Down Syndrome Abstract
of the Month: Mar 2001
Pain expression and stimulus localisation in individuals with Down's syndrome
Hennequin M, Morin C, Feine JS
Lancet 2000 Dec 2;356(9245):1882-7
Laboratoire de Physiologie Orofaciale, Faculte de Chirurgie Dentaire, Universite d'Auvergne, Clermont-Ferrand, France
Abstract:
BACKGROUND: 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.METHODS: 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.
FINDINGS: 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<0.0005] 54%; control 99%), the mouth (31%; 84%), and the face (54%; 97%).
INTERPRETATION: Individuals with Down's syndrome are not insensitive to pain. However, they do express pain or discomfort more slowly and less precisely than the general population. This implies that medical teams managing these patients should use pain-control procedures, even in the absence of obvious pain manifestations.
My comments:
This was a test with a small group of people with DS, but it does follow what many parents have told me about their children having a higher pain tolerance.
A higher sensory threshold and a decreased ability to localize stimuli could be due to a delay in pain transmission from the skin to the brain; a delay in the pain integration process in the brain; a delayed motor response to the pain; or a mixture of two or all of these factors. Whatever the cause, it's important for health care professionals and parents to realize that a delayed response to pain does not mean less of a need for analgesics.