Evaluation of the National Task Group-Early Detection Screen for Dementia: Sensitivity to 'mild cognitive impairment' in adults with Down syndrome

Practicalities (and real-life experiences) of dementia in adults with Down syndrome

Adults with down syndrome (DS) have a lifetime dementia risk in excess of 95%, with a median age of onset of 55 years, due to trisomy 21. Co-occurring Alzheimer's disease (AD) has increased morbidity and mortality, and it is now recommended to screen for AD in all adults with DS beginning at 40 years of age. In this manuscript, we present two clinical cases of adults with DS who developed AD summarizing their medical histories, presenting symptoms, path to diagnosis and psychosocial aspects of care collected from retrospective chart review with caregiver consent. These two cases were chosen due to their complexity and interwoven nature of the medical and psychosocial aspects, and highlight the complexity and nuance of caring for patients with DS and AD.

New Frontier: The First Year of an Adult Neurodevelopmental Disabilities Clinic

BACKGROUND

As patients with neurodevelopmental disorders (NDDs) transition from pediatric to adult health care systems, they often have difficulty finding physicians to address their NDD-related needs. In response to this care gap, we established a new consultation clinic within a behavioral neurology clinic in an adult neurology department to address the neurodevelopmental concerns of these adult patients.

OBJECTIVE

To characterize the population of adult patients with NDDs seen in the adult NDD clinic in its first year.

METHOD

Data were obtained by a retrospective chart review of all patients with NDDs seen in the adult NDD clinic from September 2020 through December 2021.

RESULTS

Of the 86 patients who were seen in the adult NDD clinic, the average age was 34 years (SD = 15, range = 18-74 years). Developmental diagnoses included intellectual disability (63%), autism spectrum disorder (47%), Down syndrome (15%), cerebral palsy (9%), and other genetic disorders (26%). Comorbidities addressed included behavioral concerns (34%), anxiety (29%), seizure disorders (22%), and depression (15%). Behavioral and/or mental health concerns prompted 65% of the initial clinic visits. The most common recommendation made was to begin or increase exercise (59%), followed by facilitating connection to community, social, and employment resources.

CONCLUSION

Adults with NDDs have diagnoses, comorbidities, and concerns that are similar to, but also distinct from, those addressed in other adult neurology clinics. This study addresses the need for, and feasibility of, caring for the diverse population of adults with NDDs in an adult neurology setting.

Validation of a German version of the dementia screening questionnaire for individuals with intellectual disabilities (DSQIID-G) in Down's syndrome

BACKGROUND

People with Down's syndrome (DS) are at high risk of developing Alzheimer dementia (DS-AD) due to a triplication of the amyloid precursor protein gene. While several tools to diagnose and screen for DS-AD, such as the dementia screening questionnaire for individuals with intellectual disabilities (DSQIID), are available in English, validated German versions of such instruments are scarce.

METHODS

A German version of the DSQIID questionnaire (DSQIID-G) was completed by caregivers before attending our specialist outpatient department for DS-AD. All participants were assessed blind to DSQIID-G scoring using clinical and neuropsychological examinations, including the Cambridge Examination for Mental Disorders of Older People with Down's Syndrome and Others with Intellectual Disabilities (CAMDEX-DS). ICD-10 and amyloid/tau/neurodegeneration (A/T/N) criteria were applied to detect and categorise cognitive decline.

RESULTS

Of 86 participants, 43 (50%) showed evidence of cognitive decline. A definite diagnosis of DS-AD was reached in 17 (19.8%) and mild cognitive impairment in seven (8.3%) participants. Secondary causes of cognitive decline were determined among 13 (15.1%) participants, and in six (7%) cases, the diagnosis remained unclassifiable due to co-morbidities. Compared with cognitively stable individuals, participants with cognitive decline (n = 43) displayed higher DSQIID-G total scores [median (range): 3 (0-21) vs. 19 (0-48), P < 0.001]. A total score of >7 provided a sensitivity of 0.94 against a specificity of 0.76, to discriminate DS-AD and participants without cognitive decline according to ROC analysis. The convergent validity against the CAMDEX-DS interview score was good (r = 0.74), and split-half reliability (r = 0.96), internal consistency (Cronbach's α r = 0.96), test-retest reliability (r = 0.88) (n = 25) and interrater reliability (r = 0.81) (n = 31) were excellent.

