Pain differences in cognitive impairment appear only during active motor tasks

Cognitive impairment in older adults has been associated with altered pain processing and potentially increased pain vulnerability, although findings are inconsistent. We hypothesized that cognitive impairment has a stronger impact on movement-related pain in everyday contexts than on pain sensitivity assessed in passive laboratory settings. Thirty-eight cognitively healthy and 38 cognitively impaired older adults (50% women; groups age- and sex-matched), classified using the CERAD scale (Consortium to Establish a Registry for Alzheimer's Disease), completed standardized motor tasks (walking, bed mobility, lifting tasks) and experimental pressure and heat pain assessments. Pain intensity (NRS) was recorded for all tasks. Perceived exertion was assessed during motor tasks, and clinical pain status was determined via a structured interview. Groups did not differ in baseline clinical pain or experimental pain sensitivity. However, cognitively impaired participants reported significantly higher movement-related pain during motor tasks. In a blockwise regression model, movement-related pain was significantly predicted by clinical pain and experimental pain sensitivity; however cognitive status (CERAD) explained additional variance to a similar amount. In conclusion, reduced cognitive functioning significantly predicted increased pain during active, everyday motor tasks. This may reflect diminished capacities for recall, planning, and execution of pain-minimizing movement strategies. These findings underscore the importance of assessing pain in behaviorally relevant contexts where movement provokes pain, to better understand pain mechanisms in cognitively impaired older adults.