Abnormal dynamic brain activity and functional connectivity of primary motor cortex in blepharospasm

2021 ◽  
Author(s):  
Yuhan Luo ◽  
Yaomin Guo ◽  
Linchang Zhong ◽  
Ying Liu ◽  
Chao Dang ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Brain Activity

scholarly journals Reduced functional connectivity within the primary motor cortex of patients with brachial plexus injury

2016 ◽  
Vol 12 ◽  
pp. 277-284 ◽  
Author(s):  
D. Fraiman ◽  
M.F. Miranda ◽  
F. Erthal ◽  
P.F. Buur ◽  
M. Elschot ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Motor Cortex ◽  
Brachial Plexus ◽  
Primary Motor Cortex ◽  
Brachial Plexus Injury

scholarly journals Shared functional connectivity between the dorso-medial and dorso-ventral streams in macaques

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
R. Stefan Greulich ◽  
Ramina Adam ◽  
Stefan Everling ◽  
Hansjörg Scherberger
Keyword(s):  
Functional Connectivity ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Rhesus Macaques ◽  
Premotor Cortex ◽  
Network Connectivity ◽  
Insular Cortex ◽  
Resting State Fmri ◽  
Precentral Gyrus ◽  
Related Information

Abstract Manipulation of an object requires us to transport our hand towards the object (reach) and close our digits around that object (grasp). In current models, reach-related information is propagated in the dorso-medial stream from posterior parietal area V6A to medial intraparietal area, dorsal premotor cortex, and primary motor cortex. Grasp-related information is processed in the dorso-ventral stream from the anterior intraparietal area to ventral premotor cortex and the hand area of primary motor cortex. However, recent studies have cast doubt on the validity of this separation in separate processing streams. We investigated in 10 male rhesus macaques the whole-brain functional connectivity of these areas using resting state fMRI at 7-T. Although we found a clear separation between dorso-medial and dorso-ventral network connectivity in support of the two-stream hypothesis, we also found evidence of shared connectivity between these networks. The dorso-ventral network was distinctly correlated with high-order somatosensory areas and feeding related areas, whereas the dorso-medial network with visual areas and trunk/hindlimb motor areas. Shared connectivity was found in the superior frontal and precentral gyrus, central sulcus, intraparietal sulcus, precuneus, and insular cortex. These results suggest that while sensorimotor processing streams are functionally separated, they can access information through shared areas.

scholarly journals Early parietofrontal network upregulation relates to future persistent deficits after severe stroke – a prospective cohort study

2021 ◽  
Author(s):  
Winifried Backhaus ◽  
Hanna Braaß ◽  
Focko L Higgen ◽  
Christian Gerloff ◽  
Robert Schulz
Keyword(s):  
Cohort Study ◽  
Functional Connectivity ◽  
Motor Cortex ◽  
Prospective Cohort Study ◽  
Prospective Cohort ◽  
Primary Motor Cortex ◽  
Motor Recovery ◽  
Intraparietal Sulcus ◽  
Stroke Patients ◽  
Correlative Models

Abstract Recent brain imaging has evidenced that parietofrontal networks show alterations after stroke which also relate to motor recovery processes. There is converging evidence for an upregulation of parietofrontal coupling between parietal brain regions and frontal motor cortices. The majority of studies though have included only moderately to mildly affected patients, particularly in the subacute or chronic stage. Whether these network alterations will also be present in severely affected patients and early after stroke and whether such information can improve correlative models to infer motor recovery remains unclear. In this prospective cohort study, nineteen severely affected first-ever stroke patients (mean age 74 years, 12 females) were analysed which underwent resting-state functional MRI and clinical testing during the initial week after the event. Clinical evaluation of neurological and motor impairment as well as global disability was repeated after three and six months. Nineteen healthy participants of similar age and gender were also recruited. MRI data were used to calculate functional connectivity values between the ipsilesional primary motor cortex, the ventral premotor cortex, the supplementary motor area and the anterior and caudal intraparietal sulcus of the ipsilesional hemisphere. Linear regression models were estimated to compare parietofrontal functional connectivity between stroke patients and healthy controls and to relate them to motor recovery. The main finding was a significant increase in ipsilesional parietofrontal coupling between anterior intraparietal sulcus and the primary motor cortex in severely affected stroke patients (P < 0.003). This upregulation significantly contributed to correlative models explaining variability in subsequent neurological and global disability as quantified by National Institute of Health Stroke Scale and modified Rankin Scale, respectively. Patients with increased parietofrontal coupling in the acute stage showed higher levels of persistent deficits in the late subacute stage of recovery (P < 0.05). This study provides novel insights that parietofrontal networks of the ipsilesional hemisphere undergo neuroplastic alteration already very early after severe motor stroke. The association between early parietofrontal upregulation and future levels of persistent functional deficits and dependence from help in daily living might be useful in models to enhance clinical neurorehabilitative decision making.

