virtual reality to combat phantom pain
An experience based on virtual reality and video games helped relieve the pain of the “phantom limbs” of 14 patients with one arm amputations.
Virtual reality could relieve pain in amputee patients by reactivating certain areas of the brain responsible for movement, according to a study conducted by Chalmers University of Technology in Gothenburg (Sweden).
Phantom limb pain is a fairly frequent pain that occurs after amputation. In a third of cases, they persist and affect the quality of life of patients. “After an amputation, in the case of phantom pain, the brain is deceived. He is waiting for a message from a member who no longer exists,” says Dr. Jean-Baptiste Thiebaut, at the Rotschild Foundation’s pain treatment evaluation center. “The absence of a signal will therefore lead to a malfunction of the system in the brain which leads to chronic pain.”The purpose of the trial presented is therefore to deceive the brain a second time to make it believe that the limb is still there, and thus alleviate the pain.
Fourteen patients who had had an upper limb amputated were asked, during twelve sessions spread over a period of one year, to perform several movements in front of a computer screen. The patients selected for the study were those in whom existing treatments (surgical, medical, psychological or behavioral) had failed. In the experiment, electrodes were placed on their skin at the stump. On the screen then appeared a virtual arm that followed the movements made by the patient.
The researchers then asked the patients to “move” this virtual arm to perform the various motor skills exercises: make a series of imposed movements, drive a car, or reproduce a movement shown on the screen.
By the end of the program, their pain intensity had decreased by 32%, their frequency by 61% during sleep and by 43% during wakefulness. These improvements persisted six months after the end of the experiment, and of the four patients taking pain medication, two had significantly reduced doses.
The technique is not new. Since the 1990s, doctors have been using mirror therapy. “A mirror is placed in front of the patient, with a particular angle of vision, so that the amputated limb is hidden. When the patient moves the valid arm, he has the impression that his mutilated arm exists and moves, ” explains Dr. Jean-Baptiste Thiebaut. The vision of an arm moving in place of the amputated arm makes the brain believe that everything is fine and thus temporarily stop the pain.
The University of Gothenburg uses the same principle in its study. But it goes further than mirror therapy, since virtual reality makes it possible to visualize the amputated limb as if it really existed.
However, the authors report that their study is the first of its kind with long-term results. They must now be confirmed by a clinical trial, where patients would be divided into two groups: one treated by virtual reality, and the other by conventional methods.