Symptoms of dementia among adults with Down's syndrome: a qualitative study

Mitochondrial Dysfunction Correlates with Brain Amyloid Binding, Memory, and Executive Function in Down Syndrome: Implications for Alzheimer's Disease in Down Syndrome

Background/Objectives: Mitochondrial dysfunction is increasingly recognized as a central contributor to neurodegenerative diseases and age-related cognitive decline. Individuals with Down syndrome (DS) are at high risk of neurodegeneration due to Alzheimer's disease (AD). This study aims to explore the relationship between mitochondrial dysfunction, brain amyloid-beta (Aβ) deposition, and cognitive decline in this population. Methods: We investigated mitochondrial function, brain amyloid-beta burden, and cognitive performance in a pilot study of a cohort of 10 eligible adults with DS selected from a sample of 28 individuals with DS. Phosphorus-31 magnetic resonance spectroscopy (31P-MRS) was used to assess mitochondrial function in skeletal muscle using a post-exercise paradigm, while positron emission tomography using 11C-Pittsburgh compound B (PiB-PET) measured brain Aβ deposition. Cognitive performance was evaluated using the Cambridge Cognitive Examination adapted for individuals with Down syndrome (CAMCOG-DS) and executive function batteries. Results: Significant correlations were observed between slowed phosphocreatine (PCr) recovery in muscle and increased Aβ deposition in key brain regions, particularly the striatum. Cognitive performance inversely correlated with mitochondrial function, with pronounced deficits in memory and executive function tasks. Notably, an individual carrying the APOE-ε4 allele exhibited the poorest mitochondrial function, highest Aβ burden, and most severe cognitive impairment, suggesting a potential interaction between genetic risk and mitochondrial health. Conclusions: These findings highlight the role of mitochondrial dysfunction in DS-associated AD (DSAD) and its impact on cognition in adults. The results support targeting mitochondrial pathways as a potential therapeutic strategy to mitigate AD progression in DS populations. Further research with larger cohorts and longitudinal designs is needed to clarify causative mechanisms and develop effective interventions.

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.

Symptoms and age of prodromal Alzheimer's disease in Down syndrome: a systematic review and meta-analysis

The diagnostic criteria for adult-onset Alzheimer's disease (AD) in patients with Down syndrome (DS) have not been standardised. This study investigated the specific symptoms of AD in the prodromal stage of DS, the mean age at diagnosis at each stage of dementia, and the relationship between intellectual disability (ID) and dementia. PubMed, Web of Science, and Embase were searched for studies on DS, AD, early-stage disease, initial symptoms, and prodromal dementia registered between January 2012 and January 2022. We also performed a meta-analysis of the differences between the mean age at prodromal symptoms and AD diagnosis and the proportion of mild cognitive impairment in patients with mild and moderately abnormal ID. We selected 14 articles reporting the behavioural and psychological symptoms of dementia (BPSD) and memory- and language-related impairments as early symptoms of AD in patients with DS. The specific symptoms of BPSD were classified into five categories: irritability (agitation), apathy, abnormal behaviour, adaptive functioning, and sleep disturbance. The mean age at the diagnosis of prodromal symptoms and AD dementia was 52.7 and 56.2 years, respectively (mean difference, + 3.11 years; 95% CI 1.82-4.40) in the meta-analysis. The diagnosis of mild dementia tended to correlate with ID severity (odds ratio [OR], 1.38; 95% CI 0.87-2.18). The features of behaviour-variant frontotemporal dementia may be clinically confirmed in diagnosing early symptoms of DS-associated AD (DSAD). Moreover, age-appropriate cognitive assessment is important. Further studies are required to evaluate DSAD using a combination of biomarkers and ID-related data.

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.

Causes of and Alternatives to Medication for Behaviours That Challenge in People with Intellectual Disabilities: Direct Care Providers' Perspectives

Behaviours that challenge (BtC), such as aggression and self-injury, are manifested by many people with intellectual disabilities (ID). National and international guidelines recommend non-pharmacological psychosocial intervention before considering medication to address BtC. Support staff play a pivotal role in the prescription process. Using coproduction, we developed a training programme for support staff, called SPECTROM, to give them knowledge and empower them to question inappropriate prescriptions and ask for the discontinuation of medication if appropriate and instead look for ways to help people with ID when they are distressed without relying on medication. We have presented data from two focus groups that we conducted during the development of SPECTROM: one that included support staff, and another that had service managers and trainers. In these focus groups, we explored participants' views on the use of medication to address BtC with a particular emphasis on the causes of and alternatives to medication for BtC. Along with the participants' views, we have also presented how we have addressed these issues in the SPECTROM resources.

The French translation of the dementia screening questionnaire for individuals with intellectual disabilities is a sensitive tool for screening for dementia in people with Down Syndrome

BACKGROUND

People with Down Syndrome (DS) are at an increased risk of developing Alzheimer's Disease (AD) relatively early in life. The dementia screening questionnaire for individuals with intellectual disabilities (DSQIID) has been developed for people with intellectual disabilities and was shown to have high discriminative power to distinguish between people with and without dementia. The objective of this study was to verify if the French version of the DSQIID (DSQIID-F) had a good diagnostic specificity and to determine the optimal cut-off for screening people with DS for dementia.

METHOD

This was a single-centre, retrospective, medical chart review study in people with DS aged ≥40 years. Demographics, level of intellectual disability, DSQIID-F data and clinical assessment of dementia were extracted from medical records. Sensitivity and specificity for different DSQIID-F cut-offs were calculated to determine the optimal cut-off.

RESULTS

151 people with DS were included with a median age of 51 years. The optimal DSQIID-F cut-off was 19, sensitivity was 0.940 (95 % CI: 0.830; 0.985) and specificity was 0.941 (95 % CI: 0.873; 0.975). Results were comparable to those for the English DSQIID (cut-off: 20; sensitivity: 0.92; specificity: 0.97). However, the psychometric qualities of the DSQIID-F, used for clinical follow-up, have not been verified.

CONCLUSIONS

The DSQIID-F has good discriminative power and represents a useful tool to screen people with DS for dementia.

