A review of measures used in the screening, assessment and diagnosis of dementia in people with an intellectual disability

Dementia in Rare Genetic Neurodevelopmental Disorders: A Systematic Literature Review

BACKGROUND AND OBJECTIVES

Knowledge of young-onset Alzheimer disease in adults with Down syndrome has greatly improved clinical care. However, little is known about dementia in rare genetic neurodevelopmental disorders (RGNDs). In this review, a comprehensive overview is provided of reports on dementia and cognitive/adaptive trajectories in adults with RGNDs.

METHODS

A systematic literature review was conducted in Embase, Medline ALL, and PsycINFO on December 6, 2022. The protocol was registered in PROSPERO (CRD42021223041). Search terms for dementia, cognitive and adaptive functioning, and RGNDs were combined using generic terms and the Orphanet database. Study characteristics and descriptive data on genetic diagnosis, clinical and neuropathologic features, comorbidities, and diagnostic methods were extracted using a modified version of the Cochrane Data Extraction Template.

RESULTS

The literature search yielded 40 publications (17 cohorts, 23 case studies) describing dementia and/or cognitive or adaptive trajectories in adults with 14 different RGNDs. Dementia was reported in 49 individuals (5 cohorts, 20 cases) with a mean age at onset of 44.4 years. Diagnostics were not disclosed for half of the reported individuals (n = 25/49, 51.0%). A total of 44 different psychodiagnostic instruments were used. MRI was the most reported additional investigation (n = 12/49, 24.5%). Comorbid disorders most frequently associated with cognitive/adaptive decline were epilepsy, psychotic disorders, and movement disorders.

DISCUSSION

Currently available literature shows limited information on aging in RGNDs, with relatively many reports of young-onset dementia. Longitudinal data may provide insights into converging neurodevelopmental degenerative pathways. We provide recommendations to optimize dementia screening, diagnosis, and research.

Using the learning disability screening questionnaire to help identify people with an intellectual disability in homeless services

BACKGROUND

We explored the accuracy of using the learning disability screening questionnaire (LDSQ) in services for people experiencing homelessness in the United Kingdom.

METHOD

We examined the concordance between the LDSQ outcomes and assessments of intellectual disability. Seventy adults experiencing homelessness completed the LDSQ. Staff completed the LDSQ and a measure of adaptive functioning for 38 of this group. Nine participants received an intellectual assessment.

RESULTS

Sensitivity and specificity for the LDSQ when completed by staff was 83% and 96% respectively and 50% and 92% when completed by the individual. Seven people had intellectual and adaptive functioning in the intellectual disability range.

CONCLUSION

The results suggest that the LDSQ would be an appropriate and beneficial screening tool to use within services for people experiencing homelessness. More accurate results would be likely if it were completed by staff.

Explanatory Capacity of Postural Control and Physical Fitness in Cognitive Impairment and Support Needs among Individuals with Intellectual Disabilities-A Cross-Sectional Pilot Study

Postural control is a skill associated with most motor activities and is essential for the performance of activities of daily living. People with intellectual disabilities (ID) present postural control deficits that can be attributed to several causes. The aim of this study was to determine whether postural control and physical fitness could explain the cognitive impairment and support needs in this population. A cross-sectional pilot study was conducted with 18 people with ID. Data collection was based on assessments for postural control (Mini BESTest and Berg Balance Scale) and physical fitness (Senior Fitness Test). The data were analyzed using linear regression models. Anticipatory postural adjustments were associated with support needs, explaining up to 45% of these. Consecutive postural adjustments and upper limb strength were less significantly associated with support needs. However, none of the variables used explained cognitive impairment in ID. Knowledge of the relationships and behavior of the different measurement tools is essential for the development of appropriate interventions in this population.

Group cognitive stimulation therapy versus usual care for people with intellectual disabilities and dementia (CST-IDD) in the UK: protocol for a mixed-methods feasibility randomised controlled trial

INTRODUCTION

The prevalence of dementia is almost five times higher in people with intellectual disabilities compared with the general population. However, evidence-based treatments for this population are lacking, as most randomised controlled trials for dementia interventions have not included people with intellectual disabilities. Cognitive stimulation therapy (CST) has a robust evidence base in the general dementia population, consistently showing benefits to cognition, quality of life and being cost-effective. We are conducting a mixed-methods feasibility trial of group CST for people with intellectual disabilities and dementia, to determine if a future definitive randomised controlled trial is feasible.

METHODS AND ANALYSIS

Fifty individuals with intellectual disabilities and dementia will be randomised to either the intervention arm (14 sessions of group CST plus treatment as usual) or the control arm (treatment as usual). Randomisation will occur after informed consent has been obtained and baseline assessments completed. Each arm will have 25 participants, with the intervention arm divided into five or more CST groups with three to five participants in each. The outcomes will be feasibility of recruitment, acceptability and adherence of the intervention, suitability of study outcome measures and feasibility of collecting resource use data. Quantitative and qualitative approaches, including semistructured interviews with group participants, carers and group facilitators, will be employed to assess these outcomes.

