Open AccessDegree of corticospinal tract damage correlates with motor function after stroke
Author(s) -
Maraka Stefania,
Jiang Quan,
JafariKhouzani Kourosh,
Li Lian,
Malik Shaneela,
Hamidian Hajar,
Zhang Talan,
Lu Mei,
SoltanianZadeh Hamid,
Chopp Michael,
Mitsias Panayiotis D.
Publication year - 2014
Publication title -
annals of clinical and translational neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.824
H-Index - 42
ISSN - 2328-9503
DOI - 10.1002/acn3.132
Subject(s) - medicine , corticospinal tract , motor function , stroke (engine) , physical medicine and rehabilitation , pyramidal tracts , neuroscience , anatomy , magnetic resonance imaging , radiology , diffusion mri , mechanical engineering , engineering , biology
Objectives Direct injury to the corticospinal tract ( CST ) is a major factor defining motor impairment after stroke. Diffusion tensor imaging ( DTI ) tractography allows definition of the CST . We sought to determine whether DTI ‐based assessment of the degree of CST damage correlates with motor impairment at each phase of ischemic stroke. Methods We evaluated patients at the acute (3–7 days), subacute (30 days), and chronic (90 days) phases of ischemic stroke with DTI and clinical motor scores (upper extremity Fugl‐Myer test [UE‐FM], motor items of the National Institutes of Health Stroke Scale [ mNIHSS ]). The CST was identified and virtual fiber numbers (FN) were calculated for the affected and contralateral CST. We used Spearman correlation to study the relationship of FN ratio (FNr) (affected/unaffected CST) with motor scores at each time point, and the regression model to study the association of the acute parameters with chronic motor scores. Results We studied 23 patients. Mean age was 66.7 (±12) years. FNr correlated with UE‐FM score in the acute ( r = 0.50, P = 0.032), subacute ( r = 0.57, P = 0.007), and chronic ( r = 0.67, P = 0.0008) phase, and with mNIHSS in the acute ( r = −0.48, P = 0.043), subacute ( r = −0.58, P = 0.006), and chronic ( r = −0.75, P = 0.0001) phase. The combination of acute NIHSS and FNr significantly predicted chronic UE‐FM score ( r = 0.74, P = 0.0001). Interpretation DTI ‐defined degree of CST injury correlates with motor impairment at each phase of ischemic stroke. The combination of baseline FN r and NIHSS predicts motor outcome. DTI ‐derived CST assessment could become a surrogate marker of motor impairment in the design of neurorestorative clinical trials.