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，这是一种严重影响30- 40%中风患者（每年约25，000人）生活的疾病，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，例如刷牙，穿衣服或泡茶。它可以发生在惯用手和非惯用手，而不是由于肌肉无力或感觉丧失。失用症通常在患者进入卒中单元时无法识别，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，患者可能会错过为这种残疾状况进行适当康复的机会。调查中风后语言障碍（失语症）的研究也面临着类似的挑战，因为测试时间长，难以进行适当的康复治疗。剑桥大学的研究人员最近在详细的语言评估中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，从而区分特定的语言障碍和中风后其他认知问题引起的障碍。这些已经与患者的大脑扫描相关联，以确定导致损伤的大脑区域。进一步的工作已经证明了基于大脑扫描预测损伤的能力。该研究小组目前正致力于在一个大型患者队列中验证这些方法，以确定导致康复的因素。该提案旨在应用相同的分析技术来识别语言缺陷研究的同一患者队列中的失用症。失用症经常与中风后失语症同时发生，并且两种疾病的某些缺陷可能是共同的。将邀请参加上述失语症研究的卒中患者参加本研究。他们将接受详细的失用症测试。一组有手势识别问题的失用症患者将在功能性神经成像期间接受更详细的手势识别和模仿任务。这是为了区分言语和动作理解中的大脑活动和连接变化。失用症患者在完成任务时所犯的任何错误都将被归为更简单的部分。这些与脑成像标记物相结合，将用于创建预测，以准确区分与失语症相关的问题和脑损伤，以及中风后更一般的认知障碍引起的问题和脑损伤。这将使我们能够识别与失用症相关的更简单的核心因素以及与之相关的脑损伤区域，以预测患者的失用症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屏幕，用于预测患者是否患有中风后失用症，使用比目前更简单的任务和脑成像。这些将使中风后对这种情况进行更快、更容易的测试，并能够选择以患者为中心的神经康复疗法。 这项工作产生的未来研究将旨在验证本研究中创建的新诊断和预测模型，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预测中风后从急性到慢性阶段的失用症恢复。

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.