The Clinical and Neuropathological Features of Sporadic (Late-Onset) and Genetic Forms of Alzheimer's Disease

The purpose of this review is to compare and highlight the clinical and pathological aspects of genetic versus acquired Alzheimer's disease: Down syndrome-associated Alzheimer's disease in (DSAD) and Autosomal Dominant Alzheimer's disease (ADAD) are compared with the late-onset form of the disease (LOAD). DSAD and ADAD present in a younger population and are more likely to manifest with non-amnestic (such as dysexecutive function features) in the prodromal phase or neurological features (such as seizures and paralysis) especially in ADAD. The very large variety of mutations associated with ADAD explains the wider range of phenotypes. In the LOAD, age-associated comorbidities explain many of the phenotypic differences.

Towards Designing Mobile Apps for Independent Travel

Performing daily independent activities can be a challenge for people with Down's Syndrome (DS). This article investigates how to better support these activities with smart devices based on three cycles of a collaborative participatory action research (PAR) process. The first cycle involved semi-structured interviews ( n = 4 ) with parents and an online survey ( n = 39 ) with people with DS and their parents to explore barriers and opportunities for independent activities. This cycle highlighted that travelling independently was a common challenge among discussed barriers to independent activities for young adults with DS, an issue that smart devices have the potential to overcome. The second cycle involved seven focus group discussions ( n = 20 ) with parents ( n = 13 ) and young adults with DS ( n = 7 ) for gaining deeper insights into barriers to independent travel. We explored key barriers to independent travel and gathered design requirements for smartphone apps to overcome these barriers. In the third cycle, we designed a digital prototype based on participant recommendations and conducted seven focus group meetings ( n = 19 ) with caregivers ( n = 12 ) and individuals with DS ( n = 7 ). This final cycle reviewed the proposed digital prototype and validated the key barriers found in the second cycle. Overall, our studies confirmed that mobile technology can support people with DS in performing daily life activities that increase social inclusion. The studies resulted in identified barriers and requirements along with co-designed solutions for independent travel apps.

Cognitive Function during the Prodromal Stage of Alzheimer's Disease in Down Syndrome: Comparing Models

Accurate identification of the prodromal stage of Alzheimer’s disease (AD), known as mild cognitive impairment (MCI), in adults with Down syndrome (MCI-DS) has been challenging because there are no established diagnostic criteria that can be applied for people with lifelong intellectual disabilities (ID). As such, the sequence of cognitive decline in adults with DS has been difficult to ascertain, and it is possible that domain constructs characterizing cognitive function in neurotypical adults do not generalize to this high-risk population. The present study examined associations among multiple measures of cognitive function in adults with DS, either prior to or during the prodromal stage of AD to determine, through multiple statistical techniques, the measures that reflected the same underlying domains of processing. Participants included 144 adults with DS 40–82 years of age, all enrolled in a larger, multidisciplinary study examining biomarkers of AD in adults with DS. All participants had mild or moderate lifelong intellectual disabilities. Overall AD-related clinical status was rated for each individual during a personalized consensus conference that considered performance as well as health status, with 103 participants considered cognitively stable (CS) and 41 to have MCI-DS. Analyses of 17 variables derived from 10 tests of cognition indicated that performance reflected three underlying factors: language/executive function, memory, and visuomotor. All three domain composite scores significantly predicted MCI-DS status. Based upon path modeling, the language/executive function composite score was the most affected by prodromal AD. However, based upon structural equation modeling, tests assessing the latent construct of memory were the most impacted, followed by those assessing visuomotor, and then those assessing language/executive function. Our study provides clear evidence that cognitive functioning in older adults with DS can be characterized at the cognitive domain level, but the statistical methods selected and the inclusion or exclusion of certain covariates may lead to different conclusions. Best practice requires investigators to understand the internal structure of their variables and to provide evidence that their variables assess their intended constructs.

Development of a symptom menu to facilitate Goal Attainment Scaling in adults with Down syndrome-associated Alzheimer's disease: a qualitative study to identify meaningful symptoms

Background

As life expectancy of people with Down syndrome (DS) increases, so does the risk of Alzheimer’s disease (AD). Identifying symptoms and tracking disease progression is especially challenging whenever levels of function vary before the onset of dementia. Goal Attainment Scaling (GAS), an individualized patient-reported outcome, can aid in monitoring disease progression and treatment effectiveness in adults with DS. Here, with clinical input, a validated dementia symptom menu was revised to facilitate GAS in adults living with Down Syndrome-associated Alzheimer’s disease (DS-AD).

Methods

Four clinicians with expertise in DS-AD and ten caregivers of adults living with DS-AD participated in semi-structured interviews to review the menu. Each participant reviewed 9–15 goal areas to assess their clarity and comprehensiveness. Responses were systematically and independently coded by two researchers as ‘clear’, ‘modify’, ‘remove’ or ‘new’. Caregivers were encouraged to suggest additional items and recommend changes to clarify items.

Results

Median caregiver age was 65 years (range 54–77). Most were female (9/10) with ≥15 years of education (10/10). Adults with DS-AD had a median age of 58 years (range 52–61) and either a formal diagnosis (6/10) or clinical suspicion (4/10) of dementia. The initial symptom menu consisted of 67 symptoms each with 2–12 descriptors (589 total). The clinicians’ adaptation yielded 58 symptoms each with 4–17 descriptors (580 total). Of these 580 descriptors, caregivers identified 37 (6%) as unclear; these were reworded, and one goal area (4 descriptors) was removed. A further 47 descriptors and one goal area were added to include caregiver-identified concepts. The final menu contained 58 goal areas, each with 7–17 descriptors (623 total).

Conclusions

A comprehensive symptom menu for adults living with DS-AD was developed to facilitate GAS. Incorporating expert clinician opinion and input from caregivers of adults with DS-AD identified meaningful items that incorporate patient/caregiver perspectives.

Neuropsychiatric Symptoms of Alzheimer's Disease in Down Syndrome and Its Impact on Caregiver Distress

BACKGROUND

Neuropsychiatric symptoms (NPS) are non-cognitive manifestations common to dementia and other medical conditions, with important consequences for the patient, caregivers, and society. Studies investigating NPS in individuals with Down syndrome (DS) and dementia are scarce.

OBJECTIVE

Characterize NPS and caregiver distress among adults with DS using the Neuropsychiatric Inventory (NPI).

METHODS

We evaluated 92 individuals with DS (≥30 years of age), divided by clinical diagnosis: stable cognition, prodromal dementia, and AD. Diagnosis was determined by a psychiatrist using the Cambridge Examination for Mental Disorders of Older People with Down's Syndrome and Others with Intellectual Disabilities (CAMDEX-DS). NPS and caregiver distress were evaluated by an independent psychiatrist using the NPI, and participants underwent a neuropsychological assessment with Cambridge Cognitive Examination (CAMCOG-DS).

