El trasplante de ambas manos provoca el remapeo del cerebro

Massive cortical reorganization is reversible following bilateral transplants of the hands: evidence from the first successful bilateral pediatric hand transplant patient

Abstract

In this repeated measures case study, we show that sensory deafferentation after limb amputation leads to changes in cortical somatotopic maps which are reversible after restoration of sensory input. Using magnetoencephalography (MEG), we observed in a child with bilateral hand transplants large‐scale shifts in somatosensory lip cortical representation from anatomic hand area to anatomic face region. After recovery of tactile sensation in the digits, responses to finger stimulation were localized to orthotopic sensory cortex, but with atypical electrophysiologic features (amplitude and frequencies).

Introduction

Loss of peripheral sensory inputs leads to functional reorganization of primary somatosensory cortex.1-3 Following deafferentation of the upper limb in adult primates, the area of somatosensory cortex deprived of afferent signals begins to respond to tactile stimulation of the face, a massive cortical reorganization (MCR) mediated subcortically through the cuneate nucleus.4 Similar demonstrations of MCR have also been reported in human adults with unilateral upper limb amputations using MEG.5-7 MCR has not been demonstrated in children previously, and the cortical adaptation to restoration of sensory inputs in children is unknown. We utilized the spatial and temporal resolution of MEG measurements of tactile sensory responses to provide insight into the dynamics of sensory reorganization and to ask, can massive reorganization of primary somatosensory cortex after early‐life limb loss revert to a typical somatotopic map after hand transplantation in a child?

MEG somatosensory responses and index finger touch sensitivity (using monofilament testing) were recorded over the year following transplantation at visits: 1 (6 weeks), 2 (18 weeks), 3 (33 weeks), and 4 (54 weeks). We sought to determine whether (1) MCR of face to hand area was present during the prerecovery period, (2) MCR would revert to typical orthotopic somatosensory locations with recovery of sensory function of the hands, and (3) somatosensory responses from tactile stimulation of transplanted fingers differ from age‐matched controls.