Imaging functional recovery following ischemic stroke: clinical and preclinical fMRI studies

Crofts, Andrew; Kelly, Michael E.; Gibson, Claire L.

Abstract

Disability and effectiveness of physical therapy are highly variable following ischemic stroke due to different brain regions being affected. Functional magnetic resonance imaging (fMRI) studies of patients in the months and years following stroke have given some insight into how the brain recovers lost functions. Initially, new pathways are recruited to compensate for the lost region, showing as a brighter BOLD signal over a larger area during a task than in healthy controls. Subsequently, activity is reduced to baseline levels as pathways become more efficient, mimicking the process of learning typically seen during development. Preclinical models of ischemic stroke aim to enhance understanding of the biology underlying recovery following stroke. However, the pattern of recruitment and focusing seen in humans has not been observed in preclinical fMRI studies which are highly variable methodologically. Resting-state fMRI studies show more consistency, however there are still confounding factors to address. Anaesthesia and method of stroke induction are the two main sources of variability in preclinical studies; improvements here can reduce variability and increase the intensity and reproducibility of the BOLD response detected by fMRI. Differences in task or stimulus, and differences in analysis method also present a source of variability. This review compares clinical and preclinical fMRI studies of recovery following stroke and focuses on how refinement of preclinical models and MRI methods may obtain more representative fMRI data in relation to human studies.

Citation

Crofts, A., Kelly, M. E., & Gibson, C. L. (2020). Imaging functional recovery following ischemic stroke: clinical and preclinical fMRI studies. Journal of Neuroimaging, 30(1), 5-14. https://doi.org/10.1111/jon.12668

• Journal Article Type: Article
• Acceptance Date: Sep 25, 2019
• Online Publication Date: Oct 13, 2019
• Publication Date: 2020-01
• Deposit Date: Oct 3, 2019
• Publicly Available Date: Oct 14, 2020
• Journal: Journal of Neuroimaging
• Print ISSN: 1051-2284
• Electronic ISSN: 1552-6569
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 30
• Issue: 1
• Pages: 5-14
• DOI: https://doi.org/10.1111/jon.12668
• Keywords: Radiology Nuclear Medicine and imaging; Clinical Neurology
• Public URL: https://nottingham-repository.worktribe.com/output/2741339
• Publisher URL: https://onlinelibrary.wiley.com/doi/full/10.1111/jon.12668
• Additional Information: Received: 2019-08-21; Accepted: 2019-09-25; Published: 2019-10-13
• Contract Date: Oct 3, 2019