Cognitive and executive impairments in Parkinson's disease psychosis: a Bayesian meta-analysis.

BACKGROUND: Cognitive and executive deficits lead to worsening of quality of life and are a risk factor for developing dementia in people with Parkinson's disease (PD) with psychosis (PDP). However, which key cognitive domains are differentially affected in PDP compared with those without (PDnP), remains unclear. Here, we examined this using a Bayesian meta-analytical approach. METHODS: Searches were conducted on PubMed, Web of Science, SCOPUS, Medline and PsycINFO. Hedges' g effect-size estimates were extracted from eligible studies as a measure of standard mean differences between PDP and PDnP participants. Meta-analyses were conducted separately for each cognitive domain and subdomain, we examined the effect of age, PD medications, PD duration and severity, depression and psychosis severity for all major domains with meta-regressions. RESULTS: Effect-size estimates suggest worse performance on all major domains (k=105 studies) in PDP compared with PDnP participants, with global cognition (k=103 studies, g=-0.57), processing speed (k=29 studies, g=-0.58), executive functions (k=33, g=-0.56), episodic memory (k=30 studies, g=-0.58) and perception (k=34 studies, g=-0.55) as the most likely affected domains. Age, depression and PD duration had moderating effects on task-related performance across most of the major nine domains. CONCLUSIONS: We report extensive deficits across nine domains as well as subdomains in PD psychosis, with global cognition, processing speed and executive functions as the most likely impaired. The presence of depression may influence task-related performance in PDP, alongside age and PD duration, but not dose of dopamine replacement treatments.

Microglial activation, tau and amyloid deposition in TREM2 p.R47H carriers and mild cognitive impairment patients: a multi-modal/multi-tracer PET/MRI imaging study with influenza vaccine immune challenge.

BACKGROUND: Microglia are increasingly understood to play an important role in the pathogenesis of Alzheimer's disease. The rs75932628 (p.R47H) TREM2 variant is a well-established risk factor for Alzheimer's disease. TREM2 is a microglial cell surface receptor. In this multi-modal/multi-tracer PET/MRI study we investigated the effect of TREM2 p.R47H carrier status on microglial activation, tau and amyloid deposition, brain structure and cognitive profile. METHODS: We compared TREM2 p.R47H carriers (n = 8; median age = 62.3) and participants with mild cognitive impairment (n = 8; median age = 70.7). Participants underwent two [18F]DPA-714 PET/MRI scans to assess TSPO signal, indicative of microglial activation, before and after receiving the seasonal influenza vaccination, which was used as an immune stimulant. Participants also underwent [18F]florbetapir and [18F]AV1451 PET scans to assess amyloid and tau burden, respectively. Regional tau and TSPO signal were calculated for regions of interest linked to Braak stage. An additional comparison imaging healthy control group (n = 8; median age = 45.5) had a single [18F]DPA-714 PET/MRI. An expanded group of participants underwent neuropsychological testing, to determine if TREM2 status influenced clinical phenotype. RESULTS: Compared to participants with mild cognitive impairment, TREM2 carriers had lower TSPO signal in Braak II (P = 0.04) and Braak III (P = 0.046) regions, despite having a similar burden of tau and amyloid. There were trends to suggest reduced microglial activation following influenza vaccine in TREM2 carriers. Tau deposition in the Braak VI region was higher in TREM2 carriers (P = 0.04). Furthermore, compared to healthy controls TREM2 carriers had smaller caudate (P = 0.02), total brain (P = 0.049) and white matter volumes (P = 0.02); and neuropsychological assessment revealed worse ADAS-Cog13 (P = 0.03) and Delayed Matching to Sample (P = 0.007) scores. CONCLUSIONS: TREM2 p.R47H carriers had reduced levels of microglial activation in brain regions affected early in the Alzheimer's disease course and differences in brain structure and cognition. Changes in microglial response may underlie the increased Alzheimer's disease risk in TREM2 p.R47H carriers. Future therapeutic agents in Alzheimer's disease should aim to enhance protective microglial actions.

Clinical characteristics of early-onset versus late-onset Alzheimer's disease: a systematic review and meta-analysis.

