Abstract T MP42: The Use of Voxel-Based Lesion Symptom Mapping to Relate Lesion Location to Motor Performance in Chronic Stroke Survivors
Background and Purpose: We used voxel-based lesion symptom mapping (VLSM) to determine the relationship between lesion location and performance on upper extremity behavioral outcome measures post-stroke. We hypothesized that a lesion within the upper extremity region of the primary motor cortex would correlate with poorer hand motor outcome measures.
Methods: Thirty-six chronic stroke survivors with upper extremity motor deficits who underwent 3 weeks of hand/wrist robotic therapy were included in the study. Behavioral motor outcome measures included: Fugl-Meyer Arm (FMA) Test, Action Research Arm Test (ARAT), and Box & Blocks Test (BB). Anatomical imaging included a high-resolution T1-weighted volumetric scan and a T2-weighted scan. Lesioned areas were manually traced using MRIcron; stroke masks were flipped to left and binarized. All of the subjects’ T1-weighted images were transformed to Montreal Neurological Institute (MNI) standardized stereotaxic space. Data were analyzed using the non-parametric mapping (NPM) software package in MRIcron with the Brunner-Munzel test set at 1,000 permutations and a 10% threshold. The threshold for the overlap between low behavioral scores and related brain regions was set at α= 0.01.
Results: Lesions in the inferior frontal gyrus and underlying white matter and the posterior limb of the internal capsule (PLIC) correlated with poorer motor outcomes on the FMA and ARAT, indicating a degree of anatomical overlap between impairment and activity levels of upper extremity motor performance. Lesions of the premotor area also correlated with poorer ARAT outcomes, whereas lesions of the middle frontal gyrus and underlying white matter correlated with poorer performance on the BB, reflecting the role that motor planning plays in those activities.
Conclusions: Voxel-Based Symptom Mapping adds a new dimension in clarifying the specific lesion location associated with dexterous motor function post-stroke. Activity vs. impairment deficits relate to lesions in anatomical areas involved in motor planning vs. those involved in movement execution.
Author Disclosures: K. Shibuya: None. E. Burke: None. L. Dodakian: None. J. See: None. S.C. Cramer: Consultant/Advisory Board; Modest; GlaxoSmithKline, MicroTransponder. A. McKenzie: None.
- © 2014 by American Heart Association, Inc.