Predictors of malignant swelling in space-occupying cerebellar infarction

Background: Malignant swelling is a fatal complication that can occur abruptly in space-occupying cerebellar infarction. We aimed to establish markers that predict malignant swelling in cerebellar infarction. Methods: We retrospectively analysed data of stroke patients who were treated in our hospital between 2014 and 2020. Malignant swelling was defined as a mass effect in the posterior cranial fossa, accompanied by a decrease in consciousness due to compression of the brainstem and/or the development of obstructive hydrocephalus. Statistical analyses were performed on multiple variables to identify predictors of malignant swelling. Results: Among 7284 stroke patients, we identified 487 patients with an infarct in the cerebellum. 93 patients were suitable for analysis having space-occupying cerebellar infarction. 33 of 93 (35.5%) patients developed malignant swelling. Multivariable analysis revealed infarct volume as the main predictor being independently associated with the development of malignant swelling with a cut-off infarct volume of 38 cm3 being associated with a swelling rate of >50% (OR 32.0, p<0.001). Higher NIHSS (National Institutes of Health Stroke Scale) score on admission (median NIHSS 12 vs 4, OR 1.078; p=0.008) and the presence of additional brainstem infarction (51.5% vs 16.7%, OR 5.312; p=0.013) were associated with the development of malignant swelling in univariate analyses. 13 of 33 (39.4%) cases of malignant swellings occurred after more than 3 days. Conclusions: Infarct volume was the key significant predictor of malignant swelling in space-occupying cerebellar infarction. With many cases of malignant swelling occurring after more than 72 hours, we advocate prolonged neurological monitoring.