RESULTS

Symptom severity differed between-groups for delusion, agitation, apathy, aberrant motor behavior, nighttime behavior disturbance, and total NPI scores, with NPS total score being found to be a predictor of AD in comparison to stable cognition (OR for one-point increase in the NPI = 1.342, p = 0.012). Agitation, apathy, nighttime behavior disturbances, and total NPI were associated with CAMCOG-DS, and 62% of caregivers of individuals with AD reported severe distress related to NPS. Caregiver distress was most impacted by symptoms of apathy followed by nighttime behavior, appetite/eating abnormalities, anxiety, irritability, disinhibition, and depression (R2 = 0.627, F(15,76) = 8.510, p < 0.001).

CONCLUSION

NPS are frequent and severe in individuals with DS and AD, contributing to caregiver distress. NPS in DS must be considered of critical relevance demanding management and treatment. Further studies are warranted to understand the biological underpinnings of such symptoms.

Short-term PsychoEducation for Carers To Reduce Over Medication of people with intellectual disabilities (SPECTROM): study protocol

INTRODUCTION

Psychotropic medications that are primarily licenced for the treatment of psychiatric disorders are used widely (32%-85%) among people with intellectual disabilities (ID) often for the management of problem (challenging) behaviour in the absence of a psychiatric disorder. Care staff play a pivotal role in the prescribing process. Currently, no staff training programme exists to address the issue of overprescribing of psychotropic medication in people with ID, thus highlighting an urgent need for developing a psychoeducational programme (PEP) specifically designed to address this issue. We propose to develop a PEP for care staff using the methodology described in the UK Medical Research Council guide for complex interventions.

METHODS AND ANALYSIS

The development of the PEP will involve (1) gathering information on available relevant training programmes, (2) running four focus groups with care staff and other professionals to establish the content and format of the PEP, and (3) organising a co-design event involving all relevant stakeholders to discuss the format of the PEP. A core project team will develop the PEP under guidance from the PEP Development Group which will consist of 10-12 relevant stakeholder representatives. Feedback from selected stakeholders on a draft PEP will allow us to refine the PEP before implementation. The PEP will have web-based modules supplemented by face to face training sessions. When the final draft is ready, we will field test the PEP on six to eight care staff from community care homes for people with ID. After completing the field test, we will run a focus group involving participants in the PEP to get feedback on the PEP.

ETHICS AND DISSEMINATION

Ethics approval for this study was waived by the UK Health Regulatory Authority as the study does not collect any patient related information and only include care staff outside the UK NHS. This will be the first ever such universally freely available PEP supported by training manual and slides.

The Behavioral and Psychological Symptoms of Dementia in Down Syndrome (BPSD-DS) Scale: Comprehensive Assessment of Psychopathology in Down Syndrome

People with Down syndrome (DS) are prone to develop Alzheimer’s disease (AD). Behavioral and psychological symptoms of dementia (BPSD) are core features, but have not been comprehensively evaluated in DS. In a European multidisciplinary study, the novel Behavioral and Psychological Symptoms of Dementia in Down Syndrome (BPSD-DS) scale was developed to identify frequency and severity of behavioral changes taking account of life-long characteristic behavior. 83 behavioral items in 12 clinically defined sections were evaluated. The central aim was to identify items that change in relation to the dementia status, and thus may differentiate between diagnostic groups. Structured interviews were conducted with informants of persons with DS without dementia (DS, n = 149), with questionable dementia (DS+Q, n = 65), and with diagnosed dementia (DS+AD, n = 67). First exploratory data suggest promising interrater, test-retest, and internal consistency reliability measures. Concerning item relevance, group comparisons revealed pronounced increases in frequency and severity in items of anxiety, sleep disturbances, agitation & stereotypical behavior, aggression, apathy, depressive symptoms, and eating/drinking behavior. The proportion of individuals presenting an increase was highest in DS+AD, intermediate in DS+Q, and lowest in DS. Interestingly, among DS+Q individuals, a substantial proportion already presented increased anxiety, sleep disturbances, apathy, and depressive symptoms, suggesting that these changes occur early in the course of AD. Future efforts should optimize the scale based on current results and clinical experiences, and further study applicability, reliability, and validity. Future application of the scale in daily care may aid caregivers to understand changes, and contribute to timely interventions and adaptation of caregiving.

Aging Individuals With Down Syndrome and Dementia as Teachers: Learnings from Staffin a Developmental Disability Program in Long-Term Care

Older adults with Down syndrome (DS) and dementia are an emerging sub-population. With much longer life spans than decades ago, issues have arisen as to where these aging adults will live and how nurses and other staff in facilities can provide effective care to these individuals. The current article presents a research study that examined the learnings of nurses and staff members working within a western Canadian program for older adults with DS and dementia. These learnings include: the importance of learning from each other; importance of collaboration; how individuals with developmental disabilities communicate; older adults with DS and dementia differ from older adults with dementia; and residents' impact on staff. [Journal of Gerontological Nursing, 45(5), 17-22.].

Frontal-subcortical behaviors during Alzheimer's disease in individuals with Down syndrome

There is evidence that frontal-subcortical circuits play an important role in the initial presentation of dementia in Down syndrome (DS), including changes in behavior, a decline in working memory and executive dysfunction. We evaluated 92 individuals with DS (≥30 years of age), divided into 3 groups by diagnosis-stable cognition, prodromal dementia, and Alzheimer's disease. Each individual was evaluated with an executive protocol developed for people with intellectual disabilities and was rated for behaviors related to frontal lobe dysfunction (disinhibition, executive dysfunction, and apathy) by an informant using the Frontal Systems Behavior Scale. Informant-reported behaviors related to frontal lobe dysfunction were found to correlate negatively with executive function performance. Disinhibition and executive dysfunction were associated with the clinical stage of dementia. The odds of having Alzheimer's disease increased in parallel with increases in the domain and total Frontal Systems Behavior Scale scores (p ≤ 0.5). Disinhibition, executive dysfunction and apathy should be taken into consideration during the clinical evaluation of adults with DS, and future studies should consider the intersection of neuropathology, brain connectivity, and behavior.

Aging With Down Syndrome: The Dual Diagnosis: Alzheimer's Disease and Down Syndrome

BACKGROUND

People with Down syndrome (DS) enjoy a longer life expectancy now than they ever have before and are therefore at greater risk of developing conditions associated with aging, including dementia.

