Pain in adults with Down syndrome.

This will be the first clinical study in which the pain experience is examined in adults with Down syndrome, compared with a control group and divided into the presence and absence of indicated dementia. Also, this is the first study in which the relationship between pain experience and cognitive functioning is exmined in persons with Down syndrome.



Country: The Netherlands.

Necessity:

A study on chronic pain in persons with Down syndrome is clinical relevant for 5 reasons:

1. The neuropathology of Down syndrome without and with dementia affects pain-related gray and white matter, which may alter pain experience;

2. The prevalence of age-related painful conditions is increasing in Down syndrome due to increase in estimated life expectancy;

3. Persons with Down syndrome may suffer from more painful conditions than controls do;

4. The sensory-discriminative aspect of pain appears to be abnormal in Down syndrome;

5. The relationship between cognitive functioning and pain may be altered by the presence of apolipoprotein E4 (ApoE4) in Down syndrome without and with dementia.



Aim:

To study the relationship between pain experience and cognitive functioning in adults with Down syndrome, with and without dementia. To compare pain experience between adults with Down syndrome and subjects of a control group.



Hypotheses:

1. Adults with Down syndrome will report an increased pain experience compared to the control group;

2. In Down syndrome adults with dementia, pain experience will be further increased compared to Down syndrome adults without dementia;

3. Chronic pain experience will relate negatively to cognitive functioning in Down syndrome adults (without and with dementia);

4. The ApoE e4 allele is negatively associated with cognitive functioning in Down syndrome.

Measurements will be performed in total during 45 minutes (one visit) with the control subjects and 180 minutes (several visits to prevent exhaustion) with the Down syndrome subjects.

Control group and clinical group:

The pain perception in the subject will be studied using self-reported visual analogue scales, an observation list for pain behavior, and a test for tactile perception. The self-report scales and observation lists are administred at rest and after physical examination.

During the physical examination, the client is requested by the researcher to imitate movements with joints (neck, shoulders, elbows, wrists, fingers, back, legs and jaw). In this way, we examine whether joint pain occurs.

In the test for vital sensibility, the subject is asked to judge with eyes closed whether his/her forearms are touched with a sharp or blunt edge of a Neuropen (cautiously), a hot or cold metal roller (carefully) is placed and when (at which thickness) a nylon hair is used.



Only clinical group (Down syndrome):

The ApoE genotype will be determined by striking a cotton swab along the buccal mucosa (and subsequent analysis in the laboratory).
Cognitive functioning will be investigated using a neuropsychological test battery (NETOL).
A caretaker of the subject will observe pain behavior in three situations (at rest / during an active moment of care / chewing), but the client will not be instructed during these observations.
The level of intellectual disability will be assessed by using a short test for logical reasoning (performed by subjects), a questionnaire for adaptive functioning (SRZ, completed by caretakers), and results of an intelligencetest from the personal file. Indications for dementia will be assessed by asking the caregiver to complete a dementia questionnaire (DVZ or DSDS) and by a short heteroanamnesis about indications for dementia (and pain). The scores of the SRZ and the DVZ/DSDS will be compared with data from previous completements of the same questionnaire in the care center.