A method to distinguish the different etiological mechanisms of single subcortical infarction

Objectives Although lenticulostriate artery (LSA) territorial infarcts usually appear as single subcortical infarctions (SSIs) on imaging, they are caused by various etiological mechanisms. We aimed to investigate the correlation between LSA morphology and the location or size of infarcts. Besides, we explored whether the location or size of infarcts can predict the presence of middle cerebral artery (MCA) plaques and distinguish the different etiological mechanisms of SSI patients. Methods We prospectively included patients with acute SSI in the LSA territory. The MCA plaques, infarct features, including the number of infarct slices, lowest infarct layer index (LILI), volume, maximum area and diameter, and LSA morphological characteristics, including the number of stems and branches, length, distance, and tortuosity were evaluated. Results A total of 105 patients were enrolled. Both the average length and average distance of LSAs were negatively correlated with the maximum infarct area ( P =0.048, P =0.028, respectively) and maximum infarct diameter ( P =0.016, P =0.010, respectively) on axial examination and were positively correlated with LILI ( P =0.020, P =0.003, respectively). The number of LSA branches was associated with the number of infarct slices ( P =0.040) and LILI ( P =0.043). Moreover, we found that when the LILI=1 or 2 and the number of infarct slices ≥3, the SSI patients were more likely to have MCA plaques ( P =0.045). Conclusions SSI patients with a LILI=1 or 2 and infarct slices of ≥3 were more likely to have MCA plaques. Our findings might provide a simple and feasible method to distinguish the different underlying mechanisms of SSIs for clinicians.