OBJECTIVES

To explore the phenomenon of dementia in DS.

METHODS

Medline and Google Scholar searches were conducted for relevant articles, chapters, and books published until 2017. Search terms included Alzheimer's disease, cognitive impairment, dementia, DS, and trisomy 21. Publications found through this indexed search were reviewed for further references.

RESULTS AND CONCLUSIONS

Virtually, all subject aged 35 to 40 show key neuropathologic changes characteristic of Alzheimer's disease, but only a part of them show clinical signs of dementia, usually around the age of 50 years. Early signs of dementia in people with DS may be different from those experienced by the general population. Failure to recognize this can delay diagnosis and subsequent interventions.

Down syndrome with posterior cortical atrophy

Down syndrome (DS) is caused by trisomy of chromosome 21. The average age of onset of Alzheimer's disease (AD) ranged from 50 to 55 years in DS, with early symptoms usually characterised by changes in behaviour and executive dysfunction. On the other hand, posterior cortical atrophy (PCA) is a rare neurodegenerative syndrome characterised by progressive impairment of visual functions in the absence of visual deficits and a pattern of atrophy involving posterior cortex. This syndrome is mostly caused by AD pathology. We report the case of patient with DS who developed PCA. While atypical variants of AD are commonly associated with an early age at onset, all focal forms of AD may potentially appear in DS. Specifying the phenotype has an impact on the care of DS patients and could help us to know the evolution. It could also provide a better understanding of the underlying mechanisms of focal forms.

Clinical aspects and biomarkers of Alzheimer's disease in Down syndrome

Alzheimer's disease (AD) may affect in excess of 90% of individuals with Down syndrome (DS) after age 60, due to duplication of the APP gene in trisomy of chromosome 21, with neuropathology that is comparable to Sporadic AD and Familial AD (FAD). Previous literature suggested some unique features in clinical presentation of dementia in DS (DSd), which might be due to diagnostic difficulties, or represent a real difference compared to SAD or FAD. We review current knowledge on clinical diagnosis and presentation of dementia in DS in comparison with FAD due to APP mutations and APP duplication. We suggest that the clinical presentation in DS (prominent memory decline and behavioral symptoms, and early development of myoclonus and seizures) are similar to the clinical features associated with APP mutations that is known to have an increased Aβ42/ Aβ40 ratio, and highlight the relative lack of vascular complications associated with cerebral amyloid angiopathy in DS in comparison with those rare individuals with FAD due to duplication APP. We consider the biomarker evidence associated with DS and DSd with reference to Aβ peptide levels and oxidative stress, and suggest future directions for research to explore the potential mechanisms associated with the clinical presentation of DSd.

Personality and behavioural changes do not precede memory problems as possible signs of dementia in ageing people with Down syndrome

OBJECTIVE

The objective was to find out whether changes in personality and adaptive functioning or memory processes decline first in ageing people with Down syndrome.

METHODS

We measured these variables cross-sectionally in a Dutch sample (22 to 62 years of age) of 68 institutionalised people with Down syndrome.

RESULTS

The scores on all the variables except one of the temperament scales were found to decline gradually with increasing age, but deterioration of episodic memory started earlier.

CONCLUSIONS

We argued that a subset of our sample suffered from dementia. Furthermore, the data suggested that immediate memory impairment is one of the earliest signs of the disease in people with Down syndrome, just as it is in the general population. Copyright © 2016 John Wiley & Sons, Ltd.

The Early Presentation of Dementia in People with Down Syndrome: a Systematic Review of Longitudinal Studies

Adults with Down syndrome (DS) are at a very high risk of developing early onset Alzheimer's disease (AD) due to trisomy of chromosome 21. AD is preceded by a prolonged prodromal "pre-clinical" phase presenting with clinical features that do not fulfil the diagnostic criteria for AD. It is important to clinically characterise this prodromal stage to help early detection of the disease as neuropathology of AD is almost universal by the fifth decade in DS. There is a lack of knowledge of the trajectory of decline associated with the onset of dementia in this population and early signs may be overlooked or misdiagnosed, negatively affecting the quality of life of those affected and the use of early pharmacological or psychosocial interventions. The objective of this systematic review is to evaluate the published literature on longitudinal data in order to identify the cognitive and behavioural changes occurring during the prodromal and early stages of AD in this population. Fifteen peer-reviewed articles met the inclusion criteria, including a total number of 831 participants, with the duration between baseline and follow up varying from 1 year to 47 years. Results suggest that, compared to the general population for which short-term (episodic) memory loss is the most common indicator associated with the onset of AD, in people with DS, executive dysfunction and Behavioural and Psychological Symptoms of Dementia (BPSD) are commonly observed during pre-clinical and early stages and may precede memory loss. The review highlights the importance of using a broad spectrum of assessments in the context of heterogeneity of symptoms. Theoretical and practical implications are discussed, as well as the need for further research.

An evaluation of a Singing for the Brain pilot with people with a learning disability and memory problems or a dementia

This paper presents the findings from a pilot project introducing Singing for the Brain into care centres with people with a learning disability and a form of dementia or memory problem. Through participant observations, patient and staff feedback, there was strong support for the use of Singing for the Brain with this client group, with participants reporting high levels of enjoyment and engagement in the sessions. The potential for these sessions to support communication, memory, social engagement and choice was reported by staff and participants. Whilst anecdotal reports also suggested the sessions had a positive impact on elevating mood over a sustained period of time. The pilot sessions are discussed in reference to the regular sessions run for people with dementia and comparisons drawn across the two approaches. Further evidence is required to understand the potential impact on participant’s well-being from attending these sessions.

Prevalence of dementia and organization of dementia care in Swiss disability care homes

BACKGROUND

With higher life expectancy an increasing number of people with intellectual disability (PWID) are at risk for developing dementia.

OBJECTIVE

Since PWID are an often neglected patient population, the objective of this study was to investigate the prevalence of dementia in residential disability homes in Switzerland and to describe how residential homes organize dementia care.

METHODS

All residential homes for adults with disabilities in Switzerland (N = 437) were invited to participate in a cross-sectional survey. A subset of questions covered the number of residents with diagnosed and suspected dementia and the organization of dementia care. The response rate to the dementia-related questions was 32% (n = 140 care homes with 10403 residents).

