Efficacy and Safety of Ultrasound-Guided Right-Sided Stellate Ganglion Block for Reducing the Severity and Duration of Acute Paroxysmal Sympathetic Hyperactivity in Patients with Acquired Brain Injury: A Randomized Controlled Clinical Trial

Paroxysmal sympathetic hyperactivity (PSH) is a severe autonomic disorder following acquired brain injury for which there are no effective targeted therapies. The aim of this study was to evaluate whether ultrasound-guided right-sided stellate ganglion block (RSGB) can safely and effectively attenuate acute episodes of PSH. A prospective, single-blind randomized controlled trial was conducted. Eighty patients with PSH were randomized to receive either conventional care or RSGB combined with conventional care. Primary outcomes included PSH episode intensity and duration as assessed by the Clinical Feature Score (CFS), the PSH Assessment Measure (PSH-AM), and episode duration. Secondary outcomes included plasma epinephrine, norepinephrine, and cortisol levels measured at three predefined time points: at the onset of the PSH episode (T1), 30 min after the onset (T2), and at the end of the episode (T3). Of 80 randomized participants, 76 were analyzed. Compared with the control group, the RSGB group showed a significantly greater reduction in CFS and PSH-AM scores from T1 to T2 ( p < 0.001) and a significantly shorter median duration of episodes (81.0 vs. 164.0 min, p < 0.001). RSGB significantly reduced circulating catecholamine levels at 30 min (epinephrine: p = 0.026; norepinephrine: p = 0.036) without affecting cortisol. A significant baseline imbalance in sex distribution was noted between the groups, and the primary outcomes reflect an unadjusted analysis. No adverse events were observed, confirming the safety of RSGB. RSGB can effectively and safely reduce the severity and duration of PSH attacks by targeting sympathetic overactivity, providing a new non-pharmacological adjuvant for the routine management of PSH patients.