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

Memantine for dementia in people with Down syndrome

BACKGROUND

Alzheimer's dementia (AD) is the most common form of dementia in people with Down Syndrome (DS). There is an understanding that an increase in L-glutamate contributes to the pathogenesis of cerebral ischemias and AD. Memantine acts as an antagonist of N-methyl-D-aspartate (NMDA) type receptors, which is thought to reduce abnormal activation of glutamate neurotransmission. It binds with a low affinity to the NMDA receptor and so should not prevent learning and the formation of memory. Memantine can improve cognitive function and slow the decline of AD in the general population over time, and is the subject of this review. It is important to note that people with DS tend to present with AD at a much younger age than the normal population as well as having subtle differences in physiology (e.g. metabolism and heart rate) and may therefore have different requirements from the general population.

OBJECTIVES

To determine the effectiveness and safety of memantine for people with DS who develop AD.

SEARCH STRATEGY

CENTRAL, MEDLINE, EMBASE, CINAHL, PsycINFO, BIOSIS, SCI, SSCI and the NRR were searched up to October 2008. We contacted the manufacturers of memantine, as well as experts in the field, to ask about reports of unpublished or ongoing trials.

SELECTION CRITERIA

Randomised controlled trials of participants with DS and AD in which treatment with memantine was administered compared with a placebo group.

DATA COLLECTION AND ANALYSIS

No study was identified which met the inclusion criteria for this review.

MAIN RESULTS

No study was identified which met inclusion criteria for this review, however there is an on-going randomised controlled study being conducted in the UK and data are expected in 2009.

AUTHORS' CONCLUSIONS

As there are no included trials, recommendations cannot be made about memantine for AD in DS. Well-designed, adequately powered studies are required.

Rivastigmine for dementia in people with Down syndrome

BACKGROUND

Alzheimer's dementia (AD) is the most common form of dementia in people with Down Syndrome (DS). Acetylcholine is a chemical found in the brain that has an important role in memory, attention, reason and language. Rivastigmine is a "pseudo-irreversible" inhibitor of acetylcholinesterase, which is thought to maintain levels of acetylcholine. Rivastigmine can improve cognitive function and slow the decline of AD in the general population over time. It is important to note that people with DS tend to present with AD at a much younger age than the normal population as well as having subtle differences in physiology (e.g. metabolism and heart rate) and may therefore have different requirements from the general population.

OBJECTIVES

To determine the effectiveness and safety of rivastigmine for people with DS who develop AD.

SEARCH STRATEGY

CENTRAL, MEDLINE, EMBASE, CINAHL, PsycINFO, BIOSIS, SCI, SSCI and the NRR were searched up to October 2008. We contacted the manufacturers of rivastigmine as well as experts in the field, to ask about reports of unpublished or ongoing trials.

SELECTION CRITERIA

Randomised controlled trials of participants with DS and AD in which treatment with rivastigmine was administered compared with a placebo group.

DATA COLLECTION AND ANALYSIS

No study was identified which met inclusion criteria for this review.

MAIN RESULTS

No study was identified which met inclusion criteria for this review.

AUTHORS' CONCLUSIONS

As there are no included trials, recommendations cannot be made about rivastigmine for AD in DS. Well-designed, adequately powered studies are required.

Galantamine for dementia in people with Down syndrome

BACKGROUND

Alzheimer's dementia (AD) is the most common form of dementia in people with Down Syndrome (DS). Acetylcholine is a chemical found in the brain that has an important role in memory, attention, reason and language. Galantamine both inhibits the activity of acetylcholinesterase and increases the level of acetylcholine. Galantamine can improve cognitive function and slow the decline of AD in the general population over time. It is important to note that people with DS tend to present with AD at a much younger age than the normal population as well as having subtle differences in physiology (e.g. metabolism and heart rate) and may therefore have different requirements from the general population.

OBJECTIVES

To determine the effectiveness and safety of galantamine for people with DS who develop AD.

SEARCH STRATEGY

CENTRAL, MEDLINE, EMBASE, CINAHL, PsycINFO, BIOSIS, SCI, SSCI and the NRR were searched up to October 2008. We contacted the manufacturers of galantamine as well as experts in the field, to ask about reports of unpublished or ongoing trials.

SELECTION CRITERIA

Randomised controlled trials of participants with DS and AD in which treatment with galantamine was administered compared with a placebo group.

DATA COLLECTION AND ANALYSIS

No study was identified which met inclusion criteria for this review.

MAIN RESULTS

No study was identified which met inclusion criteria for this review.