OBJECTIVES: A number of studies have compared Alzheimer's disease (AD), the commonest form of dementia, based on their age of onset, i.e. before the age of 65 years (early-onset AD, EO-AD) to those developing after 65 years of age (late-onset AD, LO-AD), but the differences are not clear. We performed a systematic review and meta-analysis to compare clinical characteristics between EO-AD and LO-AD. DESIGN, MEASUREMENTS, AND PARTICIPANTS: Medline, Embase, PsycINFO, and CINAHL databases were systematically searched for studies comparing time to diagnosis, cognitive scores, annual cognitive decline, activities of daily living (ADLs), neuropsychiatric symptoms (NPS), quality of life (QoL), and survival time for EO-AD and LO-AD patients. RESULTS: Forty-two studies were included (EO-AD participants n = 5,544; LO-AD participants n = 16,042). An inverse variance method with random effects models was used to calculate overall effect estimates for each outcome. People with EO-AD had significantly poorer baseline cognitive performance and faster cognitive decline but longer survival times than people with LO-AD. There was no evidence that EO-AD patients differ from people with LO-AD in terms of symptom onset to diagnosis time, ADLs, and NPS. There were insufficient data to estimate overall effects of differences in QoL in EO-AD compared to LO-AD. CONCLUSIONS: Our findings suggest that EO-AD differs from LO-AD in baseline cognition, cognitive decline, and survival time but otherwise has similar clinical characteristics to LO-AD. Larger studies using standardized questionnaires focusing on the clinical presentations are needed to better understand the impact of age of onset in AD.

The impact of the first UK COVID-19 lockdown on presentations with psychosis to mental health services for older adults: An electronic health records study in South London.

OBJECTIVES: Social distancing restrictions in the COVID-19 pandemic may have had adverse effects on older adults' mental health. Whereby the impact on mood is well-described, less is known about psychotic symptoms. The aim of this study was to compare characteristics associated with psychotic symptoms during the first UK lockdown and a pre-pandemic comparison period. METHODS: In this retrospective observational study we analysed anonymised records from patients referred to mental health services for older adults in South London in the 16-week period of the UK lockdown starting in March 2020, and in the comparable pre-pandemic period in 2019. We used logistic regression models to compare the associations of different patient characteristics with increased odds of presenting with any psychotic symptom (defined as hallucinations and/or delusion), hallucinations, or delusions, during lockdown and the corresponding pre-pandemic period. RESULTS: 1991 referrals were identified. There were fewer referrals during lockdown but a higher proportion of presentations with any psychotic symptom (48.7% vs. 42.8%, p = 0.018), particularly hallucinations (41.0% vs. 27.8%, p < 0.001). Patients of non-White ethnicity (adjusted odds ratio (OR): 1.83; 95% confidence interval (CI): 1.13-2.99) and patients with dementia (adjusted OR: 3.09; 95% CI: 1.91-4.99) were more likely to be referred with psychotic symptoms during lockdown. While a weaker association between dementia and psychotic symptoms was found in the pre-COVID period (adjusted OR: 1.55; 95% CI: 1.19-2.03), interaction terms indicated higher odds of patients of non-White ethnicity or dementia to present with psychosis during the lockdown period. CONCLUSIONS: During lockdown, referrals to mental health services for adults decreased, but contained a higher proportion with psychotic symptoms. The stronger association with psychotic symptoms in non-White ethnic groups and patients with dementia during lockdown suggests that barriers in accessing care might have increased during the COVID-19 pandemic.

Safety and tolerability of natural and synthetic cannabinoids in adults aged over 50 years: A systematic review and meta-analysis.

