Individual recovery of cognitive defects after stroke

在发达国家，中风是导致重大残疾的主要原因，许多人在语言、感知、运动控制和记忆方面长期存在缺陷。急性中风患者及其家属首先要问的一些问题是：“完全康复的可能性有多大？”对我来说，什么才是现实的复苏？”到目前为止，对这个紧迫的问题还没有个人的回应。目前，我们对长期恢复的建议只是基于非常笼统的观察。大约三分之二由急性中风引起的认知缺陷会恢复；三分之一的患者会经历慢性损伤。我们建议脑成像可以与急性行为相结合，为个体长期预后提供重要的生物标志物。改善预后不仅可以提供现实的期望，而且还可以指导个性化治疗（例如康复与补偿）。作为一般原理的展示，我们将集中讨论中风对右半球的影响，即空间定向和注意力障碍。这些缺陷是在广泛的日常任务中恢复不良的强有力的预测因素，包括运动恢复不良，一般认知功能障碍和康复抵抗。基于我们之前的工作，我们现在对常见右半球疾病的解剖学基础有了明确的预测。具体来说，外围区域的损伤会导致姿势和凝视的被动偏见，以及在主动感知忽视任务（我们称之为自我中心忽视）中以身体为中心的偏见。另一方面，更多的后侧损伤似乎会导致个体物体内的空间偏差（异中心忽视）。相比之下，颞顶叶交界处的损伤会导致消失（当面对多个同时发作的物体时产生偏差）。我们的目标是根据这些最新发现进行首次前瞻性纵向研究，以了解个体的长期恢复情况。我们认为，结合急性结构和功能脑成像，以及精心设计的一套急性和结果行为测量，将使我们能够了解潜在的生理学，并帮助我们确定哪些测量是准确预后所必需的。

Stroke is the leading cause of major disability throughout the developed world with many individuals suffering from long term deficits in speech, perception, motor control and memory. Some of the first questions of acute stroke patients and their families are: 'What is the likelihood for a full recovery? What is a realistic recovery in my case?' So far, there is no individual response to this urgent question. Currently our advice regarding long-term recovery is only informed by very general observations. About two-thirds of the cognitive deficits evoked by an acute stroke will recover; one-third of the patients will experience chronic impairments. We propose that brain imaging can be combined with acute behaviour to provide an important biomarker for individual long-term prognosis. Improved prognosis could not only provide realistic expectations, but would also guide individually tailored treatment (e.g. rehabilitation versus compensation). As a showcase for the general principle we will concentrate on the consequences of stroke to the right hemisphere, namely the disorders of spatial orientation and attention. These deficits are strong predictors for poor recovery on a wide range of everyday tasks including poor motor recovery, general cognitive dysfunction and resistance to rehabilitation. Based on our previous work, we now have clear predictions regarding the anatomical underpinnings of common right hemisphere disorders. Specifically, injury to perisylvian regions leads to passive biases in posture and gaze, as well as body-centered biases during active perceptual neglect tasks (which we refer to as egocentric neglect). On the other hand, more posterior injury appears to lead to spatial biases within individual objects (allocentric neglect). In contrast, injury to the temporoparietal junction results in extinction (a bias when confronted by multiple objects that share a simultaneous onset). Our objective is to conduct the first prospective longitudinal study informed by these recent findings in order to understand individual long-term recovery. We assert that the combination of acute structural and functional brain imaging, as well as a carefully designed set of acute and outcome behavioral measures, will allow us to understand the underlying physiology and help us determine which measures are required for accurate prognosis.