Mild traumatic brain injury

Mild traumatic brain injury (TBI) is a closed head injury due to a direct blow to the head or deceleration of the head from an impulsive force, resulting in a transient change in mental status.

The most common causes are motor vehicle accidents, sports, assaults, and falls.

Diagnosing mild TBI is difficult based on acute injury characteristics and presenting signs and symptoms.

Headache, mental slowing and fogginess, and memory difficulties are typical symptoms. Symptoms may fluctuate, but typically subside after 1 week to 1 month. Loss of consciousness is not necessary for a positive diagnosis.

Computed tomography scan and magnetic resonance imaging are typically normal in mild TBI.

For uncomplicated cases, physical and cognitive rest is usually sufficient.

TBI is a closed head injury due to a direct blow to the head or deceleration of the head from an impulsive force that results in a change in mental status.[1]Holm L, Cassidy JD, Carroll LJ, et al. Summary of the WHO Collaborating Centre for Neurotrauma Task Force on mild traumatic brain injury. J Rehabil Med. 2005 May;37(3):137-41. http://www.ncbi.nlm.nih.gov/pubmed/16040469?tool=bestpractice.com ​ The Glasgow Coma Scale (GCS) remains the main instrument for classifying the severity of TBI as mild (GCS 13–15), moderate (GCS 9–12), or severe (GCS ≤8).[2]Maas AIR, Menon DK, Manley GT, et al. Traumatic brain injury: progress and challenges in prevention, clinical care, and research. Lancet Neurol. 2022 Nov;21(11):1004-60. https://www.thelancet.com/journals/laneur/article/PIIS1474-4422(22)00309-X/fulltext http://www.ncbi.nlm.nih.gov/pubmed/36183712?tool=bestpractice.com  However, the GCS is confounded by several factors, including drug and alcohol use, prescription or nonprescription drugs, and tracheal intubation.[2]Maas AIR, Menon DK, Manley GT, et al. Traumatic brain injury: progress and challenges in prevention, clinical care, and research. Lancet Neurol. 2022 Nov;21(11):1004-60. https://www.thelancet.com/journals/laneur/article/PIIS1474-4422(22)00309-X/fulltext http://www.ncbi.nlm.nih.gov/pubmed/36183712?tool=bestpractice.com Concussion and mild TBI are overlapping but distinct terms; concussion can be considered a subset of mild TBI, which comprises a range of injury types at the less severe end of the brain injury spectrum (which includes concussion with other features).[3]Harmon KG, Clugston JR, Dec K, et al. American Medical Society for Sports Medicine position statement on concussion in sport. Br J Sports Med. 2019 Feb;53(4):213-25. https://bjsm.bmj.com/content/53/4/213.long http://www.ncbi.nlm.nih.gov/pubmed/30705232?tool=bestpractice.com [4]Mayer AR, Quinn DK, Master CL. The spectrum of mild traumatic brain injury: a review. Neurology. 2017 Aug 8;89(6):623-32. http://www.ncbi.nlm.nih.gov/pubmed/28701496?tool=bestpractice.com ​​ Currently there are no distinct symptom profiles, diagnostic criteria, or objective biomarkers that distinguish concussion from mild TBI.[4]Mayer AR, Quinn DK, Master CL. The spectrum of mild traumatic brain injury: a review. Neurology. 2017 Aug 8;89(6):623-32. http://www.ncbi.nlm.nih.gov/pubmed/28701496?tool=bestpractice.com Centers for Disease Control and Prevention: HEADSUP Opens in new window