BACKGROUND: Cannabinoid-based medicines (CBMs) are being used widely in the elderly. However, their safety and tolerability in older adults remains unclear. We aimed to conduct a systematic review and meta-analysis of safety and tolerability of CBMs in adults of age ≥50 years. METHODS AND FINDINGS: A systematic search was performed using MEDLINE, PubMed, EMBASE, CINAHL PsychInfo, Cochrane Library, and ClinicalTrials.gov (1 January 1990 to 3 October 2020). Randomised clinical trials (RCTs) of CBMs in those with mean age of ≥50 years for all indications, evaluating the safety/tolerability of CBMs where adverse events have been quantified, were included. Study quality was assessed using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) criteria and Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. Two reviewers conducted all review stages independently. Where possible, data were pooled using random-effects meta-analysis. Effect sizes were calculated as incident rate ratio (IRR) for outcome data such as adverse events (AEs), serious AEs (SAEs), and death and risk ratio (RR) for withdrawal from study and reported separately for studies using tetrahydrocannabinol (THC), THC:cannabidiol (CBD) combination, and CBD. A total of 46 RCTs were identified as suitable for inclusion of which 31 (67%) were conducted in the United Kingdom and Europe. There were 6,216 patients (mean age 58.6 ± 7.5 years; 51% male) included in the analysis, with 3,469 receiving CBMs. Compared with controls, delta-9-tetrahydrocannabinol (THC)-containing CBMs significantly increased the incidence of all-cause and treatment-related AEs: THC alone (IRR: 1.42 [95% CI, 1.12 to 1.78]) and (IRR: 1.60 [95% CI, 1.26 to 2.04]); THC:CBD combination (IRR: 1.58 [95% CI,1.26 to 1.98]) and (IRR: 1.70 [95% CI,1.24 to 2.33]), respectively. IRRs of SAEs and deaths were not significantly greater under CBMs containing THC with or without CBD. THC:CBD combination (RR: 1.40 [95% CI, 1.08 to 1.80]) but not THC alone (RR: 1.18 [95% CI, 0.89 to 1.57]) significantly increased risk of AE-related withdrawals. CBD alone did not increase the incidence of all-cause AEs (IRR: 1.02 [95% CI, 0.90 to 1.16]) or other outcomes as per qualitative synthesis. AE-related withdrawals were significantly associated with THC dose in THC only [QM (df = 1) = 4.696, p = 0.03] and THC:CBD combination treatment ([QM (df = 1) = 4.554, p = 0.033]. THC-containing CBMs significantly increased incidence of dry mouth, dizziness/light-headedness, and somnolence/drowsiness. Study limitations include inability to fully exclude data from those <50 years of age in our primary analyses as well as limitations related to weaknesses in the included trials particularly incomplete reporting of outcomes and heterogeneity in included studies. CONCLUSIONS: This pooled analysis, using data from RCTs with mean participant age ≥50 years, suggests that although THC-containing CBMs are associated with side effects, CBMs in general are safe and acceptable in older adults. However, THC:CBD combinations may be less acceptable in the dose ranges used and their tolerability may be different in adults over 65 or 75 years of age.

Predictive Factors for Conversion to Dementia in Individuals with Early-Onset Mild Cognitive Impairment.

INTRODUCTION: There is little research on factors predicting conversion to dementia in early-onset mild cognitive impairment (eoMCI), a transitional stage between healthy ageing and dementia in individuals below the age of 65. We aimed to examine whether sociodemographic and clinical factors at initial presentation predicted dementia progression in a cohort of eoMCI patients attending a memory service, at a university teaching hospital in the UK. METHODS: This is a retrospective case note study of individuals diagnosed with eoMCI between 2000 and 2013 at the Younger Person's Memory Service (YPMS) in Leicestershire, England. Data collected at assessment included social factors, demographic characteristics, and medical and psychiatric history, as well as standardized cognitive assessment scores. Variables were analysed using χ2 or independent sample t tests to identify associations. A Cox regression survival analysis was done to identify predictive factors for dementia conversion. An ROC analysis for total CAMCOG was used to investigate sensitivity and specificity for dementia converters versus non-converters. RESULTS: Out of 531 subjects who attended YPMS, 65 patients were given a diagnosis of eoMCI (47.7% female; mean age 56.4 ± 7.54 years). Of these, 21 (32.3%) converted to dementia during their course within the service. Comparison between subgroups revealed a significant association between dementia conversion and higher years of education and lower MMSE and CAMCOG (total and subscale) scores at baseline. Smoking history, alcohol use, or medical history such as diabetes or heart disease were not associated with conversion. Cox regression survival analysis showed higher education in years and lower total CAMCOG scores were significant predictors for conversion. Lower scores on the recent memory, remote memory, learning memory, and executive function subscales of the CAMCOG were also significant predictors for conversion. ROC curve analysis for total CAMCOG demonstrated that the best detection of dementia converters can be achieved with a cutoff score of 90.5/107 (sensitivity of 76.2% and specificity of 68.2%). Area under the curve was 0.808 (95% CI: 0.697-0.920). CONCLUSION: More years in education and lower cognitive scores on CAMCOG at initial assessment are associated with progression to dementia from eoMCI. Further research is required to explore these predictive factors more.

