Differential Cortical Oscillatory Patterns in Amputees with and Without Phantom Limb Pain

Objective: Phantom limb pain (PLP) as neuropathic pain affects the life of amputees. It is believed an efficient PLP treatment should consider the underlying neurological mechanisms. Hereby, we investigated brain activity in PLP’s and relations to the psychological and cognitive dimension of chronic pain. We investigate differences in resting brain activities between amputees with and without pain. We hypothesis significant differences in activities of the motor cortex and parietal cortex that are related to pain perception. Also, we hypothesis two groups have significant differences in cognitive and psychological components. Methods: Behavioral assessment(psychological status, life satisfaction, and pain level) and EEG signals of 19 amputees (12 without pain and 7 with pain) were recorded. Data were statistically compared between the two groups. Also, the association between behavioral and neurophysiological data was computed. Result: Results showed a significant decrease in the pain group for the Beta and Gamma waves, Also, for the Theta and Delta waves in the posterior temporal on both sides, during the eye-open condition. The eyes-closed condition showed Delta waves decrease on the right side of the cortex. Also, data showed significant differences in correlation of pain features with brain wavws between two groups. Conclusion: Significant differences were mostly observed in regions related to pain perception rather than the motor cortex. These could be because of the learned strategies to deal with pain and the degree of pain. Results showed maladaptive cognitive processes had a relationship with brain wave activities. Through results, it seems rather than neuroplasticity through amputation, cognitive factors have a role in the experience of PLP.