Two Point Discrimination

SPECIFIC AIMS Pain in both youth and adults is a complex, subjective and personal experience, and remains poorly understood. One particularly perplexing dimension of some forms of pain is the tendency of pain to spread outside of an affected body site to adjacent location, and then to unaffected body sites. Such widespread pain may reflect an altered spatial tuning of somatosensory processing, such that lateral inhibition is diminished, thereby allowing pain to spread. To date, no therapies exist which are designed specifically to diminish or even reverse the spatial spread of pain. However, training in two-point discrimination holds the potential to retune spatial aspects of somatosensory processing and may represent a novel therapy for widespread pain. Thus, the present investigation will test the following aims: Aim 1. Do youth with chronic pain have disrupted spatial tuning of somatosensory processing? Deficits in two point tactile discrimination have long been noted in adults with chronic pain, but such deficits remain poorly documented in pediatric chronic pain patients. In order to determine if such deficits exist, youth with both chronic pain and healthy youth will undergo assessment of two point discrimination thresholds. Aim 2. Does two-point discrimination training result in diminished pain and disability in youth with somatic pain? After initial characterization of tactile discrimination thresholds, youth with chronic pain will participate in multiple sessions of either two-point discrimination training or a single-point spatially-directed attentional control condition. Training will involve up to 9 additional sessions. Efficacy of training will be assessed by 1) reductions in the spatial extent of pain, 2) reductions in pain intensity and unpleasantness, and 3) reductions in pain-related disability.