Multiple large and small cerebellar infarcts.

To assess the clinical, topographical, and aetiological features of multiple cerebellar infarcts,18 patients (16.5% of patients with cerebellar infarction) were collected from a prospective acute stroke registry, using a standard investigation protocol including MRI and magnetic resonance angiography. Infarcts in the posterior inferior cerebellar artery (PICA)+superior cerebellar artery (SCA) territory were most common (9/18; 50%), followed by PICA+anterior inferior cerebellar artery (AICA)+SCA territory infarcts (6/18; 33%). One patient had bilateral AICA infarcts. No infarct involved the PICA+AICA combined territory. Other infarcts in the posterior circulation were present in half of the patients and the clinical presentation largely depended on them. Large artery disease was the main aetiology. Our findings emphasised the common occurrence of very small multiple cerebellar infarcts (<2 cm diameter). These very small multiple cerebellar infarcts may occur with (13 patients/18; 72%) or without (3/18; 22%) territorial cerebellar infarcts. Unlike previous series, they could not all be considered junctional infarcts (between two main cerebellar artery territories: 51/91), but also small territorial infarcts (40/91). It is suggested that these very small territorial infarcts may be endzone infarcts, due to the involvement of small distal arterial branches. It is possible that some very small territorial infarcts may be due to a microembolic process, but this hypothesis needs pathological confirmation.