CONCLUSIONS

The DSQIID-G showed excellent psychometric properties, including concurrent and internal validity and reliability. The cut-off value for screening was lower than in the original English validation study. For a screening instrument like DSQIID-G, a lower cut-off is preferable to increase case detection.

Validation of the German version of the DSQIID in adults with intellectual disabilities

BACKGROUND

An observer-rated screening questionnaire for dementia for people with intellectual disabilities (ID), DSQIID, was developed in the UK. So far, the German version has not yet been validated in adults with ID.

AIMS/METHODS

We validated a German version of DSQIID (DSQIID-G) among adults with ID attending a German clinic.

PROCEDURES/OUTCOMES

DSQIID-G was completed by the caregivers of 104 adults with ID at baseline (T1), 94 at six months (T2) and 83 at 12 months (T3). A Receiver Operating Curve (ROC) was used to determine the total DSQIID-G cutoff score for the best fit between sensitivity and specificity.

RESULTS

Sixteen of the 104 participants at T1 (15%) received a diagnosis of dementia. At T1, the scores among the non-dementia group ranged from 0 to 33 (mean: 6.7; SD: 7.65), and the dementia group ranged from 3 to 43 (mean: 22.12; SD: 11.6). The intergroup difference was statistically significant (W: 158; p < .001) (AUC:.89). A total score of 9 provided the best fit between sensitivity (.94) and specificity (.72).

CONCLUSIONS AND IMPLICATIONS

DSQIID-G total score can discriminate between dementia and non-dementia cases in adults with ID. A lower cutoff score with a higher sensitivity is desirable for a screening instrument.

Preliminary translation of 'Reducing Disability in Alzheimer's Disease' among individuals with intellectual disabilities and caregiver dyads

BACKGROUND

The Reducing Disability in Alzheimer's Disease in Kansas City (RDAD-KC) intervention has been shown to improve the health of individuals with dementia and caregiver dyads. This manuscript reports the results of implementing the RDAD among individuals with intellectual disabilities and caregiver dyads.

METHODS

Nine community agencies deployed the 12-week intervention. We assessed changes in individuals with intellectual disabilities' behavioural symptom related severity and physical activity, and caregivers' behavioural symptom-related distress, unmet needs, and caregiver strain.

RESULTS

Forty-four dyads enrolled, and 23 (~60 years, 48% female) completed ≥75% of the intervention. We observed decreases in behavioural symptom related severity (p = .07) and increases in physical activity (p = .20) among individuals with intellectual disabilities. We also observed decreases in behavioural symptom related distress (p = .14), unmet needs (p = .50), and caregiver strain (p = .50) among caregivers.

CONCLUSIONS

The RDAD-KC intervention showed promising, although statistically non-significant, benefits among individuals with intellectual disabilities and their caregivers.

Alzheimer's polygenic risk scores are associated with cognitive phenotypes in Down syndrome

INTRODUCTION

This study aimed to investigate the influence of the overall Alzheimer's disease (AD) genetic architecture on Down syndrome (DS) status, cognitive measures, and cerebrospinal fluid (CSF) biomarkers.

METHODS

AD polygenic risk scores (PRS) were tested for association with DS-related traits.

RESULTS

The AD risk PRS was associated with disease status in several cohorts of sporadic late- and early-onset and familial late-onset AD, but not in familial early-onset AD or DS. On the other hand, lower DS Mental Status Examination memory scores were associated with higher PRS, independent of intellectual disability and APOE (PRS including APOE, PRSAPOE , p = 2.84 × 10-4 ; PRS excluding APOE, PRSnonAPOE , p = 1.60 × 10-2 ). PRSAPOE exhibited significant associations with Aβ42, tTau, pTau, and Aβ42/40 ratio in DS.

DISCUSSION

These data indicate that the AD genetic architecture influences cognitive and CSF phenotypes in DS adults, supporting common pathways that influence memory decline in both traits.

HIGHLIGHTS

Examination of the polygenic risk of AD in DS presented here is the first of its kind. AD PRS influences memory aspects in DS individuals, independently of APOE genotype. These results point to an overlap between the genes and pathways that leads to AD and those that influence dementia and memory decline in the DS population. APOE ε4 is linked to DS cognitive decline, expanding cognitive insights in adults.

