Comparative study on the relationship between stroke hemisphere and functional evolution in right-handed individuals

Objective: The left hemisphere is supposed to be dominant for motor control and the right hemisphere dominant for spatial orientation. This study aimed to test the hypothesis that left-side lesions cause greater impairment of voluntary movement, while right-side lesions cause loss of spatial attention loss and postural control. Individuals with left-side lesions were compared with individuals with right-side lesions, in relation to initial impairment and recovery three months after their stroke. Methods: Twenty-two right-handed individuals with an ischemic lesion in the area of the middle cerebral artery (11 on the left side and 11 on the right side) were assessed monthly, for the first three months after their stroke, in terms of sensitivity, tonus, posture, gait, functional independence and spatial attention. Results: In relation to the initial impairment, there was no difference in sensitivity, tonus, strength, posture and spatial attention between the groups. The left-side lesion group presented worse initial performance in gait and functional independence tests. In relation to the recovery rate, there were no differences in sensitivity, tonus, strength, posture, spatial attention or functional independence between the two groups. However, the gait recovery rate in the left-side lesion group was slower than in the other group. Conclusions: The hypothesis that left-side lesions cause greater impairment of voluntary movement (represented by gait and functional independence) than do right-side lesions was supported. However, no evidence that right-side lesions cause greater impairment of spatial attention and posture maintenance than do left-side lesions was found.