ETHICS AND DISSEMINATION

This study has been approved by Essex REC (Ref: 21/EE/027) and the HRA ethical approval process through the Integrated Research Application System (IRAS ID: 306 756). We plan to publish the results in peer-reviewed journals and conferences as well as provide feedback to funders, sponsors and study participants.

TRIAL REGISTRATION NUMBER

ISRCTN88614460.

Young-onset dementia diagnosis, management and care: a narrative review

Young-onset dementia comprises a heterogeneous range of dementias, with onset at less than 65 years of age. These include primary dementias such as Alzheimer disease, frontotemporal and vascular dementias; genetic/familial dementias; metabolic disorders; and secondary dementias such as those that result from alcohol use disorder, traumatic brain injury, and infections. The presentation of young-onset dementia is varied and may include cognitive, psychiatric and neurological symptoms. Diagnostic delay is common, with a frequent diagnostic conundrum being, "Is this young-onset dementia or is this psychiatric?". For assessment and accurate diagnosis, a thorough screen is recommended, such as collateral history and investigations such as neuroimaging, lumbar puncture, neuropsychology, and genetic testing. The management of young-onset dementia needs to be age-appropriate and multidisciplinary, with timely access to services and consideration of the family (including children).

Experiences of people with intellectual disability and dementia: A systematic review

BACKGROUND

Dementia disproportionately affects people with intellectual disability. Most qualitative studies explore their experiences by utilising proxy-reports. A smaller number of studies illustrate the possibility of exploring perspectives directly from people with intellectual disability and dementia.

METHOD

This systematic review synthesised findings from existing studies (n = 8) that involve people with intellectual disability and dementia as participants to understand their experiences of dementia. Searches were conducted using CINAHL, PsychInfo and Social Services Abstracts.

RESULTS

Findings include descriptions of changes in individual functioning, a narrowing of social worlds and of how people made sense of the changes despite often having no knowledge of their dementia diagnosis. Additionally, discussion focuses on how people's experiences are shaped by their environments.

CONCLUSION

The review recognises the complexities of speaking to people with intellectual disability about dementia, challenges views that people with intellectual and dementia cannot be involved in research and makes recommendations to support inclusion in future studies.

The Pictorial Screening Memory Test (P-MIS) for Adults with Moderate Intellectual Disability and Alzheimer's Disease

In this study, we examined normative data and diagnostic accuracy of a pictorial screening test to detect memory impairment for mild cognitive impairment (MCI) and Alzheimer's disease (AD) in Spanish-speaking adults with intellectual disability (ID). A total of 94 volunteers with ID (60 controls, 17 MCI, and 17 AD), were evaluated by neuropsychological tests including the PMIS-ID in a cross-sectional validation study. Discriminative validity between the MCI, AD, and control group was analyzed by the area under the ROC curve. A cut-off score of 4.5 on the immediate recall trial had a sensitivity of 69% and a specificity of 80% to detect memory impairment (AUC = 0.685; 95% CI = 0.506-0.863) in the AD group. The PMIS-ID is a useful screening test to rule out a diagnosis of memory decline in people with moderate level of ID and AD, and it shows good psychometric properties.

Cognitive outcome measures for tracking Alzheimer's disease in Down syndrome

Down syndrome (DS) is now viewed as a genetic type of Alzheimer's disease (AD), given the near-universal presence of AD pathology in middle adulthood and the elevated risk for developing clinical AD in DS. As the field of DS prepares for AD clinical intervention trials, there is a strong need to identify cognitive measures that are specific and sensitive to the transition from being cognitively stable to the prodromal (e.g., Mild Cognitive Impairment-Down syndrome) and clinical AD (e.g., Dementia) stages of the disease in DS. It is also important to determine cognitive measures that map onto biomarkers of early AD pathology during the transition from the preclinical to the prodromal stage of the disease, as this transition period is likely to be targeted and tracked in AD clinical trials. The present chapter discusses the current state of research on cognitive measures that could be used to screen/select study participants and as potential outcome measures in future AD clinical trials with adults with DS. In this chapter, we also identify key challenges that need to be overcome and questions that need to be addressed by the DS field as it prepares for AD clinical trials in the coming years.

Dementia in People with Severe/Profound Intellectual (and Multiple) Disabilities: Practice-Based Observations of Symptoms

INTRODUCTION

Observable dementia symptoms are hardly studied in people with severe/profound intellectual (and multiple) disabilities (SPI(M)D). Insight in symptomatology is needed for timely signaling/diagnosis. This study aimed to identify practice-based observations of dementia symptoms in this population.

