Middle cerebral artery stroke that includes the premotor cortex reduces mobility outcome

Background and Purpose-The premotor cortex (PMC) (Brodmann 6) contributes u niquely to proximal upper and lower limb power and plays a role in the orga nization of motor behaviors. We assessed the degree to which PMC damage aff ected functional outcome. Methods-We prospectively compared the functional outcome of patients with a first stroke in the middle cerebral artery distribution that either left t he PMC intact (PMC-; n=19) or damaged the PMC (PMC+; n=12), The Functional Independence Measure for disability and the motor score of the Stroke Impai rment Assessment Set for impairment assessed outcome. Results-Demographic and clinical features and lesion volume were comparable for the PMC+ and PMC- groups. However, the PMC- group demonstrated signifi cant gain in mobility and in proximal leg movement. This focal improvement contributed to the trend in the PMC- group toward greater independent ambul ation. Conclusions-Decreased motor recovery of proximal lower limbs in humans with PMC damage supports the idea that it is the origin of corticoreticulospina l pathways that subserve proximal lower extremity function. Furthermore, pe rsistent proximal weakness after PMC damage may amplify other motor impairm ents, which include defects in planning, initiating, and sequencing. Neuror ehabilitation outcomes may contribute to a more detailed functional anatomy after stroke and partial recovery.