Brain lesion size and location: Effects on motor recovery and functional outcome in stroke patients

Objective: To investigate effects of brain lesion profiles that combined sizes and locations on motor recovery and functional outcome after stroke in hemiplegic patients. Design: Delimiting sizes (a threshold lesion size) of 5 primary locations were identified to establish brain lesion profiles based on magnetic resonance imaging findings 1 month after stroke. Motor and functional outcome were correlated with brain lesion profiles and other brain lesion factors to identify the most dominant factor. Setting: Medical center, rehabilitation department. Participants: Fifty-five hemiplegic patients. Main Outcome Measures: Brunnstrom's stages and Functional Independence Measure (FIM) scores were assessed 1 and 6 months after stroke. Results: With delimiting sizes for the cortical, corona radiata, internal capsule, putaminal, and thalamic regions set at 75, 4, .75, 22, and 12cm(3), respectively, brain lesion profiles play a dominant role in determining final Brunnstrom's stages (Spearman's rho = .861, p < .01) and FIM score (Spearman's rho = .571, p < .01). Brunnstrom's and FIM scores had no or only weak negative relationship with either absolute or relative lesion size. Conclusions: These findings may suggest that motor and functional outcomes after stroke correlate with brain lesion profiles (a combination of delimiting sizes and primary locations) more than with absolute or relative lesion sizes only. Delimiting sizes in determining final outcomes varied markedly according to the primary lesion locations.