RESULTS

In residential homes specialised in PWID, 5.8% of the residents were reported to have a diagnosed or suspected dementia. In 140 deaths of PWID, 26% (n = 37) died with a diagnosed or suspected dementia. Residential homes for PWID mostly rely on internal resources (67.7%), general practitioners (61.3%) or psychiatrists (45.2%) for the care of residents with dementia, while specialized dementia nurses are rarely involved (16.1%).

CONCLUSION

This is the first study in Switzerland to assess the prevalence of dementia in PWID. The study indicates a diagnostic gap. Dementia care is provided in a heterogeneous way across Swiss residential homes for people with disability. Since the number of PWID requiring such care will likely increase in the future, best-practice examples and guidelines are needed.

Assessing Specific Cognitive Deficits Associated with Dementia in Older Adults with Down Syndrome: Use and Validity of the Arizona Cognitive Test Battery (ACTB)

Background

Down syndrome is associated with specific cognitive deficits. Alongside this, older adults with Down syndrome are a high risk group for dementia. The Arizona Cognitive Test Battery (ACTB), a cognitive assessment battery specifically developed for use with individuals with Down syndrome, has been proposed for use as outcome measures for clinical trials in this population. It has not been validated in older adults with Down syndrome. This study aims to assess the use and validity of the ACTB in older adults with Down syndrome.

Methods

Participants with Down syndrome aged 45 and over were assessed using the ACTB, standard tabletop tests and informant ratings.

Results

Assessment outcomes of 49 participants were analysed. Of these, 19 (39%) had a diagnosis of dementia or possible dementia. Most participants were able to attempt most of the tasks, although some tasks had high floor effects (including CANTAB Intra-Extra Dimensional shift stages completed and Modified Dots Task). Of the ACTB tasks, statistically significant differences were observed between the dementia and no dementia groups on CANTAB Simple Reaction Time median latency, NEPSY Visuomotor Precision—Car and Motorbike and CANTAB Paired Associates Learning stages completed. No significant differences were observed for CANTAB Intra-Extra Dimensional Shift, Modified Dots Task, Finger Sequencing, NEPSY Visuomotor precision—Train and Car and CANTAB Paired Associates Learning first trial memory score. Several of the tasks in the ACTB can be used in older adults with Down syndrome and have mild to moderate concurrent validity when compared to tabletop tests and informant ratings, although this varies on a test by test basis.

Conclusions

Overall, scores for a number of tests in the ACTB were similar when comparing dementia and no dementia groups of older adults with Down syndrome, suggesting that it would not be an appropriate outcome measure of cognitive function for clinical trials of dementia treatments without further modification and validation.

Down syndrome in adults: a 27-year follow-up of adaptive skills

In 1988, we assessed the adaptive skills of 45 adults with Down syndrome (DS) (21 women and 24 men, age 20-58) with the Portage scale. Since then, we have followed them and also screened for signs of clinical dementia with the Present Psychiatric State - Learning Disabilities assessment. The mean adaptive age (AA) of the study group decreased with increasing age; the age of 35 being the turning point in the clinical course of DS. The mean AA was 4.4 years between ages 20 and 34, 3.4 years between ages 35 and 49, and 2.4 years between ages 50 and 66. Inter-individual variation was, however, large. Between ages 20 and 25, the AA of the study subjects ranged from 2.3 to 6 years; and after the age of 50, from 0.3 to 4.8 years. By the end of the study, all subjects showed signs of clinical dementia. These appeared most frequently as reduced self-care skills, loss of energy, forgetfulness, and impaired understanding. We found no connection between apolipoprotein E genotype and the clinical course of DS. We recommend follow-up of adaptive skills and screening for dementia signs in adults with DS.

Cognitive Rehabilitation of Dementia in Adults with Down Syndrome: A Review of Non-Pharmacological Interventions

Background

There is a close genetic relationship between Alzheimer's disease (AD) and Down syndrome (DS), AD being the most severe mental disorder affecting ageing individuals with DS. The objective of the present study was to evaluate the efficacy of cognitive rehabilitation interventions in DS patients with AD by means of a critical literature review.

Summary

Because AD is progressive and irreversible, treatment is aimed at delaying and reducing the cognitive and functional decline in order to preserve or improve quality of life. The effects that pharmacological treatments and cognitive interventions have on elderly individuals with AD are well documented. Recent clinical trials have investigated the use of pharmacological treatment in DS patients with AD, generating preliminary results that have been unfavourable.

Key Messages

There is a clear lack of studies addressing the efficacy of cognitive rehabilitation interventions in DS patients with AD, and there is an urgent need for studies providing evidence to inform decisions regarding the appropriate choice of treatment strategies.

Association between adaptive behaviour and age in adults with Down syndrome without dementia: examining the range and severity of adaptive behaviour problems

BACKGROUND

Studies on adaptive behaviour and ageing in adults with Down syndrome (DS) (without dementia) have typically analysed age-related change in terms of the total item scores on questionnaires. This research extends the literature by investigating whether the age-related changes in adaptive abilities could be differentially attributed to changes in the number or severity (intensity) of behavioural questionnaire items endorsed.

METHODS

The Adaptive Behaviour Assessment System-II Adult (ABAS-II Adult) was completed by parents and caregivers of 53 adults with DS aged between 16 and 56 years. Twenty adults with DS and their parents/caregivers were a part of a longitudinal study, which provided two time points of data. In addition 33 adults with DS and their parents/caregivers from a cross-sectional study were included. Random effects regression analyses were used to examine the patterns in item scores associated with ageing.

RESULTS

Increasing age was found to be significantly associated with lower adaptive behaviour abilities for all the adaptive behaviour composite scores, expect for the practical composite. These associations were entirely related to fewer ABAS-II Adult items being selected as present for the older participants, as opposed to the scores being attributable to lower item severity.

CONCLUSIONS

This study provides evidence for a differential pattern of age-related change for various adaptive behaviour skills in terms of range, but not severity. Possible reasons for this pattern will be discussed. Overall, these findings suggest that adults with DS may benefit from additional support in terms of their social and conceptual abilities as they age.

Dementia diagnostic criteria in Down syndrome

OBJECTIVE

Dementia is a common clinical presentation among older adults with Down syndrome. The presentation of dementia in Down syndrome differs compared with typical Alzheimer's disease. The performance of manualised dementia criteria in the International Classification of Diseases (ICD)-10 and Diagnostic and Statistical Manual of Mental Disorders-IV-Text Revision (DSM-IV-TR) is uncertain in this population.We aimed to determine the concurrent validity and reliability of clinicians' diagnoses of dementia against ICD-10 and DSM-IV-TR diagnoses. Validity of clinical diagnoses were also explored by establishing the stability of diagnoses over time.

