Paroxysmal sympathetic hyperactivity (PSH) is characterized by episodes of excessive sympathetic activity and is associated with poor outcomes in brain injuries, yet its impact on severe intracerebral hemorrhage (ICH) remains unclear. This study investigates the association between PSH and clinical outcomes in patients with severe ICH.

We conducted a prospective observational cohort study of patients with severe ICH from January 2018 to December 2022. Severe ICH was defined as ICH with a Glasgow Coma Scale score ≤ 8 on admission, indicating significant neurological impairment. Patients were assessed for PSH using the PSH-Assessment Measure, and categorized into probable, possible, and unlikely PSH groups. Propensity score matching was used to adjust for baseline differences among three groups. The primary outcome was the 90-day mortality rate. Secondary outcomes included a favorable functional outcome at 90 days, defined by a modified Rankin Scale score of 0–2. Statistical analyses were performed using Cox proportional hazards regression and Kaplan–Meier survival analysis.

After propensity score matching, 177 patients (59 in each group) were analyzed. The 90-day mortality rate was significantly higher (P < 0.01) in the probable PSH group (67.8%), compared with possible (47.5%) and unlikely PSH groups (35.6%). The Kaplan–Meier survival curve further illustrates a significantly increased risk of 90-day mortality in the probable PSH group (Log rank test P < 0.01). Multivariate Cox proportional hazards regression analysis confirmed that, after adjusting for confounders, the presence of probable PSH (hazard ratio 3.86, 95% confidence interval 2.17–6.87; P < 0.01) was independently associated with a higher risk of 90-day mortality. Functional outcomes at 90 days were poorer in the probable PSH group.

Probable PSH is significantly associated with worse outcomes in severe ICH, underscoring the importance of early recognition and targeted management strategies.