Fatigue in multiple sclerosis: The contribution of resting-state functional connectivity reorganization

2017 ◽  
Vol 24 (13) ◽  
pp. 1696-1705 ◽  
Author(s):  
Alvino Bisecco ◽  
Federica Di Nardo ◽  
Renato Docimo ◽  
Giuseppina Caiazzo ◽  
Alessandro d’Ambrosio ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Regression Analysis ◽  
Functional Connectivity ◽  
Motor Cortex ◽  
Resting State ◽  
Primary Motor Cortex ◽  
Linear Regression Analysis ◽  
Posterior Cingulate Cortex ◽  
Resting State Functional Connectivity ◽  
Sensorimotor Network

Objectives: To investigate resting-state functional connectivity (RS-FC) of the default-mode network (DMN) and of sensorimotor network (SMN) network in relapsing remitting (RR) multiple sclerosis (MS) patients with fatigue (F) and without fatigue(NF). Methods: In all, 59 RRMS patients and 29 healthy controls (HC) underwent magnetic resonance imaging (MRI) protocol including resting-state fMRI (RS-fMRI). Functional connectivity of the DMN and SMN was evaluated by independent component analysis (ICA). A linear regression analysis was performed to explore whether fatigue was mainly driven by changes observed in the DMN or in the SMN. Regional gray matter atrophy was assessed by voxel-based morphometry (VBM). Results: Compared to HC, F-MS patients showed a stronger RS-FC in the posterior cingulate cortex (PCC) and a reduced RS-FC in the anterior cingulated cortex (ACC) of the DMN. F-MS patients, compared to NF-MS patients, revealed (1) an increased RS-FC in the PCC and a reduced RS-FC in the ACC of the DMN and (2) an increased RS-FC in the primary motor cortex and in the supplementary motor cortex of the SMN. The regression analysis suggested that fatigue is mainly driven by RS-FC changes of the DMN. Conclusions: Fatigue in RRMS is mainly associated to a functional rearrangement of non-motor RS networks.

116. Functional connectivity between cortical speech network and primary motor cortex is abnormal in spasmodic dysphonia

2015 ◽  
Vol 126 (1) ◽  
pp. e27 ◽  
Author(s):  
F. Giovannelli ◽  
L. Marsili ◽  
A. Suppa ◽  
F. Di Stasio ◽  
L. Rocchi ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Spasmodic Dysphonia

scholarly journals Corticospinal Tract Anatomy and Functional Connectivity of Primary Motor Cortex in Autism

2015 ◽  
Vol 54 (10) ◽  
pp. 859-867 ◽  
Author(s):  
Ruth A. Carper ◽  
Seraphina Solders ◽  
Jeffrey M. Treiber ◽  
Inna Fishman ◽  
Ralph-Axel Müller
Keyword(s):  
Functional Connectivity ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Corticospinal Tract

Functional Connectivity Between Secondary and Primary Motor Areas Underlying Hand–Foot Coordination

2007 ◽  
Vol 98 (1) ◽  
pp. 414-422 ◽  
Author(s):  
Winston D. Byblow ◽  
James P. Coxon ◽  
Cathy M. Stinear ◽  
Melanie K. Fleming ◽  
Garry Williams ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Motor Cortex ◽  
Muscle Activation ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Hand Movement ◽  
Physiological Basis ◽  
Activation Conditions ◽  
Motor Representations ◽  
Motor Areas

Coincident hand and foot movements are more reliably performed in the same direction than in opposite directions. Using transcranial magnetic stimulation (TMS) to assess motor cortex function, we examined the physiological basis of these movements across three novel experiments. Experiment 1 demonstrated that upper limb corticomotor excitability changed in a way that facilitated isodirectional movements of the hand and foot, during phasic and isometric muscle activation conditions. Experiment 2 demonstrated that motor cortex inhibition was modified with active, but not passive, foot movement in a manner that facilitated hand movement in the direction of foot movement. Together, these findings demonstrate that the coupling between motor representations within motor cortex is activity dependent. Because there are no known connections between hand and foot areas within primary motor cortex, experiment 3 used a dual-coil paired-pulse TMS protocol to examine functional connectivity between secondary and primary motor areas during active ankle dorsiflexion and plantarflexion. Dorsal premotor cortex (PMd) and supplementary motor area (SMA) conditioning, but not ventral premotor cortex (PMv) conditioning, produced distinct phases of task-dependent modulation of excitability of forearm representations within primary motor cortex (M1). Networks involving PMd–M1 facilitate isodirectional movements of hand and foot, whereas networks involving SMA–M1 facilitate corticomotor pathways nonspecifically, which may help to stabilize posture during interlimb coordination. These results may have implications for targeted neurorehabilitation after stroke.

scholarly journals Muscle and Timing-specific Functional Connectivity between the Dorsolateral Prefrontal Cortex and the Primary Motor Cortex

2013 ◽  
Vol 25 (4) ◽  
pp. 558-570 ◽  
Author(s):  
Alkomiet Hasan ◽  
Joseph M. Galea ◽  
Elias P. Casula ◽  
Peter Falkai ◽  
Sven Bestmann ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Motor Cortex ◽  
Animal Studies ◽  
Primary Motor Cortex ◽  
Adjacent Area ◽  
Left Dlpfc ◽  
Dorsolateral Prefrontal ◽  
The Difference ◽  
Selection Tasks ◽  
The Right

The pFC has a crucial role in cognitive control, executive function, and sensory processing. Functional imaging, neurophysiological, and animal studies provide evidence for a functional connectivity between the dorsolateral pFC (DLPFC) and the primary motor cortex (M1) during free choice but not instructed choice selection tasks. In this study, twin coil, neuronavigated TMS was used to examine the precise timing of the functional interaction between human left DLPFC and ipsilateral M1 during the execution of a free/specified choice selection task involving the digits of the right hand. In a thumb muscle that was not involved in the task, a conditioning pulse to the left DLPFC enhanced the excitability of the ipsilateral M1 during free selection more than specified selection 100 msec after presentation of the cue; the opposite effect was seen at 75 msec. However, the difference between free and externally specified conditions disappeared when a task-specific muscle was investigated. In this case, the influence from DLPFC was dominated by task involvement rather than mode of selection, suggesting that other processes related to movement execution were also operating. Finally, we show that the effects were spatially specific because they were absent when an adjacent area of DLPFC was stimulated. These results reveal temporally and spatially selective interactions between BA 46 and M1 that are both task and muscle specific.

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