Functional reorganization oF the primary motor cortex in a patient with a large arteriovenous malFormation involving the precentral gyrus

2013 ◽  
Vol 4 (2) ◽  
Author(s):  
Milan Radoš ◽  
Ines Nikić ◽  
Marko Radoš ◽  
Ivica Kostović ◽  
Patrick Hof ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Right Hemisphere ◽  
Motor Area ◽  
Lower Limbs ◽  
Motor Deficits ◽  
Precentral Gyrus ◽  
Functional Reorganization ◽  
The Right ◽  
The Brain

AbstractIt is known that the brain can compensate for deficits induced by acquired and developmental lesions through functional reorganization of the remaining parenchyma. Arteriovenous malformations (AVM) usually appear prenatally before a functional regional organization of the brain is fully established and patients generally do not present with motor deficits even when the AVM is located in the primary motor area indicating the redistribution of functions in cortical areas that are not pathologically altered. Here we present reorganization of the motor cortex in a patient with a large AVM involving most of the left parietal lobe and the paramedian part of the left precentral gyrus that is responsible for controlling the muscles of the lower limbs. Functional MRI showed that movements of both the right and left feet activated only the primary motor cortex in the right hemisphere, while there was no activation in the left motor cortex. This suggests that complete ipsilateral control over the movements of the right foot had been established in this patient. A reconstruction of the corticospinal tract using diffusion tensor imaging showed a near-complete absence of corticospinal fibers from the part of the left precentral gyrus affected by the AVM. From this clinical presentation it can be concluded that full compensation of motor deficits had occurred by redistributing function to the corresponding motor area of the contralateral

Motor control: spinal and cortical mechanisms

2016 ◽  
Author(s):  
David Burke
Keyword(s):  
Motor Control ◽  
Motor Cortex ◽  
Voluntary Movement ◽  
Primary Motor Cortex ◽  
Lower Limbs ◽  
Spinal Reflex ◽  
Extensive Literature ◽  
Spinal Level ◽  
Corticospinal System ◽  
The Brain

There is extensive machinery at cerebral and spinal levels to support voluntary movement, but spinal mechanisms are often ignored by clinicians and researchers. For movements of the upper and lower limbs, what the brain commands can be modified or even suppressed completely at spinal level. The corticospinal system is the executive pathway for movement arising largely from primary motor cortex, but movement is not initiated there, and other pathways normally contribute to movement. Greater use of these pathways can allow movement to be restored when the corticospinal system is damaged by, e.g. stroke, but there can be unwanted consequences of this ‘plasticity’. There is an extensive literature on cerebral mechanisms in the control of movement, and an equally large literature on spinal reflex function and the changes that occur during movement, and when pathology results in weakness and/or spasticity.

Improvement of spasticity following intermittent theta burst stimulation in multiple sclerosis is associated with modulation of resting-state functional connectivity of the primary motor cortices

2016 ◽  
Vol 23 (6) ◽  
pp. 855-863 ◽  
Author(s):  
Clémence Boutière ◽  
Caroline Rey ◽  
Wafaa Zaaraoui ◽  
Arnaud Le Troter ◽  
Audrey Rico ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Motor Cortex ◽  
Resting State ◽  
Primary Motor Cortex ◽  
Rehabilitation Programme ◽  
Lower Limbs ◽  
Theta Burst Stimulation ◽  
Burst Stimulation ◽  
Functional Reorganization ◽  
Theta Burst

Background: Intermittent theta burst stimulation (iTBS) of the primary motor cortex improves transiently lower limbs spasticity in multiple sclerosis (MS). However, the cerebral mechanisms underlying this effect have never been investigated. Objective: To assess whether modulation of spasticity induced by iTBS is underlined by functional reorganization of the primary motor cortices. Methods: A total of 17 patients with MS suffering from lower limbs spasticity were randomized to receive real iTBS or sham iTBS during the first half of a 5-week indoor rehabilitation programme. Spasticity was assessed using the Modified Ashworth Scale and the Visual Analogue Scale at baseline, after the stimulation session and at the end of the rehabilitation programme. Resting-state functional magnetic resonance imaging (fMRI) was performed at the three time points, and brain functional networks topology was analysed using graph-theoretical approach. Results: At the end of stimulation, improvement of spasticity was greater in real iTBS group than in sham iTBS group ( p = 0.026). iTBS had a significant effect on the balance of the connectivity degree between the stimulated and the homologous primary motor cortex ( p = 0.005). Changes in inter-hemispheric balance were correlated with improvement of spasticity (rho = 0.56, p = 0.015). Conclusion: This longitudinal resting-state fMRI study evidences that functional reorganization of the primary motor cortices may underlie the effect of iTBS on spasticity in MS.

