Augmented reality may help relieve phantom limb pain

A small study published in The Lancet involved 14 patients who began experiencing phantom limb pain soon after arm amputation and had not benefited from other treatments.

For a third of amputation cases pain becomes very severe, leading to poor quality of life, worse disability, poorer mental health and greater difficulty in prosthesis use than for amputees without phantom limb pain. Surgery and drug therapy have limited success with these patients.

The treatment in this study, called ‘phantom motor execution’, is based on mirror therapy that uses reflections of the unaffected limb, allowing the patient to ‘move’ the limb out of painful positions and relieve pain.

In the study, researchers placed sensors on the patients’ stumps to detect muscular activity for the missing arm. The signals were then fed into a computer that decoded and used them to create an active virtual arm on a computer screen, representing the missing limb.

The study found that on average the intensity, quality and frequency of phantom limb pain halved following treatment — with a 32% reduction in the intensity of the pain, a 51% reduction in pain quality and  a 47% reduction in its duration, frequency and intensity. The researchers found that there was a 43% reduction in the amount that pain interrupted patients’ daily activities and a 61% reduction in how often pain interrupted their sleep.