Loneliness in older adult mental health services during the COVID-19 pandemic and before: Associations with disability, functioning and pharmacotherapy.

OBJECTIVES: Loneliness is associated with psychiatric morbidity. Restrictions placed on the population during the first COVID-19 lockdown may have disproportionately affected older adults, possibly through increasing loneliness. We sought to investigate this by examining loneliness in referrals to mental health of older adults (MHOA) services during the first UK COVID-19 lockdown. METHODS: Referrals to MHOA services from a large South London catchment area were identified for the 16-week period of the UK lockdown starting in March 2020 and for the corresponding period in 2019. A natural language processing algorithm identified loneliness in the patients' records. We applied logistic regression models adjusted for age, gender, ethnicity and diagnosis, to examine associations of loneliness in the study population. RESULTS: 1991 referrals were identified, 56.9% of whom were female, with a mean age of 77.9 years. Only 26.9% occurred during the 2020 lockdown, but with a higher prevalence of loneliness (22.0 vs. 17.7%, p = 0.028). In the whole sample, loneliness was associated with non-accidental self-injury (Odds ratio [OR]: 1.65), depressed mood (OR: 1.73), psychotic symptoms (OR: 1.65), relationship problems (OR: 1.49), problems with daytime activities (OR: 1.36), and antidepressant use (OR: 2.11). During lockdown, loneliness was associated with non-accidental self-injury (OR: 2.52), problem drinking or drug-taking (OR 2.33), and antidepressant use (OR 2.10). CONCLUSIONS: Loneliness is associated with more severe symptoms of affective illness, worse functional problems and increased use of antidepressant medication in older adults. During lockdown, loneliness in referrals to MHOA services increased and was associated with increased risk-taking behaviour. Loneliness is a potential modifiable risk factor for mental illness, and efforts to minimise it in older adults should be prioritised as we emerge from the pandemic.

Patient experience and satisfaction with remote memory assessment: Responding to clinical need in times of COVID-19 restrictions.

BACKGROUND: The suspension of memory services during the COVID-19 pandemic delayed dementia diagnosis and access to early intervention. Some services responded to the challenge by developing a remote memory assessment pathway to comply with reduced social contact measures to protect vulnerable patients. The aim of the study was to establish whether remote model is considered a satisfactory experience within the context of the COVID-19 pandemic and to understand the factors associated with patient and carer satisfaction of remote pathway. METHOD: 73 participants recruited from patients referred to memory clinic in West Sussex, who were assessed over a video or telephone. Participants completed an 11-item questionnaire capturing satisfaction across a range of elements, contextual items (the impact of the pandemic, loneliness, previous experience of using teleconference technology and diagnosis), as well as 3 dimensions from Patient Experience Questionnaire. Descriptive statistics are reported at a whole sample level, separated by patient and carer status. A hypothesis driven set of bivariate analyses (Spearman's rank) was used to understand the association between overall satisfaction and key independent factors across the whole sample. RESULTS: 73 participants were typically older adults (M=68.5, SD=13.3) and female (n=40, 54.8%). The patient was more likely to be older, feel lonely within the past week and to have used video call software when compared to the carer (p> 0.05). Participants were generally satisfied with the remote pathway with 95.8% (n=69) agreeing or strongly agreeing with the statement "Overall, I was satisfied with the assessment". Patients and carers did not significantly differ on any satisfaction response, apart from the ease of use of technology, in which carers were more likely to find the technology easy to use (U= 432.5; p=0.01). Worry about contracting COVID and communication experience was positively associated with overall satisfaction, whilst perceived communication barriers were significantly negatively associated with overall satisfaction. CONCLUSIONS: Remote memory assessment was a positive and satisfactory experience for most patient and carers. The remote pathway should be considered as an option available during and beyond the pandemic to improve access and patient choice of assessment modality.

Neuropsychiatric Symptoms in Mild Cognitive Impairment: A Literature Review.

