Mild traumatic brain injury (TBI), previously termed concussion, 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.
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.
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 that results in a change in mental status. 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). However, the GCS is confounded by several factors, including drug and alcohol use, medications, and tracheal intubation. Concussion is a subset of mild TBI which is typically classified based on acute injury characteristics at the less severe end of the brain injury spectrum. However, currently there are no distinct symptom profiles, diagnostic criteria, or objective biomarkers that distinguish concussion from mild TBI. Centers for Disease Control and Prevention: HEADSUP Opens in new window
History and exam
Key diagnostic factors
- direct blow to the head or deceleration of the head from an impulsive force
- previous brain trauma, substance use, or alcohol misuse
Other diagnostic factors
- feeling foggy/slow
- dizziness/balance problems
- memory difficulties
- neck pain
- normal physical neurologic exam
- abnormalities on neuropsychological testing
- head injury
- previous brain trauma
- alcohol and drug misuse
- poor neck strength
1st investigations to order
- CT head
Investigations to consider
- MRI head
- PET, single-photon emission CT (SPECT) of head
- multimodal MRI technologies
- Moderate/severe traumatic brain injury (TBI)
- General trauma or injury to the body not involving the head
- Critical Issues in the management of adult patients presenting to the emergency department with mild traumatic brain injury
- Concussion/mild traumatic brain injury and persistent symptoms: for adults over 18 years of age
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