Intracortical Inhibition in the Affected Hemisphere in Limb Amputation
Open Access
- 30 July 2020
- journal article
- review article
- Published by Frontiers Media SA in Frontiers in Neurology
- Vol. 11, 720
- https://doi.org/10.3389/fneur.2020.00720
Abstract
Phantom limb pain (PLP) affects up to 80% of amputees. Despite the lack of consensus about the etiology and pathophysiology of phantom experiences, previous evidence pointed out the role of changes in motor cortex excitability as an important factor associated with amputation and PLP. In this systematic review, we investigated changes in intracortical inhibition as indexed by transcranial magnetic stimulation (TMS) in amputees and its relationship to pain. Four electronic databases were screened to identify studies using TMS to measure cortical inhibition, such as short intracortical inhibition (SICI), long intracortical inhibition (LICI) and cortical silent period (CSP). Seven articles were included and evaluated cortical excitability comparing the affected hemisphere with the non-affected hemisphere or with healthy controls. None of them correlated cortical disinhibition and clinical parameters, such as the presence or intensity of PLP. However, most studies showed decreased SICI in amputees affected hemisphere. These results highlight that although SICI seems to be changed in the affected hemisphere in amputees, most of the studies did not investigate its clinical correlation. Thus, the question of whether they are a valid diagnostic marker remains unanswered. Also, the results were highly variable for both measurements due to the heterogeneity of study designs and group comparisons in each study. Although these results underscore the role of inhibitory networks after amputation, more studies are needed to investigate the role of a decreased inhibitory drive in the motor cortex to the cause and maintenance of PLP.This publication has 48 references indexed in Scilit:
- Cortical motor activity and reorganization following upper-limb amputation and subsequent targeted reinnervationNeuroImage: Clinical, 2013
- Phantom Limb Pain: Mechanisms and Treatment ApproachesPain Research and Treatment, 2011
- Reversal of Cortical Reorganization in Human Primary Motor Cortex Following Thumb ReconstructionJournal of Neurophysiology, 2010
- Chronic Motor Cortex Stimulation for Phantom Limb PainNeurosurgery, 2008
- Short interval intracortical inhibition and facilitation during the silent period in humanJournal Of Physiology-London, 2007
- Phantom limb pain: a case of maladaptive CNS plasticity?Nature Reviews Neuroscience, 2006
- Short‐interval paired‐pulse inhibition and facilitation of human motor cortex: the dimension of stimulus intensityJournal Of Physiology-London, 2002
- Phantom-limb pain as a perceptual correlate of cortical reorganization following arm amputationNature, 1995
- MOTOR REORGANIZATION AFTER UPPER LIMB AMPUTATION IN MANBrain, 1991