Elucidating the neural oscillations of the sensory-discriminative and affective-motivational dimensions of pain.

Project Summary Pain is complex and consists of three dimensions: sensory-discriminative, affective-motivational, and cognitive- evaluative, yet the EEG profile of the cortical activity that underlies the cognitive processing of the pain dimensions is not known. Pain questionnaires such as the widely utilized McGill Pain Questionnaire (MPQ)

contain sections that assess the sensory and affective dimensions of pain, and it is well known that these pain dimensions are associated with activity in select cortical areas. However, the pain literature lacks a comprehensive and methodologically robust profile of the EEG cortical activity that underlies cognitive

processing of the multidimensional pain experience, particularly in osteoarthritis. Further, recent systematic reviews suggested that there is a need for significant advancement in methodological robustness in EEG pain studies. The primary objective of this basic/ disease-related research, is to provide a methodologically robust,

cortex-wide, full-frequency band profile of cortical EEG activity associated with the cognitive processing of the sensory-discriminative and affective-motivational dimensions of osteoarthritis knee pain. We will record cortical activity using EEG in participants without and with chronic knee pain (osteoarthritis) at both baseline resting-

state and during experimentally-induced pain (cold pressor task) with simultaneous presentation of previously validated sensory dimension and affective dimension questions from the MPQ. Aim 1 is to elucidate the cortical EEG response that underlies the cognitive processing of the sensory-discriminative dimensions of pain

by presenting sensory stimuli during an acute pain stimulus in participants both with and without chronic osteoarthritis knee pain. Aim 2 is to investigate the cortical EEG response that underlies the cognitive processing of the affective-motivational dimension of pain by presenting affective stimuli during an acute pain

stimulus in participants both with and without chronic osteoarthritis knee pain. Aim 3 is to use a new approach to overcome barriers to progress in the field that occur due to narrow reporting of EEG outcomes and lack of rigor. We used recent systematic reviews to identify key barriers to advancement in the field due to rigor. At the

conclusion of this work we will provide a comprehensive EEG profile including full-frequency band activities from all electrodes, with coherence, absolute, and overall power, to be conducted in a robust sample of participants with sex-matched controls, a large number of experimental trials, and statistical adjustments for

multiple comparisons. Due to the robust methodological and statistical design that sets this study apart, findings will be meaningful even if the hypotheses are not supported. These data will provide novel insights into the cortical EEG profile of the cognitive processing of the multidimensional pain experience in knee

osteoarthritis. Imaging of cortical activity during pain can reveal mechanisms of pain processing which is indispensable for knowledge of pain physiology as well as development of novel treatment targets.