Experimental pain processing in individuals with cognitive impairment

Abstract

Cognitive impairment (CI) can develop during the course of ageing and is a feature of many neurological and neurodegenerative diseases. Many individuals with CI have substantial, sustained, and complex health care needs, which frequently include pain. However, individuals with CI can have difficulty communicating the features of their pain to others, which in turn presents a significant challenge for effective diagnosis and treatment of their pain. Herein, we review the literature on responsivity of individuals with CI to experimental pain stimuli. We discuss pain responding across a large number of neurological and neurodegenerative disorders in which CI is typically present. Overall, the existing data suggest that pain processing is altered in most individuals with CI compared with cognitively intact matched controls. The precise nature of these alterations varies with the type of CI (or associated clinical condition) and may also depend on the type of pain stimulation used and the type of pain responses assessed. Nevertheless, it is clear that regardless of the etiology of CI, patients do feel noxious stimuli, with more evidence for hypersensitivity than hyposensitivity to these stimuli compared with cognitively unimpaired individuals. Our current understanding of the neurobiological mechanisms underpinning these alterations is limited but may be enhanced through the use of animal models of CI, which also exhibit alterations in nociceptive responding. Further research using additional behavioural indices of pain is warranted. Increased understanding of altered experimental pain processing in CI will facilitate the development of improved diagnostic and therapeutic approaches for pain in individuals with CI.

Postoperative Treatment of Pain after Hip Fracture in Elderly Patients with Dementia

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Tail-flick test response in 3×Tg-AD mice at early and advanced stages of disease

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“…In the case of Alzheimer's disease (AD), the most common dementia in the elderly, clinical evidences warn that pain is grossly undertreated in these patients. The scientific consensus estimates that several factors contribute to this management: (1) The increased pain co-morbidity in aging; (2) The reduced selfreport due to the poor verbal communicative abilities that worsen with the progress of the disease until being completely absent; (3) The complex progressive nature of the neurodegenerative disorder [2,3]. It is known that the sensory-discriminative dimension of pain, which depends on the lateral nociceptive pathway, is prehttp://dx.doi.org/10.1016/j.neulet.2015.06.007 0304-3940/© 2015 Elsevier Ireland Ltd. All rights reserved.…”

Is pain sensitivity altered in people with Alzheimer's disease? A systematic review and meta-analysis of experimental pain research

“…Three independent reviewers (BS, TT, MS) performed electronic database searches using EMBASE (1974 to present), MEDLINE (1946 to present) and PsycINFO (1967 [18] studies were also considered for potentially relevant articles.…”

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