scholarly journals Amble Gait EEG Points at Complementary Cortical Networks Underlying Stereotypic Multi-Limb Co-ordination

2021 ◽  
Vol 15 ◽  
Author(s):  
Joyce B. Weersink ◽  
Natasha M. Maurits ◽  
Bauke M. de Jong
Keyword(s):  
Lower Limb ◽  
Primary Motor Cortex ◽  
Right Hemisphere ◽  
Gait Pattern ◽  
Lower Limbs ◽  
Human Gait ◽  
Hemisphere Dominance ◽  
The Right ◽  
Spectral Perturbation ◽  
Healthy Participants

BackgroundWalking is characterized by stable antiphase relations between upper and lower limb movements. Such bilateral rhythmic movement patterns are neuronally generated at levels of the spinal cord and brain stem, that are strongly interconnected with cortical circuitries, including the Supplementary Motor Area (SMA).ObjectiveTo explore cerebral activity associated with multi-limb phase relations in human gait by manipulating mutual attunement of the upper and lower limb antiphase patterns.MethodsCortical activity and gait were assessed by ambulant EEG, accelerometers and videorecordings in 35 healthy participants walking normally and 19 healthy participants walking in amble gait, where upper limbs moved in-phase with the lower limbs. Power changes across the EEG frequency spectrum were assessed by Event Related Spectral Perturbation analysis and gait analysis was performed.ResultsAmble gait was associated with enhanced Event Related Desynchronization (ERD) prior to and during especially the left swing phase and reduced Event Related Synchronization (ERS) at final swing phases. ERD enhancement was most pronounced over the putative right premotor, right primary motor and right parietal cortex, indicating involvement of higher-order organization and somatosensory guidance in the production of this more complex gait pattern, with an apparent right hemisphere dominance. The diminished within-step ERD/ERS pattern in amble gait, also over the SMA, suggests that this gait pattern is more stride driven instead of step driven.ConclusionIncreased four-limb phase complexity recruits distributed networks upstream of the primary motor cortex, primarily lateralized in the right hemisphere. Similar parietal-premotor involvement has been described to compensate impaired SMA function in Parkinson’s disease bimanual antiphase movement, indicating a role as cortical support regions.

Para-Sports can Promote Functional Reorganization in the Ipsilateral Primary Motor Cortex of Lower Limbs Amputee

2021 ◽  
pp. 154596832110566
Author(s):  
Tomoya Nakanishi ◽  
Nobuaki Mizuguchi ◽  
Kento Nakagawa ◽  
Kimitaka Nakazawa
Keyword(s):  
Motor Cortex ◽  
Lower Limb ◽  
Primary Motor Cortex ◽  
Chronic Phase ◽  
Sports Participation ◽  
Lower Limbs ◽  
Limb Amputation ◽  
Functional Reorganization ◽  
Lower Limb Amputees

Background. Drastic functional reorganization was observed in the ipsilateral primary motor cortex (M1) of a Paralympic long jumper with a unilateral below-knee amputation in our previous study. However, it remains unclear whether long-term para-sports are associated with ipsilateral M1 reorganization since only 1 athlete with amputation was investigated. Objective. This study aimed to investigate the relationship between the long-term para-sports and ipsilateral M1 reorganization after lower limb amputation. Methods. Lower limb rhythmic muscle contraction tasks with functional magnetic resonance imaging and T1-weighted structural imaging were performed in 30 lower limb amputees with different para-sports experiences in the chronic phase. Results. Brain activity in the ipsilateral primary motor and somatosensory areas (SM1) as well as the contralateral dorsolateral prefrontal cortex, SM1, and inferior temporal gyrus showed a positive correlation with the years of routine para-sports participation (sports years) during contraction of the amputated knee. Indeed, twelve of the 30 participants who exhibited significant ipsilateral M1 activation during amputated knee contraction had a relatively longer history of para-sports participation. No significant correlation was found in the structural analysis. Conclusions. Long-term para-sports could lead to extensive reorganization at the brain network level, not only bilateral M1 reorganization but also reorganization of the frontal lobe and visual pathways. These results suggest that the interaction of injury-induced and use-dependent cortical plasticity might bring about drastic reorganization in lower limb amputees.

scholarly journals Structural and functional brain changes following four weeks of unimanual motor training: evidence from behaviour, neural stimulation, cortical thickness and functional MRI

2016 ◽  
Author(s):  
Martin V. Sale ◽  
Lee B. Reid ◽  
Luca Cocchi ◽  
Alex M. Pagnozzi ◽  
Stephen E. Rose ◽  
...  
Keyword(s):  
Functional Mri ◽  
Left Hemisphere ◽  
Cortical Thickness ◽  
Primary Motor Cortex ◽  
Right Hemisphere ◽  
Brain Plasticity ◽  
Motor Evoked Potential ◽  
Precentral Gyrus ◽  
Control Sequence ◽  
The Right

