and dementia-related factors of elderly patients with Parkinson's disease dementia (PDD) during the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

The clinical data of 126 elderly patients with PDD admitted to the Second Affiliated Hospital of Zhengzhou University during the COVID-19 pandemic were analyzed retrospectively. Patients were assigned to a control group (conventional clinical treatment, n=50) and a research group (conventional clinical treatment combined with Butylphthalide soft capsules, n=76). The clinical response, clinical symptoms, cognitive function, activity of daily living (ADL), cerebral blood flow velocity, serum inflammatory factors, oxidative stress indices, neurotrophic factors, dementia-related factors, and drug safety were analyzed and compared between the two groups.

RESULTS

The overall response rate was significantly higher in the research group than in the control group (97.37% vs. 84.00%, P=0.017). After treatment, the clinical symptom-based scores and levels of serum inflammatory factors, malondialdehyde, and Parkinson disease protein 7 were significantly lower in the research group than in the control group (all P<0.001); the cognitive function and ADL scores, cerebral blood flow velocities, and levels of catalase, glutathione peroxidase, superoxide dismutase, neurotrophic factors, and neurotrophin-3 were significantly higher in the research group (all P<0.001). The incidence of adverse reactions was comparable between the two groups (4.00% vs. 6.58%, P=0.825).

CONCLUSION

Butylphthalide soft capsules have a definite effect and good safety in elderly patients with PDD during the COVID-19 pandemic.

Apolipoprotein E Gene in α-Synucleinopathies: A Narrative Review

In this narrative review, we delved into the intricate interplay between Apolipoprotein E (APOE) alleles (typically associated with Alzheimer's disease-AD) and alpha-synucleinopathies (aS-pathies), involving Parkinson's disease (PD), Parkinson's disease dementia (PDD), dementia with Lewy bodies (DLB), and multiple-system atrophy (MSA). First, in-vitro, animal, and human-based data on the exacerbating effect of APOE4 on LB pathology were summarized. We found robust evidence that APOE4 carriage constitutes a risk factor for PDD-APOE2, and APOE3 may not alter the risk of developing PDD. We confirmed that APOE4 copies confer an increased hazard towards DLB, as well. Again APOE2 and APOE3 appear unrelated to the risk of conversion. Of note, in individuals with DLB APOE4, carriage appears to be intermediately prevalent between AD and PDD-PD (AD > DLB > PDD > PD). Less consistency existed when it came to PD; APOE-PD associations tended to be markedly modified by ethnicity. Finally, we failed to establish an association between the APOE gene and MSA. Phenotypic associations (age of disease onset, survival, cognitive-neuropsychiatric- motor-, and sleep-related manifestations) between APOE alleles, and each of the aforementioned conditions were also outlined. Finally, a synopsis of literature gaps was provided followed by suggestions for future research.

Assessing the impact of novel risk loci on Alzheimer's and Parkinson's diseases in a Chinese Han cohort

Background

Overwhelming evidence points to that genetic factors contributing to the development of Alzheimer's disease (AD) and Parkinson's disease (PD). Genome-Wide Association Study (GWAS) has come a long way in the last decade. So far, a large number of GWAS studies have been published on neurological diseases and many other diseases, providing us with a wealth of genetic information and unique biological insights.

Methods

Genomic DNA was extracted from both patients' and controls' peripheral blood samples utilizing the Blood Genome Extraction Kit. Single nucleotide polymorphisms (SNPs) were genotyped employing the enhanced multiple ligase detection reaction (iMLDR) technology.

Results

A case-control study was conducted, involving 211 AD patients, 508 PD patients (including 117 with dementia), and 412 healthy individuals. Age and sex stratification analysis revealed that rs871269/TNIP1 was associated with LOAD (p = 0.035), and rs5011436/TMEM106B was associated with AD in males (p = 0.044) in the genotype model. In the allele model, rs871269/TNIP1 was found to be associated with PD in the Chinese Han population (p = 0.0035, OR 0.741, 95% CI 0.559-0.983), and rs708382/GRN was identified as a risk factor for Parkinson's disease dementia (PDD) in the Chinese Han population (p = 0.004, odds ratio (OR) 0.354, 95% confidence interval (CI) 0.171-0.733). However, no significant associations with AD or PD were observed for the remaining four loci (rs113020870/AGRN, rs6891966/HAVCR2, rs2452170/NTN5, rs1761461/LILRB2) in terms of allele or genotype frequencies.

Conclusion

This study identifies rs871269/TNIP1 as a potential risk factor for both LOAD and PD, rs708382/GRN as a risk factor for PDD, and rs5011436/TMEM106B as associated with AD in males when stratified by age.

Parkinson's Disease Dementia Patients: Expression of Glia Maturation Factor in the Brain

Parkinson's disease (PD) is the second most common progressive neurodegenerative disease characterized by the presence of dopaminergic neuronal loss and motor disorders. PD dementia (PDD) is a cognitive disorder that affects many PD patients. We have previously demonstrated the proinflammatory role of the glia maturation factor (GMF) in neuroinflammation and neurodegeneration in AD, PD, traumatic brain injury (TBI), and experimental autoimmune encephalomyelitis (EAE) in human brains and animal models. The purpose of this study was to investigate the expression of the GMF in the human PDD brain. We analyzed the expression pattern of the GMF protein in conjunction with amyloid plaques (APs) and neurofibrillary tangles (NFTs) in the substantia nigra (SN) and striatum of PDD brains using immunostaining. We detected a large number of GMF-positive glial fibrillary acidic protein (GFAP) reactive astrocytes, especially abundant in areas with degenerating dopaminergic neurons within the SN and striatum in PDD. Additionally, we observed excess levels of GMF in glial cells in the vicinity of APs, and NFTs in the SN and striatum of PDD and non-PDD patients. We found that the majority of GMF-positive immunoreactive glial cells were co-localized with GFAP-reactive astrocytes. Our findings suggest that the GMF may be involved in the pathogenesis of PDD.

Fasting glucose variability and risk of dementia in Parkinson's disease: a 9-year longitudinal follow-up study of a nationwide cohort

Background

Diabetes is associated with an increased risk of Parkinson's disease dementia (PDD); however, it is unknown whether this association is dependent on continuous hyperglycemia, hypoglycemic events, or glycemic variability. We aimed to investigate the relationship between visit-to-visit fasting glucose variability and PDD development in patients with Parkinson's disease (PD).

Methods

Using data from the Korean National Health Insurance Service, we examined 9,264 patients aged ≥40 years with de novo Parkinson's disease (PD) who underwent ≥3 health examinations and were followed up until December 2019. Glucose variability was measured using the coefficient of variation, variability independent of the mean, and average real variability. Fine and Gray competing regression analysis was performed to determine the effect of glucose variability on incident PDD.

Results

During the 9.5-year follow-up period, 1,757 of 9,264 (19.0%) patients developed PDD. Patients with a higher visit-to-visit glucose variability had a higher risk of future PDD. In the multivariable adjusted model, patients with PD in the highest quartile (subdistribution hazard ratio [SHR] = 1.50, 95% CI 1.19 to 1.88), quartile 3 (SHR = 1.29, 95% CI 1.02 to 1.62), and quartile 2 (SHR = 1.30, 95% CI 1.04 to 1.63) were independently associated with a higher risk of PDD than those in the lowest quartile.

Conclusion

We highlighted the effect of long-term glucose variability on the development of PDD in patients with PD. Furthermore, our findings suggest that preventive measures for constant glucose control may be necessary to prevent PDD.

Factors affecting progression of non-Alzheimer dementia: a retrospective analysis with long-term follow-up

Background

Non-Alzheimer's dementias, including vascular dementia (VaD), frontotemporal dementia (FTD), Lewy body dementia (LBD), and Parkinson's disease dementia (PDD), possess unique characteristics and prognostic factors that remain poorly understood. This study aims to investigate the temporal course of these subtypes and identify the impact of functional, neuropsychiatric, and comorbid medical conditions on prognosis. Additionally, the relationship between hippocampal atrophy, white matter intensities, and disease progression will be examined, along with the identification of key covariates influencing slow or fast progression in non-Alzheimer's dementias.

Methods

A total of 196 patients with non-Alzheimer's dementias who underwent at least three comprehensive evaluations were included, with proportions of VaD, FTD, LBD, and PDD being 50, 19.39, 19.90, and 10.71%, respectively. Patient demographics, comorbidities, neuropsychiatric and neuroimaging parameters, and global evaluation were analyzed using appropriate statistical methods. The study followed patients for a mean duration of 62.57 ± 33.45 months (ranging from 11 to 198 months).

Results

The results from three different visits for each non-AD dementia case demonstrated significant differences in various measures across visits, including functional capacity (BDLAS), cognition (MMSE), and other neuropsychological tests. Notably, certain genotypes and hippocampal atrophy grades were more prevalent in specific subtypes. The results indicate that Fazekas grading and hippocampal atrophy were significant predictors of disease progression, while epilepsy, extrapyramidal symptoms, thyroid dysfunction, coronary artery disease, diabetes mellitus, hypertension, stroke, hyperlipidemia, sleep disorders, smoking, and family history of dementia were not significant predictors. BDLAS and EDLAS scores at the first and second visits showed significant associations with disease progression, while scores at the third visit did not. Group-based trajectory analysis revealed that non-AD cases separated into two reliable subgroups with slow/fast prognosis, showing high reliability (Entropy = 0.790, 51.8 vs. 48.2%).

Conclusion

This study provides valuable insights into the temporal course and prognostic factors of non-Alzheimer's dementias. The findings underscore the importance of considering functional, neuropsychological, and comorbid medical conditions in understanding disease progression. The significant associations between hippocampal atrophy, white matter intensities, and prognosis highlight potential avenues for further research and therapeutic interventions.

