Pain assessment in elderly adults with dementia

Summary

Chronic pain is highly prevalent in the ageing population. Individuals with neurological disorders such as dementia are susceptible patient groups in which pain is frequently under-recognised, underestimated, and undertreated. Results from neurophysiological and neuroimaging studies showing that elderly adults are particularly susceptible to the negative effects of pain are of additional concern. The inability to successfully communicate pain in severe dementia is a major barrier to effective treatment. The systematic study of facial expressions through a computerised system has identified core features that are highly specific to the experience of pain, with potential future effects on assessment practices in people with dementia. Various observational–behavioural pain assessment instruments have been reported to be both reliable and valid in individuals with dementia. These techniques need to be interpreted in the context of observer bias, contextual variables, and the overall state of the individual's health and wellbeing.

Introduction

Despite its limitations, self-report of pain is often deemed to be the gold standard in pain assessment. However, self-report might become compromised in neurological disorders, such as dementia, in which individuals often have little ability to communicate.¹ With increasing severity of cognitive impairment, the ability to self-report pain diminishes, contributing to difficulties in recognising and controlling pain.2, 3, 4 That said, pain in dementia is not consistently reported to be undertreated. For example, the authors of a Swedish population-based study,⁵ who reported similar pain treatment in samples of individuals with or without dementia, acknowledged that their findings contradicted previous research and attributed these results to the possibility of increased awareness of the need for adequate pain management in dementia. In addition to the incapacity to communicate pain, inadequate pain assessment, biases including racial and ethnic disparities, and altered pain processing owing to the underlying neuropathology might limit access to appropriate treatment.6, 7 In these susceptible populations, a systematic, evidence-based approach is needed to best address this fundamental aspect of patient care.

The projected ageing of our population, combined with a parallel increase in the worldwide prevalence of dementia and stroke, make effective pain assessment in dementia of paramount importance. Chronic pain in people aged 85 years or older is common and has a prevalence of 40–79%.⁸ The estimated incidence of chronic pain in adults is 4·69 per 100 person-years, and is similar between individuals aged younger than 50 years and those older than 80 years.⁹ Therefore, health-care providers should actively screen for pain in elderly adults, and recognise that treatment disparities exist in this patient population. Improved recognition and treatment of pain has implications for improvement of quality of life, and reduction of fall risk, agitation, depression, and anxiety in elderly people.10, 11

The assessment of pain in non-verbal adults with neurological disease is clinically challenging and requires an understanding of the neurobiology of both pain experience and expression, along with knowledge of the available range of clinical assessment instruments. In this Review we summarise the published work on the pain experience in people with dementia and describe the state of the art in pain assessment in this population, with primary emphasis on original studies published in the past 5 years. This Review provides the necessary background on the relevant topics and a clinical approach to this challenging and important scenario. We aim to highlight the usefulness of non-verbal cues (eg, facial expression) as a means of accessing the subjective pain experience of an individual, an approach that in many ways has advantages compared with self-report. We chose to focus on dementia in view of the abundance of published work pertaining to this population; however, the general principles might prove applicable to patients with other neurological disorders who are also at risk of inadequate pain management, such as those with post-stroke aphasia.¹²