METHODS

We used clinical data from memory assessments of 85 people with Down syndrome, of whom 64 (75.3%) had a diagnosis of dementia. The cases of dementia were presented to expert raters who rated the case as dementia or no dementia using ICD-10 and DSM-IV-TR criteria and their own clinical judgement.

RESULTS

We found that clinician's judgement corresponded best with clinically diagnosed cases of dementia, identifying 84.4% cases of clinically diagnosed dementia at the time of diagnosis. ICD-10 criteria identified 70.3% cases, and DSM-IV-TR criteria identified 56.3% cases at the time of clinically diagnosed dementia. Over time, the proportion of cases meeting ICD-10 or DSM-IV-TR diagnoses increased, suggesting that experienced clinicians used their clinical knowledge of dementia presentation in Down syndrome to diagnose the disorder at an earlier stage than would have been possible had they relied on the classic description contained in the diagnostic systems.

CONCLUSIONS

Clinical diagnosis of dementia in Down syndrome is valid and reliable and can be used as the standard against which new criteria such as the DSM-5 are measured.

Validation of the Chinese version of the dementia screening questionnaire for individuals with intellectual disabilities (DSQIID-CV)

BACKGROUND

An increasing number of people with intellectual disabilities (ID) are at risk of developing age-related disorders such as dementia because of a dramatic increase in life expectancy in this population in the recent years. There is no validated dementia screening instrument for Chinese people with ID. The Dementia Screening Questionnaire for Individuals with Intellectual Disabilities (DSQIID) was reported to be a valid, user-friendly, easy-to-use observer-rated instrument. It was developed in the UK and has good psychometric properties. Validation of a Chinese version of the DSQIID will facilitate its application among the Chinese population.

METHOD

The DSQIID was translated into the Chinese version (DSQIID-CV). By purposive sampling, service users with ID aged 40 years or over were recruited through two large centres serving adults with ID in Hong Kong. Carers who had taken care of the participants continuously for the past 6 months were invited to complete the DSQIID-CV. All participants were examined by qualified psychiatrists to determine the presence or absence of dementia.

RESULTS

Two hundred people with ID whose age ranged between 40 and 73 years (mean 51 years, SD=7.34 years) were recruited to the study. A clinical diagnosis of dementia was established in 13 participants. An overall total score of 22 as a screening cut-off provided the optimum levels of specificity (0.995) and sensitivity (0.923). The DSQIID-CV showed good internal consistency (alpha=0.945) for all its 53 items, and excellent test-retest reliability (0.978, n=46) and inter-rater reliability (1.000, n=47). Exploratory factor analysis resulted in a four-factor solution explaining 45% of the total variance.

CONCLUSIONS

The DSQIID-CV is shown to have robust psychometric properties. It is the first valid and reliable dementia screening instrument for Chinese adults with ID.

Care pathways for dementia: current perspectives

Uncertainty appears to typify the experience of living with dementia. With an uncertain illness trajectory and unpredictable levels of deterioration and stability in symptoms, people with a diagnosis of dementia may live with uncertainty and anxiety and find it hard to make plans or decisions for their future. People with memory problems and caregivers seeking a diagnosis of dementia may also potentially find themselves navigating a labyrinth-like maze of services, practitioners, assessments, and memory tests, with limited understanding of test scores and little information about what support is available. In this context of uncertainty, the apparent clarity and certainty of a “dementia care pathway” may be attractive. However, the term “dementia care pathway” has multiple and overlapping meanings, which can potentially give rise to further confusion if these are ill-defined or a false consensus is presumed. This review distinguishes four meanings: 1) a mechanism for the management and containment of uncertainty and confusion, useful for the professional as well as the person with dementia; 2) a manual for sequencing care activities; 3) a guide to consumers, indicating eligibility for care activities, or a guide to self-management for dementia dyads, indicating the appropriateness of care activities; and 4) a manual for “walking with” the person. Examples of these approaches are presented from UK dementia services with illustrations of existing care pathways and associated time points, specifically focusing on: 1) early symptom identification and first service encounters, 2) assessment process, 3) diagnostic disclosure, 4) postdiagnostic support, and 5) appropriate interventions. We review the evidence around these themes, as well as discuss service pathways and referral routes used by some services in England and internationally. We conclude that the attraction of the term “care pathway” is seductive, but caution is needed in taking shared understandings for granted.

Age-related changes of adaptive and neuropsychological features in persons with Down Syndrome

Down Syndrome (DS) is characterised by premature aging and an accelerated decline of cognitive functions in the vast majority of cases. As the life expectancy of DS persons is rapidly increasing, this decline is becoming a dramatic health problem. The aim of this study was to thoroughly evaluate a group of 67 non-demented persons with DS of different ages (11 to 66 years), from a neuropsychological, neuropsychiatric and psychomotor point of view in order to evaluate in a cross-sectional study the age-related adaptive and neuropsychological features, and to possibly identify early signs predictive of cognitive decline. The main finding of this study is that both neuropsychological functions and adaptive skills are lower in adult DS persons over 40 years old, compared to younger ones. In particular, language and short memory skills, frontal lobe functions, visuo-spatial abilities and adaptive behaviour appear to be the more affected domains. A growing deficit in verbal comprehension, along with social isolation, loss of interest and greater fatigue in daily tasks, are the main features found in older, non demented DS persons evaluated in our study. It is proposed that these signs can be alarm bells for incipient dementia, and that neuro-cognitive rehabilitation and psycho-pharmacological interventions must start as soon as the fourth decade (or even earlier) in DS persons, i.e. at an age where interventions can have the greatest efficacy.

Bereavement and behavioral changes as risk factors for cognitive decline in adults with Down syndrome

BACKGROUND

Cognitive decline and Alzheimer's disease often affect older adults with Down syndrome (DS) much earlier than those in the general population. There is also growing evidence of the effects of negative life events on the mental health and behavior of individuals with intellectual disability. However, to our knowledge, this is the first study investigating objective cognitive decline following bereavement in aging individuals with DS.

OBJECTIVE

The objective of this study was to determine whether cognitive decline correlates with bereavement following the recent loss of a caregiver or with behavioral changes in a sample of adult individuals with DS who do not meet the criteria for dementia or depression, using the longitudinal assessment of the Cambridge Cognitive Examination (CAMCOG), together with the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE).

