An isolated pontine infarct extending to the basal pontine surface has a higher abnormal ankle-brachial index.

Patients with ischemic stroke and branch atheromatous disease (BAD) have worse neurological deficits and prognoses than those with small vessel occlusion (SVO). However, both disorders are forms of deep brain infarctions. This study aimed to investigate an MRI-based etiological classification for isolated pontine infarctions and assess differences in vascular risk factors and peripheral arterial disease among etiological subtypes. Consecutive data of patients admitted for acute ischemic stroke or transient ischemic attack between August 2016 and July 2019 were reviewed. Acute isolated pontine infarcts were classified into 3 groups: BAD, SVO, and large-artery atherosclerosis (LAA), according to basilar or vertebral artery steno-occlusion and the extent of the infarct lesion on the basal pontine surface as displayed on magnetic resonance imaging and angiography. Vascular risk factors, ankle-brachial index (ABI), and brachial-ankle pulse wave velocity were analyzed in the 3 groups. Among 64 enrolled patients, BAD was the most common cause of isolated pontine infarct. The BAD group had a higher frequency of abnormal ABI and hypertension than the SVO group. The BAD group had abnormal ABI and hyperlipidemia more frequently than the LAA group. No significant difference was found in diabetes or brachial-ankle pulse wave velocity incidence between the BAD and SVO groups. ABI and vascular risk factors in the BAD group were more similar to those in the LAA group than to those in the SVD group. This finding suggests that pontine lesions extending to the basal pontine surface have an atherosclerotic mechanism in BAD, requiring potent antiplatelet therapy for the secondary prevention of ischemic stroke.