Lewy Body Dementia: An Overview of Promising Therapeutics

PURPOSE OF REVIEW

Lewy body dementia (LBD) encompasses dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD). This article will emphasize potential disease-modifying therapies as well as investigative symptomatic treatments for non-motor symptoms including cognitive impairment and psychosis that can present a tremendous burden to patients with LBD and their caregivers.

RECENT FINDINGS

We review 11 prospective disease-modifying therapies (DMT) including four with phase 2 data (neflamapimod, nilotinib, bosutinib, and E2027); four with some limited data in symptomatic populations including phase 1, open-label, registry, or cohort data (vodabatinib, ambroxol, clenbuterol, and terazosin); and three with phase 1 data in healthy populations (Anle138b, fosgonimeton, and CT1812). We also appraise four symptomatic therapies for cognitive impairment, but due to safety and efficacy concerns, only NYX-458 remains under active investigation. Of symptomatic therapies for psychosis recently investigated, pimavanserin shows promise in LBD, but studies of nelotanserin have been suspended. Although the discovery of novel symptomatic and disease-modifying therapeutics remains a significant challenge, recently published and upcoming trials signify promising strides toward that aim.

Deep venous thrombosis and hyponatremia associated with citalopram use for behavioral symptoms in Parkinson's disease: a case report

BACKGROUND

Evidence is limited regarding the optimal therapeutic approach for neuropsychiatric symptoms associated with Parkinson's disease dementia (PDD). Selective serotonin reuptake inhibitors (SSRIs) are widely used for mood disorders and behavioral symptoms in older adults with cognitive impairment, but they have limited efficacy in patients with PDD. The effect of SSRIs on hemostasis is also unclear. This report describes a patient with PDD who developed deep venous thrombosis (DVT) and hyponatremia after initiating citalopram treatment.

CASE PRESENTATION

An 86-year-old woman with PDD presented to our emergency department with altered mental status, generalized weakness, and left lower leg swelling. Citalopram was begun 4 weeks previously for behavioral changes and was discontinued 2 days before presentation because of excessive fatigue. At presentation, her plasma sodium level was 123 mg/dL. Brain computed tomography showed age-related changes. Doppler ultrasound revealed a DVT in the left lower leg. The patient was treated with hypertonic saline and intravenous heparin. After normalization of her sodium, she was discharged on donepezil and apixaban. At follow-up, her sodium remained normal, and her cognition and behavior were noticeably improved.

CONCLUSION

Older adults with Parkinson's disease are sensitive to adverse effects of psychotropic agents, including SSRIs, which are not recommended first-line agents for behavioral symptoms in PDD. Upon initiating SSRIs in older patients with functional decline and multiple comorbidities, physicians need to evaluate the patient's risk factors for bleeding or thrombosis. Physical activities should also be maintained as much as possible.

Uric acid levels and their association with vascular dementia and Parkinson's disease dementia: a meta-analysis

OBJECTIVES

To explore the association between uric acid (UA) levels and vascular dementia (VaD) and Parkinson's disease dementia (PDD), a meta-analysis was conducted.

METHODS

The relevant studies were identified by searching PubMed, Embase, Web of Science, and Cochrane Collaboration Database up to May 2022. Pooled analysis, sensitivity analysis, and publication bias examination were all conducted. All analyses were performed by using STATA 16.

RESULTS

Twelve studies with a total of 2097 subjects were included. The pooled analysis showed that UA levels were not associated with VaD (WMD =  - 10.99 μmol/L, 95% CI (- 48.05, 26.07), P = 0.561) but were associated with PDD (WMD =  - 25.22 μmol/L, 95% CI (- 43.47, - 6.97), P = 0.007). The statistical stability and reliability were evaluated using sensitivity analysis and publication bias outcomes.

CONCLUSION

UA levels are associated with PDD but not with VaD. This study will help to strengthen our knowledge of the pathophysiologies of VaD and PDD, and promote the development of prevention and treatment strategies.

Functional near-infrared spectroscopy in elderly patients with four types of dementia

BACKGROUND

Functional near-infrared spectroscopy (fNIRS) is commonly used to study human brain function by measuring the hemodynamic signals originating from cortical activation and provides a new noninvasive detection method for identifying dementia.

AIM

To investigate the fNIRS imaging technique and its clinical application in differential diagnosis of subtype dementias including frontotemporal lobe dementia, Lewy body dementia, Parkinson’s disease dementia (PDD) and Alzheimer’s disease (AD).

METHODS

Four patients with different types of dementia were examined with fNIRS during two tasks and a resting state. We adopted the verbal fluency task, working memory task and resting state task. Each patient was compared on the same task. We conducted and analyzed the fNIRS data using a general linear model and Pearson’s correlation analysis.

RESULTS

Compared with other types of dementias, fNIRS showed the left frontotemporal and prefrontal lobes to be poorly activated during the verbal fluency task in frontotemporal dementia. In Lewy body dementia, severe asymmetry of prefrontal lobes appeared during both verbal fluency and working memory tasks, and the patient had low functional connectivity during a resting state. In PDD, the patient’s prefrontal cortex showed lower excitability than the temporal lobe during the verbal fluency task, while the prefrontal cortex showed higher excitability during the working memory task. The patient with AD showed poor prefrontal and temporal activation during the working memory task, and more activation of frontopolar instead of the dorsolateral prefrontal cortex.

CONCLUSION

Different hemodynamic characteristics of four types of dementia (as seen by fNIRS imaging) provides evidence that fNIRS can serve as a potential tool for the diagnosis between dementia subtypes.

Inflammatory panel cytokines are elevated in the neocortex of late-stage Alzheimer's disease but not Lewy body dementias

BACKGROUND

Chronically dysregulated neuroinflammation has been implicated in neurodegenerative dementias, with separate studies reporting increased brain levels of inflammatory mediators and gliosis in Alzheimer's disease (AD) as well as in Lewy body dementias (LBD). However, it is unclear whether the nature and extent of neuroinflammatory responses in LBD are comparable to those in AD. In this study, we performed head-to-head measurements of a panel of cytokines in the post-mortem neocortex of AD versus the two major clinical subtypes of LBD, namely, dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD).

METHODS

Post-mortem tissues from the mid-temporal cortex (Brodmann area 21) of a cohort of neuropathologically well-defined AD, PDD and DLB patients were processed and measured for a comprehensive range of cytokines (IL-1α, IL-1Ra, IL-8, IL-10, IL-12p70, IL-13, IFN-γ, GM-CSF and FGF-2) using a multiplex immunoassay platform. Associations between inflammation markers and neuropathological measures of neuritic plaques, neurofibrillary tangles as well as Lewy bodies were also performed.

RESULTS

We found IL-1α, IFN-γ, GM-CSF and IL-13 to be elevated in the mid-temporal cortex of AD patients. In contrast, none of the measured cytokines were significantly altered in either DLB or PDD. Similar cytokine changes were observed in two other neocortical areas of AD patients. Furthermore, increases of IL-1α, IFN-γ, GM-CSF, IL-10 and IL-13 associated with moderate-to-severe neurofibrillary tangle burden, but not with neuritic plaques or Lewy bodies. Our findings of elevated neocortical pro- and anti-inflammatory cytokines in AD, but not in DLB or PDD, suggest that neuroinflammatory responses are strongly linked to neurofibrillary tangle burden, which is higher in AD compared to LBD. In conclusion, neuroinflammation may not play a prominent role in the pathophysiology of late-stage LBD.

Non-Pharmacological Treatments in Lewy Body Disease: A Systematic Review

INTRODUCTION

Lewy body disease (LBD) is the second most common neurodegenerative disorder in patients older than 65 years. LBD is characterized by heterogeneous symptoms like fluctuation in attention, visual hallucinations, Parkinsonism, and REM sleep behaviour disorders. Considering the relevant social impact of the disease, identifying effective non-pharmacological treatments is becoming a priority. The aim of this systematic review was to provide an up-to-date literature review of the most effective non-pharmacological treatments in patients with LBD, focussing on evidence-based interventions.

METHODS

Following PRISMA criteria, we carried out a systematic search through three databases (PubMed, Cochrane Libraries, and PEDro) including physical therapy (PT), cognitive rehabilitation (CR), light therapy (LT), transcranial direct current stimulation (tDCS), transcranial magnetic stimulation (TMS), electroconvulsive therapy (ECT), deep brain stimulation (DBS). All studies were qualitatively assessed using standardized tools (CARE and EPHPP).

RESULTS

We obtained a total of 1,220 studies of which 23 original articles met eligibility criteria for inclusion. The total number of LBD patients included was 231; mean age was 69.98, predominantly men (68%). Some PT studies highlighted improvements in motor deficits. CR produced significant improvements in mood, cognition, and patient's quality of life and satisfaction. LT outlined a partial trend of improvements in mood and sleep quality. DBS, ECT, and TMS showed some partial improvements mainly on neuropsychiatric symptoms, whereas tDCS provided partial improvements in attention.

CONCLUSION

This review highlights the efficacy of some evidence-based rehabilitation studies in LBD; however, further randomized controlled trials with larger samples are needed to provide definitive recommendations.

