Plasticity in the Motor Network Following Primary Motor Cortex Lesion

Author(s):  
Numa Dancause
2021 ◽  
pp. 0271678X2110029
Author(s):  
Mitsouko van Assche ◽  
Elisabeth Dirren ◽  
Alexia Bourgeois ◽  
Andreas Kleinschmidt ◽  
Jonas Richiardi ◽  
...  

After stroke restricted to the primary motor cortex (M1), it is uncertain whether network reorganization associated with recovery involves the periinfarct or more remote regions. We studied 16 patients with focal M1 stroke and hand paresis. Motor function and resting-state MRI functional connectivity (FC) were assessed at three time points: acute (<10 days), early subacute (3 weeks), and late subacute (3 months). FC correlates of recovery were investigated at three spatial scales, (i) ipsilesional non-infarcted M1, (ii) core motor network (M1, premotor cortex (PMC), supplementary motor area (SMA), and primary somatosensory cortex), and (iii) extended motor network including all regions structurally connected to the upper limb representation of M1. Hand dexterity was impaired only in the acute phase ( P = 0.036). At a small spatial scale, clinical recovery was more frequently associated with connections involving ipsilesional non-infarcted M1 (Odds Ratio = 6.29; P = 0.036). At a larger scale, recovery correlated with increased FC strength in the core network compared to the extended motor network (rho = 0.71; P = 0.006). These results suggest that FC changes associated with motor improvement involve the perilesional M1 and do not extend beyond the core motor network. Core motor regions, and more specifically ipsilesional non-infarcted M1, could hence become primary targets for restorative therapies.


Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Doris D Wang ◽  
Coralie de Hemptinne ◽  
Svjetlana Miocinovic ◽  
Witney Chen ◽  
Jill L Ostrem ◽  
...  

Abstract INTRODUCTION In Parkinson's disease, the emergence of motor dysfunction is thought to be related to an imbalance between antikinetic and prokinetic patterns of oscillatory activity in the motor network. Invasive recordings from the basal ganglia and cortex in surgical patients have suggested that levodopa and therapeutic deep brain stimulation can suppress antikinetic beta band (13-30 Hz) rhythms while promoting prokinetic gamma band (60-90 Hz) rhythms. Surgical ablation of the globus pallidus internus is one of the oldest effective therapies for Parkinson's disease and gives a remarkable immediate relief from rigidity and bradykinesia, but its effects on oscillatory activity in the motor network have not been studied. We characterize the effects of pallidotomy on cortical oscillatory activity in Parkinson's disease patients. METHODS Using a temporary 6-contact lead placed over the sensorimotor cortex in the subdural space, we recorded acute changes in cortical oscillatory activities in 3 Parkinson's disease patients undergoing pallidotomy and compared the results to that of 3 essential tremor patients undergoing thalamotomy. RESULTS In all 3 Parkinson's disease patients, we observed the emergence of an approximately 70 to 80 Hz narrow-band oscillation with effective thermolesion of the pallidum. This gamma oscillatory activity was spatially localized over the primary motor cortex, was minimally affected by voluntary movements, and was not found in the motor cortex of essential tremor patients undergoing thalamotomy. CONCLUSION Our finding suggests that acute lesioning of the pallidum promotes cortical gamma band oscillations. This may represent an important mechanism for alleviating bradykinesia in Parkinson's disease.


Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Mitsouko van Assche ◽  
Elisabeth Dirren ◽  
Alexia Bourgeois ◽  
Andreas Kleinschmidt ◽  
Jonas Richiardi ◽  
...  

Background and Purpose: After stroke restricted to the primary motor cortex (M1), it is uncertain whether network reorganization associated with motor recovery involves the periinfarct or more remote brain regions. In humans, the challenge is to recruit patients with similar lesions in size and location. Methods: We studied 16 patients with focal M1 stroke and hand paresis. Motor function and resting-state MRI functional connectivity (FC) were studied at three time points: acute (<10 days), early subacute (3 weeks), and late subacute (3 months). FC correlates of motor recovery were investigated at three spatial scales, i) ipsilesional non-infarcted M1, ii) core motor network (including M1, premotor cortex (PMC), supplementary motor area (SMA), and primary somatosensory cortex), and iii) extended motor network including all regions structurally connected to the upper limb representation of M1. Results: Hand dexterity was impaired only in the acute phase ( P =0.036). At a small spatial scale, improved dexterity was associated with increased FC involving mainly the ipsilesional non-infarcted M1 and contralesional motor regions (cM1: rho=0.732; P =0.004; cPMC: rho=0.837, P <0.001; cSMA: rho=0.736; P =0.004). At a larger scale, motor recovery correlated with the relative increase in total FC strength in the core motor network compared to the extended motor network (rho=0.71; P =0.006). Conclusions: FC changes associated with motor improvement involve the perilesional M1 and do not extend beyond the core motor network. The ipsilesional non-infarcted M1 and core motor regions could hence be primary targets for future restorative therapies.


1995 ◽  
Vol 73 (2) ◽  
pp. 891-895 ◽  
Author(s):  
D. S. Hoffman ◽  
P. L. Strick

1. We lesioned the contralateral arm area of the primary motor cortex (M1) in a monkey that had been trained to make rapid step-tracking movements of the wrist in different directions. We examined movement kinematics and electromyographic (EMG) activity of forearm muscles both before and 3.5-5 mo after the lesion. 2. The lesion caused marked changes in movement kinematics and the patterns of activity in agonist, synergist, and antagonist muscles. 3. After the lesion, movements to all targets were performed more slowly. In addition, some movements were misdirected. For example, most movements to the target that required wrist flexion and radial deviation were made in two steps, instead of in a single smooth trajectory. 4. After the lesion, distinct bursts of muscle activity were no longer observed during step-tracking movements. In addition, suppression of antagonist activity at movement onset was abolished or reduced. The relative timing of agonist and synergist muscle activity was markedly altered. 5. We conclude that M1 contributes to the precise spatiotemporal patterning of muscle activity during step-tracking movements.


2007 ◽  
Vol 21 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Kathleen M. Friel ◽  
Scott Barbay ◽  
Shawn B. Frost ◽  
Erik J. Plautz ◽  
Ann M. Stowe ◽  
...  

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