Triple dissociation of attention networks in stroke according to lesion location

OBJECTIVE:To determine whether behavioral dissociations and interactions occur between the attentional functions—alerting, orienting, and conflict resolution—depending upon stroke location and to determine the approximate proportion of patients who can be classified into 1 of these 3 anatomical networks. METHODS:We recruited 110 anatomically unselected acute stroke patients and 62 age-matched controls. Subjects underwent the attention network test (ANT), which provides a measure of each attention type. Their performance was related to lesion anatomy on MRI using a voxel-lesion mapping approach. RESULTS:Patients as a whole performed poorer than controls, but there were no group differences in the size of attentional effects. Specific deficits in 1 of the 3 ANT-tested functions were found in the following lesion locationsalerting deficiency with bilateral anteromedial thalamus and upper brainstem (17% of patients); orienting impairment with right pulvinar and right temporoparietal cortex (15%); conflict resolution with bilateral prefrontal and premotor areas (23%). Lesions to right frontoparietal regions also modified interactions among the 3 types of attention. CONCLUSIONS:More than half of all stroke patients can be expected to have a lesion location classifiable into 1 of the 3 principal attention networks. Our results have potential implications for therapy personalization in focal brain diseases including stroke.