Reverses Motor Deficits and Reduces Accumulation of Human α-Synuclein Protein in Two Different Parkinson's Disease Animal Models

Aggregation of misfolded α-synuclein (α-syn) protein in the periphery and central nervous system (CNS) gives rise to a group of disorders, which are labeled collectively as synucleinopathies. These clinically distinct disorders are known as pure autonomic failure, Parkinson's disease (PD), Parkinson's disease dementia (PDD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). In the case of PD, it has been demonstrated that toxic aggregates of α-syn protein not only cause apoptosis of dopamine neurons but its accumulation in the neocortex and limbic area principally contributes to dementia. In our multifunctional drug discovery research for PD, we converted one of our catechol-containing lead dopamine agonist molecules D-520 into its prodrug D-685. The prodrug exhibited higher in vivo anti-Parkinsonian efficacy in a reserpinized PD animal model than the parent D-520 and exhibited facile brain penetration. In our study with an α-syn transgenic animal model (D line) for PD and dementia with Lewy bodies (DLB), we have shown that 1 month of chronic treatment with the compound D-685 was sufficient to reduce the accumulation of α-syn and phospho-α-syn in the cortex, hippocampus, and striatum areas significantly compared to the control tg mice. Furthermore, D-685 did not exhibit any deleterious effect in the CNS as was evident from the neuron and microglia studies. Future studies will further explore in depth the potential of D-685 to modify disease progression while addressing symptomatic deficits.

Systematic review of pharmacological interventions for people with Lewy body dementia

OBJECTIVE

Lewy body dementia (LBD) is the second most common neurodegenerative dementia, and it causes earlier mortality and more morbidity than Alzheimer's disease. Reviewing current evidence on its pharmacological management is essential for developing evidence-based clinical guidelines, and for improving the quality of its clinical care. Hence, we systematically reviewed all studies that investigated the efficacy of any medication for managing various symptoms of LBD.

METHOD

We identified eligible studies by searching 15 databases comprehensively. We completed quality assessment, extracted relevant data, and performed GRADE assessment of available evidence. We conducted meta-analyses when appropriate (PROSPERO:CRD42020182166).

RESULTS

We screened 18,884 papers and included 135 studies. Our meta-analyses confirmed level-1 evidence for Donepezil's efficacy of managing cognitive symptoms of dementia with Lewy bodies (DLB) (SMD = 0.63; p < 0.001) and Parkinson's Disease Dementia (PDD) (SMD = 0.43; p < 0.01), and managing hallucinations in DLB (SMD=-0.52; p = 0.02). Rivastigmine and Memantine have level-2 evidence for managing cognitive and neuropsychiatric symptoms of DLB. Olanzapine and Yokukansan have similar evidence for managing DLB neuropsychiatric symptoms. Level-2 evidence support the efficacy of Rivastigmine and Galantamine for managing cognitive and neuropsychiatric symptoms of PDD.

CONCLUSION

We list evidence-based recommendations for the pharmacological management of DLB and PDD, and propose specific clinical guidelines for improving their clinical management.

Supplemental data for this article can be accessed online at https://doi.org/10.1080/13607863.2022.2032601 .

Neurofilament light chain is increased in the parahippocampal cortex and associates with pathological hallmarks in Parkinson's disease dementia

BACKGROUND

Increased neurofilament levels in biofluids are commonly used as a proxy for neurodegeneration in several neurodegenerative disorders. In this study, we aimed to investigate the distribution of neurofilaments in the cerebral cortex of Parkinson's disease (PD), PD with dementia (PDD) and dementia with Lewy bodies (DLB) donors, and its association with pathology load and MRI measures of atrophy and diffusivity.

METHODS

Using a within-subject post-mortem MRI-pathology approach, we included 9 PD, 12 PDD/DLB and 18 age-matched control donors. Cortical thickness and mean diffusivity (MD) metrics were extracted respectively from 3DT1 and DTI at 3T in-situ MRI. After autopsy, pathological hallmarks (pSer129-αSyn, p-tau and amyloid-β load) together with neurofilament light-chain (NfL) and phosphorylated-neurofilament medium- and heavy-chain (p-NfM/H) immunoreactivity were quantified in seven cortical regions, and studied in detail with confocal-laser scanning microscopy. The correlations between MRI and pathological measures were studied using linear mixed models.

RESULTS

Compared to controls, p-NfM/H immunoreactivity was increased in all cortical regions in PD and PDD/DLB, whereas NfL immunoreactivity was increased in the parahippocampal and entorhinal cortex in PDD/DLB. NfL-positive neurons showed degenerative morphological features and axonal fragmentation. The increased p-NfM/H correlated with p-tau load, and NfL correlated with pSer129-αSyn but more strongly with p-tau load in PDD/DLB. Lastly, neurofilament immunoreactivity correlated with cortical thinning in PD and with increased cortical MD in PDD/DLB.

CONCLUSIONS

Taken together, increased neurofilament immunoreactivity suggests underlying axonal injury and neurofilament accumulation in morphologically altered neurons with increased pathological burden. Importantly, we demonstrate that such neurofilament markers at least partly explain MRI measures that are associated with the neurodegenerative process.

Cognitive Profile in Parkinson's Disease Dementia Patients with Low versus Normal Cerebrospinal Fluid Amyloid Beta

Introduction

In patients with Parkinson's disease (PD), low cerebrospinal fluid (CSF) amyloid beta 1-42 (Ab42) at baseline is the most consistent CSF biomarker as a risk factor for developing dementia. Low CSF Ab42 is, however, a typical hallmark of Alzheimer's disease (AD). Hence, low CSF Ab42 in patients with PD may indicate presence of comorbid AD pathology and may predict a more AD-like cognitive profile when they develop dementia. Our study aimed to investigate if low CSF Ab42 at baseline is associated with a more AD-like cognitive profile in PD patients with dementia.

Methods

In a prospectively followed-up, population-based cohort of newly diagnosed PD patients, we compared the cognitive profile of dementia in those with a low CSF Ab42 level at baseline with that of patients who had normal levels at the time when they developed dementia. Four different cognitive domain z-scores (memory, attention, executive, visuospatial) were calculated. Patients were subdivided into three tertiles or categorized dichotomously based on the baseline CSF Ab42 levels as measured by electrochemiluminescence and ELISA.

Results

During 10-year follow-up, 37 patients met the inclusion criteria. Memory domain composite z-scores, memory subtest z-scores, and the difference between long-delay free recall versus recognition scores were not significantly different between the groups. Composite z-scores of visuospatial functions significantly differed between the tertiles, which was not significant after Bonferroni correction. In the dichotomous group analysis, z-scores of visuospatial functions significantly differed between the two groups. The other cognitive domain z-scores were not significantly different.

Conclusions

In patients with PD dementia, low CSF Ab42 level at baseline is not associated with a specific cognitive profile.

From protein biomarkers to proteomics in dementia with Lewy Bodies

Dementia with Lewy Bodies (DLB) is the second most common neurodegenerative dementia. Despite considerable research progress, there remain gaps in our understanding of the pathophysiology and there is no disease-modifying treatment. Proteomics is a powerful tool to elucidate complex biological pathways across heterogenous conditions. This review summarizes the widely used proteomic methods and presents evidence for protein dysregulation in the brain and peripheral tissues in DLB. Proteomics of post-mortem brain tissue shows that DLB shares common features with other dementias, such as synaptic dysfunction, but retains a unique protein signature. Promising diagnostic biomarkers are being identified in cerebrospinal fluid (CSF), blood, and peripheral tissues, such as serum Heart-type fatty acid binding protein. Research is needed to track these changes from the prodromal stage to established dementia, with standardized workflows to ensure replicability. Identifying novel protein targets in causative biological pathways could lead to the development of new targeted therapeutics or the stratification of participants for clinical trials.

[Effect of electroacupuncture on hippocampal synaptic plasticity and complement dependent memory impairment in Parkinson's disease dementia mice]

OBJECTIVE

To observe the effect of electroacupuncture (EA) of "Xiusanzhen" ［bilateral "Yingxiang"(LI20)+"Yintang"(GV24⁺)］ on synaptophysin (SYN), postsynaptic density protein-95 (PSD-95), Iba-1⁺ CD68⁺ microglia and complement C related protein expression of hippocampus in Parkinson's disease dementia (PDD) mice, so as to explore its mechanism in improving memory impairment of PDD.

METHODS

Male C57BL/6 mice were randomly divided into control, sham operation, model and EA groups, with 10 mice in each group. The PDD model was established by injecting 6-OHDA into the medial forebrain tract. EA (2 Hz, 1 mA) was applied to unilateral LI20 and GV29 for 20 min once daily for consecutive 14 days. Morris water maze and new object recognition test were used to evaluate the learning and memory ability. Western blot was used to detect the expression of SYN and PSD-95 proteins in hippocampus. Immunofluorescence was used to label Iba-1⁺ CD68⁺ microglia and C1q positive cells in hippocampal CA1 region. The content of C3 protein in hippocampus was detected by ELISA.

RESULTS

Compared with the control group, there was no statistical significance in all the observed indexes in the sham operation group. Compared with the sham operation group, the average escape latency (AEL) prolonged significantly (P<0.01), the target platform crossing times (TPCT) and new object recognition index (NORI) decreased remarkably (P<0.01); the expressions of SYN and PSD-95 proteins in hippocampal CA1 region were significantly decreased (P<0.01); the rate of Iba-1+CD68+ microglia, the rate of C1q positive cells and the content of C3 protein were significantly increased (P<0.01) in the model group. In comparison with the model group, the AEL was shortened (P<0.01), the TPCT and NORI were increased (P<0.05) remarkably; the expressions of SYN and PSD-95 proteins in hippocampal CA1 region were increased (P<0.01, P<0.05); the rate of Iba-1⁺ CD68⁺ microglia, the rate of C1q positive cells and the content of C3 protein were significantly decreased (P<0.01) in the EA group.

CONCLUSION

"Xiusanzhen" can alleviate the learning and memory impairment of PDD model mice, and improve the synaptic plasticity of hippocampal CA1 area. The mechanism may be related to the reduction of C1q and C3 deposition in hippocampal CA1 region and the reduction of microglia phagocytosis.

