title: DTI measures track and predict motor function outcomes in stroke rehabilitation utilizing BCI technology.
abstract: Tracking and predicting motor outcomes is important in determining effective stroke rehabilitation strategies. Diffusion tensor imaging (DTI) allows for evaluation of the underlying structural integrity of brain white matter tracts and may serve as a potential biomarker for tracking and predicting motor recovery. In this study, we examined the longitudinal relationship between DTI measures of the posterior limb of the internal capsule (PLIC) and upper-limb motor outcomes in 13 stroke patients (median 20-month post-stroke) who completed up to 15 sessions of intervention using brain-computer interface (BCI) technology. Patients' upper-limb motor outcomes and PLIC DTI measures including fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) were assessed longitudinally at four time points: pre-, mid-, immediately post- and 1-month-post intervention. DTI measures and ratios of each DTI measure comparing the ipsilesional and contralesional PLIC were correlated with patients' motor outcomes to examine the relationship between structural integrity of the PLIC and patients' motor recovery. We found that lower diffusivity and higher FA values of the ipsilesional PLIC were significantly correlated with better upper-limb motor function. Baseline DTI ratios were significantly correlated with motor outcomes measured immediately post and 1-month-post BCI interventions. A few patients achieved improvements in motor recovery meeting the minimum clinically important difference (MCID). These findings suggest that upper-limb motor recovery in stroke patients receiving BCI interventions relates to the microstructural status of the PLIC. Lower diffusivity and higher FA measures of the ipsilesional PLIC contribute toward better motor recovery in the stroke-affected upper-limb. DTI-derived measures may be a clinically useful biomarker in tracking and predicting motor recovery in stroke patients receiving BCI interventions.
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI USA ; Department of Radiology, 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.
authors.forename: Veena A
authors.initials: VA
authors.lastname: Nair
authors.affiliation: Department of Radiology, University of Wisconsin-Madison, Madison, WI USA ; Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI USA ; Medical Scientist Training Program, University of Wisconsin-Madison, Madison, WI USA.
authors.forename: Brittany M
authors.initials: BM
authors.lastname: Young
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI USA ; Neuroscience Training Program, University of Wisconsin-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: Zack
authors.initials: Z
authors.lastname: Nigogosyan
authors.affiliation: Department of Radiology, University of Wisconsin-Madison, Madison, WI USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Remsik
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI USA ; Department of Orthopedics and Rehabilitation, University of Wisconsin-Madison, Madison, WI USA.
authors.forename: Mitchell E
authors.initials: ME
authors.lastname: Tyler
authors.affiliation: Departments of Kinesiology, University of Wisconsin-Madison, Madison, WI USA ; Departments 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: Department 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-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 Biomedical Engineering, University of Wisconsin-Madison, Madison, WI USA ; Department of Radiology, University of Wisconsin-Madison, Madison, WI USA ; Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI USA ; Medical Scientist Training Program, University of Wisconsin-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: DTI; axial diffusivity; brain-computer interface; fractional anisotropy; mean diffusivity; motor recovery; radial diffusivity; stroke rehabilitation