Grant: New Investigator Award - Priority Announcement: Clinical Research

Pain has an inhibitory effect on the motor areas of the brain, and interferes with motor control. In patients who have both pain and a motor deficit the pain might hamper proper activation of motor areas during attempts to move, thereby limiting motor improvement during rehabilitation. Therefore it is important to have a comprehensive understanding of the pathophysiology of disorders that include both motor deficits and pain. An innovative approach to studying interactions between the motor system and pain is to study the phantom limb phenomenon, which is the vivid sensation that a missing body part is still there after an amputation. The majority of amputees report pain in the missing limb, called phantom limb pain, as well as the perceived ability to perform voluntary movements with their phantom limb. Amputation induces a reorganisation of the motor areas of the brain (motor plasticity), and this plasticity appears to be related to phantom limb pain as well as to the perceived ability to perform movements with the phantom limb. The main objective of this research program is to gain a better understanding of the relationship between pain, motor control, and motor plasticity using neuroimaging and neurostimulation approaches. First, in healthy individuals, experimentally-controlled pain and experimentally-induced nerve block (that produces reversible amputation-like effects in the brain) will be used to look at how brain motor areas reorganise as a function of whether pain or nerve block occur alone or in combination. Second, in amputees suffering from phantom pain, a non invasive brain stimulation technique will be used to induce transitory changes in the excitability of motor areas in order to study the relationship between physiological changes induced and clinical changes in pain levels and voluntary movements of the phantom limb. Finally, in upper limb amputees, the effect of prosthesis use on motor area plasticity and phantom sensations will be assessed.