METHODS

Care professionals and family members were invited to complete a survey about symptoms. Quantitatively analyzed survey data were further deepened through semi-structured interviews with care professionals having vast experience in signaling/diagnosing dementia in this population. Symptoms were categorized using a symptom matrix.

RESULTS

Survey respondents and interviewees frequently observed a decline in activities of daily living (ADL) functioning and behavioral and psychological changes, like increased irritability, anxiety, apathy and decreased eating/drinking behavior. Cognitive symptoms were particularly recognized in persons with verbal communication and/or walking skills. To lesser extent motor changes and medical comorbidities were reported.

CONCLUSION

Increased insight in dementia symptoms contributes to developing a dedicated screening instrument for dementia in people with SPI(M)D.

Dementia in people with severe or profound intellectual (and multiple) disabilities: Focus group research into relevance, symptoms and training needs

BACKGROUND

Differentiating dementia from baseline level of functioning is difficult among people with severe/profound intellectual (and multiple) disabilities. Moreover, studies on observable dementia symptoms are scarce. This study examined (a) the relevance of dementia diagnosis, (b) observable symptoms and (c) training/information needs.

METHODS

Four explorative focus groups were held with care professionals and family members who have experience with people with severe/profound intellectual (and multiple) disabilities (≥40 years) and decline/dementia.

RESULTS

Thematic analysis showed that participants wanted to know about a dementia diagnosis for a better understanding and to be able to make informed choices (question 1). Using a categorisation matrix, cognitive and behavioural changes were shown to be most prominent (question 2). Participants indicated that they needed enhanced training, more knowledge development and translation, and supportive organisational choices/policies (question 3).

CONCLUSIONS

Timely identifying/diagnosing dementia allows for a timely response to changing needs. This requires a better understanding of symptoms.

The neglected puzzle of dementia in people with severe/profound intellectual disabilities: A systematic literature review of observable symptoms

BACKGROUND

Dementia is increasingly prevalent in people with severe/profound intellectual disabilities. However, early detection and diagnosis of dementia is complex in this population. This study aimed to identify observable dementia symptoms in adults with severe/profound intellectual disabilities in available literature.

METHOD

A systematic literature search was conducted in PubMed, PsycINFO and Web of Science with an exhaustive search string using a combination of search terms for severe/profound intellectual disabilities and dementia/ageing.

RESULTS

Eleven studies met inclusion criteria. Cognitive decline, behavioural and psychological alterations, decline in activities of daily living as well as neurological and physical changes were found.

CONCLUSIONS

Only a very limited number of studies reported symptoms ascribed to dementia in adults with severe/profound intellectual disabilities. Given the complexity of signalling and diagnosing dementia, dedicated studies are required to unravel the natural history of dementia in this population.

Assessment of dementia in a clinical sample of persons with intellectual disability

BACKGROUND

Assessment of age-associated disorders has become increasingly important.

METHODS

In a clinical setting, people with intellectual disability with and without dementia were assessed retrospectively using the Neuropsychological Test Battery (NTB) and the Dementia Questionnaire for People with Learning Disabilities (DLD) at two different times to analyse neuropsychological changes and diagnostic validity. One group (n = 44) was assessed with both instruments, while the DLD was applied in 71 patients.

RESULTS

In the NTB (n = 44), only patients with dementia (n = 26) showed a decline in the NTB total score and three subscales. Receiver operating characteristic analysis revealed a diagnostic sensitivity of .67, a specificity of .81, and an area under the curve (AUC) of .767. In the DLD group (n = 71), only those with dementia displayed a decrease in the cognitive and social scale; diagnostic sensitivity and specificity values were low (.61/.63) and the AUC was .704.

CONCLUSIONS

Neuropsychological assessment was sensitive to detect cognitive changes over time. Sensitivity values of both instruments suggest a reassessment at a later time point.

Short forms of Prudhoe Cognitive Function Test in adults and aging people with intellectual disabilities: Italian validation study

BACKGROUND

We aimed to validate the Italian version of the two parallel short forms of the Prudhoe Cognitive Function Test (s-PCFT-I) in adults and seniors with intellectual disabilities (ID) of any aetiology and level of severity.

METHODS

Our validation is a multicentre study attended by 211 subjects with ID, 125 male and 86 female, aged 40 years and above for people with Down syndrome and aged 50 years for people with other forms of disabilities.