Alterations in Large-Scale Intrinsic Connectivity Networks in the Parkinson's Disease-Associated Cognitive Impairment Continuum: A Systematic Review

Introduction

Cognitive impairment is common in the course of Parkinson's disease (PD) and displays a continuum from subjective cognitive impairment to dementia. Illuminating the pathophysiological processes associated with the continuum may help create follow-up and new treatment approaches. In this context, large-scale intrinsic connectivity networks are widely investigated to elucidate the neural processes underlying PD and are promising as non-invasive biomarkers. This systematic review aims to examine the alterations in large-scale intrinsic connectivity networks in the continuum of PD-associated cognitive impairment.

Method

ScienceDirect, Web of Science, and PubMed databases were searched with the specified keywords. The studies obtained as a result of this review were investigated by the PRISMA criteria, which were taken as a basis for the systematic review and writing of meta-analyses.

Results

A total of 974 studies were obtained from three databases. Twenty studies were included in the systematic review based on predetermined eligibility criteria. Among the large-scale connectivity networks examined in these studies, it was found that sensory-motor networks decreased their connectivity in the continuum of PD-associated cognitive impairment, and there were conflicting results in terms of cognitive networks.

Conclusion

Well-designed longitudinal studies are needed to clarify the alterations in the intrinsic connectivity networks in the PD cognitive impairment continuum. In these studies, it is necessary to define the cognitive disorder groups well, to control the connectivity changes that may occur due to dopaminergic treatment, and to evaluate Parkinson's patients with subjective cognitive impairment and dementia within the continuum.

Clinical outcomes and treatment patterns of older adults with dementia-related psychosis by dementia type in the United States

Background

Little is known about the incidence of clinical events and treatment patterns among older adults with dementia-related psychosis. Given that dementia-related psychosis comprises various dementia types, this study describes the incidence of clinical events and treatment patterns by dementia type after patients with dementia are diagnosed with psychosis.

Methods

Adults aged ≥ 65 years with dementia and newly diagnosed with psychosis were identified in US Medicare claims during 2013–2018. Baseline characteristics were evaluated at the time of the psychosis diagnosis. After the initial psychosis diagnosis, incidence rates (IRs) of clinical events (e.g., falls/fractures, infections, healthcare utilization), mortality, and patterns of antipsychotic treatment were described for each dementia type (Alzheimer’s disease [AD], Parkinson’s disease dementia [PDD], dementia with Lewy bodies [DLB], frontotemporal dementia [FTD], vascular dementia [VD], and unspecified dementia). Daily mean cumulative counts were estimated to describe the incidence of recurrent events over time. Mortality was described using Kaplan–Meier survival curves.

Results

We identified 484,520 patients with dementia-related psychosis: mean age, 84 years (standard deviation, 7.8); female, 66%. At the time of psychosis diagnosis, the most prevalent type of dementia was unspecified dementia (56%), followed by AD (31%), VD (12%), PDD (10%), DLB (3%), and FTD (< 1%), and most patients had scores indicating severe illness on the Charlson Comorbidity Index (71%) and frailty index (62%). Across all dementia types, IRs (per 100 person-years) were high for emergency department visits, oral anti-infective use, and urinary tract infections after the initial psychosis diagnosis. Patients with DLB had the highest incidence of most clinical outcomes. After 1 year of follow-up, the cumulative probability of death was about 30% for all dementia types, and after 5 years, was about 80% among patients with DLB, VD, AD, or PDD and about 60%-65% among patients with FTD or unspecified dementia.

Conclusions

Patients with dementia-related psychosis had a high burden of comorbidities, frailty, emergency department visits, infections, and death. Specifically, after DRP diagnosis, patients with DLB and VD had the highest burden of clinical events of interest.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03489-3.

Sleep disturbances in Lewy body dementia: A systematic review

BACKGROUND

Lewy body dementia (LBD) refers to both dementia with Lewy bodies (DLB) and Parkinson's disease with dementia (PDD). Sleep disturbances are common in LBD, and can include poor sleep quality, excessive daytime sleepiness (EDS), and rapid eye movement behaviour disorder (RBD). Despite the high clinical prevalence of sleep disturbances in LBD, they are under-studied relative to other dementias. The aim of the present systematic review was to examine the nature of sleep disturbances in LBD, summarise the effect of treatment studies upon sleep, and highlight specific and necessary directions for future research.

METHODS

Published studies in English were located by searching PubMED and PSYCArticles databases (until 10 June 2022). The search protocol was pre-registered in PROSPERO (CRD42021293490) and performed in accordance with PRISMA guidelines.

RESULTS

Following full-text review, a final total of 70 articles were included. These included 20 studies focussing on subjective sleep, 14 on RBD, 8 on EDS, 7 on objective sleep, and 1 on circadian rhythms. The majority of the 18 treatment studies used pharmacological interventions (n = 12), had an open-label design (n = 8), and were of low-to-moderate quality. Most studies (n = 55) included only patients with DLB. Due to the heterogeneity of the studies, we reported a narrative synthesis without meta-analysis.

CONCLUSIONS

At least one form of sleep disturbance may be present in as many as 90% of people with LBD. Subjectively poor sleep quality, excessive daytime sleepiness, and RBD are more common and severe in LBD relative to other dementias.

The presence and co-incidence of geriatric syndromes in older patients with mild-moderate Lewy body dementia

INTRODUCTION

Geriatric symptoms are common in dementia cases, while few studies have focused on these symptoms in Lewy body dementia (LBD). The purpose of this study is to investigate the distributions of Apolipoprotein E (APOE) ε4 and geriatric symptoms, and explore their associaitons in Dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD).

METHODS

A retrospective study with 185 mild-moderate probable DLB (n = 93) and PDD (n = 92) patients was assigned. Demographic and clinical characteristics, neuropsychological assessments, and APOE genotypes were recorded. Description, correlation and logistic regression models were used to analyze the presence of geriatric symptom complaints and their associations with APOE ε4.

RESULTS

DLB patients displayed more frequency of fluctuating cognition, visual hallucination, rapid eye movement sleep behavior disorder, delusion, depression, anxiety, apathy, and loss of appetite, whereas the PDD cases had constipation, fear of falling, and insomnia more frequently. The APOE ε4 allele was more common in DLB than PDD (29.9% vs. 7.0%, p < 0.001), and the patients with DLB + APOE ε4 (+) were presented more delusions (p = 0.005) and apathy (p = 0.007) than patients with PDD + APOE ε4 (+). We also found that the APOE ε4 allele was significantly associated with hyperhidrosis (OR = 3.472, 95%CI: 1.082-11.144, p = 0.036) and depression (OR = 3.002, 95%CI: 1.079-8.353, p = 0.035) in DLB patients, while there were no significant associations between APOE ε4 allele and the age at visit, the age at onset, scores of MDS-UPDRS III, H&Y stage, ADL, MMSE, MOCA and NPI, as well as the presences of fluctuating cognition, VH, parkinsonism and RBD in both groups.

CONCLUSION

The presence and co-incidence of geriatric symptoms are common in patients with mild-moderate LBD. The presence of APOE ε4 allele is associated with hyperhidrosis and depression, but not global cognition, activitives of daily life, motor function and other neuropsychitric symptoms in DLB. These findings improve the awareness of geriatric symptoms, and contribute to the healthcare management of mild-moderate DLB and PDD.

Attitudes toward own aging and cognition among individuals living with and without dementia: findings from the IDEAL programme and the PROTECT study

Background

It is unclear whether people with dementia (PwD) have more negative attitudes toward own aging (ATOA) than people without dementia and what factors influence ATOA among PwD. We investigated whether PwD have more negative ATOA than individuals without dementia and whether cognition and dementia subtype are associated with ATOA in PwD.

Methods

Data from the IDEAL and PROTECT studies were used to compare ATOA between 1502 PwD (mean (SD) age = 76.3 (8.5)) and 6377 individuals without dementia (mean (SD) age = 66.1 (7.1)). Linear regressions and ANOVA were used.

Results

PwD reported slightly more negative ATOA than people without dementia; this relationship disappeared after controlling for depression and self-rated health. In PwD more positive ATOA showed negligible associations with better general cognition, memory performance, verbal fluency, and visuospatial ability. However, after adjusting for covariates only better visuospatial ability predicted more positive ATOA. Additional analyses showed that before and after controlling for covariates, individuals with poorer self-reported visual acuity have more negative ATOA. Amongst dementia subtypes, people with Parkinson’s disease dementia and dementia with Lewy bodies reported most negative ATOA.

Conclusions

ATOA between PwD and people without dementia do not differ. ATOA in PwD appear to be affected not by cognitive impairment but by other characteristics that vary across dementia subtypes. Among PwD, those with Parkinson’s disease dementia and dementia with Lewy bodies may have higher risk of experiencing negative ATOA due to the motor and visual impairments that they experience.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03336-5.

Anticholinergic Medication Burden in Parkinson's Disease Outpatients

BACKGROUND

Individuals with Parkinson's disease (PD) may be especially vulnerable to future cognitive decline from anticholinergic medications.

OBJECTIVE

To characterize anticholinergic medication burden, determine the co-occurrence of anticholinergic and cholinesterase inhibitors, and to assess the correlations among anticholinergic burden scales in PD outpatients.

METHODS

We studied 670 PD outpatients enrolled in a clinic registry between 2012 and 2020. Anticholinergic burden was measured with the Anticholinergic Cognitive Burden Scale (ACB), Anticholinergic Drug Scale (ADS), Anticholinergic Risk Scale (ARS), and Drug Burden Index-Anticholinergic component (DBI-Ach). Correlations between scales were assessed with weighted kappa coefficients.

