Biomarkers for Concussion

Abstract

Diagnostic and prognostic tools for risk stratification of concussion patients are limited in the early stages of injury in the acute setting. Unlike other organ-based diseases where rapid diagnosis employing biomarkers from blood tests is clinically essential to guide diagnosis and treatment, such as for myocardial ischemia or kidney and liver dysfunction, there are no rapid, definitive diagnostic tests for traumatic brain injury (TBI). Research in the field of TBI biomarkers has increased exponentially over the last 20 years with most of the publications on the topic of TBI biomarkers occurring in the last 10 years. Accordingly, studies assessing biomarkers in TBI have looked at a number of potential markers that could lend diagnostic and, prognostic, as well as therapeutic information. Despite the large number of published studies, there is still a lack of any FDA-approved biomarkers for clinical use in adults and children. Developments in the field of proteomics, along with improved laboratory techniques, have led to the discovery and rapid detection of new biomarkers not previously available. Proteomic research has recently developed due to advances in protein separation, identification, and quantification technologies that only became available in the last decade. Some proteins are highly expressed in the cerebrospinal fluid following a TBI. However, this does not necessarily translate into availability in peripheral blood. With the increasing sensitivity of analytical tools for biomarker detection, measurement of biomarkers in peripheral blood has also improved. In an effort to prevent chronic traumatic encephalopathy (CTE) and long-term consequences of concussion/mild TBI, early diagnostic and prognostic tools are becoming increasingly important, particularly in sports injuries and in military personnel where concussions/mild TBI are common occurrences. The studies conducted on biofluid biomarkers for mild TBI to date show great promise. Should serum biomarkers for TBI be validated and become widely available, they could have many roles. They could help with clinical decision making by clarifying injury severity and help monitor progression of injury and/or recovery. Biomarkers could have a role in managing patients at high risk of repeated injury and could be incorporated into guidelines for return to duty, work, or sports activities. This chapter will discuss the current literature on biofluid biomarkers for concussion/mild TBI, address gaps in research, and discuss their future role.