Paroxysmal Sympathetic Hyperactivity in Moderate-to-Severe Traumatic Brain Injury and the Role of Beta-Blockers: A Scoping Review

Abstract

Introduction. Most cases of paroxysmal sympathetic hyperactivity (PSH) result from traumatic brain injury (TBI). Little is known about its pathophysiology and treatment, and several neuroprotective drugs are used including beta-blockers. The aim of our study is to collate existing evidence of the role of beta-blockers in the treatment of PSH. Methods. We searched MEDLINE, ResearchGate, and Google Scholar, for keywords related to PSH and the role of beta-blockers in moderate-to-severe TBI on September 23, 2020. Two authors blindly screened the articles found with Rayyan. Both resolved their conflicts by mutual consent. If no solution was found, a third author was consulted. Simple descriptive data analysis was performed and the results were presented both in a narrative and tabular form. Results. Of the 19 items found, 10 met the criteria for inclusion. 50% were systematic reviews without meta-analysis, 40% were observational studies, and 10% were experimental studies. Propranolol was the main beta-blocker found in 80% of the studies and was the only molecule used in the treatment of paroxysmal sympathetic hyperactivity in 40% of the included studies. Only two studies evaluated and showed a significant association between beta-blockers and mortality rate (5.1% vs. 10.8%; $P=0.03$ ), (3% vs. 15%; $P=0.002$ ), respectively. Conclusion. Propranolol is the beta-blocker that has been shown to be effective in reducing the length of stay and mortality rate in moderate-severe traumatic brain injury patients with PSH. However, further studies are needed to precisely define the terms and conditions of its use.