RESULTS

Between 31.5 to 46.3% of PD patients were taking medications with anticholinergic properties. Among the scales applied, the ACB produced the highest prevalence of medications with anticholinergic properties (46.3%). Considering only medications with definite anticholinergic activity (scores of 2 or 3 on ACB, ADS, or ARS), the most common anticholinergic drug classes were antiparkinsonian (8.2%), antipsychotic (6.4%), and urological (3.3%) medications. Cholinesterase inhibitors and medications with anticholinergic properties were co-prescribed to 5.4% of the total cohort. The most highly correlated scales were ACB and ADS (κ= 0.71), ACB and ARS (κ= 0.67), and ADS and ARS (κ= 0.55).

CONCLUSION

A high proportion of PD patients (20%) were either taking antiparkinsonian, urological, or antipsychotic anticholinergic medications or were co-prescribed anticholinergic medications and cholinesterase inhibitors. By virtue of its detection of a high prevalence of anticholinergic medication usage and its high correlation with other scales, our data support use of the ACB scale to assess anticholinergic burden in PD patients.

Effect of comorbid Parkinson's disease and Parkinson's disease dementia on the course of idiopathic normal pressure hydrocephalus

OBJECTIVE

The objective of this study was to analyze the effect of concomitant Parkinson's disease (PD) and PD dementia (PD/PDD) on the course of idiopathic normal pressure hydrocephalus (iNPH), especially as related to the outcome of lumboperitoneal shunt (LPS) surgery.

METHODS

The authors retrospectively analyzed patients with iNPH without accompanying disorders (iNPH alone [iNPHa]) and iNPH concomitant with PD/PDD (iNPHc+PD/PDD) who had presented to their department between 2010 and 2019. The diagnosis of iNPHc+PD/PDD was established using the diagnostic criteria of the Movement Disorder Society. The effect of LPS surgery on clinical symptoms and striatum volumes was evaluated.

RESULTS

Thirty-three patients with iNPHa and 23 patients with iNPHc+PD/PDD were identified. Comorbid PD/PDD significantly worsened clinical outcome as measured by the iNPH grading scale, modified Rankin Scale (mRS), and Hoehn and Yahr (HY) scale. LPS surgery improved the iNPH score including gait disturbance (p < 0.01), cognitive impairment (p = 0.02), and urinary disturbance (p < 0.01) in iNPHa and improved gait disturbance (p = 0.01) and urinary disturbance (p = 0.03) in iNPHc+PD/PDD for 1 year. Comorbid synucleinopathies maintained worse mRS scores and HY stages for 3 years, and LPS surgery extended overall survival (p = 0.003), as well as the period of sustained mRS scores (p = 0.04) and HY stages (p = 0.004) in iNPHc+PD/PDD. Both caudate and putamen volumes were reduced in iNPHa (p < 0.01) compared to those in controls and in patients with iNPHc+PD/PDD compared to those in patients with PD/PDD (p < 0.01), and LPS surgery restored caudate volumes in both groups.

CONCLUSIONS

These results revealed that comorbid PD/PDD deteriorates the clinical course of iNPH and that LPS surgery is recommended regardless of this comorbidity.

Serendipitous Stimulation of Nucleus Basalis of Meynert-The Effect of Unintentional, Long-Term High-Frequency Stimulation on Cognition in Parkinson's Disease

There is a growing interest in deep brain stimulation (DBS) of the nucleus basalis of Meynert (NBM) as a potential therapeutic modality for Parkinson’s disease dementia (PDD). Low-frequency stimulation has yielded encouraging results in individual patients; however, these are not yet sustained in larger studies. With the aim to expand the understanding of NBM-DBS, we share our experience with serendipitous NBM-DBS in patients treated with DBS of the internal Globus pallidus (GPi) for Parkinson’s disease. Since NBM is anatomically located ventral to GPi, several GPi-treated patients appeared to have the distal contact of DBS-electrode(s) positioned in the NBM. We hypothesized that unintentional high-frequency NBM-DBS over a period of one year would result in the opposite effect of low-frequency NBM-stimulation and cause cognitive decline. We studied a cohort of 33 patients with bilateral high-frequency DBS in the GPi for Parkinson’s disease, of which twelve were unintentionally co-stimulated in NBM. The subgroups of unintentional unilateral (N = 7) and bilateral NBM-DBS (N = 5) were compared to the control group of bilateral GPi-DBS (N = 11). Here, we show that unintentional high-frequency NBM-DBS did not cause a significantly faster decline in cognitive function. Further research is warranted for characterizing the therapeutic role of NBM-DBS.

The Use and Costs of Paid and Unpaid Care for People with Dementia: Longitudinal Findings from the IDEAL Cohort

BACKGROUND

The drivers of costs of care for people with dementia are not well understood and little is known on the costs of care for those with rarer dementias.

OBJECTIVE

To characterize use and costs of paid and unpaid care over time in a cohort of people with dementia living in Britain. To explore the relationship between cohort members' demographic and clinical characteristics and service costs.

METHODS

We calculated costs of health and social services, unpaid care, and out-of-pocket expenditure for people with mild-to-moderate dementia participating in three waves of the IDEAL cohort (2014- 2018). Latent growth curve modelling investigated associations between participants' baseline sociodemographic and diagnostic characteristics and mean weekly service costs.

RESULTS

Data were available on use of paid and unpaid care by 1,537 community-dwelling participants with dementia at Wave 1, 1,199 at Wave 2, and 910 at Wave 3. In models of paid service costs, being female was associated with lower baseline costs and living alone was associated with higher baseline costs. Dementia subtype and caregiver status were associated with variations in baseline costs and the rate of change in costs, which was additionally influenced by age.

CONCLUSION

Lewy body and Parkinson's disease dementias were associated with higher service costs at the outset, and Lewy body and frontotemporal dementias with more steeply increasing costs overall, than Alzheimer's disease. Planners of dementia services should consider the needs of people with these relatively rare dementia subtypes as they may require more resources than people with more prevalent subtypes.

Parkinson's Disease Dementia: Synergistic Effects of Alpha-Synuclein, Tau, Beta-Amyloid, and Iron

Parkinson’s disease dementia (PDD) is a common complication of Parkinson’s disease that seriously affects patients’ health and quality of life. At present, the process and pathological mechanisms of PDD remain controversial, which hinders the development of treatments. An increasing number of clinical studies have shown that alpha-synuclein (α-syn), tau, beta-amyloid (Aβ), and iron are closely associated with PDD severity. Thus, we inferred the vicious cycle that causes oxidative stress (OS), due to the synergistic effects of α-syn, tau, Aβ, and, iron, and which plays a pivotal role in the mechanism underlying PDD. First, iron-mediated reactive oxygen species (ROS) production can lead to neuronal protein accumulation (e.g., α-syn andAβ) and cytotoxicity. In addition, regulation of post-translational modification of α-syn by iron affects the aggregation or oligomer formation of α-syn. Iron promotes tau aggregation and neurofibrillary tangles (NFTs) formation. High levels of iron, α-syn, Aβ, tau, and NFTs can cause severe OS and neuroinflammation, which lead to cell death. Then, the increasing formation of α-syn, Aβ, and NFTs further increase iron levels, which promotes the spread of α-syn and Aβ in the central and peripheral nervous systems. Finally, iron-induced neurotoxicity promotes the activation of glycogen synthase kinase 3β (GSK3β) related pathways in the synaptic terminals, which in turn play an important role in the pathological synergistic effects of α-syn, tau and Aβ. Thus, as the central factor regulating this vicious cycle, GSK3β is a potential target for the prevention and treatment of PDD; this is worthy of future study.

Substantively Lowered Levels of Pantothenic Acid (Vitamin B5) in Several Regions of the Human Brain in Parkinson's Disease Dementia

Pantothenic acid (vitamin B5) is an essential trace nutrient required for the synthesis of coenzyme A (CoA). It has previously been shown that pantothenic acid is significantly decreased in multiple brain regions in both Alzheimer's disease (ADD) and Huntington's disease (HD). The current investigation aimed to determine whether similar changes are also present in cases of Parkinson's disease dementia (PDD), another age-related neurodegenerative condition, and whether such perturbations might occur in similar regions in these apparently different diseases. Brain tissue was obtained from nine confirmed cases of PDD and nine controls with a post-mortem delay of 26 h or less. Tissues were acquired from nine regions that show high, moderate, or low levels of neurodegeneration in PDD: the cerebellum, motor cortex, primary visual cortex, hippocampus, substantia nigra, middle temporal gyrus, medulla oblongata, cingulate gyrus, and pons. A targeted ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) approach was used to quantify pantothenic acid in these tissues. Pantothenic acid was significantly decreased in the cerebellum (p = 0.008), substantia nigra (p = 0.02), and medulla (p = 0.008) of PDD cases. These findings mirror the significant decreases in the cerebellum of both ADD and HD cases, as well as the substantia nigra, putamen, middle frontal gyrus, and entorhinal cortex of HD cases, and motor cortex, primary visual cortex, hippocampus, middle temporal gyrus, cingulate gyrus, and entorhinal cortex of ADD cases. Taken together, these observations indicate a common but regionally selective disruption of pantothenic acid levels across PDD, ADD, and HD.

