Abstract DP150: Hand recovery substrates depend on the stroke phases

Introduction: There is a growing population of stroke survivors who exhibit lifelong physical disability. Hand impairment is a major contributor to this. New strategies boosting the benefits of conventional rehabilitation are needed. One way is to develop mechanism-targeted approaches, but our current knowledge of neural mechanisms of motor recovery derives largely from animal stroke models. We studied longitudinal trajectories of MR Spectroscopy-detected biomarkers of several neural mechanisms proposed for hand recovery in survivors of a single subcortical stroke. Hypothesis: We hypothesized that neural targets relevant to hand recovery in the subacute phase may not be relevant in the chronic phase of disease. Methods: Stroke survivors in the subacute (n=21, 23.9[20.4] (mean[SD]) days post-onset, 66.2[9.9] years old, 14% female, Fugl-Meyer, 40.8[23.1] hand impairment; data analysis is underway) and chronic (n=21, 42.4[38.2] months, 58.5[10.8] years old, 16% female, Fugl-Meyer, 41.5[17.1]) phases of disease and 26 matched healthy controls were included. MEGA-sLASER was used to detect the biomarkers related to neuronal metabolic depression (N-acetylaspartate-NAA), glial changes ( myo -Inositol-mI), neuroinflammation (choline-Cho), and excitation-inhibition (E-I) imbalance (glutamate-glutamine complex-Glx and GABA). These measures were performed bilaterally in radiologically normal-appearing motor and premotor cortices. Results: Compared to controls, the subacute group showed neuronal metabolic depression (lower NAA) and increased neuroinflammation (higher Cho) and inhibition (higher GABA/lower Glx) across all cortices, along with increased glial activity/number (higher mI) in the cortices of the injured hemisphere (ipsilesional) ( p