RESULTS

The s-PCFT-I shows a wide range of scores in the absence of floor effects with minimal ceiling effects. A Cronbach's α coefficient of 0.85 and a mean inter-item correlation of 0.21 indicate high internal consistency. The tool demonstrates good agreement between testers and near excellent temporal stability with intraclass correlation coefficients respectively of 0.85 and 0.90. s-PCFT-I total scores do not differ by sex or age, while statistically significant differences are observed between people with different levels of severity of ID. Moderate to good and highly significant correlations (-0.40 to -0.66) among the s-PCFT-I total scores and subscores and the Sum of Cognitive Score of the informant-based Dementia Questionnaire for Persons with Intellectual Disabilities suggest an acceptable level of concurrent criterion validity. Cognitive decliners according to Prasher's Dementia Questionnaire for Persons with Intellectual Disabilities cut-off scores perform significantly lower on s-PCFT-I than non-decliners.

CONCLUSIONS

The s-PCFT-I has good psychometric properties and user friendliness and may therefore be a valuable addition to the current informant-rated tools for screening and assessment of cognition in aging people with ID.

Informant-based assessment instruments for dementia and their measurement properties in persons with intellectual disability: systematic review protocol

INTRODUCTION

Persons with intellectual disability (ID) are at a higher risk of developing dementia than persons without ID, with an expected earlier onset. Assessment methods for the general population cannot be applied for persons with ID due to their pre-existing intellectual and functional impairments. As there is no agreed-upon measure to assess dementia in persons with ID, multiple instruments for this purpose have been developed and adapted in the past decades. This review aimed to identify all available informant-based instruments for the assessment of dementia in persons with ID, to evaluate and compare them according to their measurement properties, and to provide a recommendation for the most suitable instruments. Additionally, an overview of the amount and quality of research on these instruments will be provided.

METHODS AND ANALYSIS

This review will be conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. We will adhere to the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines and use a set of characteristics developed for assessment instruments for persons with ID, the Characteristics of Assessment Instruments for Psychiatric Disorders in Persons with Intellectual Developmental Disorders. Two comprehensive, systematic literature searches will be applied in 10 international databases, including ASSIA, CINAHL, Cochrane Library, ERIC, MEDLINE, PsycINFO, Scopus, Web of Science, OpenGrey and ProQuest Dissertations and Theses Global. Risk of bias and quality assessment will be done according to COSMIN guidelines. We will apply the modified Grading of Recommendations, Assessment, Development and Evaluation approach to rate the overall quality of the available evidence.

ETHICS AND DISSEMINATION

No ethics statement is needed for this study. The results will be submitted to a peer-reviewed journal and will be presented at international conferences.

Internalize at your peril: internalizing disorders as risk factors for dementia-cohort study

Few studies examined comorbid anxiety and depression's independent association with dementia. We assessed internalizing disorders as risk factors for dementia to avoid pitfalls inherent in separating anxiety and depression. Retrospectively designed prospective comparative cohort study using New Zealand's (NZ) National Minimum Dataset of hospital discharges. Hazards ratios (HRs), estimated from parametric survival models, compared the time to incident dementia after a minimal latency interval of 10 years between those with and without prior diagnosis of an internalizing disorder. A total of 47,932 patients aged 50-54 years were discharged from a publicly funded hospital events in NZ between 1988 and 1992. Of these, 37,631 (79%) met eligibility criteria, and incident dementia was diagnosed in 1594. Rates of incident dementia were higher among patients with an earlier diagnosis of internalizing disorders (572 vs 303 per 100,000 person years at risk (PYAR)). After adjustment for age, sex, ethnicity, and region, those with internalizing disorders were estimated to have a higher risk of developing dementia than those without (adjusted HR = 1.57, 95% CI 1.17-2.10). Females with an earlier diagnosis of internalizing disorders were estimated to have almost twice the risk of developing dementia (adjusted HR 1.80, 95% CI 1.25-2.59). Internalizing disorders affect one in five adults globally. Our findings suggest a significant increase in risk of dementia more than 10 years after the diagnosis of internalizing disorder.

Signs in People with Intellectual Disabilities: Interviews with Managers and Staff on the Identification Process of Dementia

The life expectancy of people with intellectual disabilities (ID) has steadily increased, which has been accompanied by an increased risk of dementia. Staff and managers are key resources for safety diagnosis since they deliver information about people with ID behavior every day. The aim of the present study was to explore the identification process employed by staff and managers to detect signs of suspected dementia in people with an ID within intellectual disability services (ID-services). Twenty managers and 24 staff within an ID-service were interviewed and qualitative latent content analysis was applied. A model consisting of three themes on three levels of resources for the identification process of signs of suspected dementia emerged from the analysis. On the first level was the time and continuity in the care relationship, which is crucial for identifying and responding to changes in cognitive ability that indicate dementia. On the second level, the staff identify deficiencies in their own knowledge, seek support from colleagues and managers within their workplace and, on the third level, outside their workplace. Staff and managers expressed a need for early and continuous guidance and education from specialists in dementia and primary healthcare. This finding indicates an urgent need for intervention research and digital support for staff in dementia care.