Phantom limb pain induced in amputee by strong magnetic fields.

An amputee (traumatic) experienced increased phantom limb pain when exposed to the magnetic fields of two magnetic resonance imagers. With a visual analog scale used to measure pain, electric stimulation studies demonstrated that the residual limb was unusually sensitive to subthreshold (for muscle twitch) levels of current. The painful symptoms produced mimicked those experienced in the presence of the imagers.