The International Association for the Study of Pain (IASP) defines pain as "special sensory and emotional experience, associated with actual or potential tissue damage or described as such in any case”. The IASP wanted to highlight the fact that the pain is not equivalent to a simple nociception and has emphasized the subjective nature: "... each individual learns the meaning of pain through experiences related to injury during the first years of life. ... The somatic component is accompanied by an emotional charge". Such definitions and these considerations seem to be difficult to apply to people with Intellectual Developmental Disorder (IDD), who often have difficulty with verbalization and / or general communication. For a long time it has been argued that people with IDD do not express pain in the same way as people with average cognitive abilities do, and who were less sensitive or even insensitive to painful stimuli. Over the years this point of view has gained support and continues to get disconfirmation by the scientific community. However, there are still a few studies that have examined the problem of pain in IDD in terms of prevalence, assessment, etiology and management-care. The lack of epidemiological data appears to be partly due to methodological difficulties. The manifestations of pain are often atypical, for example through changes in behavior or problem behavior such as aggression. The sources of information are almost always represented by proxy, family or providers of professional assistance. The most recent literature emphasizes instead the importance of integrating self- evaluations. In case of serious impairment of the ability to communicate a detection method with good reliability and validity seems to be a structured and systematized observation of behavior by different proxies. The available studies indicate a high vulnerability to the development of physical health problems and then to repeated painful experiences. Chronic pain seems to afflict about 15% of people with IDD. By studying some of the most common genetic syndromes including IDD, Drs De Knegt and Scherder, researchers from the Department of Clinical Neuropsychology at the University of Amsterdam, argue that IDD and dementia in some structural changes in white and gray matter areas of the brain are related to possible changes in pain perception. The reduction of white matter characterizing the fragile X syndrome, for example, seems to be correlated with a lower tolerance to pain, while the alterations particular to the Prader-Willi syndrome are associated with a high threshold to pain and to altered temperature perception. In 2011, Dr. Walsh and his colleagues from the School of Psychology at the National University of Ireland identified some risk factors specific to the IDD for the development of clinical conditions including pain. These include low levels of physical activity, greater tendency to accidental injury, reduced involvement in decision-making aspects related to health, limited access to services for the management of pain and premature aging (arthritis, arthrosis). There is also an increased prevalence of musculoskeletal disorders in Down syndrome, fragile X syndrome and Williams syndrome. Although the focus is increasing, the assessment of pain in people with IDD is not yet part of routine clinical practice. Further efforts are desirable for the production and dissemination of specialized knowledge. Neuroimaging and electrophysiological measures seem to be able to make significant contributions.
REFERENCES
- McGuire BE, Kennedy S. Pain in people with an intellectual disability. Curr Opin Psychiatry. 2013 May;26(3):270-5.
- Pain terms: a list with definitions and notes on usage, Pain 1979; 6: 249-52.
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- De Knegt N, Scherder E. Pain in adults with intellectual disabilities. Pain 2010; 152:971–974.
- McGuire BE, Daly P, Smyth F. Chronic pain in people with an intellectual disability: under-recognised and under-treated? J Intellect Disabil Res 2010; 54:240–245.
- Walsh M, Morrison T, McGuire BE. Chronic pain in adults with an intellectual disability: prevalence, impact and health service use based on caregiver report. Pain 2011; 152:1951–1957.