Effects of cerebral venous outflow patterns on functional outcome in space-occupying cerebellar infarction

Background: Space-occupying cerebellar infarction can be catastrophic, leading to brainstem compression, transtentorial herniation, and obstructive hydrocephalus. Herein, we investigated the association between the venous outflow pattern based on transverse sinus (TS) shape and the outcome of space-occupying cerebellar infarction. Methods: Patients with space-occupying cerebellar infarctions were enrolled, and data on baseline demographics, clinical factors, and venous outflow patterns, including the type of TS were collected. Low-functioning ipsilateral TS was defined as aplasia, occlusion, or hypoplasia on the side ipsilateral to the space-occupying cerebellar infarction. Conversely, properly functioning ipsilateral TS was defined as: 1) bilateral symmetric TS and 2) normal ipsilateral TS with aplasia, occlusion, or hypoplasia observed on the side contralateral to the spaceoccupying cerebellar infarction. The primary outcome was the attainment of a modified Rankin Scale (mRS) score of 0-2 at three months. Results: Among 42 patients, low-functioning ipsilateral TS was observed in 17 (40.5 %). Initial National Institutes of Health Stroke Scale score was significantly higher in patients with properly functioning ipsilateral TS (0.0 [0.0-1.0] vs. 2.0 [1.0-3.0], P=0.010). Moreover, the primary outcome was significantly more favorable in patients with low-functioning ipsilateral TS (1.0 [1.0-2.0] vs. 3.0 [1.0-3.0], P=0.016). Multivariable logistic regression analysis showed that patients with low-functioning ipsilateral TS (P=0.040) was associated with functional independence. Conclusions: Patients with low-functioning ipsilateral TS exhibit more favorable outcomes than those with properly functioning ipsilateral TS in space-occupying cerebellar infarctions. The assessment of venous outflow functionality is a potential predictor of functional outcomes in space-occupying cerebellar infarctions.