Down syndrome and Alzheimer's disease: A scoping review of functional performance and fall risk

Introduction

Alzheimer's disease (AD) occurs in aging adults with Down syndrome (DS) at a higher prevalence and an earlier age than in typical aging adults. As with the general aging adult population, there is an urgent need to understand the preclinical and early phases of AD progression in the adult population with DS. The aim of this scoping review was to synthesize the current state of the evidence and identify gaps in the literature regarding functional activity performance and falls and their significance to disease staging (i.e., mild, moderate, and severe defined staging criteria) in relation to Alzheimer's disease and related dementias (ADRD) in adults with DS.

Methods

This scoping review included six electronic databases (e.g., PsycInfo, Academic Search Complete, CINAHL, COCHRANE Library, MEDLINE, and PubMed). Eligible studies included participants with DS ≥25 years of age, studies with functional measures and/or outcomes (e.g., activities of daily living, balance, gait, motor control, speech, behavior, and cognition; falls; and fall risks), and studies that investigated AD pathology and implications.

Results

Fourteen eligible studies were included and categorized through a thematic analysis into the following themes: (1) physical activity and motor coordination (PAMC), (2) cognition, (3) behavior, and (4) sleep. The studies indicated how functional activity performance and engagement may contribute to early identification of those at risk of cognitive decline and AD development and/or progression.

Discussion

There is a need to expand the research regarding ADRD pathology relative to functional outcomes in adults with DS. Functional measures related to disease staging and cognitive impairment are essential to understanding how AD progression is characterized within real-world settings. This scoping review identified the need for additional mixed-methods research to examine the use of assessment and intervention related to function and its detection of cognitive decline and AD progression.

The Global Deterioration Scale for Down Syndrome Population (GDS-DS): A Rating Scale to Assess the Progression of Alzheimer's Disease

The aim of this study is to adapt and validate the global deterioration scale (GDS) for the systematic tracking of Alzheimer's disease (AD) progression in a population with Down syndrome (DS). A retrospective dual-center cohort study was conducted with 83 participants with DS (46.65 ± 5.08 years) who formed the primary diagnosis (PD) group: cognitive stability (n = 48), mild cognitive impairment (n = 24), and Alzheimer's disease (n = 11). The proposed scale for adults with DS (GDS-DS) comprises six stages, from cognitive and/or behavioral stability to advanced AD. Two neuropsychologists placed the participants of the PD group in each stage of the GDS-DS according to cognitive, behavioral and daily living skills data. Inter-rater reliability in staging with the GDS-DS was excellent (ICC = 0.86; CI: 0.80-0.93), and the agreement with the diagnosis categories of the PD group ranged from substantial to excellent with κ values of 0.82 (95% CI: 0.73-0.92) and 0.85 (95% CI: 0.72, 0.99). Performance with regard to the CAMCOG-DS total score and orientation subtest of the Barcelona test for intellectual disability showed a slight progressive decline across all the GDS-DS stages. The GDS-DS scale is a sensitive tool for staging the progression of AD in the DS population, with special relevance in daily clinical practice.

Diagnostic Sensitivity and Specificity of Cognitive Tests for Mild Cognitive Impairment and Alzheimer's Disease in Patients with Down Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

Improved health care for people with Down syndrome (DS) has resulted in an increase in their life expectancy therefore increasing comorbidities associated with age-related problems in this population, the most frequent being Alzheimer's disease (AD). To date, several cognitive tests have been developed to evaluate cognitive changes related to the development of mild cognitive impairment (MCI) and AD in people with DS.

OBJECTIVE

Identify and evaluate available cognitive tests for the diagnosis of MCI and AD in people with DS.

METHODS

A systematic search of the Pubmed and PsycInfo databases was performed to identify articles published from January 1, 2000 and July 1, 2022. Keysearch terms were DS, AD or MCI, cognition, and assessment. Relevant studies assessing the diagnostic accuracy of cognitive tests for AD or MCI with standard clinical evaluation were extracted. Risk of bias was assessed using the QUADAS 2.

RESULTS

We identified 15 batteries, 2 intelligence scales, 14 memory tests, 11 executive, functioning tests, 11 motor and visuospatial functioning tests, 5 language tests, 3 attention tests, and 2 orientation tests. Analysis showed that the CAMCOG-DS present a fair to excellent diagnostic accuracy for detecting AD in patients with DS. However, for the diagnosis of MCI, this battery showed poor to good diagnostic accuracy.

