Resting-state EEG and cognitive function in older adults with chronic pain

Abstract

[eng] Understanding how chronic pain affects cognitive function and causes functional brain changes in older adults can guide clinical investigation and future therapeutic interventions. To our knowledge there are no studies to date focused on the relationship between chronic pain, cognitive function, and functional brain abnormalities in older adults. To address this question, we conducted a study of 26 older adults with chronic pain (CPOA), 30 pain-free older adults (OA), and 31 healthy younger adults (YA). We administered a battery of neurocognitive tests and recorded electroencephalography (EEG) during resting-state to assess frequency bands oscillations in 92 participants. Consistent with our hypothesis CPOA showed significant reduced performance than OA in Stroop test; some variables of the WCST as correct answers and errors; and Digit Span. We also found differences between groups on statistical maps of source analyses of EEG power spectra, both older adults’ groups showed significant higher beta activity than YA, and CPOA had significant overactivity of beta-2 in comparison to OA. And correlations pointed out that, for CPOA, higher beta activity was associated to reduced performance in the WCST (reduced percentage of correct answers, and augmented percentages of errors and perseverative responses). In contrast, in OA we found these correlations in the opposite direction, showing an improvement in the WCST associated to augmented beta. Our results evidence that chronic pain in older adults is related to impaired executive functions and abnormal brain activity, which means that long-term pain could be accelerating brain aging.