title: Role of corpus callosum integrity in arm function differs based on motor severity after stroke.
abstract: While the corpus callosum (CC) is important to normal sensorimotor function, its role in motor function after stroke is less well understood. This study examined the relationship between structural integrity of the motor and sensory sections of the CC, as reflected by fractional anisotropy (FA), and motor function in individuals with a range of motor impairment level due to stroke. Fifty-five individuals with chronic stroke (Fugl-Meyer motor score range 14 to 61) and 18 healthy controls underwent diffusion tensor imaging and a set of motor behavior tests. Mean FA from the motor and sensory regions of the CC and from corticospinal tract (CST) were extracted and relationships with behavioral measures evaluated. Across all participants, FA in both CC regions was significantly decreased after stroke (p< 0.001) and showed a significant, positive correlation with level of motor function. However, these relationships varied based on degree of motor impairment: in individuals with relatively less motor impairment (Fugl-Meyer motor score > 39), motor status correlated with FA in the CC but not the CST, while in individuals with relatively greater motor impairment (Fugl-Meyer motor score ≤ 39), motor status correlated with FA in the CST but not the CC. The role interhemispheric motor connections play in motor function after stroke may differ based on level of motor impairment. These findings emphasize the heterogeneity of stroke, and suggest that biomarkers and treatment approaches targeting separate subgroups may be warranted.
authors.affiliation: Program in Physical Therapy, Department of Exercise Science, University of South Carolina, Columbia, SC 29208, USA.
authors.forename: Jill Campbell
authors.initials: JC
authors.lastname: Stewart
authors.affiliation: Departments of Neurology and Anatomy & Neurobiology, University of California, Irvine, CA 92697, USA.
authors.forename: Pritha
authors.initials: P
authors.lastname: Dewanjee
authors.affiliation: Departments of Neurology and Anatomy & Neurobiology, University of California, Irvine, CA 92697, USA.
authors.forename: George
authors.initials: G
authors.lastname: Tran
authors.affiliation: Departments of Neurology and Anatomy & Neurobiology, University of California, Irvine, CA 92697, USA.
authors.forename: Erin Burke
authors.initials: EB
authors.lastname: Quinlan
authors.affiliation: Departments of Neurology and Anatomy & Neurobiology, University of California, Irvine, CA 92697, USA.
authors.forename: Lucy
authors.initials: L
authors.lastname: Dodakian
authors.affiliation: Department of Physical Therapy, Chapman University, Orange, CA 92866, USA.
authors.forename: Alison
authors.initials: A
authors.lastname: McKenzie
authors.affiliation: Departments of Neurology and Anatomy & Neurobiology, University of California, Irvine, CA 92697, USA.
authors.forename: Jill
authors.initials: J
authors.lastname: See
authors.affiliation: Departments of Neurology and Anatomy & Neurobiology, University of California, Irvine, CA 92697, USA.
authors.forename: Steven C
authors.initials: SC
authors.lastname: Cramer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016880:Anisotropy; D001132:Arm / Q000503:physiopathology*; D003337:Corpus Callosum / Q000000981:diagnostic imaging*; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000473:pathology; D011712:Pyramidal Tracts / Q000000981:diagnostic imaging; D012720:Severity of Illness Index; D020521:Stroke / Q000150:complications*; D066127:White Matter / Q000000981:diagnostic imaging; D055815:Young Adult
keywords: Diffusion tensor imaging; Motor; Rehabilitation; Stroke