Traumatic brain injury and mitochondrial dysfunction.

Traumatic brain injury (TBI) is a major cause of death and disability in the United States and causes mitochondrial damage leading to impaired brain function. The purpose of this review is to (1) describe TBI processes and manifestations, (2) examine the mitochondrial alterations after TBI, specifically increased reactive oxygen species production, decreased bioenergetics and apoptosis and (3) current TBI treatments. There are various degrees of severity of TBI, yet all affect mitochondrial function. Currently, health care professionals use various methods to assess TBI severity-from brain imaging to serum biomarkers. The major cause of TBI-associated brain damage is secondary injury, which is mainly from mitochondrial injury dysfunction. Mitochondrial injury leads to oxidative stress and subsequent apoptosis and decreased cellular energy production. These brain cellular alterations impair neurologic functions, which are observed in individuals with TBI. The complex mitochondrial dysfunction after TBI requires treatment that specifically addresses the secondary injury. There are numerous therapies being used, including (1) hypothermia, (2) hyperbaric oxygen, (3) exercise and (4) antioxidants. Researchers are exploring novel approaches to prevent, diagnose and treat TBI focusing on maintaining mitochondrial function.