Morphological classification of acute isolated pontine infarction and it's clinical relevance

Abstract

Objective: To investigate a diffusion weighted imaging (DWI)-based morphological classification for acute isolated pontine infarcts (AIPI) and to assess differences in clinical characteristics, risk factors and functional outcomes among the different morphologies. Methods: All participants from SMART cohort with DWI-proven AIPI were included and categorized into 3 groups: basilar artery branch disease (BABD) group, small artery disease (SAD) group and large-artery-occlusive disease (LAOD) group, according to lesion extent of the transverse axial plane and basilar artery atherosclerosis severity. The clinical characteristics, vascular risk factors and 6-month's functional outcome was analyzed among 3 groups. Results: Of the 1 129 patients enrolled, 175 had AIPI. BABD was the most frequent subtype of AIPI (46.3%), followed by SAD (36.0%) and LAOD (17.7%). Neurological impairment on admission was more severe in the LAOD and BABD group than SAD group (P<0.001). In terms of risk factors, the percentage of hypertension was significant different among three groups (P<0.05). The average National Institute of Health stroke scale was 3.49 for SAD group, 5.93 for LAOD group, 5.97 for BABD group, and the differences were significant (P<0.001). The Poor outcome (mRS>2) was found in only 13.7% of patients at 6-month post-stroke and there was no difference among 3 groups. Conclusions: According to the morphological classification, BABD is the most frequent subtype of AIPI. The differences of the clinical characteristics and risk factors among three groups indicate that differences observed in morphology might have distinct pathophysiologic mechanisms. AIPI can be reliably classified based on morphology using clinical magnetic resonance images.