Impaired sensory evidence accumulation and network function in Lewy body dementia

Deficits in attention underpin many of the cognitive and neuropsychiatric features of Lewy body dementia. These attention-related symptoms remain difficult to treat and there are many gaps in our understanding of their neurobiology. An improved understanding of attention-related impairments can be achieved via mathematical modelling approaches, which identify cognitive parameters to provide an intermediate level between observed behavioural data and its underlying neural correlate. Here, we apply this approach to identify the role of impaired sensory evidence accumulation in the attention deficits that characterize Lewy body dementia. In 31 people with Lewy body dementia (including 13 Parkinson's disease dementia and 18 dementia with Lewy bodies cases), 16 people with Alzheimer's disease, and 23 healthy controls, we administered an attention task whilst they underwent functional 3 T MRI. Using hierarchical Bayesian estimation of a drift-diffusion model, we decomposed task performance into drift rate and decision boundary parameters. We tested the hypothesis that the drift rate-a measure of the quality of sensory evidence accumulation-is specifically impaired in Lewy body dementia, compared to Alzheimer's disease. We further explored whether trial-by-trial variations in the drift rate related to activity within the default and dorsal attention networks, to determine whether altered activity in these networks was associated with slowed drift rates in Lewy body dementia. Our results revealed slower drift rates in the Lewy body dementia compared to the Alzheimer's disease group, whereas the patient groups were equivalent for their decision boundaries. The patient groups were reduced relative to controls for both parameters. This highlights sensory evidence accumulation deficits as a key feature that distinguishes attention impairments in Lewy body dementia, consistent with impaired ability to efficiently process information from the environment to guide behaviour. We also found that the drift rate was strongly related to activity in the dorsal attention network across all three groups, whereas the Lewy body dementia group showed a divergent relationship relative to the Alzheimer's disease and control groups for the default network, consistent with altered default network modulation being associated with impaired evidence accumulation. Together, our findings reveal impaired sensory evidence accumulation as a specific marker of attention problems in Lewy body dementia, which may relate to large-scale network abnormalities. By identifying impairments in a specific sub-process of attention, these findings will inform future exploratory and intervention studies that aim to understand and treat attention-related symptoms that are a key feature of Lewy body dementia.

Added Value of QEEG for the Differential Diagnosis of Common Forms of Dementia

INTRODUCTION

Quantitative electroencephalography (QEEG) has been documented as a helpful tool in the differential diagnosis of Alzheimer's disease (AD) with common forms of dementia. The main objective of the study was to assess the role of QEEG in AD differential diagnosis with other forms of dementia: Lewy body dementia (LBD), Parkinson's disease dementia (PDD), frontotemporal dementia (FTD), and vascular dementia (VaD).

METHODS

We searched PubMed, Embase, and PsycNET, for articles in English published in peer-reviewed journals from January 1, 1980 to April 23, 2019 using adapted search strategies containing keywords quantitative EEG and Alzheimer. The risk of bias was assessed by applying the QUADAS tool. The systematic review was conducted in line with the PRISMA methodology.

RESULTS

We identified 10 articles showcasing QEEG features used in diagnosing dementia, EEG slowing phenomena in AD and PDD, coherence changes in AD and VaD, the role of LORETA in dementia, and the controversial QEEG pattern in FTD. Results vary significantly in terms of sociodemographic features of the studied population, neuropsychological assessment, signal acquisition and processing, and methods of analysis.

DISCUSSION

This article provides a comparative synthesis of existing evidence on the role of QEEG in diagnosing dementia, highlighting some specific features for different types of dementia (eg, the slow-wave activity has been remarked in both AD and PDD, but more pronounced in PDD patients, a diminution in anterior and posterior alpha coherence was noticed in AD, and a lower alpha coherence in the left temporal-parietal-occipital regions was observed in VaD).

CONCLUSION

QEEG may be a useful investigation for settling the diagnosis of common forms of dementia. Further research of quantitative analyses is warranted, particularly on the association between QEEG, neuropsychological, and imaging features. In conjunction, these methods may provide superior diagnostic accuracy in the diagnosis of dementia.

Clinical characteristics of Lewy body dementia in Chinese memory clinics

Background

Lewy body dementia (LBD), consisting of dementia with Lewy bodies (DLB) and Parkinson’s disease dementia (PDD), is the second most common type of neurodegenerative dementia in older people. The current study aimed to investigate the clinical characteristics of LBD in Chinese memory clinics.

Methods

A total of 8405 dementia medical records were reviewed, revealing 455 patients with LBD. Demographic data, neuropsychological scores, and the scale for Medial Temporal lobe Atrophy (MTA) were then analyzed from nine memory clinics in the China Lewy Body Disease Collaborative Alliance.

Results

The clinical proportion of LBD among the subjects and among all dementia types was 5.4% (4.9–5.9%) and 7.3% (6.7–8.0%), respectively, with a mean onset age of 68.6 ± 8.4 years. Patients with DLB comprised 5.6% (n = 348, age of onset 69.1 ± 8.3), while PDD comprised 1.7% (n = 107, age of onset 66.7 ± 8.8) of all dementia cases. There were slightly more males than females with DLB (n = 177, 50.9%) and PDD (n = 62, 57.9%). Patients with DLB had a poorer performance compared to those with PDD on the MMSE (16.8 ± 7.1 vs. 19.5 ± 5.7, p = 0.001), the MoCA (11.4 ± 6.6 vs. 14.0 ± 5.8, p<0.001), the CDR (1.8 ± 0.7 vs. 1.6 ± 0.7, p = 0.002), and the MTA (1.8 ± 0.7 vs. 1.2 ± 0.6, p = 0.002). Diagnostic differences for LBD exist among the centers; their reported proportions of those with DLB ranged from 0.7 to 11.4 and those with PDD ranged from 0.0 to 2.9%.

Conclusions

Variations of diagnoses exists in different regions and the clinical proportion of LBD is likely to be underestimated in China and other regions.

Predicting the Severity of Parkinson's Disease Dementia by Assessing the Neuropsychiatric Symptoms with an SVM Regression Model

In this study, we measured the convergence rate using the mean-squared error (MSE) of the standardized neuropsychological test to determine the severity of Parkinson's disease dementia (PDD), which is based on support vector machine (SVM) regression (SVR) and present baseline data in order to develop a model to predict the severity of PDD. We analyzed 328 individuals with PDD who were 60 years or older. To identify the SVR with the best prediction power, we compared the classification performance (convergence rate) of eight SVR models (Eps-SVR and Nu-SVR with four kernel functions (a radial basis function (RBF), linear algorithm, polynomial algorithm, and sigmoid)). Among the eight models, the MSE of Nu-SVR-RBF was the lowest (0.078), with the highest convergence rate, whereas the MSE of Eps-SVR-sigmoid was 0.110, with the lowest convergence rate. The results of this study imply that this approach could be useful for measuring the severity of dementia by comprehensively examining axial atypical features, the Korean instrumental activities of daily living (K-IADL), changes in rapid eye movement sleep behavior disorder (RBD), etc. for optimal intervention and caring of the elderly living alone or patients with PDD residing in medically vulnerable areas.

Introduction of an assessment toolkit associated with increased rate of DLB diagnosis

Background

Dementia with Lewy bodies (DLB) and dementia in Parkinson’s disease (PDD) are recognised to be under-recognised in clinical practice in the UK, with only one third to a half of expected cases diagnosed. We aimed to assess whether clinical diagnostic rates could be increased by the introduction of a structured assessment toolkit for clinicians.

Methods

We established baseline diagnostic rates for DLB and PDD in four memory clinics and three movement disorder/Parkinson’s disease (PD) clinics in two separate geographical regions in the UK. An assessment toolkit specifically developed to assist with the recognition and diagnosis of DLB and PDD was then introduced to the same clinical teams and diagnostic rates for DLB and PDD were reassessed.

For assessing DLB diagnosis, a total of 3820 case notes were reviewed before the introduction of the toolkit, and 2061 case notes reviewed after its introduction. For PDD diagnosis, a total of 1797 case notes were reviewed before the introduction of the toolkit and 3405 case notes after it. Mean values and proportions were analysed using Student’s t test for independent samples and χ² test, respectively.

Results

DLB was diagnosed in 4.6% of dementia cases prior to the introduction of the toolkit, and 6.2% of dementia cases afterwards, an absolute rise of 1.6%, equal to a 35% increase in the number of DLB cases diagnosed when using the toolkit (χ² = 4.2, P = 0.041).

The number of PD patients diagnosed with PDD was not found overall to be significantly different when using the toolkit: 9.6% of PD cases before and 8.2% of cases after its introduction (χ² = 1.8, P = 0.18), though the ages of PD patients assessed after the toolkit’s introduction were lower (73.9 years vs 80.0 years, t = 19.2, p < 0.001).

Conclusion

Introduction of the assessment toolkit was associated with a significant increase in the rate of DLB diagnosis, suggesting that a structured means of assessing symptoms and clinical features associated with DLB can assist clinicians in recognising cases. The assessment toolkit did not alter the overall rate of PDD diagnosis, suggesting that alternate means may be required to improve the rate of diagnosis of dementia in Parkinson’s disease.

Functional connectivity of the nucleus basalis of Meynert in Lewy body dementia and Alzheimer's disease

Cholinergic deficits are a hallmark of Alzheimer's disease (AD) and Lewy body dementia (LBD). The nucleus basalis of Meynert (NBM) provides the major source of cortical cholinergic input; studying its functional connectivity might, therefore, provide a tool for probing the cholinergic system and its degeneration in neurodegenerative diseases. Forty-six LBD patients, 29 AD patients, and 31 healthy age-matched controls underwent resting-state functional magnetic resonance imaging (fMRI). A seed-based analysis was applied with seeds in the left and right NBM to assess functional connectivity between the NBM and the rest of the brain. We found a shift from anticorrelation in controls to positive correlations in LBD between the right/left NBM and clusters in right/left occipital cortex. Our results indicate that there is an imbalance in functional connectivity between the NBM and primary visual areas in LBD, which provides new insights into alterations within a part of the corticopetal cholinergic system that go beyond structural changes.

Comparison of the Caregiving Experience of Grief, Burden, and Quality of Life in Dementia with Lewy Bodies, Alzheimer's Disease, and Parkinson's Disease Dementia

BACKGROUND

Caregivers of persons living with Alzheimer's disease (AD), dementia with Lewy bodies (DLB), and Parkinson's disease dementia (PDD) are faced with numerous challenges. However, little is known about the caregiving experience across different dementias.

OBJECTIVE

The aims of this cross-sectional study were to examine the differences in the caregiver experience between DLB, PDD, and AD.

