Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Paris 75013, France.
Neurocenter, Luzerner Kantonsspital, Lucerne 6016, Switzerland.
J Neurosci. 2024 May 22;44(21):e1311232024. doi: 10.1523/JNEUROSCI.1311-23.2024.
Left-sided spatial neglect is a very common and challenging issue after right-hemispheric stroke, which strongly and negatively affects daily living behavior and recovery of stroke survivors. The mechanisms underlying recovery of spatial neglect remain controversial, particularly regarding the involvement of the intact, contralesional hemisphere, with potential contributions ranging from maladaptive to compensatory. In the present prospective, observational study, we assessed neglect severity in 54 right-hemispheric stroke patients (32 male; 22 female) at admission to and discharge from inpatient neurorehabilitation. We demonstrate that the interaction of initial neglect severity and spared white matter (dis)connectivity resulting from individual lesions (as assessed by diffusion tensor imaging, DTI) explains a significant portion of the variability of poststroke neglect recovery. In mildly impaired patients, spared structural connectivity within the lesioned hemisphere is sufficient to attain good recovery. Conversely, in patients with severe impairment, successful recovery critically depends on structural connectivity within the intact hemisphere and between hemispheres. These distinct patterns, mediated by their respective white matter connections, may help to reconcile the dichotomous perspectives regarding the role of the contralesional hemisphere as exclusively compensatory or not. Instead, they suggest a unified viewpoint wherein the contralesional hemisphere can - but must not necessarily - assume a compensatory role. This would depend on initial impairment severity and on the available, spared structural connectivity. In the future, our findings could serve as a prognostic biomarker for neglect recovery and guide patient-tailored therapeutic approaches.
左侧空间忽略是右半球卒中后非常常见且具有挑战性的问题，它强烈且负面地影响卒中幸存者的日常生活行为和康复。空间忽略恢复的机制仍存在争议，特别是关于完整的对侧半球的参与，其潜在贡献从适应不良到补偿不等。在本前瞻性观察研究中，我们在右半球卒中患者（32 名男性；22 名女性）入院和出院时评估了忽略严重程度。我们证明，初始忽略严重程度和个体病变导致的未受损白质（连接）连通性（通过弥散张量成像（DTI）评估）的相互作用解释了卒中后忽略恢复的很大一部分可变性。在轻度受损的患者中，病变半球内的结构连通性足以获得良好的恢复。相反，在严重受损的患者中，成功的恢复严重依赖于完整半球内和半球间的结构连通性。这些不同的模式由它们各自的白质连接介导，可能有助于调和关于对侧半球作为完全补偿或非补偿作用的二分法观点。相反，它们提出了一个统一的观点，即对侧半球可以——但不一定必须——承担补偿作用。这将取决于初始损伤严重程度和可用的、未受损的结构连通性。在未来，我们的研究结果可以作为忽略恢复的预后生物标志物，并指导针对患者的治疗方法。
