Relationship between ischemic lesion volume and functional status in the 2nd week after middle cerebral artery stroke

To examine the relationship between the volume of the middle cerebral artery stroke lesion and functional status in the subacute phase of stroke. Methods. Infarct volumes of 94 patients with a 1st middle cerebral artery stroke assessed on conventional MRI scans obtained in the 2nd week poststroke were related to a clinical measure of stroke severity (National Institutes of Health Stroke Scale [NIHSS]) and to functional status: motor impairment (Motricity Index [MI]) and limitation in activities (Barthel index [BI] and modified Rankin Scale). Separate correlations were computed for patients with large (> 30 ml) and small (≤ 30 ml) lesions, and to investigate the influence of lesion location on the relationship between volume and functional status, correlations were computed for patients with left and right hemisphere lesions and for patients with cortical and subcortical lesions. Results. Lesion volume correlated strongly with NIHSS scores (R = 0.61) and moderately with the patient's functional status (MI [R between -0.42 and 0.49], BIN =-0.43], and Modified Rankin Scale [R = 0.45]). Right hemisphere lesions and cortical lesions had a stronger correlation with functional status. In patients with small lesion volumes (0-30 ml), no relationship between lesion volumes and functional status was seen at all. Conclusions. Lesion volume is moderately to strongly related to the functional status in the 2nd week poststroke.