METHODS

Respondents were caregivers (N = 515; 384 DLB, 69 AD, 62 PDD) who completed a 230-question survey including sociodemographics, disease severity, neuropsychiatric symptoms, and measures of grief, burden, depression, quality of life, social support, well-being, care confidence, and mastery/self-efficacy.

RESULTS

There were no differences in caregiver age, sex, race, or education, or in the distribution of disease severity between diagnostic groups. Constructs were highly intercorrelated with positive attributes (caregiver QoL, care recipient QoL, social support, well-being, mastery and care confidence) being inversely correlated with negative attributes (burden, grief, and depression). Across dementia etiologies, no differences were reported for quality of life, social support, depression, well-being, psychological well-being, mastery, care confidence, burden or grief. Instead, we found that the caregiver's experience was dependent on caregiver characteristics, person living with dementia characteristics and their most disturbing symptom, with behavior, personality changes, and sleep having the greatest effect on constructs.

CONCLUSION

Caregiver ratings of psychosocial constructs may be more dependent on care recipient-caregiver dyad characteristics and the current symptoms than the underlying cause of those symptoms. Interventions to improve the caregiving experience should be developed to address specific psychosocial constructs rather than focusing on disease etiology or stage.

Combined subthalamic and nucleus basalis of Meynert deep brain stimulation for Parkinson's disease with dementia (DEMPARK-DBS): protocol of a randomized, sham-controlled trial

Introduction

Dementia in Parkinson’s disease (PDD) is a common non-motor symptom of advanced disease, associated with pronounced neocortical cholinergic deficits due to neurodegeneration of the nucleus basalis of Meynert (NBM) and its cholinergic terminals. In advanced PD, patients often require advanced therapies such as infusion therapy or deep brain stimulation (DBS) to improve motor control. However, patients with associated dementia are commonly excluded from DBS because of potential deterioration of cognitive functions. Yet marked reductions in dopaminergic medication and the subsequent risk of side effects (e.g., cognitive decline, psychosis, delirium) suggest that critical re-consideration of DBS of the subthalamic nucleus (STN-DBS) for advanced stages of PD and PDD is worthwhile. In this Phase 1b study, we will provide STN-DBS to a cohort of PDD patients with severe motor fluctuations and combine two additional electrodes for augmentative neurostimulation of the NBM.

Methods

We aim to include 12 patients with mild-to-moderately severe PDD who fulfill indication criteria regarding motor symptoms for STN-DBS. Eligible patients will undergo implantation of a neurostimulation system with bilateral electrodes in both the STN and NBM. After 12 weeks of STN-DBS (visit 1/V1), participants will be randomized to receive either effective neurostimulation of the NBM (group 1) or sham stimulation of the NBM (group 2). NBM-DBS will be activated in all participants after 24 weeks of blinded treatment (visit 2/V2). The primary outcome will be the safety of combined bilateral STN- and NBM-DBS, determined by spontaneously-reported adverse events. Other outcome measures will comprise changes on scales evaluating cognition, activities of daily living functioning and clinical global impression, as well as motor functions, mood, behavior, caregiver burden and health economic aspects, and several domain-specific cognitive tests. Changes in scores (V1 – V2) for both treatment arms will undergo analysis of covariances, with baseline scores as covariates.

Perspective

The feasibility and safety of combined STN-NBM-DBS in patients with PDD will be assessed to determine whether additional NBM-DBS improves or slows the progression of cognitive decline. Positive results would provide a basic concept for future studies evaluating the efficacy of NBM-DBS in larger PDD cohorts. Indirectly, proof-of-safety of STN-DBS in PDD might influence patient selection for this standard treatment option in advanced PD.

Trial registration

ClinicalTrials.gov identifier (NCT number): NCT02589925.

Neuroinflammation and protein pathology in Parkinson's disease dementia

Parkinson’s disease dementia is neuropathologically characterized by aggregates of α-synuclein (Lewy bodies) in limbic and neocortical areas of the brain with additional involvement of Alzheimer’s disease-type pathology. Whilst immune activation is well-described in Parkinson’s disease (PD), how it links to protein aggregation and its role in PD dementia has not been explored. We hypothesized that neuroinflammatory processes are a critical contributor to the pathology of PDD. To address this hypothesis, we examined 7 brain regions at postmortem from 17 PD patients with no dementia (PDND), 11 patients with PD dementia (PDD), and 14 age and sex-matched neurologically healthy controls. Digital quantification after immunohistochemical staining showed a significant increase in the severity of α-synuclein pathology in the hippocampus, entorhinal and occipitotemporal cortex of PDD compared to PDND cases. In contrast, there was no difference in either tau or amyloid-β pathology between the groups in any of the examined regions. Importantly, we found an increase in activated microglia in the amygdala of demented PD brains compared to controls which correlated significantly with the extent of α-synuclein pathology in this region. Significant infiltration of CD4⁺ T lymphocytes into the brain parenchyma was commonly observed in PDND and PDD cases compared to controls, in both the substantia nigra and the amygdala. Amongst PDND/PDD cases, CD4⁺ T cell counts in the amygdala correlated with activated microglia, α-synuclein and tau pathology. Upregulation of the pro-inflammatory cytokine interleukin 1β was also evident in the substantia nigra as well as the frontal cortex in PDND/PDD versus controls with a concomitant upregulation in Toll-like receptor 4 (TLR4) in these regions, as well as the amygdala. The evidence presented in this study show an increased immune response in limbic and cortical brain regions, including increased microglial activation, infiltration of T lymphocytes, upregulation of pro-inflammatory cytokines and TLR gene expression, which has not been previously reported in the postmortem PDD brain.

Dementia risk in Parkinson's disease is associated with interhemispheric connectivity loss and determined by regional gene expression

Parkinson's dementia is a common and devastating part of Parkinson's disease. Whilst timing and severity vary, dementia in Parkinson's is often preceded by visual dysfunction. White matter changes, representing axonal loss, occur early in the disease process. Clarifying which white matter connections are affected in Parkinson's with visual dysfunction and why specific connections are vulnerable will provide important mechanistic insights. Here, we use diffusion tractography in 100 Parkinson's patients (33 low visual performers) and 34 controls to identify patterns of connectivity loss in Parkinson's with visual dysfunction. We examine the relationship between regional transcription and connectivity loss, using the Allen Institute for Brain Science transcriptome atlas. We show that interhemispheric connections are preferentially affected in Parkinson's low visual performers. Interhemispheric connection loss was associated with downweighted genes related to the smoothened signalling pathway (enriched in glutamatergic neurons) and upweighted metabolic genes. Risk genes for Parkinson's but not Alzheimer's or Dementia with Lewy bodies were over-represented in upweighted genes associated with interhemispheric connection loss. Our findings suggest selective vulnerability in Parkinson's patients at highest risk of dementia (those with visual dysfunction), where differences in gene expression and metabolic dysfunction, affecting longer connections with higher metabolic burden, drive connectivity loss.

Cognitive Impairment, P300, and Transforming Growth Factor β1 in Different Forms of Dementia

BACKGROUND

There are currently few biomarkers to assist in early diagnosis of dementias.

OBJECTIVE

To distinguish between different dementias: Alzheimer's disease (AD), vascular dementia (VaD), and Parkinson's disease dementia (PDD) using simple neurophysiologic (P300) and laboratory markers (transforming growth factor β1 "TGF-β1").

METHODS

The study included 15 patients for each type of dementia and 25 age- and sex-matched control subjects. Dementia patients were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders 4th edition-revised (DSM-IV-R). Modified Mini-Mental State Examination (3MS), Memory Assessment Scale (MAS), P300, and TGF-β1 were examined for each participant.

RESULTS

There were no significant differences between groups as regard to age, sex, and education, social, and economic levels. Significant differences between groups were observed in registration and naming variables of the 3MS. Compared with the control group, P300 latency was prolonged in all groups, although to a greater extent in AD and PDD than in VaD. A serum level of TGF-β1 was significantly elevated in all groups but was significantly higher in AD and VaD than in PDD. 3MS tended to correlate with P300 more than TGF-β1, and to be stronger in AD than the other groups.

CONCLUSION

Measurements of P300 latency and serum levels of TGF-β1 can help distinguish AD, PDD, and VaD. P300 was more prolonged in AD and PDD than VaD whereas TGF-β1 was significantly higher in AD and VaD than PDD. Thus P300 and TGF-β1 may be useful biomarkers for detection and evaluation of the extent of cognitive dysfunction.

The Impact of Amyloid-Beta Positivity with 18F-Florbetaben PET on Neuropsychological Aspects in Parkinson's Disease Dementia

The neuropathology of Parkinson’s disease dementia (PDD) is heterogenous, and the impacts of each pathophysiology and their synergistic effects are not fully understood. The aim of this study was to evaluate the frequency and impacts of co-existence with Alzheimer’s disease in patients with PDD by using 18F-florbetaben PET imaging. A total of 23 patients with PDD participated in the study. All participants underwent 18F-florbetaben PET and completed a standardized neuropsychological battery and assessment of motor symptoms. The results of cognitive tests, neuropsychiatric symptoms, and motor symptoms were analyzed between the positive and negative 18F-florbetaben PET groups. Four patients (17.4%) showed significant amyloid burden. Patients with amyloid-beta showed poorer performance in executive function and more severe neuropsychiatric symptoms than those without amyloid-beta. Motor symptoms assessed by UPDRS part III and the modified H&Y Scale were not different between the two groups. The amyloid PET scan of a patient with PDD can effectively reflect a co-existing Alzheimer’s disease pathology. Amyloid PET scans might be able to help physicians of PDD patients showing rapid progression or severe cognitive/behavioral features.