AbstractAlthough different aspects of neuroplasticity can be quantified with behavioural probes, brain stimulation, and brain imaging assessments, no study to date has combined all these approaches into one comprehensive assessment of brain plasticity. Here, 24 healthy right-handed participants practised a sequence of finger-thumb opposition movements for 10 minutes each day with their left hand. After four weeks, performance for the practised sequence improved significantly (p < 0.05 FWE) relative to a matched control sequence, with both the left (mean increase: 53.0% practised, 6.5% control) and right (21.0%; 15.8%) hands. Training also induced significant (cluster p-FWE < 0.001) reductions in functional MRI activation for execution of the learned sequence, relative to the control sequence. These changes were observed as clusters in the premotor and supplementary motor cortices (right hemisphere, 301 voxel cluster; left hemisphere 700 voxel cluster), as well as sensorimotor cortices and superior parietal lobules (right hemisphere 864 voxel cluster; left hemisphere, 1947 voxel cluster). Transcranial magnetic stimulation over the right (‘trained’) primary motor cortex yielded a 58.6% mean increase in a measure of motor evoked potential amplitude, as recorded at the left abductor pollicis brevis muscle. Cortical thickness analyses based on structural MRI suggested changes in the right precentral gyrus, right post central gyrus, right dorsolateral prefrontal cortex and potentially the right supplementary motor area. Such findings are consistent with LTP-like neuroplastic changes in areas that were already responsible for finger sequence execution, rather than improved recruitment of previously non-utilised tissue.

scholarly journals Reduced Interhemispheric Coherence in Cerebellar Kainic Acid-Induced Lateralized Dystonia

2020 ◽  
Vol 11 ◽  
Author(s):  
Elena Laura Georgescu Margarint ◽  
Ioana Antoaneta Georgescu ◽  
Carmen Denise Mihaela Zahiu ◽  
Stefan-Alexandru Tirlea ◽  
Alexandru Rǎzvan Şteopoaie ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Kainic Acid ◽  
Primary Motor Cortex ◽  
Low Frequency ◽  
Muscular Activity ◽  
Cerebellar Hemisphere ◽  
Interhemispheric Coherence ◽  
General Locomotor Activity ◽  
Complex Circuits ◽  
The Right

The execution of voluntary muscular activity is controlled by the primary motor cortex, together with the cerebellum and basal ganglia. The synchronization of neural activity in the intracortical network is crucial for the regulation of movements. In certain motor diseases, such as dystonia, this synchrony can be altered in any node of the cerebello-cortical network. Questions remain about how the cerebellum influences the motor cortex and interhemispheric communication. This research aims to study the interhemispheric cortical communication between the motor cortices during dystonia, a neurological movement syndrome consisting of sustained or repetitive involuntary muscle contractions. We pharmacologically induced lateralized dystonia to adult male albino mice by administering low doses of kainic acid on the left cerebellar hemisphere. Using electrocorticography and electromyography, we investigated the power spectral densities, cortico-muscular, and interhemispheric coherence between the right and left motor cortices, before and during dystonia, for five consecutive days. Mice displayed lateralized abnormal motor signs, a reduced general locomotor activity, and a high score of dystonia. The results showed a progressive interhemispheric coherence decrease in low-frequency bands (delta, theta, beta) during the first 3 days. The cortico-muscular coherence of the affected side had a significant increase in gamma bands on days 3 and 4. In conclusion, lateralized cerebellar dysfunction during dystonia was associated with a loss of connectivity in the motor cortices, suggesting a possible cortical compensation to the initial disturbances induced by cerebellar left hemisphere kainate activation by blocking the propagation of abnormal oscillations to the healthy hemisphere. However, the cerebellum is part of several overly complex circuits, therefore other mechanisms can still be involved in this phenomenon.

scholarly journals Is Lateropulsion Really Related with a Specific Lesion of the Brain?

