Early imaging correlates of subsequent motor recovery after stroke.

Abstract

To determine whether functional magnetic resonance imaging activation obtained in the first few days after stroke correlates with subsequent motor recovery. Twenty-three patients with hemiparesis after first-time stroke were scanned at 2.0 +/- 0.9 days while performing a simple motor task. We defined recovery as the change in Fugl-Meyer score from time of scan to approximately 3 months later (90 +/- 8 days). We performed three different tests to assess correlations between brain activation and change in Fugl-Meyer score: (1) multivariate (most sensitive to spatially diffuse activation); (2) voxel-wise Statistical Parametric Mapping (most sensitive to focal activation), and (3) primary motor cortex region-of-interest analysis (most sensitive to average activation within this region). All tests controlled for initial stroke severity and lesion volume, as well as other established clinical variables. The multivariate test was significant [F (595, 4,934) = 1.93; p < 0.001]. The Statistical Parametric Mapping test detected two small clusters of focal activity located in the ipsilesional postcentral gyrus and cingulate cortex (p < 0.05, corrected). The region-of-interest test was not significant. There is a pattern of brain activation present in the first few days after stroke, of which the postcentral gyrus and cingulate cortex are a part, that correlates with subsequent motor recovery. This result suggests that there are recovery processes engaged early after stroke that could provide a target for intervention.