title: Motor recovery and microstructural change in rubro-spinal tract in subcortical stroke.
abstract: The mechanism of motor recovery after stroke may involve reorganization of the surviving networks. However, details of adaptive changes in structural connectivity are not well understood. Here, we show long-term changes in white matter microstructure that relate to motor recovery in stroke patients. We studied ten subcortical ischemic stroke patients who showed motor hemiparesis at the initial clinical examination and an infarcted lesion centered in the posterior limb of internal capsule of the unilateral hemisphere at the initial diffusion-weighted magnetic resonance imaging scan. The participants underwent serial diffusion tensor imaging and motor function assessments at three consecutive time points; within 2 weeks, and at 1 and 3 months after the onset. Fractional anisotropy (FA) was analyzed for regional differences between hemispheres and time points, as well as for correlation with motor recovery using a tract-based spatial statistics analysis. The results showed significantly increased FA in the red nucleus and dorsal pons in the ipsi-lesional side at 3 months, and significantly decreased FA in the ipsi-lesional internal capsule at all time points, and in the cerebral peduncle, corona radiata, and corpus callosum at 3 months. In the correlation analysis, FA values of clusters in the red nucleus, dorsal pons, midbody of corpus callosum, and cingulum were positively correlated with recovery of motor function. Our study suggests that changes in white matter microstructure in alternative descending motor tracts including the rubro-spinal pathway, and interhemispheric callosal connections may play a key role in compensating for motor impairment after subcortical stroke.
authors.affiliation: Division of Neurology, Department of Stroke and Cerebrovascular Diseases, National Cerebral and Cardiovascular Center, Osaka, Japan ; Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Takenobu
authors.affiliation: Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan ; Functional Architecture Imaging Unit, RIKEN Center for Life Science Technologies, Kobe, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Hayashi
authors.affiliation: Division of Neurology, Department of Stroke and Cerebrovascular Diseases, National Cerebral and Cardiovascular Center, Osaka, Japan ; Department of Neurology, Kansai Rosai Hospital, Hyogo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Moriwaki
authors.affiliation: Division of Neurology, Department of Stroke and Cerebrovascular Diseases, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Nagatsuka
authors.affiliation: Division of Neurology, Department of Stroke and Cerebrovascular Diseases, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Naritomi
authors.affiliation: Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Hidenao
authors.initials: H
authors.lastname: Fukuyama
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020520:Brain Infarction / Q000209:etiology / Q000473:pathology; D056324:Diffusion Tensor Imaging; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D009415:Nerve Net / Q000473:pathology*; D011712:Pyramidal Tracts / Q000473:pathology*; D020127:Recovery of Function / Q000502:physiology*; D020521:Stroke / Q000473:pathology* / Q000503:physiopathology; D013997:Time Factors
keywords: CC, Corpus callosum; CP, Cerebral peduncle; CR, Corona radiata; DTI, Diffusion tensor imaging; Diffusion tensor image; EPT, Extrapyramidal tract; FA, Fractional Anisotropy; FMMS, Fugl-Meyer Motor Scale; Motor recovery; PLIC, Posterior limb of internal capsule; PT, Pyramidal tract; Reorganization; Subcortical stroke; TBSS, Tract-based spatial statistics; Tract-based spatial statistics