METHODS

We evaluated 18 subjects at baseline and over a follow-up period of 14-22 months, attempting to determine whether cognitive decline correlates with bereavement following the recent loss of the main caregiver or with behavioral changes (as assessed with the Neuropsychiatric Inventory).

RESULTS

The mean rate of change in CAMCOG was -1.83 (standard deviation 4.51). Behavioral changes had a significant direct influence on cognitive decline. When bereavement was accompanied by behavioral changes, the probability of cognitive decline was 87% (odds ratio 3.82).

CONCLUSION

The occurrence of behavioral changes attributed to bereavement following the loss of the primary caregiver significantly increases the probability of cognitive decline in individuals with DS. Longitudinal comparison of the CAMCOG and use of the IQCODE appear to enrich the analysis of cognitive decline in individuals with DS. Further studies involving larger samples are needed in order to corroborate and expand upon our findings, which can have implications for the clinical management of older adults with DS.

Dementia in people with intellectual disability: insights and challenges in epidemiological research with an at-risk population

The population with intellectual disability (ID) is ageing, but age-related health concerns such as dementia have received little research attention thus far. We review evidence regarding the prevalence and incidence of dementia in people with ID, and discuss some possible explanations for an increased risk, such as shared genetic risk factors, co-morbid physical and mental disorders, lifestyle factors, trauma, and lowered brain reserve. We discuss practical and theoretical challenges facing researchers in this field, before highlighting the implications of findings to date for future research and clinical care. Research on dementia in this at-risk population has the potential to help us understand dementia in general and to improve services for this group of vulnerable individuals.

Psychosocial factors that shape patient and carer experiences of dementia diagnosis and treatment: a systematic review of qualitative studies

BACKGROUND

Early diagnosis and intervention for people with dementia is increasingly considered a priority, but practitioners are concerned with the effects of earlier diagnosis and interventions on patients and caregivers. This systematic review evaluates the qualitative evidence about how people accommodate and adapt to the diagnosis of dementia and its immediate consequences, to guide practice.

METHODS AND FINDINGS

We systematically reviewed qualitative studies exploring experiences of community-dwelling individuals with dementia, and their carers, around diagnosis and the transition to becoming a person with dementia. We searched PubMed, PsychINFO, Embase, CINAHL, and the British Nursing Index (all searched in May 2010 with no date restrictions; PubMed search updated in February 2012), checked reference lists, and undertook citation searches in PubMed and Google Scholar (ongoing to September 2011). We used thematic synthesis to identify key themes, commonalities, barriers to earlier diagnosis, and support identified as helpful. We identified 126 papers reporting 102 studies including a total of 3,095 participants. Three overarching themes emerged from our analysis: (1) pathways through diagnosis, including its impact on identity, roles, and relationships; (2) resolving conflicts to accommodate a diagnosis, including the acceptability of support, focusing on the present or the future, and the use or avoidance of knowledge; and (3) strategies and support to minimise the impact of dementia. Consistent barriers to diagnosis include stigma, normalisation of symptoms, and lack of knowledge. Studies report a lack of specialist support particularly post-diagnosis.

CONCLUSIONS

There is an extensive body of qualitative literature on the experiences of community-dwelling individuals with dementia on receiving and adapting to a diagnosis of dementia. We present a thematic analysis that could be useful to professionals working with people with dementia. We suggest that research emphasis should shift towards the development and evaluation of interventions, particularly those providing support after diagnosis.

Prevalence, associated factors and treatment of sleep problems in adults with intellectual disability: a systematic review

In people with intellectual disability (ID), impaired sleep is common. Life expectancy has increased in this group, and it is known that in general population sleep deteriorates with aging. Therefore the aims of this systematic review were to examine how sleep problems are defined in research among adults and older people with ID, and to collect information on the prevalence, associated factors and treatment of sleep problems in this population. PubMed, EMBase, PsycINFO and Web of Science were searched for studies published between January 1990 and August 2011. All empirical studies covering sleep problems in adults with ID were included, and assessed on quality (level of evidence), using a slightly modified version of the SIGN-50 methodology checklist for cohort studies. Of 50 studies that were included for systematic review, one was of high quality, 14 were well conducted, 14 were well conducted but with a high risk of bias, and 21 were non-analytical. The reported estimated prevalence rates of sleep problems in adults with ID ranged from 8.5% to 34.1%. A prevalence of 9.2% was reported for significant sleep problems. Sleep problems were associated with the following factors: challenging behavior; respiratory disease; visual impairment; psychiatric conditions; and using psychotropic, antiepileptic and/or antidepressant medication. Little information was found on older people specifically. Two studies reported treatment effects on sleep problems in larger populations; their findings suggest that non-pharmaceutical interventions are beneficial. Research on the prevalence, associated factors and treatment of sleep problems in adults and older people with ID has mainly focused on subjectively derived data. The definitions used to describe a sleep problem are not uniform, and associations are mainly described as correlations. In order to give recommendations for clinical practice further research is needed, involving objective measurements and multivariate analysis.

Acute neuropsychiatric disorders in adolescents and young adults with Down syndrome: Japanese case reports

BACKGROUND

The aim of this study was to evaluate acute neuropsychiatric disorders in adolescents and young adults with Down syndrome. We report 13 Japanese adolescents or young adults with Down syndrome who developed acute neuropsychiatric disorders including withdrawal, depression, obsessive-compulsive behaviors, and occasional delusions or hallucinations.

METHODS

THE FOLLOWING INFORMATION WAS COLLECTED FROM EACH PATIENT: age at onset of acute neuropsychiatric disorder, complications, signs and symptoms, personality traits before the onset of the acute neuropsychiatric disorder, prescribed medications with their respective doses and the response to treatment, and senile changes observed on magnetic resonance imaging or computed tomography.

RESULTS

The mean age at onset of these disorders was 21.2 years. Brain imaging showed almost senile changes; patients responded well to low-dose psychotropic therapy. Patients had an onset at a young age and presented with treatable conditions, although the average age of the onset of Alzheimer's disease is generally over 40 years of age in patients with Down syndrome.

CONCLUSION

These findings suggest that the pathology of acute neuropsychiatric disorder in patients with Down syndrome may be related to presenile changes; however, these disorders present features and a clinical course that is different from those presented in typical Alzheimer's disease with Down syndrome.