AUTHORS' CONCLUSIONS

As there are no included trials, recommendations cannot be made about galantamine for AD in DS. Well-designed, adequately powered studies are required.

Donepezil for dementia in people with Down syndrome

BACKGROUND

Alzheimer's dementia (AD) is the most common form of dementia in people with Down Syndrome [DS]. Acetylcholine is a chemical found in the brain that has an important role in memory, attention, reason and language. Donepezil a reversible inhibitor of acetylcholinesterase, which is thought to maintain levels of acetylcholine, and is reported to have some benefits for people with AD in the general population. It is important to note that people with DS tend to present with AD at a much younger age than the normal population as well as having subtle differences in physiology (e.g. metabolism and heart rate) and may therefore have different requirements from the general population.

OBJECTIVES

To determine the effectiveness and safety of donepezil for people with DS who develop AD.

SEARCH STRATEGY

CENTRAL, MEDLINE, EMBASE, CINAHL, PsycINFO, BIOSIS, SCI, SSCI and the NRR were searched up to October 2008. We contacted the manufacturers of donepezil as well as experts in the field, to ask about reports of unpublished or ongoing trials.

SELECTION CRITERIA

Randomised controlled trials of participants with DS and AD in which treatment with donepezil was administered compared with a placebo group.

DATA COLLECTION AND ANALYSIS

Data were extracted from the published reports of the one relevant study identified.

MAIN RESULTS

The one study included in this review is a small (n=30) randomised controlled trial lasting 24 weeks. It was followed-up by an open label study with a crossover design.No significant differences were found on any four validated outcomes including global functioning and three measures of cognitive abilities and behavioural problems. 6 out of 16 carers (37%) of participants on donepezil and 2 out of 15 (13%) on placebo reported improvement. No data were available for day to day skills, institutionalisation, reduction in carers' stress or economic outcomes. Half the intervention group and 20% of the placebo group reported adverse events; two participants left because of adverse events.

AUTHORS' CONCLUSIONS

To date there is only one small randomised controlled study on the effect of donepezil. This shows, at best, a modest, non statistically significant trend in favour of people with Down syndrome and Alzheimer's dementia who are able to tolerate donepezil (this drug is currently only dispensed in relatively large doses and is contraindicated for those with cardiac and respiratory problems).This study does not provide good evidence on which to base practice. Findings in an open-label follow up to this study suggest possible benefit in some individuals. Further, larger randomised controlled studies with longer-term follow up are required.

Health indicators and intellectual disability

PURPOSE OF REVIEW

Health disparities are evident between people with intellectual disabilities and the general population. Despite the potential of indicators for measuring disparities and planning interventions to address inequalities- currently a priority health policy target- few studies have mapped the physical or mental health of people with intellectual disabilities onto the growing territory of health disparities, health information systems and health indicators. This review summarizes recent publications about the role of indicators in gathering optimal health information on behalf of this segment of the population.

RECENT FINDINGS

Studies related to measures of the health of people with intellectual disabilities are presented in three sections: information captured in general population surveys; measures of health status of people with intellectual disabilities at country and regional levels; and their use of healthcare systems. The work of the Pomona group of European partners who have devised and applied a set of health indicators specifically for people with intellectual disabilities is presented.

SUMMARY

Health indicators yield data to identify health conditions, plan interventions and compare populations or segments of the population. It is suggested that better definitions, measures and surveillance will yield comparable information to inform public health policy and clinical practice.

Dementia screening questionnaire for individuals with intellectual disabilities

BACKGROUND

Many adults with Down's syndrome develop Alzheimer's dementia relatively early in their lives, but accurate clinical diagnosis remains difficult.

AIMS

To develop a user-friendly observer-rated dementia screening questionnaire with strong psychometric properties for adults with intellectual disabilities.

METHOD

We used qualitative methods to gather information from carers of people with Down's syndrome about the symptoms of dementia. This provided the items for the Dementia Screening Questionnaire for Individuals with Intellectual Disabilities (DSQIID), which we then tested for its psychometric properties.

RESULTS

The DSQIID was administered to carers of 193 adults with Down's syndrome, 117 of whom were examined by clinicians who confirmed a diagnosis of dementia for 49 according to modified ICD-10 criteria. We established that a total score of 20 provides maximum sensitivity (0.92) and optimum specificity (0.97) for screening. The DSQIID has sound internal consistency (alpha=0.91) for all its 53 items, and good test-retest and interrater reliability. We established a good construct validity by dividing the items into four factors.

CONCLUSIONS

The DSQIID is a valid, reliable and user-friendly observer-rated questionnaire for screening for dementia among adults with Down's syndrome.