Brain Psychology: Cortical Reorganization & Phantom Limbs

Abstract

This paper serves to explore the evolution of neuroplasticity and its implication for phantom limbs. Various studies have shown phantom limb sensations to be a product of cortical reorganization of motor and somatosensory representations. The paper pays special attention to the literature of Dr. V.S. Ramachandran who led the scientific breakthroughs for phantom limb research in the 1990’s as well as the work of Melita Giummarra in more recent years. Advances in research of phantom limbs are needed to better equip physicians to aid in the treatment of pain that plagues approximately 80% of amputees.  

Phantom limb sensations are sensory perceptions of a limb that no longer exists or has never existed as a physical part of the body. This can occur by way of amputation, congenital birth defect, nerve avulsion or from a stroke. While, the mystery of the phantom limb is one that has plagued the neuroscience community for centuries, it is only in the last couple of decades that any real advance in an understanding of this phenomenon been made. Today, the phantom limb is no longer an intangible marvel but rather a mechanism that provides a unique insight to cortical plasticity and the way in which the brain creates body representations. A brief history will aid in the understanding of the scientific course this phenomenon has taken.

First recorded in the 16th century by Ambroise Paré, the enduring sensation of a missing limb was associated more with folklore than it was science. Despite being the first to address these sensations in Western literature, Paré was quite correct to implicate the brain, though he led with the theory that the pain described was the product of convulsions caused by the shifting of severed nerve stumps. This was the foundation of the first theory for phantom limb pain, that it resulted from traumatic neuromas, the irregular growth of damaged nerve fibers after an amputation surgery. The French philosopher, Rene Descartes, was...