After decades of research, the origin of phantom limb pain are still unclear, and recent research findings have done little to advance our understanding of the syndrome. The difficulty in treating pain from a nonexistent body part have made the condition frustrating for clinicians and sufferers alike, and interest is high in deciphering the neural causes that underlie phantom limb pain. But results of a recent study appearing in the journal Brain appear to challenge the veracity of one of the favored causal theories, maladaptive brain plasticity.
Originally, phantom limb pain was thought to emanate from injury to the nerves transmitting information from the amputated body part into the spinal cord. Since these nerves normally provide information of touch and pain, false input transmitted via these nerves could explain phantom sensations. More recently, phantom pain has been thought to be driven by brain changes in body representation, triggered by loss of input from the missing part. Called maladaptive brain plasticity, the theory posits that the region in the brain originally in charge of the amputated limb is invaded by neighboring brain representations. But treatments based on the maladaptive brain theory don’t appear to work consistently, and results of the current research fail to support the concept of territorial invasion in the brain. So, the mystery continues.
Read a news story about the current state of understanding concerning phantom limb pain here.
The journal article detailing the recent research may be read here.