Date Presented 4/20/2018
In chronic stroke survivors, stroke lesion volume predicted change in motor recovery with rehabilitation, but significantly only in those with nondominant hemiparesis. Stroke survivors with nondominant hemiparesis may have unique rehabilitation needs compared with those with dominant hemiparesis.
Primary Author and Speaker: Lauren Wengerd
Additional Authors and Speakers: Stephen Page, Andrew Persch
Contributing Authors: Samir Belagaje
PURPOSE AND BACKGROUND: The purpose of this study was to examine whether stroke lesion volume (LV) correlates with magnitude of response to occupational therapy intervention in chronic stroke survivors with upper extremity (UE) hemiparesis. Stroke remains a leading cause of long–term disability in the United States, often leading to UE motor impairment and consequent decline in functional independence with activities of daily living (ADLs). Although a variety of UE interventions have been proven efficacious in chronic stroke populations, it remains unclear what factors best predict survivors’ capacity to improve with rehabilitation.
METHOD: This study was a secondary analysis of data from the Everest Clinical Trial, a study that investigated the effect of cortical stimulation on rehabilitation outcomes in chronic stroke survivors. Participants were 54 chronic stroke survivors randomized to the control group (UE rehabilitation only, no cortical stimulation) in the Everest Clinical Trial.
Before intervention, the UE section of the Fugl–Meyer Assessment (FMA) and the Arm Motor Ability Test (AMAT) were administered to determine baseline motor impairment and functional ability, respectively. After initial assessment, participants underwent a 6–wk standardized, task–oriented, UE rehabilitation protocol carried out by an occupational therapy practitioner. The FMA and AMAT were readministered 4 wk postintervention, and change scores were calculated by taking the difference between preintervention and postintervention scores for each assessment.
Multiple linear regression analyses were performed to examine the effect of LV on FMA and AMAT change scores while controlling for pretest scores and time since stroke. A post hoc subgroup analysis was conducted to determine whether the correlation between LV and change scores was the same for both dominant and nondominant hemiparesis groups.
RESULTS: LV was a significant predictor of FMA change scores (B = –.30, p < .05) when controlling for FMA pretest scores and time since stroke; however, LV was not a significant predictor of AMAT change scores (B = –.01, p = .50) when controlling for AMAT pretest scores and time since stroke. Interestingly, LV was a significant predictor of FM change scores only in participants with nondominant hemiparesis (B = –.06, p = .01), and not in those with dominant hemiparesis (B = –.01, p = .76). LV was not a significant predictor of AMAT change scores for either group.
CONCLUSION: Results indicate that initial LV predicted magnitude of motor recovery after rehabilitation for people with chronic stroke, but only for those with nondominant hemiparesis. LV was not, however, a significant predictor of capacity to increase UE function for ADLs. These findings suggest that people with hemiparesis of the nondominant UE may have unique occupational therapy rehabilitation needs compared with those with dominant hemiparesis.
IMPACT STATEMENT: Initial stroke lesion volume may have a significant impact on rehabilitation outcomes in chronic stroke survivors with nondominant hemiparesis, but not those with dominant hemiparesis, and future work should investigate differences in recovery between these groups. This study was a follow–up to previous work conducted in our lab suggesting that initial lesion volume does not predict baseline motor impairment in chronic stroke survivors.
References
Almhdawi, K. A., Mathiowetz, V. G., White, M., & delMas, R. C. (2016). Efficacy of occupational therapy task–oriented approach in upper extremity post–stroke rehabilitation. Occupational Therapy International, 23, 444–456. https://doi.org/10.1002/oti.1447
Page, S. J., Gauthier, L. V., & White, S. (2013). Size doesn’t matter: Cortical stroke lesion volume is not associated with upper extremity motor impairment and function in mild, chronic hemiparesis. Archives of Physical Medicine and Rehabilitation, 94, 817–821. https://doi.org/10.1016/j.apmr.2013.01.010
Stinear, C. M., Barber, P. A., Smale, P. R., Coxon, J. P., Fleming, M. K., & Byblow, W. D. (2007). Functional potential in chronic stroke patients depends on corticospinal tract integrity. Brain, 130, 170–180. https://doi.org/10.1093/brain/awl333
