Mapping phantom movement representations in the motor cortex of amputees
- PMID: 16844715
- DOI: 10.1093/brain/awl180
Mapping phantom movement representations in the motor cortex of amputees
Abstract
Limb amputation results in plasticity of connections between the brain and muscles, with the cortical motor representation of the missing limb seemingly shrinking, to the presumed benefit of remaining body parts that have cortical representations adjacent to the now-missing limb. Surprisingly, the corresponding perceptual representation does not suffer a similar fate but instead persists as a phantom limb endowed with sensory and motor qualities. How can cortical reorganization after amputation be reconciled with the maintenance of a motor representation of the phantom limb in the brain? In an attempt to answer this question we explored the relationship between the cortical representation of the remaining arm muscles and that of phantom movements. Using transcranial magnetic stimulation (TMS) we systematically mapped phantom movement perceptions while simultaneously recording stump muscle activity in three above-elbow amputees. TMS elicited sensations of movement in the phantom hand when applied over the presumed hand area of the motor cortex. In one subject the amplitude of the perceived movement was positively correlated with the intensity of stimulation. Interestingly, phantom limb movements that the patient could not produce voluntarily were easily triggered by TMS, suggesting that the inability to voluntarily move the phantom is not equivalent to a loss of the corresponding movement representation. We suggest that hand movement representations survive in the reorganized motor area of amputees even when these cannot be directly accessed. The activation of these representations is probably necessary for the experience of phantom movement.
Similar articles
-
Persistent hand motor commands in the amputees' brain.Brain. 2006 Aug;129(Pt 8):2211-23. doi: 10.1093/brain/awl154. Epub 2006 Jun 24. Brain. 2006. PMID: 16799174
-
The motor cortex and its role in phantom limb phenomena.Neuroscientist. 2008 Apr;14(2):195-202. doi: 10.1177/1073858407309466. Epub 2007 Nov 7. Neuroscientist. 2008. PMID: 17989169 Review.
-
Motor control over the phantom limb in above-elbow amputees and its relationship with phantom limb pain.Neuroscience. 2009 Aug 4;162(1):78-86. doi: 10.1016/j.neuroscience.2009.04.061. Epub 2009 May 3. Neuroscience. 2009. PMID: 19406214
-
Neuroelectric source imaging of steady-state movement-related cortical potentials in human upper extremity amputees with and without phantom limb pain.Pain. 2004 Jul;110(1-2):90-102. doi: 10.1016/j.pain.2004.03.013. Pain. 2004. PMID: 15275756
-
[Phantom limb pain originates from dysfunction of the primary motor cortex].Masui. 2010 Nov;59(11):1364-9. Masui. 2010. PMID: 21077303 Review. Japanese.
Cited by
-
Plasticity of face-hand sensorimotor circuits after a traumatic brachial plexus injury.Front Neurosci. 2023 Aug 7;17:1221777. doi: 10.3389/fnins.2023.1221777. eCollection 2023. Front Neurosci. 2023. PMID: 37609451 Free PMC article.
-
Phantom limb therapy improves cortical efficiency of the sensorimotor network in a targeted muscle reinnervation amputee: a case report.Front Neurosci. 2023 May 10;17:1130050. doi: 10.3389/fnins.2023.1130050. eCollection 2023. Front Neurosci. 2023. PMID: 37234264 Free PMC article.
-
[Clinical updates on phantom limb pain : German version].Schmerz. 2023 Jun;37(3):195-214. doi: 10.1007/s00482-022-00629-x. Epub 2022 Mar 21. Schmerz. 2023. PMID: 35312841 Review. German.
-
Characterisation of Phantom Limb Pain in Traumatic Lower-Limb Amputees.Pain Res Manag. 2021 Dec 13;2021:2706731. doi: 10.1155/2021/2706731. eCollection 2021. Pain Res Manag. 2021. PMID: 34938379 Free PMC article.
-
Parietal Lobe Reorganization and Widespread Functional Connectivity Integration in Upper-Limb Amputees: A rs-fMRI Study.Front Neurosci. 2021 Jul 20;15:704079. doi: 10.3389/fnins.2021.704079. eCollection 2021. Front Neurosci. 2021. PMID: 34354568 Free PMC article.
Publication types
MeSH terms
LinkOut - more resources
Full Text Sources
Medical