Temporal dynamics of ICP, PRx, CPP, and CPPopt in relation to functional outcome in spontaneous cerebellar hemorrhage

Spontaneous cerebellar hemorrhage (sCH) is a severe condition, due to the limited space in the posterior fossa. The temporal dynamics of cerebral physiological variables such as intracranial pressure (ICP), pressure reactivity index (PRx), cerebral perfusion pressure (CPP), "optimal" CPP (CPPopt), and CPP deviation from CPPopt (ΔCPPopt) and associations with functional outcome remain insufficiently characterized in sCH.

This study retrospectively analyzed 94 adult sCH patients treated at the neurointensive care (NIC) unit in Uppsala University Hospital, Sweden, between 2008 and 2024, with collected high resolution monitoring data. The association between insult intensity-duration, temporal dynamics, and interactions with cerebrovascular autoregulation of the cerebral physiological variables with Glasgow Outcome Scale at discharge (GODS) were analyzed in outcome heatmaps. Formal statistical analyses between % of good monitoring time (%GMT) of the cerebral physiological variables within/outside certain thresholds were analyzed in relation to GODS.

In the exploratory analyses, ICP > 15 mmHg demonstrated a descriptive trend toward unfavorable outcome irrespective of duration, particularly the first two days post-injury. Still, the association lacked significance (p = 0.85). Sustained PRx elevations > 0.2 showed a descriptive trend toward worse outcome, with expanding vulnerability over time. However, this association was not significant (p = 0.26). CPP < 80 mmHg was associated with worse outcome, particularly if PRx was elevated. In addition, CPP < 60 mmHg was associated with worse outcome, while CPP > 80 mmHg was associated with favorable outcome (p = 0.02, respectively). Negative ΔCPPopt for longer durations and if PRx was elevated correlated with lower GODS. ΔCPPopt < -5 mmHg was associated with worse outcome (p = 0.04).

Cerebral physiological monitoring provides important prognostic information in sCH. Optimal targets differ from supratentorial acute brain injuries, with an apparent benefit of higher CPP in sCH. ICP, CPP, and ΔCPPopt remain central, warranting larger multi-center studies to define sCH-specific targets.