Brain EEG activity correlates of chronic pain in persons with spinal cord injury: clinical implications

Abstract

Group comparison and cross-sectional study. To replicate previous findings regarding electroencephalographic (EEG) pattern differences in a larger sample of patients with spinal cord injury (SCI) and chronic pain than previously studied, and examine associations between pain severity and EEG activity in a sample of patients with SCI and chronic pain. USA. EEG data were collected in an eyes-closed condition from 38 individuals with SCI and chronic pain, 16 individuals with SCI who did not have chronic pain and 28 healthy controls. Pain intensity experienced during the EEG assessment was assessed in the chronic pain group. Absolute and relative power in four frequency bands (delta, theta, alpha, and beta) were compared between the groups, and correlation coefficients between bandwidth activity and pain intensity in the pain group were computed. Previously identified activity pattern differences (that is, more theta and less alpha) in those with SCI and chronic pain versus individuals with SCI and no pain and healthy controls were largely replicated. However, few significant associations between pain severity and EEG activity measures activity were found, and those that were found (more alpha activity associated with more pain as measured from frontal electrode sites) was in a direction opposite than predicted. The findings indicate that certain EEG activity patterns may be associated with more pain or a vulnerability to experience chronic pain in persons with SCI. Research examining the extent to which changes in this EEG activity may result in pain relief is warranted.