BACKGROUND: Neuropsychiatric symptoms (NPS) in dementia have received much attention due to their high prevalence and their significant implications. NPS in mild cognitive impairment (MCI), a clinical concept proposed as an intermediate state between normal aging and dementia, is now gradually gaining in interest. We aimed to conduct a selective review to examine the prevalence rate of NPS in MCI and associations of NPS symptoms with disease progression. SUMMARY: We searched the PubMed database for articles on NPS in MCI and included articles that fulfilled the inclusion criteria. NPS was present in 35-85% of MCI patients. The most common symptoms were depression, irritability, apathy, anxiety, agitation, and sleep problems. Although the associated risk for disease progression of some symptoms, such as apathy and anxiety, was more consistent across studies, evidence was conflicting for symptoms like depression and sleep problems. NPS tend to co-occur, and certain combinations of NPS had a mutual or cumulative effect on disease progression. Late-onset NPS, even in a mild form (mild behavioural impairment) were found to be associated with an increased risk of dementia, even in the absence of cognitive impairment. Key Messages: NPS are highly prevalent in MCI patients and associated with subsequent cognitive deterioration. Late-onset NPS should raise suspicions of neurodegeneration. Future studies with improvised methodology are required to understand the interrelations of NPS and the role they play in the prognosis for patients with MCI.

Smell identification function in early-onset Alzheimer's disease and mild cognitive impairment.

Little is known about olfactory identification (OI) function in early-onset Alzheimer's disease (EOAD) and early-onset mild cognitive impairment (eoMCI) with age of onset <65 years. We aimed to study OI in EOAD compared with eoMCI and age-matched healthy controls (HC). Nineteen EOAD subjects with mild to moderate dementia, 17 with eoMCI, and 21 HC recruited as a convenience sample from memory services were assessed for cognition, behavioral symptoms, and activities for daily living. The OI was tested using the University of Pennsylvania smell identification test (UPSIT). EOAD participants performed worse compared with eoMCI and HC on cognitive tests and OI (p < 0.001). Although eoMCI had poorer cognitive scores compared to HC, they were similar in their OI function. OI correlated with attention (r = 0.494, p = 0.031), executive functions (r = 0.508, p = 0.026), and praxis (r = 0.455, p = 0.05) within the EOAD group. OI impairment was significantly associated with the diagnosis of EOAD versus eoMCI, but not with eoMCI when compared with HC. OI could potentially be useful in differentiating EOAD from eoMCI. Studies with late-life MCI patients showing OI impairment relative to HC may be attributed to a different disease process. Independent replication in a larger sample is needed to validate these findings.

New Therapeutic Strategies for Lewy Body Dementias.

This article reviews current treatment strategies and recent advances for the Lewy body dementias (LBDs). Current available symptom treatment strategies are based on monoaminergic, cholinergic and glutaminergic neurotransmitter systems. Relatively robust evidence exists for cholinesterase inhibitors for cognitive impairment in LBD and in Parkinson's disease for antidepressants, clozapine and recently pimavanserin for psychosis. interpidine (RVT 101) and nelotanserin are currently under investigation. Non-pharmacological interventions, such as cognitive stimulation, physical exercises and neuromodulation strategies, may be useful in Parkinson's disease but have not yet been tested in dementias. Disease-modifying approaches are aimed at preventing, slowing or ameliorating the production, aggregation and deposition of pathological proteins, including immunotherapy targeting α-synuclein and an ongoing trial using ambroxol which increases glucocerebrosidase activity to lower the levels of the protein alpha-synuclein. Other disease-modifying clinical trials are using agents to augment insulin signalling, stem cell therapy, reducing amyloid pathology and gene therapy.

Association of blood lipids with Alzheimer's disease: A comprehensive lipidomics analysis.

INTRODUCTION: The aim of this study was to (1) replicate previous associations between six blood lipids and Alzheimer's disease (AD) (Proitsi et al 2015) and (2) identify novel associations between lipids, clinical AD diagnosis, disease progression and brain atrophy (left/right hippocampus/entorhinal cortex). METHODS: We performed untargeted lipidomic analysis on 148 AD and 152 elderly control plasma samples and used univariate and multivariate analysis methods. RESULTS: We replicated our previous lipids associations and reported novel associations between lipids molecules and all phenotypes. A combination of 24 molecules classified AD patients with >70% accuracy in a test and a validation data set, and we identified lipid signatures that predicted disease progression (R2 = 0.10, test data set) and brain atrophy (R2 ≥ 0.14, all test data sets except left entorhinal cortex). We putatively identified a number of metabolic features including cholesteryl esters/triglycerides and phosphatidylcholines. DISCUSSION: Blood lipids are promising AD biomarkers that may lead to new treatment strategies.