Description (from grant): 

Significance: Post-stroke language deficits are common and can be devastating to social relationships, vocational success, and independence in daily activities. We will characterize how language deficits resolve or improve over the first year after left hemisphere stroke, by carrying out longitudinal language assessments and brain imaging. We aim to identify demographic, genetic, and imaging variables that predict improvement in discourse comprehension, reading, spelling through (1) restoration of blood flow to brain specific regions, (2) repurposing of healthy brain areas to take over functions of areas damaged by stroke, or (3) development of compensatory strategies. Language deficits after stroke resolve to different degrees across individuals. We have characterized distinct mechanisms of recovery, including restoration of blood flow to tissue surrounding the infarct and reorganization of brain networks underlying specific language functions. We propose to characterize mechanisms of recovery of discourse comprehension, reading, and spelling (functions that are increasingly critical in a society dependent on internet use such as online banking and shopping, email, texting, and so on) in each individual with aphasia over the course of one year. In addition, we will evaluate use of compensation by learning to accomplish the function in a different way or using different modalities to communicate, as another mechanism of recovery. We will use longitudinal structural and perfusion imaging, along with language assessments twice within 10 days of stroke onset (once before and once after intervention to restore blood flow or 3 days after initial testing in cases of no intervention) and again at 3 months, 6 months, and 12 months after acute left hemisphere ischemic stroke. We also propose to identify variables that predict recovery through each mechanism and determine which demographic, imaging, and genetic factors influence the success of each mechanism. Results will allow clinicians to focus treatment strategies on the mechanisms most likely to be successful for an individual. Thus, the combination of imaging and behavioral data will help us achieve another important clinical goal: to improve prognosis for aphasia recovery at an individual level.