CONCLUSION

The findings highlight important limitations of the current assessment available for the screening of mild cognitive impairment and AD in patients with DS and support the need for more clinical trials to ensure better screening for this highly at-risk population.

A modified Cued Recall Test for detecting prodromal AD in adults with Down syndrome

Introduction

The development of valid methods to diagnose prodromal Alzheimer's disease (AD) in adults with Down syndrome (DS) is one of the many goals of the Alzheimer's Biomarkers Consortium-Down Syndrome (ABC-DS).

Methods

The diagnostic utility of a modified Cued Recall Test (mCRT) was evaluated in 332 adults with DS ranging from 25 to 81 years of age. Total recall was selected a priori, as the primary indicator of performance. Multiple regression and receiver-operating characteristic (ROC) analyses were used to compare diagnostic groups.

Results

Performance on the mCRT, as indicated by the total recall score, was highly sensitive to differences between diagnostic groups. ROC areas under the curve (AUCs) ranging from 0.843 to 0.955, were observed.

Discussion

The mCRT has strong empirical support for its use in clinical settings, as a valuable tool in studies targeting biomarkers of AD, and as a potential outcome measure in clinical trials targeting AD in this high-risk population.

Adults with Down syndrome in randomized clinical trials targeting prevention of Alzheimer's disease

INTRODUCTION

Adults with Down syndrome, the largest population genetically predisposed to high risk for Alzheimer's disease (AD), are ideally suited participants for clinical trials targeting prevention. Critically important considerations for the design of such trials include appropriate selection of participants, outcome measures, and duration of follow-up.

METHODS

Archived data for 12 measures of performance over a 3-year period were analyzed for 185 adults with Down syndrome 36 years of age and older with presumptive preclinical AD.

RESULTS

Declines over 3 years were not observed prior to 46 years of age. However, declines were observed at older ages, increasing monotonically for groups aged 46-49, 50-55, and >55, as did incidence of prodromal AD and dementia.

DISCUSSION

Significant decline over a 2- to 3-year period for a prospective placebo group of adults with Down syndrome enrolled in clinical prevention trials can only be expected when inclusion is limited to adults older than 45 years of age.

Intestinal Flora Balance Therapy Based on Probiotic Support Improves Cognitive Function and Symptoms in Patients with Alzheimer's Disease: A Systematic Review and Meta-analysis

Objective

The clinical value of intestinal flora balance therapy based on probiotic support in improving cognitive function and symptoms of patients with Alzheimer's disease was to systematically evaluate, so as to provide evidence-based medicine basis for the promotion and use of this therapy.

Methods

The randomized controlled trials (RCTs) were searched for the improvement of cognitive function and symptoms of patients with Alzheimer's disease by intestinal flora balance therapy supported mainly by probiotics in PubMed, EMBASE, ScienceDirect, Cochrane Library, China Knowledge Network Database (CNKI), China VIP database, Wanfang database, and China Biomedical Literature Database (CBM) online database (RCT). Data were extracted independently by two researchers, and the literature was assessed for risk of bias according to the Cochrane Handbook 5.1.0 criteria. The data were meta-analyzed using RevMan 5.4 statistical software.

Results

Finally, 5 randomized controlled trials were included, with a total sample size of 386 cases. The results of meta-analysis showed that Chi2 = 13.14, df = 2, P = 0.001, and I 2 = 85% showed significant heterogeneity in the inclusion of the study data. Probiotic-supported intestinal microflora balance therapy improves cognitive function in patients with Alzheimer's disease. Through meta-analysis of transient memory scores, it is concluded that intestinal flora balance therapy based on probiotic support can improve transient memory in patients with Alzheimer's disease. Meta-analysis of ADAS-COG score showed that intestinal flora balance therapy supported by probiotics could improve the cognitive function of patients with Alzheimer's disease. The ADL score was analyzed by meta, and the heterogeneity test result was Chi2 = 0.79, df = 1, P = 0.37 > 0.05, and I 2 = 0%, indicating that the intestinal flora balance therapy supported by probiotics can improve the ability of daily living of patients with Alzheimer's disease.

Conclusion

Intestinal flora balance therapy based on probiotic support can effectively improve cognitive function, instantaneous memory, and ability of daily life in patients with Alzheimer's disease. However, more studies and long-term follow-up studies with higher methodological quality are needed to further verify.

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.

