Neuropsychological assessment of older adults with Down's syndrome: An epidemiological study using the Cambridge Cognitive Examination (CAMCOG)

Objectives. The Cambridge Cognitive Examination (CAMCOG) was designed for the general elderly population to assess cognitive impairments characteristic of dementia. CAMCOG yields a total score as well as separate scores on seven subscales. In this study the suitability of the CAMCOG for older adults with Down's Syndrome (DS) at the age of risk for dementia was assessed. Design. A near total population sample of people with DS aged 30 years and over (range 30-65 years) living in a single Health Authority catchment area was identified and assessed using the CAMCOG. The use of an unselected sample ensured that the value of this assessment instrument could be established across all levels of disability in those with DS. A lower age limit of 30 years was used, as from this age significant Alzheimer-like neuropathology is present and prevalence rates of Alzheimer's disease begin to increase. Methods. The CAMCOG was administered in a familiar setting together with other neuropsychological tests. Gender and age differences and the characteristics of those at the floor of the test were investigated. Results. Of the 77 people with DS aged 30 years or older, 74 agreed to rake part. Scores on the CAMCOG were well distributed, with only eight participants (11%) scoring 0 on the test. This contrasted favourably with performance on the Mini-Mental State Examination where there was a narrower range of scores and a higher percentage scoring 0. There was a significant difference in cognitive performance between younger (30-44 years) and older (45+ years) participants on the total CAMCOG score and on six out of the seven CAMCOG subscales. Conclusions. The CAMCOG, with minor modifications, is a useful test to assess those areas of cognitive function known to decline with dementia. Apart from those with pre-existing severe learning disability, severe sensory impairments and/or already advanced dementia, people with DS were able to score above the floor of the test.