Abstract DP312: The neuroanatomy of activities of daily living after stroke

Introduction: Dependency in activities of daily living (ADL) is a common consequence of stroke, affecting 60% of patients acutely, at least half of whom remain severely affected. Independence in ADLs is related to motor, cognitive, and mood-related symptoms, but little is known about how it is related to stroke injury and its effects on brain networks. Hypothesis: This study tests the hypothesis that ADL dependence is associated with injury to heteromodal cortex and to widespread structural disconnections between motor, cognitive, and limbic brain networks. Methods: Stroke patients during rehabilitation were assessed for ADL independence at admission and discharge. Stroke lesions were outlined on acute clinical neuroimages, which were used to [1] test for associations between lesion location and ADL independence and changes in ADL independence using voxel-lesion symptom mapping (VLSM) and [2] compute structural disconnections between the main brain networks, which were examined in relation to ADL independence and change in ADL independence. Results: Sixty subjects (age 69.2±15.4 yr) were enrolled 10.4±5 days after stroke. Lesions (Fig 1A) had volume ranging from 0.09 to 354.65 ml, and patients had on average moderate deficits in ADL independence at admission (mean 20.6±6.5). Poorer ADL independence at admission was significantly associated with [1] lesions in anterior insula (z=-3.6, Fig 1B) and [2] structural disconnection of networks (Fig 2A) including ipsilesional sensorimotor network (SMN), ventral attention network, limbic network (LMN), frontoparietal network (FPN), and default mode network (DMN). Recovery of ADL independence was associated structural disconnections between DMN, FPN, and subcortical networks bilaterally and with disconnections to and from SMN of the contralesional hemisphere (Fig 1C and 2B). Conclusions: These findings support our hypotheses, as ADL independence was related to integrity of anterior insula, which is involved in sensorimotor, emotional, and cognitive functions; and to structural disconnection of networks related to the same functions. Affected networks included those related to sustained attention (DAN), monitoring one’s performance (DMN), executing motor plans (SMN), and integrating and regulating emotions (LMN)--functions that are especially important for performing ADLs. The findings underscore the importance of measuring stroke effects on network integrity in order to understand functional consequences such as loss of ADLs.