Objective To characterise the topographic patterns of thalamic infarcts associated with various stroke syndromes and aetiologies.

Methods In this study, 168 consecutive patients with acute infarcts involving the thalamus were investigated by use of diffusion weighted MR imaging. Involved thalamic territories were classified into four vascular territories: anterior (polar artery), posteromedial (thalamoperforating artery), ventrolateral (thalamogeniculate artery) and posterolateral (posterior choroidal artery) territory. The distribution of thalamic infarcts involving specific vascular territories in association with various stroke syndromes and aetiologies were analysed.

Results There was a significant association between involvement of the ventrolateral thalamus and isolated thalamic infarcts (49 patients (73%), p<0.01) or posterior cerebral artery infarcts (29 patients (76%), p=0.02), and between involvement of the posteromedial thalamus and top of the basilar artery syndrome (17 patients (77%), p<0.001) or extended posterior circulation infarcts (29 patients (71%), p<0.001). The ventrolateral territory was most commonly affected in association with small vessel disease (43 patients (72%), p=0.03) and the posteromedial territory in association with large artery disease (19 patients (63%), p<0.01). In cardioembolic stroke, the ventrolateral, posteromedial and posterolateral territories were equally affected.

Conclusions The results of the present study indicate a specific association between the topographic patterns of thalamic infarcts and the stroke syndromes and aetiologies.