Infratentorial Pressure Monitoring in Cerebellar Stroke: Feasibility and Prognostic Utility.

Background: Although supratentorial intracranial pressure (ICP) monitoring represents the current standard in neurocritical care, its validity for assessing infratentorial pathologies remains uncertain. This multicenter, prospective study aimd to (1) evaluate the feasibility and clinical utility of infratentorial ICP monitoring in acute posterior fossa pathologies and (2) develop a prognostic model for functional outcomes based on infratentorial pressure dynamics.

Methods: We conducted a prospective cohort study across three tertiary neurovascular centers in Germany (2021-2024), enrolling 35 consecutive patients with cerebellar stroke requiring surgical decompression and external ventricular drainage. All participants underwent simultaneous supratentorial and infratentorial ICP monitoring for seven posteroperative days. Functional outcomes were assessed using the modified Rankin scale at discharge and at six-month follow-up (FU). The primary end point was the comparison of ICP gradients between compartments; secondary analyses evaluated the association between infratentorial ICP and functional outcomes.

Results: The mean infratentorial ICP was significantly higher than the supratentorial ICP (11.9 mm Hg [95% confidence interval (CI) 10.5-13.3] vs. 8.8 mm Hg [95% CI 7.4-10.1], P < 0.001). Patients with unfavorable outcomes had significantly higher infratentorial ICP values compared with those with favorable outcomes at FU (13.1 mm Hg [95% CI 11.1-15.1] vs. 9.5 mm Hg [95% CI 6.8-12.1], P = 0.042). Multivariate logistic regression analysis identified a novel scoring system-calculated as patient age (years) plus four times the mean infratentorial ICP (mm Hg)-as a significant predictor of unfavorable outcomes at both discharge and FU (P < 0.001 and P = 0.001, respectively), with area under the curve (AUC) values of 0.88 and 0.89. A cutoff value of 115 was established to predicting unfavorable outcomes at FU.

Conclusions: This study establishes that infratentorial ICP monitoring (1) reveals clinically significant pressure gradients undetctable by supratentorial measurement alone, (2) provides superior prognostic information compared with conventional monitoring, and (3) can be safely implemented with 94% technical success rate. These findings advocate for the integration of infratentorial ICP assessment into the neurocritical care paradigm for posterior fossa pathologies.