Pain expression and stimulus localisation in individuals with Down's syndrome

Individuals with Down's syndrome do not always exhibit signs of distress in reaction to noxious stimuli comparable with the general population. This pilot study was designed to measure the ability of individuals with Down's syndrome to detect and express sensation in comparison with healthy volunteers. In the first test, the latency of pain detection to self-administered cold stimuli on the wrist and on the temple was measured. The second test was designed to assess ability to localise cold stimuli on sites on the hand, on the face, and in the mouth. 75 control individuals and 26 individuals with Down's syndrome were tested. Individuals with Down's syndrome had significantly longer median latencies than controls: Down's syndrome median (quartiles) 28·7 s (1st 18·0, 3rd 47·6); controls 20·6 s (1st 12·4, 3rd 31·0); p=0·0005. In addition, more individuals with Down's syndrome had difficulties in localising the cold stimulus. The differences in distribution for precise localisation were significant for the hand (Down's syndrome [p