Physical activity benefits and needs in adults with intellectual disabilities: systematic review of the literature

Regular physical activity is vital for adult individuals with intellectual disabilities. The purpose of this review was to assess critically the evidence on effectiveness of physical activity interventions for adults with intellectual disability. An electronic database search was conducted. Research was then assessed for methodological rigor, and strength of the evidence was determined. Eleven clinical studies met inclusion criteria. Interventions studied included a variety of physical activity modes. Critical review revealed moderate to strong evidence that physical activity positively affected balance, muscle strength, and quality of life in individuals with intellectual disability. The authors also found that the research in this area needs to be translated into practice, specifically the development of physical activity programs that are adaptable to the needs of individuals with intellectual disability.

Cognitive deficits and associated neurological complications in individuals with Down's syndrome

Improvements in medical interventions for people with Down's syndrome have led to a substantial increase in their longevity. Diagnosis and treatment of neurological complications are important in maintaining optimal cognitive functioning. The cognitive phenotype in Down's syndrome is characterised by impairments in morphosyntax, verbal short-term memory, and explicit long-term memory. However, visuospatial short-term memory, associative learning, and implicit long-term memory functions are preserved. Seizures are associated with cognitive decline and seem to cause additional decline in cognitive functioning, particularly in people with Down's syndrome and comorbid disorders such as autism. Vision and hearing disorders as well as hypothyroidism can negatively impact cognitive functioning in people with Down's syndrome. Dementia that resembles Alzheimer's disease is common in adults with Down's syndrome. Early-onset dementia in adults with Down's syndrome does not seem to be associated with atherosclerotic complications.

Compliance Training in an Adult With Dementia of the Alzheimer’s Type and Down Syndrome

The authors describe the treatment of noncompliance and public stripping in a 53-year-old man with Down syndrome and dementia. On the basis of a review of the relevant literature and a comprehensive functional behavioral analysis, an intervention procedure utilizing contingent reinforcement of compliance is conducted. Compliance with requests to allow assistance getting dressed is reinforced with a combination of verbal praise, physical contact, and edible reinforcers. Noncompliance decreases by 85.22% at follow-up. Factors responsible for intervention success and implications for clinicians are discussed.

Communication breaks-Down: from neurodevelopment defects to cognitive disabilities in Down syndrome

Down syndrome (DS) is the leading cause of genetically-defined intellectual disability and congenital birth defects. Despite being one of the first genetic diseases identified, only recently, thanks to the phenotypic analysis of DS mouse genetic models, we have begun to understand how trisomy may impact cognitive function. Cognitive disabilities in DS appear to result mainly from two pathological processes: neurogenesis impairment and Alzheimer-like degeneration. In DS brain, suboptimal network architecture and altered synaptic communication arising from neurodevelopmental impairment are key determinants of cognitive defects. Hypocellularity and hypoplasia start at early developmental stages and likely depend upon impaired proliferation of neuronal precursors, resulting in reduction of numbers of neurons and synaptic contacts. The impairment of neuronal precursor proliferation extends to adult neurogenesis and may affect learning and memory. Neurodegenerative mechanisms also contribute to DS cognitive impairment. Early onset Alzheimer disease occurs with extremely high incidence in DS patients and is causally-related to overexpression of beta-amyloid precursor protein (betaAPP), which is one of the triplicated genes in DS. In this review, we will survey the available findings on neurodevelopmental and neurodegenerative changes occurring in DS throughout life. Moreover, we will discuss the potential mechanisms by which defects in neurogenesis and neurodegenerative processes lead to altered formation of neural circuits and impair cognitive function, in connection with findings on pharmacological treatments of potential benefit for DS.

Compliance Training in an Adult With Dementia of the Alzheimer’s Type and Down Syndrome

The authors describe the treatment of noncompliance and public stripping in a 53-year-old man with Down syndrome and dementia. Based on a review of the relevant literature and a comprehensive functional behavioral analysis, an intervention procedure utilizing contingent reinforcement of compliance was conducted. Compliance with requests to allow assistance getting dressed was reinforced with a combination of verbal praise, physical contact, and edible reinforcers. Noncompliance had decreased by 85.22% at follow-up. Factors responsible for intervention success and implications for clinicians are discussed.

Diagnosing Alzheimer's dementia in Down syndrome: problems and possible solutions

It is widely accepted that people with Down syndrome are more likely than the general population to develop Alzheimer's dementia as they age. However, the diagnosis can be problematic in this population for a number of reasons. These include: the large intra-individual variability in cognitive functioning, the different diagnostic and methodological procedures used in the field and the difficulty in obtaining baseline levels of cognitive functioning in this population with which to assess cognitive and behavioral change. Recent researchers have begun to suggest ways around these difficulties. This review explores these recent developments and provides recommendations which may aid clinicians in their attempts to diagnose Alzheimer's dementia in the early stages in the Down syndrome population.

Associations between repetitive questioning, resistance to change, temper outbursts and anxiety in Prader-Willi and Fragile-X syndromes

BACKGROUND

The behavioural phenotypes of Prader-Willi (PWS) and Fragile-X (FraX) syndromes both comprise repetitive behaviours with differences between the profiles. In this study we investigated the context and antecedents to the repetitive behaviours and the association with other behavioural phenotypic characteristics in order to generate testable hypotheses regarding the cause of the behaviours.

METHOD

The parents or carers of 46 children with PWS (mean age 14.1 years; 20 girls), and 33 boys with FraX (mean age 13.11 years) were interviewed about their children's repetitive behaviour in a semi-structured format.

RESULTS

Children showed negative emotional behaviour (PWS: 87.0%; FraX: 79.4%) and repetitive questions (PWS: 78.3%; FraX: 73.5%) following changes in routine or expectations. Significantly more temper outbursts were reported to follow changes in children with PWS (89.1%) compared with boys with FraX (41.2%) (chi(2) = 20.93; P < 0.001). Anxiety that was frequently associated with repetitive and self-injurious behaviours in boys with FraX, followed changes in significantly more boys with FraX (76.5%) compared with children with PWS (6.5%) (chi(2) = 43.19, P < 0.001).

DISCUSSION

On the basis of these reports and existing literature, we hypothesise that decreases in predictability are aversive to children with PWS and FraX. We also hypothesise that these children have a propensity to show a syndrome-related pattern of behaviour (temper outbursts in PWS and displays of anxiety in FraX) when an event in the environment has this aversive property. We hypothesise that questions may be reinforcing to children in their own right by increasing the predictability of the environment. We outline how a specific cognitive deficit in the endophenotypes associated with both PWS and FraX could be investigated as a potential explanation for the hypothesised aversive properties of decreased predictability.