Informant-based assessment instruments for dementia in people with intellectual disability: A systematic review and standardised evaluation

BACKGROUND

Dementia in people with intellectual disability (ID) is frequent but hard to recognise. Evidence-based recommendations for suitable instruments are lacking.

AIMS

The present study set out to evaluate informant-based dementia assessment instruments and to provide evidence-based recommendations for instruments most suitable in clinical practice and research.

METHOD AND PROCEDURES

A systematic review was conducted across ten international electronic databases. The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidelines, including a risk of bias assessment, was applied to extract information and to evaluate measurement properties and the quality of available evidence.

OUTCOMES AND RESULTS

In total, 42 studies evaluating 18 informant-based assessment instruments were analysed. For screening purposes, we recommend the Behavioral and Psychological Symptoms of Dementia in Down Syndrome Scale (BPSD-DS), the Cognitive Scale for Down Syndrome (CS-DS), and the Dementia Screening Questionnaire for Individuals with Intellectual Disabilities (DSQIID). For a more thorough dementia assessment, we recommend the Cambridge Examination for Mental Disorders of Older People with Down's Syndrome and Others with Intellectual Disabilities (CAMDEX-DS).

CONCLUSIONS AND IMPLICATIONS

Our study informs clinicians and researchers about adequate, well-evaluated dementia assessment instruments for people with ID, and highlights the need for high quality studies, especially regarding content validity.

Training professional caregivers to screen for report of cognitive changes in persons with intellectual disability

Introduction

By age 60, 60% of adults with Down syndrome (DS) have dementia. Detecting dementia in persons with intellectual disability (ID) can be challenging because their underlying cognitive impairment can confound presentation of dementia symptoms and because adults with ID may have difficulty reporting symptoms. The National Task Group Early Detection Screen for Dementia (NTG‐EDSD) was developed to aid detection of report of cognitive impairment in adults with ID. We implemented an educational curriculum using the NTG‐EDSD and evaluated the impact of the intervention on professional caregivers’ self‐assessed capacity to identify persons with ID and dementia.

Methods

We held five in‐person training sessions for professional caregivers of persons with ID, partnering with various managed care organizations and social services agencies. We assessed knowledge and attitudes at baseline; immediately after training; and 1 week, 1 month, and 6 months after training.

Results

A total of 154 direct care workers, case managers, health‐care providers, and other social services staff attended the trainings. Satisfaction with the NTG‐EDSD training was high; 94% of attendees agreed or strongly agreed that they could use the NTG‐EDSD with their clients. After training, attendees reported a marked increase in confidence in their ability to track various health circumstances and detect functional decline in their clients, although some gains were not sustained over time. As a result of the training, one managed care organization made the NTG‐EDSD a standard part of its assessment of adults with DS starting at age 40.

Discussion

Social services and health‐care professionals can learn to document signs of cognitive decline in adults with ID using the NTG‐EDSD. Attendees were highly satisfied with the training, experienced an increase in confidence in their care of persons with ID, and found the NTG‐ EDSD feasible to use. Because not all gains were sustained over time, booster trainings may be necessary.

Acquired mild cognitive impairment in adults with Down syndrome: Age-related prevalence derived from single point assessment data normed by degree of intellectual disability

BACKGROUND

Individuals with Down syndrome (DS) are at significant risk for early onset Alzheimer's disease (AD), likely due to the triplication of genes on chromosome 21 that facilitate AD neuropathology. To aid the effective early diagnosis of dementia in DS, we demonstrate the strategy of using single point assessment of cognitive performance with scoring normed for degree of intellectual disability to generate age related prevalence data for acquired mild cognitive impairment (AMCI).

METHODS

Four hundred and twelve adults with DS were assessed using the Neuropsychological Assessment of dementia in adults with Intellectual Disability. Normative data, banded by degree of intellectual disability, allowed identification of AMCI by atypical deviation from expected performance.

RESULTS

AMCI was evident in approximately 20% of adults with DS aged 40 and under, 40% aged 41-50 and 45% aged 51 and over. Relative risk increased significantly in those aged 46 and over. Analysis of prevalence by 5-year age bands revealed two peaks for higher prevalence of AMCI.

CONCLUSIONS

Psychometric data indicate single point assessment of AMCI is possible for the majority of adults with DS. Two peaks for age-related prevalence of AMCI suggest the risk for onset of AD conferred by trisomy of chromosome 21 is moderated by another factor, possibly ApoE status.