Abstract
Background: Bilateral changes in the hemispheric reorganisation have been observed chronically after unilateral stroke. Our hypotheses were that activity dependent competition between the lesioned and non-lesioned corticospinal systems would result in persisting asymmetry and be associated with poor recovery. Methods: Eleven subjects (medium 6.5. years after stroke) were compared to 9 age-matched controls. The power spectral density (PSD) of the sensorimotor electroencephalogram (SM1-EEG) and electromyogram (EMG) and corticomuscular coherence (CMC) were studied during rest and isometric contraction of right or left opponens pollicis (OP). Global recovery was assessed using NIH score. Findings: There was bilateral loss of beta frequency activity in the SM1-EEGs and OP-EMGs in strokes compared to controls. There was no difference between strokes and controls in symmetry indices estimated between the two corticospinal systems for SM1-EEG, OP-EMG and CMC. Performance correlated with preservation of beta frequency power in OP-EMG in both hands. Symmetry indices for the SM1-EEG, OP-EMG and CMC correlated with recovery. Interpretation: Significant changes occurred at both cortical and spinomuscular levels after stroke but to the same degree and in the same direction in both the lesioned and non-lesioned corticospinal systems. Global recovery correlated with the degree of symmetry between corticospinal systems at all three levels - cortical and spinomuscular levels and their connectivity (CMC), but not with the absolute degree of abnormality. Re-establishing balance between the corticospinal systems may be important for overall motor function, even if it is achieved at the expense of the non-lesioned system.
| Original language | English |
|---|---|
| Pages (from-to) | 168-175 |
| Number of pages | 8 |
| Journal | Experimental Neurology |
| Volume | 238 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Dec 2012 |
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Keywords
- Corticomuscular coherence
- Corticospinal
- EEG
- EMG
- Homeostatic plasticity
- Motor
- Recovery
- Reorganisation
- Stroke
- Symmetry
ASJC Scopus subject areas
- Neurology
- Developmental Neuroscience
Cite this
The myth of the 'unaffected' side after unilateral stroke : Is reorganisation of the non-infarcted corticospinal system to re-establish balance the price for recovery? / Graziadio, S.; Tomasevic, L.; Assenza, G.; Tecchio, F.; Eyre, J. A.
In: Experimental Neurology, Vol. 238, No. 2, 12.2012, p. 168-175.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The myth of the 'unaffected' side after unilateral stroke
T2 - Is reorganisation of the non-infarcted corticospinal system to re-establish balance the price for recovery?
AU - Graziadio, S.
AU - Tomasevic, L.
AU - Assenza, G.
AU - Tecchio, F.
AU - Eyre, J. A.
PY - 2012/12
Y1 - 2012/12
N2 - Background: Bilateral changes in the hemispheric reorganisation have been observed chronically after unilateral stroke. Our hypotheses were that activity dependent competition between the lesioned and non-lesioned corticospinal systems would result in persisting asymmetry and be associated with poor recovery. Methods: Eleven subjects (medium 6.5. years after stroke) were compared to 9 age-matched controls. The power spectral density (PSD) of the sensorimotor electroencephalogram (SM1-EEG) and electromyogram (EMG) and corticomuscular coherence (CMC) were studied during rest and isometric contraction of right or left opponens pollicis (OP). Global recovery was assessed using NIH score. Findings: There was bilateral loss of beta frequency activity in the SM1-EEGs and OP-EMGs in strokes compared to controls. There was no difference between strokes and controls in symmetry indices estimated between the two corticospinal systems for SM1-EEG, OP-EMG and CMC. Performance correlated with preservation of beta frequency power in OP-EMG in both hands. Symmetry indices for the SM1-EEG, OP-EMG and CMC correlated with recovery. Interpretation: Significant changes occurred at both cortical and spinomuscular levels after stroke but to the same degree and in the same direction in both the lesioned and non-lesioned corticospinal systems. Global recovery correlated with the degree of symmetry between corticospinal systems at all three levels - cortical and spinomuscular levels and their connectivity (CMC), but not with the absolute degree of abnormality. Re-establishing balance between the corticospinal systems may be important for overall motor function, even if it is achieved at the expense of the non-lesioned system.
AB - Background: Bilateral changes in the hemispheric reorganisation have been observed chronically after unilateral stroke. Our hypotheses were that activity dependent competition between the lesioned and non-lesioned corticospinal systems would result in persisting asymmetry and be associated with poor recovery. Methods: Eleven subjects (medium 6.5. years after stroke) were compared to 9 age-matched controls. The power spectral density (PSD) of the sensorimotor electroencephalogram (SM1-EEG) and electromyogram (EMG) and corticomuscular coherence (CMC) were studied during rest and isometric contraction of right or left opponens pollicis (OP). Global recovery was assessed using NIH score. Findings: There was bilateral loss of beta frequency activity in the SM1-EEGs and OP-EMGs in strokes compared to controls. There was no difference between strokes and controls in symmetry indices estimated between the two corticospinal systems for SM1-EEG, OP-EMG and CMC. Performance correlated with preservation of beta frequency power in OP-EMG in both hands. Symmetry indices for the SM1-EEG, OP-EMG and CMC correlated with recovery. Interpretation: Significant changes occurred at both cortical and spinomuscular levels after stroke but to the same degree and in the same direction in both the lesioned and non-lesioned corticospinal systems. Global recovery correlated with the degree of symmetry between corticospinal systems at all three levels - cortical and spinomuscular levels and their connectivity (CMC), but not with the absolute degree of abnormality. Re-establishing balance between the corticospinal systems may be important for overall motor function, even if it is achieved at the expense of the non-lesioned system.
KW - Corticomuscular coherence
KW - Corticospinal
KW - EEG
KW - EMG
KW - Homeostatic plasticity
KW - Motor
KW - Recovery
KW - Reorganisation
KW - Stroke
KW - Symmetry
UR - http://www.scopus.com/inward/record.url?scp=84866666971&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84866666971&partnerID=8YFLogxK
U2 - 10.1016/j.expneurol.2012.08.031
DO - 10.1016/j.expneurol.2012.08.031
M3 - Article
C2 - 22981842
AN - SCOPUS:84866666971
VL - 238
SP - 168
EP - 175
JO - Experimental Neurology
JF - Experimental Neurology
SN - 0014-4886
IS - 2
ER -