To investigate the clinical and imaging features of different types of acute cerebellar infarction and their possible pathogenetic mechanisms.

A total of 300 patients with acute cerebellar infarction admitted to the Department of Neurology, Beijing Chaoyang Hospital, Capital Medical University, between January 2016 and December 2020 were enrolled. According to the extent of the ischemic lesion, they were divided into a territorial infarction (TI) group of 130 cases and a non-territorial infarction (non-TI) group of 170 cases. The clinical and imaging characteristics between the two patient groups were compared. Continuous data were compared using the independent samples t-test or the Mann-Whitney U test, while categorical data were analyzed using the Chi-square test.

No statistically significant intergroup differences were observed in conventional vascular risk factors, including age, hypertension, diabetes mellitus, dyslipidemia, coronary artery disease, atrial fibrillation, smoking, or alcohol consumption (all P>0.05). The proportion of intracranial vertebral artery stenosis, basilar artery stenosis, and combined vertebral and basilar artery stenosis were relatively high in both groups, without significant between-group differences (all P>0.05). In contrast, the TI cohort exhibited a significantly higher rate of extracranial vertebral artery stenosis than the non-TI cohort (65.38% vs 54.12%, χ²=3.866, P=0.049) and a significantly lower rate of extra-cerebellar infarction (40.00% vs 54.71%, χ²=6.377, P=0.012). Etiological subtyping revealed large-artery atherosclerosis in 116 TI patients, other determined causes in 7, cryptogenic stroke in 5, and cardio-embolism in 2. The distribution of etiological subtypes differed significantly between groups (χ²=22.525, P<0.001). Clinically, the TI group presented with vertigo and headache more frequently than the non-TI group (vertigo: 52.31% vs 28.24%, χ²=17.041, P<0.001; headache: 23.85% vs 10.00%, χ²=10.220, P=0.001). On neurological examination, positive nystagmus and ataxia were also more prevalent in the TI group (nystagmus: 23.08% vs 12.35%, χ²=5.935, P=0.015; ataxia: 39.23% vs 22.35%, χ²=10.229, P=0.006).

Acute territorial and non-territorial cerebellar infarction patients had similar cardiovascular risk factors and similar frequencies of vertebral artery and basilar artery stenosis. For patients with presenting vertigo, headache, nystagmus and ipsilateral limb ataxia on physical examination, cerebellar territorial infarction should be the leading diagnostic consideration, and focus should be placed on identifying evidence of large-artery atherosclerosis and cardiogenic embolism.