BACKGROUND: Dementia-related missing incidents are highly prevalent but still poorly understood. This is particularly true for environmental/geospatial risk factors, which might contribute to these missing incidents. OBJECTIVE: The study aimed to conduct a retrospective, observational analysis on a large sample of missing dementia patient case records provided by the police (n = 210), covering dates from January 2014 to December 2017. In particular, we wanted to explore i) hotspot regions of missing incidents and ii) the relationship between outdoor landmark density and missing incidents. METHODS: Global spatial autocorrelation (Moran's I) was used to identify the potential hotspot regions for missing incidents. Meanwhile, spatial buffer and regression modelling were used to determine the relationship between landmark density and missing incidents. RESULTS: Our demographics measures replicated and extended previous studies of dementia-related missing incidents. Meanwhile, no hotspot regions for missing incidents were identified, whilst higher outdoor landmark density lead to increased missing incidents. CONCLUSION: Our results highlight that missing incidents do not occur in isolated hotspots of regions but instead are endemic in patients regardless of location. Higher landmark density emerges as a significant geospatial factor for missing incidents in dementia, which crucially informs future safeguarding/intervention studies.

The Virtual Supermarket Task (VST) and Sea Hero Quest detect high-genetic-risk Alzheimer's disease (AD). We aimed to determine their test-retest reliability in a preclinical AD population. Over two time points, separated by an 18-month period, 59 cognitively healthy individuals underwent a neuropsychological and spatial navigation assessment. At baseline, participants were classified as low-genetic-risk of AD or high-genetic-risk of AD. We calculated two-way mixed effects intraclass correlation coefficients (ICC) for task parameters and used repeated measures ANOVAS to determine whether genetic risk or sex contributed to test-retest variability. The egocentric parameter of the VST measure showed the highest test-retest reliability (ICC = .72), followed by the SHQ distance travelled parameter (ICC = .50). Post hoc longitudinal analysis showed that boundary-based navigation predicts worsening episodic memory concerns in high-risk (F = 5.01, P = 0.03), but in not low-risk, AD candidates. The VST and the Sea Hero Quest produced parameters with acceptable testretest reliability. Further research in larger sample sizes is desirable.

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There is increasing evidence that menopausal changes can have an impact on women’s cognition and potentially, the future development of dementia. In particular, the role of reduced levels of estrogen in postmenopausal changes has been linked to an increased risk of developing dementia in observational studies. Not surprisingly, this has led to several clinical trials investigating whether postmenopausal hormone replacement therapy can potentially delay/avoid cognitive changes and subsequently, the onset of dementia. However, the evidence of these trials has been mixed, with some showing positive effects while others show no or even negative effects. In the current review, we investigate this controversy further by reviewing the existing studies and trials in cognition and dementia. Based on the current evidence, we conclude that previous approaches may have used a mixture of women with different genetic risk factors for dementia which might explain these contradicting findings. Therefore, it is recommended that future interventional studies take a more personalised approach towards hormone replacement therapy use in postmenopausal women, by taking into account the women’s genetic status for dementia risk.

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Background and Objectives People with dementia are at risk of exiting premises unsupervised, eloping, or getting lost, potentially leading to harmful or distressing consequences. This review aimed to estimate the effectiveness of interventions for preventing people with dementia from exiting or getting lost. Research Design and Methods A systematic review of English sources was undertaken. Health care (EMBASE, BNI, Medline, PubMed, CINAHL, PsycINFO, AMED, HTA, CENTRAL) and gray literature (OpenGrey) databases were searched using prespecified search terms. Additional studies were identified by hand-searching bibliographies of relevant reviews and included studies. Wide inclusion criteria were set to capture a range of intervention types. Data extraction and risk of bias assessment were completed independently by two reviewers. Methods were preregistered on PROSPERO. Results Individual and overall risk of bias was too high for statistical meta-analyses. A narrative synthesis was therefore performed. Twenty-five studies with 814 participants were included, investigating a range of nonpharmacological interventions aiming to prevent exiting, facilitate retrieval, educate participants, or a combination of these. Seventeen (68%) of the included studies had critical risks of internal bias to outcomes, providing no useful evidence for the effectiveness of their respective interventions. The remaining 8 (32%) studies had serious risks of bias. Narrative synthesis of results yielded no overall robust evidence for the effectiveness of any interventions. Discussion and Implications No evidence was found to justify the recommendation of any interventions included in this review. Future studies should focus on high-quality, controlled study designs.

Path integration spatial navigation processes are emerging as promising cognitive markers for prodromal and clinical Alzheimer’s disease (AD). However, such path integration changes have been little explored in Vascular Cognitive Impairment (VCI), despite neurovascular change being a major contributing factor to dementia and potentially AD. In particular, the sensitivity and specificity of path integration impairments in VCI compared to AD is unclear. In the current pilot study, we explore path integration performance in AD and VCI patient groups and hypothesise that i) medial parietal mediated egocentric processes will be more affected in VCI and ii) medial temporal mediated allocentric processes will be more affected in AD. This retrospective cross-sectional study included early stage VCI patients (n=9), AD patients (n=10) and healthy age-matched controls (n=20). All participants underwent extensive neuropsychological testing, as well as spatial navigation testing. The spatial navigation tests included the virtual reality ‘Supermarket’ task assessing egocentric (body-based) and allocentric (map-based) navigation as well as the ‘Clock Orientation’ test assessing egocentric and path integration processes. Results showed that egocentric path integration processes are only impaired in VCI, potentially distinguishing it from AD. However, in contrast to our prediction, allocentric path integration was similarly impaired for VCI and AD. These preliminary findings suggest limited specificity of allocentric path integration deficits between VCI and AD. By contrast, egocentric path integration deficits emerge as more specific to VCI, potentially allowing for more specific diagnostic and treatment outcome measures for vascular impairment in dementia.

Impairment of navigation is one of the earliest symptoms of Alzheimer’s disease (AD), but to date studies have involved proxy tests of navigation rather than studies of real life behaviour. Here we use GPS tracking to measure ecological outdoor behaviour in AD. The aim was to use data-driven machine learning approaches to explore spatial metrics within real life navigational traces that discriminate AD patients from controls. 15 AD patients and 18 controls underwent tracking of their outdoor navigation over two weeks. Three kinds of spatiotemporal features of segments were extracted, characterising the mobility domain (entropy, segment similarity, distance from home), spatial shape (total turning angle, segment complexity), and temporal characteristics (stop duration). Patients significantly differed from controls on entropy (p-value 0.008), segment similarity (p-value $${10}^{-7}$$ 10 - 7 ), and distance from home (p-value $${10}^{-14}$$ 10 - 14 ). Graph-based analyses yielded preliminary data indicating that topological features assessing the connectivity of visited locations may also differentiate patients from controls. In conclusion, our results show that specific outdoor navigation features discriminate AD patients from controls, which has significant implication for future AD diagnostics, outcome measures and interventions. Furthermore, this work illustrates how wearables-based sensing of everyday behaviour may be used to deliver ecologically-valid digital biomarkers of AD pathophysiology.