Waking EEG Cortical Markers of Chronic Pain and Sleepiness.

Objective: Spectral power analyses of EEG recordings are reported to distinguish the cortical activity of individuals with chronic pain from those of controls. Further study of these spectral patterns may provide a greater understanding of the processes associated with chronic pain, in addition to providing potential biometric markers of chronic pain for use in both clinical and research settings. However, sleep deprived groups have demonstrated similar characteristics in their spectral power characteristics, particularly in alpha bandwidth power activity.

Methods: 103 individuals with chronic pain provided resting awake EEG data in addition to ratings of pain and sleep quality. Two Principal Axis Factor analyses using Promax rotation produced one pain and one sleep factor from relevant questionnaire data provided by participants. These factors were then used to test hypothesized relationships with alpha and theta bandwidth power at the frontal and parietal areas of the cortex.

Results: Our findings suggest that reductions in alpha bandwidth power are independently associated with both chronic pain intensity ratings and measures of sleep deficits. Conversely, theta bandwidth power was not found to be associated with either chronic pain or sleep quality measures.

Conclusions: This study's findings support that chronic pain intensity and sleep deficits are related to the Alpha spectral bandwidth activity in individuals with chronic pain.