Prediction of prognosis of post-stroke hemiparesis using tractography of the pyramidal tract

2021 Fiscal Year Final Research Report

• Project/Area Number: 17K01464
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Rehabilitation science/Welfare engineering
• Research Institution: International University of Health and Welfare
• Principal Investigator: Kato Hiroyuki 国際医療福祉大学, 医学部, 教授 (60224531)
• Project Period (FY): 2017-04-01 – 2022-03-31
• Keywords: 脳卒中 / リハビリテーション / 片麻痺 / MRI / トラクトグラフィー

Outline of Final Research Achievements

The aim of this study was to clarify the relation between post-stroke hemiparesis and the involvement of the pyramidal tract visualized by tractography in 41 patients with subcortical infarction who underwent MRI 3-11 days after onset. In patients with severe hemiparesis, almost all the pyramidal tracts were involved within the infarcts visualized by diffusion-weighted images. However, many patients presented with less severe hemiparesis although the pyramidal tracts were involved considerably in infarcts. Severe hemiparesis was seen predominantly in patients with branch atheromatous disease compared to those with lacunar infarcts. The sizes of infarction visualized by diffusion-weighted images were always greater than or comparable to those shown by T1-weighted images. The above findings suggest that the severity of post-stroke hemiparesis is related to (1) how much of the pyramidal tract is involved in the infarct and (2) how severe is the tissue damage caused by infarction.

Free Research Field

脳神経内科学

Academic Significance and Societal Importance of the Research Achievements

われわれは、脳卒中後の運動機能（片麻痺）の回復は、損傷脳において運動ネットワークが再構築され、学習機構が誘導され、可塑性が発揮されることによって促進されると考えている。そのため、運動ネットワークの主たる構成員である錐体路の構造が脳梗塞によってどの程度傷害され、その機能がどの程度まで障害されたかを評価することが決定的に重要であると考えている。今回、拡散テンソル・トラクトグラフィーによって描出される錐体路の構造と運動障害（片麻痺）の程度には一定の関連性が認められたことにより、脳機能再生のために神経科学を基盤とするリハビリテーション法を確立する基本的な考え方を提供できたと考えている。