Traumatic brain injury (TBI) is a disruption in the normal function of the brain that can be caused by physical trauma. TBIs are classified as either “closed”, meaning the skull remains intact, or “open”, meaning the skull has been fractured.^[1]. TBIs are further classified as mild, moderate, or severe. Mild TBI is often referred to as concussion. Severe brain injury can cause coma, permanent disability, or death.^[2]

Mild TBI results in signs and symptoms such as the following:^[3]

• Headache
• Nausea and vomiting
• Fatigue
• Loss of balance or dizziness
• Blurred vision
• Trouble with memory and concentration
• Sleep disturbances

Moderate and severe TBI can initially look similar to mild TBI, with symptoms becoming worse over time. Signs and symptoms of a moderate or severe TBI can include the following:^[4]

• Persistent or worsening headache
• Severe vomiting
• Slurred speech
• Loss of vision
• Confusion or agitation
• Loss of coordination
• Seizures

Clinically, medical professionals assess TBI by taking a thorough history and completing a neurological examination looking for signs and symptoms of TBI in order to classify it appropriately. A TBI is diagnosed if one or more of the following clinical signs is noted after head trauma:

• A decreased level of consciousness or a loss of consciousness after the injury
• Alterations of mental state (e.g., confusion)
• Post-traumatic amnesia
• Neurological deficits (e.g., loss of balance, slurred speech, visual loss)
• An intracranial lesion

A computed tomography (CT) scan or magnetic resonance imaging (MRI) of the brain may be done to check for any head or brain injuries that require neurosurgical intervention.^[5]

Mild TBI can be treated with monitoring and appropriate strategies for returning to normal daily activities and sport. This doesn’t usually require medication, although medicines for managing symptoms like pain and nausea could be used.^[3]

In moderate to severe cases, patients receive emergency neurological life support with an emphasis on monitoring pressure on the brain. Surgery to relieve this pressure may be necessary.^[6] Once the patient is stable, monitoring of the pressure will continue and patients may receive non-invasive treatments to reduce the pressure, such as osmotic therapy. ^[7]

Vitamin E and vitamin C supplementation have shown some positive effects in the context of TBI, but more research is needed to identify the ideal timing and dosing of each.^[8] Curcumin, found naturally in tumeric, has potential anti-inflammatory effects and could help by blocking pathways that cause neuroinflammation after TBI.^[9] Supplementing with docosahexaenoic acid (DHA), an omega-3 fatty acid, has some promising outcomes in early research, but further studies are needed to offer dosages specifically for TBI. A vitamin D supplement could help with recovery from TBI in people with low vitamin D levels at the time of the injury. Similarly, supplementing with magnesium could help improve long-term outcomes.^[10]

There are no specific dietary strategies that are closely related to improved recovery from TBI. However, having a BMI within normal ranges and eating a diet that contains sufficient micronutrients is likely to be valuable when recovering from a TBI. In particular, being underweight can worsen outcomes, although this is not specific to TBI.^[11]

Multiple new medical treatments are being studied for use in TBI. Statins, a class of drugs used primarily to reduce cholesterol, can reduce inflammation in the vascular system, and may reduce neural cell death after an injury.^[12] Progesterone, a neurosteroid, is being investigated for potential neuroprotective effects.^[13] Cyclosporin A is an immunosuppressive drug that is also being looked into for neuroprotective properties, although finding an effective dosage is difficult because high doses can have severe side effects.^[14] Targeted temperature management is sometimes used as a neuroprotective strategy. It involves lowering the body temperature in an attempt to lower the oxygen demand of the brain tissue.^[15] Hyperbaric oxygen therapy focuses instead on providing more oxygen to the damaged tissue. High pressure environments, like those generated in a hyperbaric oxygen chamber, make it possible to have higher than normal oxygenation levels in the blood. This oxygen can be absorbed into the brain tissue, and potentially help the brain to heal more efficiently.^[16][17] Erythropoietin (EPO) treatment has been used for TBI as well. EPO is a type of cytokine that helps the body produce red blood cells. It has antioxidant and anti-inflammatory effects and shows some promise in neuroprotection and improving outcomes in people with TBI.^[18][19] Persisting functional impairments may require long-term interventions from medical specialists. These may include cognitive behavioral therapy, balance training, and vestibular therapy.^[20][21][22]

TBI is caused by an external force applied to the head, resulting in an injury to the brain. In people over 65, TBIs are most commonly caused by a fall. In younger people, they are most commonly caused by motor vehicle accidents, sports injuries, and interpersonal violence.^[2]