Characterising and predicting apraxic deficits in patients with chronic aphasia caused by left hemisphere stroke

这项研究将调查中风后的失用症，这种情况严重影响30-40%的中风患者(每年约25,000人)的生活，使他们无法照顾自己。失用症会导致计划和执行日常行动的问题，如刷牙、穿衣或泡茶。它既可以发生在优势和非优势手，也不是由于肌肉无力或感觉丧失。当患者被送入卒中病房时，失用通常不被识别，因为识别需要详细的神经心理学测试，这不是标准化的，而且很耗时。因此，患者可能会错过针对这种致残情况进行适当康复的机会。研究中风后语言障碍(失语症)的研究也面临着类似的挑战，因为漫长的测试和针对适当康复的困难。剑桥大学的研究人员最近对详细的语言评估实施了新的分析技术。这使得能够识别导致失语症的行为成分，从而将特定的语言障碍与中风后其他认知问题造成的障碍区分开来。这些都与患者的大脑扫描有关，以确定导致损伤的大脑区域。进一步的研究证明了根据脑部扫描预测损伤的能力。该研究小组目前正致力于在一大批患者中验证这些方法，以确定导致康复的因素。这项建议旨在应用相同的分析技术，在同一个研究语言缺陷的患者队列中识别失用症。失用症通常与失语症在中风后并存，这两种疾病中的一些缺陷可能是共同的。参加过上述失语症研究的中风患者将被邀请参加这项研究。他们将接受失用测试的详细任务。失用症患者中有手势识别问题的一组患者将在功能神经成像过程中接受更详细的手势识别和模仿任务。这是为了区分语言和动作理解中的大脑活动和连通性变化。患者在失用任务中犯的任何错误都将被归类为更简单的组成部分。这些与大脑成像标记物相结合，将被用来创建预测，以准确区分与失用症有关的问题和脑损伤，与失语症有关的问题和脑损伤，以及中风后更常见的认知障碍造成的问题和脑损伤。这将使我们能够确定与失用相关的更简单的核心因素以及与它们相关的脑损伤区域，以预测患者的失用问题并指导未来的康复需求。拟议研究的关键成果将是创建准确的筛查，使用比目前更简单的任务来预测中风后患者是否有失用症，以及脑成像。然后，这些将允许更快、更容易地测试中风后的这种情况，并将使以患者为中心的神经康复治疗方案的选择成为可能。这项工作引发的未来研究将致力于验证在这项研究中创建的新的诊断和预测模型，方法是在中风后的急性和慢性阶段对患者进行纵向队列测试，以确定它们是否可以准确地预测中风后从急性阶段到慢性阶段的失用恢复。

This study will investigate apraxia after stroke, a condition which significantly affects the lives of 30- 40% stroke patients (some 25,000 people annually) making them unable to care for themselves. Apraxia causes problems with planning and executing everyday actions, such as brushing teeth, getting dressed, or making a cup of tea. It can occur both in the dominant and non-dominant hand and is not due to muscle weakness or sensory loss. Apraxia is often not recognised when patients are admitted into stroke units because identification requires detailed neuropsychology testing which is not standardised and is time-consuming. As a result, patients may miss the opportunity to get appropriate rehabilitation for this disabling condition. Studies investigating language impairments (aphasia) after stroke have faced similar challenges because of lengthy tests and difficulties targeting appropriate rehabilitation. Researchers at the University of Cambridge have recently implemented new analysis techniques on detailed language assessments. This has allowed identification of behavioural components causing aphasia that could distinguish specific language impairments from impairments caused by other cognitive problems following a stroke. These have been linked to the patient's brain scans to identify the brain regions causing the impairments. Further work has demonstrated the ability to predict impairments based on brain scans. The research group is currently working to validate these methods in a large cohort of patients over time to identify factors leading to recovery. This proposal aims to apply the same analysis techniques to identify apraxia in the same patient cohort studied for language deficits. Apraxia often co-occurs with aphasia after stroke, and some of the deficits in both disorders may be shared. Stroke patients who have participated in the aphasia studies outlined above will be invited to take part in the study. They will undergo detailed tasks of apraxia testing. A subgroup of patients with apraxia who have problems recognising gestures will undergo more detailed gesture recognition and imitation tasks during functional neuroimaging. This is to differentiate brain activity and connectivity changes in speech and action understanding. Any errors patients make on apraxia tasks will be grouped into simpler components. These, combined with brain imaging markers, will be used to create predictions to accurately distinguish problems and brain lesions relating to apraxia from those related to aphasia and from those caused by more generic cognitive impairments after stroke. This will enable us to identify simpler core factors associated with apraxia and the areas of brain damage associated with them, to predict patient apraxia problems and guide future rehabilitation needs. The key outcomes of the proposed studies will be the creation of accurate screens for predicting whether patients have apraxia after stroke, using simpler tasks than currently, and brain imaging. These will then allow for quicker, easier testing for this condition after stroke and will enable selection of patient-centred therapies for neuro-rehabilitation. Future studies arising from this work will aim to validate the new diagnostic and prediction models created in this study by testing them in a longitudinal cohort of patients, tested both at acute and chronic stages after stroke, to identify if they can accurately predict recovery from apraxia from the acute to the chronic stages after stroke.