Cerebrospinal fluid markers analysis in the differential diagnosis of dementia with Lewy bodies and Parkinson's disease dementia

Dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD) share a couple of clinical similarities that is often a source of diagnostic pitfalls. We evaluated the discriminatory potential of brain-derived CSF markers [tau, p-tau (181P), Aβ_1-42, NSE and S100B] across the spectrum of Lewy body disorders and assessed whether particular markers are associated with cognitive status in investigated patients. The tau CSF level, amyloid β_1-42 and p-tau/tau ratio were helpful in the distinction between DLB and PDD (p = 0.04, p = 0.002 and p = 0.02, respectively) as well as from PD patients (p < 0.001, p = 0.001 and p = 0.002, respectively). Furthermore, the p-tau/tau ratio enabled the differentiation of DLB with mild dementia from PDD patients (p = 0.02). The CSF tau and p-tau levels in DLB and CSF tau and p-tau/tau ratio in PDD patients reflected the severity of dementia. Rapid disease course was associated with the decrease of Aβ_1-42 in DLB but not in PDD. Elevation of S100B in DLB (p < 0.0001) as well as in PDD patients (p = 0.002) in comparison to controls was estimated. Hence, with the appropriate clinical context; the CSF marker profile could be helpful in distinguishing DLB from PDD patients even in early stages of dementia.

Pathological and clinical comparison of Parkinson’s disease dementia and dementia with Lewy bodies

Dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD) are two major neurodegenerative diseases sharing common clinical, pathophysiological and morphologic features. The pathological hallmark of both diseases is the presence of Lewy-bodies (LB). The main constituent of these inclusions is the pathologically aggregated α-synuclein protein. In DLB, LBs are predominantly located in the cortex, whereas in PDD, the subcortical regions are predominantly affected. Furthermore, in DLB, coexisting Alzheimer's disease (AD), pathology with β-amyloid plaques and neurofibrillary tangles are more common. It is still debated whether DLB and PDD are two distinct entities or different phenotypes of the same disease. Clinical diagnosis is based on the temporal sequence of motor and cognitive symptoms. Dementia often precedes parkinsonism in DLB, while in PDD, cognitive decline generally appears after the onset of motor symptoms. Also, fluctuation of cognitive functions and neuroleptic sensitivity is more severe in DLB than PDD. The recent advancements of imaging techniques revealed that cortical damage, cholinergic deficit and concomitant AD pathology are more severe in DLB compared to PDD. The analysis of cerebrospinal fluid biomarkers shows higher oligomeric α-synuclein burden in PDD. Levodopa is less effective in DLB than in PDD and may increase the risk of psychosis. In this review, we comprehensively analyse the pathological, radiological and clinical features of DLB and PDD, highlighting the overlaps and differences. Orv Hetil. 2020; 161(18): 727-737.

Local cortical overexpression of human wild-type alpha-synuclein leads to increased dendritic spine density in mouse

Lewy body dementias are characterized by deposition of alpha-synuclein (α-syn) protein aggregates known as Lewy bodies and Lewy neurites in cortical regions, in addition to brainstem. These aggregates are thought to cause the death of dopaminergic neurons in the substantia nigra and other vulnerable cell types in patients, leading to parkinsonism. There is evidence from mice that localized overexpression of wild-type α-syn leads to dopaminergic cell death in the substantia nigra. However, it is not known how cortical neurons are affected by α-syn. In this study, we used viral overexpression of α-syn to investigate whether localized overexpression within the cortex affects the density, length, and morphology of dendritic spines, which serve as a measure of synaptic connectivity. An AAV2/6 viral vector coding for wild-type human α-syn was used to target overexpression bilaterally to the medial prefrontal cortex within adult mice. After ten weeks the brain was stained using the Golgi-Cox method. Density of dendritic spines in the injected region was increased in layer V pyramidal neurons compared with animals injected with control virus. Immunohistochemistry in separate animals showed human α-syn expression throughout the region of interest, especially in presynaptic terminals. However, phosphorylated α-syn was seen in a discrete number of cells at the region of highest overexpression, localized mainly to the soma and nucleus. These findings demonstrate that at early timepoints, α-syn overexpression may alter connectivity in the cortex, which may be relevant to early stages of the disease. In addition, these findings contribute to the understanding of α-syn, which when overexpressed in the wildtype, non-aggregated state may promote spine formation. Loss of spines secondary to α-syn in cortex may require higher expression, longer incubation, cellular damage, concomitant dopaminergic dysfunction or other two-hit factors to lead to synaptic degeneration.

Epigenetic regulation in the pathophysiology of Lewy body dementia

Lewy body dementia encompasses both dementia with Lewy bodies and Parkinson's disease dementia. Although both are common causes of dementia, they remain relatively understudied. The review summarises the clinico-pathologic characteristics of Lewy Body dementia and discusses the genetic and environmental evidence contributing to the risk of developing the condition. Considering that the pathophysiology of Lewy body dementia is not yet fully understood, here we focus on the role of epigenetic mechanisms as potential key mediators of gene-environment interactions in the development of the disease. We examine available important data on genomics, epigenomics, gene expression and proteomic studies in Lewy body dementia on human post-mortem brain and peripheral tissues. Genetic variation and epigenetic modifications in key genes involved in the disorder, such as apolipoprotein E (APOE), α-synuclein (SNCA) and glucocerobrosidase (GBA), suggest a central involvement of epigenetics in DLB but conclusive evidence is scarce. This is due to limitations of existing literature, such as small sample sizes, lack of replication and lack of studies interrogating cell-type specific epigenetic modifications in the brain. Future research in the field can improve the understanding of this common but complex and rapidly progressing type of dementia and potentially open early diagnostic and effective therapeutic targets.

Exploring the Predictors of Rapid Eye Movement Sleep Behavior Disorder for Parkinson's Disease Patients Using Classifier Ensemble

The rapid eye movement sleep behavior disorder (RBD) of Parkinson's disease (PD) patients can be improved with medications such as donepezil as long as it is diagnosed with a thorough medical examination, since identifying a high-risk group of RBD is a critical issue to treat PD. This study develops a model for predicting the high-risk groups of RBD using random forest (RF) and provides baseline information for selecting subjects for polysomnography. Subjects consisted of 350 PD patients (Parkinson's disease with normal cognition (PD-NC) = 48; Parkinson's disease with mild cognitive impairment (PD-MCI) = 199; Parkinson's disease dementia (PDD) = 103) aged 60 years and older. This study compares the prediction performance of RF, discriminant analysis, classification and regression tree (CART), radial basis function (RBF) neural network, and logistic regression model to select a final model with the best model performance and presents the variable importance of the final model's variable. As a result of analysis, the sensitivity of RF (79%) was superior to other models (discriminant analysis = 14%, CART = 32%, RBF neural network = 25%, and logistic regression = 51%). It was confirmed that age, the motor score of Untitled Parkinson's Disease Rating (UPDRS), the total score of UPDRS, the age when a subject was diagnosed with PD first time, the Korean Mini Mental State Examination, and Korean Instrumental Activities of Daily Living, were major variables with high weight for predicting RBD. Among them, age was the most important factor. The model for predicting Parkinson's disease RBD developed in this study will contribute to the screening of patients who should receive a video-polysomnography.

Application of Machine Learning Technique to Distinguish Parkinson's Disease Dementia and Alzheimer's Dementia: Predictive Power of Parkinson's Disease-Related Non-Motor Symptoms and Neuropsychological Profile. J Pers Med. 2020;10. [PMID: 32354187 PMCID: PMC7354548 DOI: 10.3390/jpm10020031]

In order to develop a predictive model that can distinguish Parkinson’s disease dementia (PDD) from other dementia types, such as Alzheimer’s dementia (AD), it is necessary to evaluate and identify the predictive accuracy of the cognitive profile while considering the non-motor symptoms, such as depression and rapid eye movement (REM) sleep behavior disorders. This study compared Parkinson’s disease (PD)’s non-motor symptoms and the diagnostic predictive power of cognitive profiles that distinguish AD and PD using machine learning. This study analyzed 118 patients with AD and 110 patients with PDD, and all subjects were 60 years or older. In order to develop the PDD prediction model, the dataset was divided into training data (70%) and test data (30%). The prediction accuracy of the model was calculated by the recognition rate. The results of this study show that Parkinson-related non-motor symptoms, such as REM sleep behavior disorders, and cognitive screening tests, such as Korean version of Montreal Cognitive Assessment, were highly accurate factors for predicting PDD. It is required to develop customized screening tests that can detect PDD in the early stage based on these results. Furthermore, it is believed that including biomarkers such as brain images or cerebrospinal fluid as input variables will be more useful for developing PDD prediction models in the future.

Evidence Supports PA Prescription for Parkinson's Disease: Motor Symptoms and Non-Motor Features: A Scoping Review

Parkinson’s disease (PD) is a prevalent neurodegenerative disorder, which relates to not only motor symptoms, but also cognitive, autonomic, and mood impairments. The literature suggests that pharmacological or surgical treatment has a limited effect on providing relief of the symptoms and also restricting its progression. Recently, research on non-pharmacological interventions for people living with PD (pwPD) that alleviate their motor and non-motor features has shown a new aspect in treating this complex disease. Numerous studies are supporting exercise intervention as being effective in both motor and non-motor facets of PD, such as physical functioning, strength, balance, gait speed, and cognitive impairment. Via the lens of the physical profession, this paper strives to provide another perspective for PD treatment by presenting exercise modes categorized by motor and non-motor PD symptoms, along with its effects and mechanisms. Acknowledging that there is no “one size fits all” exercise prescription for such a variable and progressive disease, this review is to outline tailored physical activities as a credible approach in treating pwPD, conceivably enhancing overall physical capacity, ameliorating the symptoms, reducing the risk of falls and injuries, and, eventually, elevating the quality of life. It also provides references and practical prescription applications for the clinician.