Functional Activation-Informed Structural Changes during Stroke Recovery: A Longitudinal MRI Study

Abstract

Objective Neuroimaging studies revealed the functional reorganization or the structural changes during stroke recovery. However, previous studies did not combine the functional and structural information and the results might be affected by heterogeneous lesion. This study aimed to investigate functional activation-informed structural changes during stroke recovery. Methods MRI data of twelve stroke patients were collected at four consecutive time points during the first 3 months after stroke onset. Functional activation during finger-tapping task was used to inform the analysis of structural changes of activated brain regions. Correlation between structural changes in motor-related activated brain regions and motor function recovery was estimated. Results The averaged gray matter volume (aGMV) of contralesional activated brain regions and laterality index of gray matter volume (LIGMV) increased during stroke recovery, and LIGMV was positively correlated with Fugl-Meyer Index (FMI) at initial stage after stroke. The aGMV of bilateral activated brain regions was negatively correlated with FMI during the stroke recovery. Conclusion This study demonstrated that combining the stroke-induced functional reorganization and structural change provided new insights into the underlying innate plasticity process during stroke recovery. Significance This study proposed a new approach to integrate functional and structural information for investigating the innate plasticity after stroke.

Neuromodulation of Executive Dysfunction in Patients with Acute Stroke Using Transcranial Direct Current Stimulation: Study Protocol for a Triple-Blind, Randomized Sham-Controlled Trial

“…Furthermore, the mechanism by which the neural effects of electrical stimulation are achieved is not fully elucidated, yet few clinical trials have included neurophysiological or functional neuroimaging techniques in their protocols. Functional magnetic resonance and molecular brain imaging, such positron emission tomography and single photon emission computed tomography, have been useful in understanding the neural mechanisms after brain disease; however, they are expensive and hardly available techniques [71,72]. Exploring functional connectivity using cheaper and more portable techniques such as fNIRS will be implemented to analyse its feasibility and to further explore the mechanisms underlying the effect of tDCS in the recruited subjects.…”

The Impact of Voluntary Exercise on Stroke Recovery

“…New insights in the therapeutic effects of exercise after ischemic stroke are available, showing benefits in restoring brain damage as well as functional rehabilitation ( Luo et al, 2007 ; Voss et al, 2013 ; Zhang et al, 2013 ). While there is general consensus that recovery of brain connectivity (structural and functional) is crucial for functional stroke rehabilitation, studies investigating the impact of exercise on brain networks are lacking ( Wu et al, 2017 ). Therefore, we assessed the impact of voluntary exercise on the recovery of stroke induced mice with a combination of functional and structural MRI measures (DTI, rsfMRI, CBF), behavioral parameters, molecular markers (inflammation, vascular density and quality, angiogenesis) and compared their recovery to a control group without access to running wheels.…”

“…A persistent lack of knowledge exists concerning efficacy of voluntary exercise in recovering of structural and functional brain networks and subsequent functional recovery after stroke ( Wu et al, 2017 ). The cerebral capability for functional changes, such as better connectivity between brain regions, as well as structural changes, including better WM integrity, has been reported to be crucial for motor function recovery ( Wu et al, 2017 ).…”

“…A persistent lack of knowledge exists concerning efficacy of voluntary exercise in recovering of structural and functional brain networks and subsequent functional recovery after stroke ( Wu et al, 2017 ). The cerebral capability for functional changes, such as better connectivity between brain regions, as well as structural changes, including better WM integrity, has been reported to be crucial for motor function recovery ( Wu et al, 2017 ). Though progress has been made in studying the impact of physical exercise on stroke rehabilitation, no studies are available investigating whether exercise can help to attenuate stroke induced brain network damage, impaired WM integrity and related motor deficits.…”

Variation in brain connectivity during motor imagery and motor execution in stroke patients based on electroencephalography

“…Therefore, we can infer that the PMA plays a more crucial role in motor execution in hemiplegic patients. In addition, some studies have reported that activation during dominant hand movements is relatively greater than that during non-dominant hand movements (Wu et al, 2017). Therefore, in this study, we also compared the EEG signals between brain regions during the execution of right-handed movements in healthy participants and patients with right hemiplegia and discovered that the activation of the movement-related brain regions was greater than that of healthy participants during the execution of movements in patients with hemiplegia and that the activation of the PMA was more evident, similar to the findings of the study conducted by Chunyong et al (2023).…”