title: Characterizing relationships of DTI, fMRI, and motor recovery in stroke rehabilitation utilizing brain-computer interface technology.
abstract: The relationship of the structural integrity of white matter tracts and cortical activity to motor functional outcomes in stroke patients is of particular interest in understanding mechanisms of brain structural and functional changes while recovering from stroke. This study aims to probe these underlying mechanisms using diffusion tensor imaging (DTI) and fMRI measures. We examined the structural integrity of the posterior limb of the internal capsule (PLIC) using DTI and corticomotor activity using motor-task fMRI in stroke patients who completed up to 15 sessions of rehabilitation therapy using Brain-Computer Interface (BCI) technology. We hypothesized that (1) the structural integrity of PLIC and corticomotor activity are affected by stroke; (2) changes in structural integrity and corticomotor activity following BCI intervention are related to motor recovery; (3) there is a potential relationship between structural integrity and corticomotor activity. We found that (1) the ipsilesional PLIC showed significantly decreased fractional anisotropy (FA) values when compared to the contralesional PLIC; (2) lower ipsilesional PLIC-FA values were significantly associated with worse motor outcomes (i.e., ipsilesional PLIC-FA and motor outcomes were positively correlated.); (3) lower ipsilesional PLIC-FA values were significantly associated with greater ipsilesional corticomotor activity during impaired-finger-tapping-task fMRI (i.e., ipsilesional PLIC-FA and ipsilesional corticomotor activity were negatively correlated), with an overall bilateral pattern of corticomotor activity observed; and (4) baseline FA values predicted motor recovery assessed after BCI intervention. These findings suggest that (1) greater vs. lesser microstructural integrity of the ipsilesional PLIC may contribute toward better vs. poor motor recovery respectively in the stroke-affected limb and demand lesser vs. greater cortical activity respectively from the ipsilesional motor cortex; and that (2) PLIC-FA is a promising biomarker in tracking and predicting motor functional recovery in stroke patients receiving BCI intervention.
authors.affiliation: Department of Radiology, University of Wisconsin - Madison Madison, WI, USA ; Department of Biomedical Engineering, University of Wisconsin - Madison Madison, WI, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Song
authors.affiliation: Department of Radiology, University of Wisconsin - Madison Madison, WI, USA ; Medical Scientist Training Program, University of Wisconsin School of Medicine and Public Health - Madison Madison, WI, USA ; Neuroscience Training Program, University of Wisconsin School of Medicine and Public Health - Madison Madison, WI, USA.
authors.forename: Brittany M
authors.initials: BM
authors.lastname: Young
authors.affiliation: Department of Radiology, University of Wisconsin - Madison Madison, WI, USA.
authors.forename: Zack
authors.initials: Z
authors.lastname: Nigogosyan
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison Madison, WI, USA ; Neuroscience Training Program, University of Wisconsin School of Medicine and Public Health - Madison Madison, WI, USA.
authors.forename: Leo M
authors.initials: LM
authors.lastname: Walton
authors.affiliation: Department of Radiology, University of Wisconsin - Madison Madison, WI, USA.
authors.forename: Veena A
authors.initials: VA
authors.lastname: Nair
authors.affiliation: Department of Radiology, University of Wisconsin - Madison Madison, WI, USA.
authors.forename: Scott W
authors.initials: SW
authors.lastname: Grogan
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison Madison, WI, USA ; Departments of Orthopedics and Rehabilitation, University of Wisconsin - Madison Madison, WI, USA.
authors.forename: Mitchell E
authors.initials: ME
authors.lastname: Tyler
authors.affiliation: Department of Kinesiology, University of Wisconsin - Madison Madison, WI, USA ; Department of Medicine, University of Wisconsin - Madison Madison, WI, USA ; Department of Neurology, University of Wisconsin - Madison Madison, WI, USA.
authors.forename: Dorothy
authors.initials: D
authors.lastname: Farrar-Edwards
authors.affiliation: Departments of Orthopedics and Rehabilitation, University of Wisconsin - Madison Madison, WI, USA.
authors.forename: Kristin E
authors.initials: KE
authors.lastname: Caldera
authors.affiliation: Department of Neurology, University of Wisconsin - Madison Madison, WI, USA.
authors.forename: Justin A
authors.initials: JA
authors.lastname: Sattin
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison Madison, WI, USA ; Neuroscience Training Program, University of Wisconsin School of Medicine and Public Health - Madison Madison, WI, USA ; Department of Neurosurgery, University of Wisconsin - Madison Madison, WI, USA.
authors.forename: Justin C
authors.initials: JC
authors.lastname: Williams
authors.affiliation: Department of Radiology, University of Wisconsin - Madison Madison, WI, USA ; Medical Scientist Training Program, University of Wisconsin School of Medicine and Public Health - Madison Madison, WI, USA ; Neuroscience Training Program, University of Wisconsin School of Medicine and Public Health - Madison Madison, WI, USA ; Department of Neurology, University of Wisconsin - Madison Madison, WI, USA ; Department of Psychiatry, University of Wisconsin - Madison Madison, WI, USA ; Department of Psychology, University of Wisconsin - Madison Madison, WI, USA.
authors.forename: Vivek
authors.initials: V
authors.lastname: Prabhakaran
keywords: BCI; DTI; FA; fMRI; motor recovery; stroke rehabilitation