An Approach for fMRI-Guided Targeted TMS on Stroke Rehabilitation
Poster No:
2316
Submission Type:
Abstract Submission
Authors:
Jue Wang1, Ming Zeng2, Qiu Lin3, Qiu Ge3, Yang Qiao3, Yun-Song Hu3, Jian-Ming Fu4, Xu-Dong Gu4, Yu-Feng ZANG3
Institutions:
1Institute of sports medicine and health, Chengdu Sport University, Chengdu, Sichuan, 2he Second Affiliated Hospital of Jiaxing University, Jiaxing, Zhejiang, 3The Affiliated Hospital of Hangzhou Normal University, Hangzhou, Zhejiang, 4The Second Affiliated Hospital of Jiaxing University, Jiaxing, Zhejiang
First Author:
Co-Author(s):
Introduction:
More than half of stroke patients have not recovered their hand function on the affected side at 3-6 months after the incident (Abo, et al., 2014). Promoting the recovery of hand function is one of the challenges in clinical rehabilitation. The effectiveness of repetitive Transcranial Magnetic Stimulation (rTMS) greatly varies across individuals (Du, et al., 2019; Meng, et al., 2020; Xiang, et al., 2019). The traditionally used target is a hotspot identified by a TMS-induced motor evoked potential (MEP), but it is challenging to identify such a hotspot in the affected hemisphere in patients undergoing post-stroke rTMS because of the inability to evoke MEP responses. Therefore, a mirror-point of the hotspot on the unaffected hemisphere is used as target, but this approach lacks a neuroscientific basis. Our prior research demonstrated that brain activation during a finger tapping task not only represents voluntary movements, but also is functionally specific. Finger tapping task exhibits a broad range of activity and intense functional connectivity (FC) with the motor cognition network (Wang, et al., 2020), and earlier studies reported strong FC between the activation of a finger tapping task in the bilateral motor cortex (Biswal, et al., 1995). This FC was shown to perform as well or better than task-based functional magnetic resonance imaging (fMRI) when localizing the representation area in patients with tumors in the sensorimotor cortex (Zhang, et al., 2009). On the basis of the aforementioned evidence and prior experimental data obtained by our research group, we established a robust methodology for identifying the therapeutic targets for stroke.
Methods:
To accomplish this goal, we undertook the following steps: (1) performed task activation detection and functional connectivity at the group level to define the bilateral motor area in healthy participants; (2) validated the spatial relationships between task activation and contralateral functional connectivity peak voxels at the individual level, ensuring the accuracy and precision of our targets; (3) simulated application of both low-frequency and high-frequency rTMS to the activation and functional connectivity targets, based on an interhemispheric competition model, with the hypothesis that rTMS would lead to functional reorganization within brain regions implicated in voluntary movement; and (4) applied these targets to facilitate individualized clinical treatment for post-stroke patients, with a particular emphasis on the affected hemisphere.
Results:
The cluster of bilateral hemisphere hand motor areas in group level were centered at X = −36, Y = −14, Z = 57, and X = 35, Y = −16, Z = 62. Paired t-tests showed that the amplitude of low frequency fluctuation (ALFF) and regional homogeneity (ReHo) values were significantly altered after simulating bilateral rTMS (GRF correction, voxel level p < 0.001, cluster level p < 0.05; Figure 1). The clinical assessments of all patients exhibited varying degrees of improvement. The imaging patterns of the rTMS modulatory effect (ALFF and ReHo) differed between patients in respect to brain regions, activity extents, and intensity (Figure 2). All motor-related brain regions (such as the basal ganglia, thalamus, cerebellum, and motor cortex) showed individual alterations after rTMS and the insular showed commonly modulatory effect.
Conclusions:
Our methodology overcomes the challenge of precise target localization, especially on the affected hemisphere. The clinical assessments of all patients exhibited varying degrees of improvement, and the brain functions of all motor-related regions were modulated by rTMS, albeit with individual differences. The fMRI-guided-targets might be promising for post-stroke rTMS treatment and need further investigation.
Brain Stimulation:
Non-invasive Magnetic/TMS 2
Disorders of the Nervous System:
Neurodegenerative/ Late Life (eg. Parkinson’s, Alzheimer’s)
Novel Imaging Acquisition Methods:
BOLD fMRI 1
Keywords:
ADULTS
FUNCTIONAL MRI
Sub-Cortical
Transcranial Magnetic Stimulation (TMS)
Treatment
1|2Indicates the priority used for review
·Figure 1. ALFF and ReHo values were significantly altered after simulating bilateral rTMS (GRF correction, voxel level p < 0.001, cluster level p < 0.05).
·Figure 2. The different patterns of imaging maps in patients. The maps were subjected to a threshold for each metric to depict the observed patterns, without undergoing statistical analysis.
Provide references using author date format
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