Diffusion anisotrophy in the early stages of stroke can predict motor outcome

Article type: Research Article

Authors: Jang, Sung Ho | Cho, Sang-Hyun | Kim, Yun-Hee | Han, Bong Soo | Byun, Woo Mok | Son, Soo-Min | Kim, Seong Ho | Lee, Se Jin

Affiliations: Department of Physical Medicine and Rehabilitation, School of Medicine, Yeungnam University, Taegu, Republic of Korea | Department of Physical Therapy, Yonsei University College of Health Science, Wonju-si, Kangwon-do, Republic of Korea | Department of Physical Medicine and Rehabilitation, College of Medicine Pochon Jungmoon University, Bundang CHA General Hospital, Sungnam, Republic of Korea | Department of Radiation Science, College of Health Science, Yonsei University, Kangwon-do, Republic of Korea | Department of Neurosurgery, College of Medicine, Yeungnam University, Taegu, Republic of Korea | Department of Neurology, College of Medicine, Yeungnam University, Taegu, Republic of Korea

Note: [] Corresponding author. Tel.: +82 053 620 3269; Fax: +82 53 625 3508; E-mail: strokerehab@hanmail.net

Abstract: Purpose: This study examined whether the degree of impairment of diffusion anisotrophy in the early stages of a stroke can predict the motor function outcome. Methods: Thirty-one hemiplegic stroke patients were enrolled to this study. Diffusion anisotropy was measured by determining fractional anisotropy (FA) in the two ROIs (region of interests) at corona radiata (CR) and in the posterior limb of internal capsule (IC) during the early stages of stoke (average 7.9 days after stroke onset) and compared with motor outcome of the affected hand 3 months after stroke onset. Results: Both ROIs (CR or IC) and lesion types (hemorrhage or infarction) did not have significant effect on the SBFA (symmetry of bilateral FA) and dMRC (medical research council score improvement), either. Patients with greater initial MRC score had significantly greater SBFA and dMRC. The regression equation between the dMRC (Y axis) and the SBFA (X axis) was semi-linear and significant (P < 0.05); for CR group, Y = 3.296 - 0.1192X + 0.0015X^{2}; for IC group, Y = 2.342 - 0.0533X +0.0007^{2}. The regression lines had 'threshold points' where a minute SBFA change would make a steep increase in dMRC. Conclusion: The degree of impairment in diffusion anisotropy during the early stages of stroke appears to have the potential to predict motor outcome.

Keywords: stroke, diffusion tensor imaging, anisotropy, MRI, motor function

Journal: Restorative Neurology and Neuroscience, vol. 23, no. 1, pp. 11-17, 2005