Intracortical inhibition is modulated by phase of prosthetic rehabilitation in transtibial amputees
Reorganisation of primary motor cortex (M1) is well described in long-term lower limb amputees. In contrast cortical reorganisation during the rehabilitation period after amputation is poorly understood. Thirteen transtibial amputees and thirteen gender matched control participants of similar age we...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2015-05-01
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| Series: | Frontiers in Human Neuroscience |
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| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fnhum.2015.00276/full |
| _version_ | 1819099175039533056 |
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| author | Brenton eHordacre Lynely eBradnam Lynely eBradnam Lynely eBradnam Christopher eBarr Benjamin ePatritti Maria eCrotty |
| author_facet | Brenton eHordacre Lynely eBradnam Lynely eBradnam Lynely eBradnam Christopher eBarr Benjamin ePatritti Maria eCrotty |
| author_sort | Brenton eHordacre |
| collection | DOAJ |
| description | Reorganisation of primary motor cortex (M1) is well described in long-term lower limb amputees. In contrast cortical reorganisation during the rehabilitation period after amputation is poorly understood. Thirteen transtibial amputees and thirteen gender matched control participants of similar age were recruited. Transcranial magnetic stimulation was used to assess corticomotor and intracortical excitability of M1 bilaterally. Neurophysiological assessments were conducted at admission, prosthetic casting, first walk and discharge. Gait variability at discharge was assessed as a functional measure. Compared to controls, amputees had reduced short-latency intracortical inhibition for the ipsilateral M1 at admission (p=0.01). Analysis across rehabilitation revealed short-latency intracortical inhibition was reduced for the contralateral M1 at first walk compared to discharge (p=0.003). For the ipsilateral M1 both short and long-latency intracortical inhibition were reduced at admission (p<0.05) and prosthetic casting (p<0.02). Analysis of the neurophysiology and gait function revealed several interesting relationships. For the contralateral M1, reduced inhibition at admission (p=0.04) and first walk (p=0.05) was associated with better gait function. For the ipsilateral M1, reduced inhibition at discharge (p=0.05) was associated with poor gait function. This study characterised intracortical excitability in rehabilitating amputees. A dichotomous relationship between reduced intracortical inhibition for each M1 and gait function was observed at different times. Intracortical inhibition may be an appropriate cortical biomarker of gait function in lower limb amputees during rehabilitation, but requires further investigation. Understanding M1 intracortical excitability of amputees undertaking prosthetic rehabilitation provides insight into brain reorganisation in the sub-acute post amputation period and may guide future studies seeking to improve rehabilitation outcomes. |
| first_indexed | 2024-12-22T00:42:42Z |
| format | Article |
| id | doaj.art-43c7ce7939704a7ab5065966299b2a5d |
| institution | Directory Open Access Journal |
| issn | 1662-5161 |
| language | English |
| last_indexed | 2024-12-22T00:42:42Z |
| publishDate | 2015-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Human Neuroscience |
| spelling | doaj.art-43c7ce7939704a7ab5065966299b2a5d2022-12-21T18:44:38ZengFrontiers Media S.A.Frontiers in Human Neuroscience1662-51612015-05-01910.3389/fnhum.2015.00276132100Intracortical inhibition is modulated by phase of prosthetic rehabilitation in transtibial amputeesBrenton eHordacre0Lynely eBradnam1Lynely eBradnam2Lynely eBradnam3Christopher eBarr4Benjamin ePatritti5Maria eCrotty6Flinders UniversityFlinders UniversityFlinders UniversityUniversity of Technology, SydneyFlinders UniversityFlinders UniversityFlinders UniversityReorganisation of primary motor cortex (M1) is well described in long-term lower limb amputees. In contrast cortical reorganisation during the rehabilitation period after amputation is poorly understood. Thirteen transtibial amputees and thirteen gender matched control participants of similar age were recruited. Transcranial magnetic stimulation was used to assess corticomotor and intracortical excitability of M1 bilaterally. Neurophysiological assessments were conducted at admission, prosthetic casting, first walk and discharge. Gait variability at discharge was assessed as a functional measure. Compared to controls, amputees had reduced short-latency intracortical inhibition for the ipsilateral M1 at admission (p=0.01). Analysis across rehabilitation revealed short-latency intracortical inhibition was reduced for the contralateral M1 at first walk compared to discharge (p=0.003). For the ipsilateral M1 both short and long-latency intracortical inhibition were reduced at admission (p<0.05) and prosthetic casting (p<0.02). Analysis of the neurophysiology and gait function revealed several interesting relationships. For the contralateral M1, reduced inhibition at admission (p=0.04) and first walk (p=0.05) was associated with better gait function. For the ipsilateral M1, reduced inhibition at discharge (p=0.05) was associated with poor gait function. This study characterised intracortical excitability in rehabilitating amputees. A dichotomous relationship between reduced intracortical inhibition for each M1 and gait function was observed at different times. Intracortical inhibition may be an appropriate cortical biomarker of gait function in lower limb amputees during rehabilitation, but requires further investigation. Understanding M1 intracortical excitability of amputees undertaking prosthetic rehabilitation provides insight into brain reorganisation in the sub-acute post amputation period and may guide future studies seeking to improve rehabilitation outcomes.http://journal.frontiersin.org/Journal/10.3389/fnhum.2015.00276/fullAmputationGaitMotor CortexRehabilitationTranscranial Magnetic Stimulationhuman |
| spellingShingle | Brenton eHordacre Lynely eBradnam Lynely eBradnam Lynely eBradnam Christopher eBarr Benjamin ePatritti Maria eCrotty Intracortical inhibition is modulated by phase of prosthetic rehabilitation in transtibial amputees Frontiers in Human Neuroscience Amputation Gait Motor Cortex Rehabilitation Transcranial Magnetic Stimulation human |
| title | Intracortical inhibition is modulated by phase of prosthetic rehabilitation in transtibial amputees |
| title_full | Intracortical inhibition is modulated by phase of prosthetic rehabilitation in transtibial amputees |
| title_fullStr | Intracortical inhibition is modulated by phase of prosthetic rehabilitation in transtibial amputees |
| title_full_unstemmed | Intracortical inhibition is modulated by phase of prosthetic rehabilitation in transtibial amputees |
| title_short | Intracortical inhibition is modulated by phase of prosthetic rehabilitation in transtibial amputees |
| title_sort | intracortical inhibition is modulated by phase of prosthetic rehabilitation in transtibial amputees |
| topic | Amputation Gait Motor Cortex Rehabilitation Transcranial Magnetic Stimulation human |
| url | http://journal.frontiersin.org/Journal/10.3389/fnhum.2015.00276/full |
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