Pharmacologic Neuroprotection for Functional Outcomes After Traumatic Brain Injury: A Systematic Review of the Clinical Literature

Shaun E. Gruenbaum, Alexander Zlotnik, Benjamin F. Gruenbaum, Denise Hersey, Federico Bilotta

Traumatic brain injury (TBI) is a major cause of death and disability worldwide. The deleterious effects of secondary brain injury may be attenuated by early pharmacological therapy in the emergency room and intensive care unit (ICU). Current medical management of acute TBI is primarily supportive, aimed at reducing intracranial pressure (ICP) and optimizing cerebral perfusion. There are no pharmacological therapies to date that have been unequivocally demonstrated to improve neurological outcomes after TBI. The purpose of this systematic review was to evaluate the recent clinical studies from January 2013 through November 2015 that investigated neuroprotective functional outcomes of pharmacological agents after TBI. The following databases were searched for relevant studies: MEDLINE (OvidSP January Week 1, 2013-November Week 2 2015), Embase (OvidSP 2013 January 1-2015 November 24), and the unindexed material in PubMed (National Library of Medicine/National Institutes of Health [NLM/NIH]). This systematic review included only full-length clinical studies and case series that included at least five patients and were published in the English language. Only studies that examined functional clinical outcomes were included. Twenty-five of 527 studies met our inclusion criteria, which investigated 15 independent pharmacological therapies. Eight of these therapies demonstrated possible neuroprotective properties and improved functional outcomes, of which five were investigated with randomized clinical trials: statins, N-acetyl cysteine (NAC), Enzogenol, Cerebrolysin, and nitric oxide synthase inhibitor (VAS203). Three pharmacological agents did not demonstrate neuroprotective effects, and four agents had mixed results. While there is currently no single pharmacological therapy that will unequivocally improve clinical outcomes after TBI, several agents have demonstrated promising clinical benefits for specific TBI patients and should be investigated further.