2021 ◽  
Vol 11 (3) ◽  
pp. 354
Author(s):  
Kyoung Lee ◽  
Sang Yoo ◽  
Eun Ji ◽  
Woo Hwang ◽  
Yeun Yoo ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Parietal Lobe ◽  
Inferior Frontal Gyrus ◽  
Brain Lesions ◽  
Vertical Posture ◽  
Lesion Volume ◽  
Precentral Gyrus ◽  
Stroke Patients ◽  
The Right ◽  
Right Hemisphere Stroke

Lateropulsion (pusher syndrome) is an important barrier to standing and gait after stroke. Although several studies have attempted to elucidate the relationship between brain lesions and lateropulsion, the effects of specific brain lesions on the development of lateropulsion remain unclear. Thus, the present study investigated the effects of stroke lesion location and size on lateropulsion in right hemisphere stroke patients. The present retrospective cross-sectional observational study assessed 50 right hemisphere stroke patients. Lateropulsion was diagnosed and evaluated using the Scale for Contraversive Pushing (SCP). Voxel-based lesion symptom mapping (VLSM) analysis with 3T-MRI was used to identify the culprit lesion for SCP. We also performed VLSM controlling for lesion volume as a nuisance covariate, in a multivariate model that also controlled for other factors contributing to pusher behavior. VLSM, combined with statistical non-parametric mapping (SnPM), identified the specific region with SCP. Lesion size was associated with lateropulsion. The precentral gyrus, postcentral gyrus, inferior frontal gyrus, insula and subgyral parietal lobe of the right hemisphere seemed to be associated with the lateropulsion; however, after adjusting for lesion volume as a nuisance covariate, no lesion areas were associated with the SCP scores. The size of the right hemisphere lesion was the only factor most strongly associated with lateropulsion in patients with stroke. These results may be useful for planning rehabilitation strategies of restoring vertical posture and understanding the pathophysiology of lateropulsion in stroke patients.

Neurospect Findings in Patients Exposed to Neurotoxic Chemicals

1994 ◽  
Vol 10 (4-5) ◽  
pp. 561-571
Author(s):  
Gunnar Heuser ◽  
Ismael Mena ◽  
Francisca Alamos
Keyword(s):  
Elderly Patients ◽  
Qualitative Analysis ◽  
Right Hemisphere ◽  
Young Patients ◽  
Chronic Fatigue ◽  
Psychiatric Symptomatology ◽  
Elderly Individuals ◽  
Parietal Lobes ◽  
The Right ◽  
The Brain

Exposures to neurotoxic chemicals such as pesticides, glues, solvents, etc. are known to induce neurologic and psychiatric symptomatology. We report on 41 patients 16 young patients (6 males, 10 females, age 34 8 yrs.) and 25 elderly patients (9 males, 16 females, age 55 7 yrs). Fifteen of them were exposed to pesticides, and 29 to solvents. They were studied with quantitative and qualitative analysis of regional cerebral bood flow (rCBF), performed with 30 mCi of Xe-133 by inhalation, followed by 30 mCi of Tc-HMPAO given intravenously. Imaging was performed with a brain dedicated system, distribution of rCBF was assessed with automatic ROI definition, and HMPAO was normalized to maximal pixel activity in the brain. Results of Xe rCBF are expressed as mean and S.D. in ml/min/100g, and HMPAO as mean and S.D. uptake per ROI, and compared with age-matched controls 10 young and 20 elderly individuals. Neurotoxics HMPAO Uptake Young Elderly R. Orbital frontal R. Dorsal frontal .70 .66 p < 0.05 R. Temporal .64 p < 0.001 R. Parietal .66 .66 We conclude that patients exposed to chemicals present with diminished CBF, worse in the right hemisphere, with random presentation of areas of hypoperfusion, more prevalent in the dorsal frontal and parietal lobes. These findings are significantly different from observations in patients with chronic fatigue and depression, suggesting primary cortical effect, possibly due to a vasculitis process.

Effects of the SNAP25 on Integration Ability of Brain Functions in Children With ADHD

2020 ◽  
pp. 108705472096456
Author(s):  
Yue Yang ◽  
Gang Peng ◽  
Hongwu Zeng ◽  
Diangang Fang ◽  
Linlin Zhang ◽  
...  
Keyword(s):  
Time Window ◽  
Precentral Gyrus ◽  
Children With Adhd ◽  
Brain Functions ◽  
Lingual Gyrus ◽  
Window Method ◽  
Central Gyrus ◽  
The Right ◽  
The Brain ◽  
Insight Into

Objective: The present study aimed to examine the effects of SNAP25 on the integration ability of intrinsic brain functions in children with ADHD, and whether the integration ability was associated with working memory (WM). Methods: A sliding time window method was used to calculate the spatial and temporal concordance among five rs-fMRI regional indices in 55 children with ADHD and 20 healthy controls. Results: The SNAP25 exhibited significant interaction effects with ADHD diagnosis on the voxel-wise concordance in the right posterior central gyrus, fusiform gyrus and lingual gyrus. Specifically, for children with ADHD, G-carriers showed increased voxel-wise concordance in comparison to TT homozygotes in the right precentral gyrus, superior frontal gyrus, postcentral gyrus, and middle frontal gyrus. The voxel-wise concordance was also found to be related to WM. Conclusion: Our findings provided a new insight into the neural mechanisms of the brain function of ADHD children.

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