Concussion (mild, traumatic brain injury) 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 concussion 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 concussive injury.
For uncomplicated cases, physical and cognitive rest is usually sufficient.
Concussion (mild traumatic brain injury) 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. 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 or alcohol misuse
Other diagnostic factors
- feeling foggy/slow
- dizziness/balance problems
- memory difficulties
- normal physical neurologic exam
- abnormalities on neuropsychological testing
- previous brain trauma
- alcohol and drug misuse
- poor neck strength
1st investigations to order
- CT head
Investigations to consider
- MRI head
- functional MRI (fMRI)
- PET, single-photon emission CT (SPECT) of head
- alternative imaging techniques
- anatomic brain imaging techniques
Luke C. Henry, PhD
Department of Neurological Surgery
Senior Clinical Neuropsychologist
University of Pittsburgh
LCH declares that he has no competing interests.
Maria Twichell, MD
Assistant Clinical Professor
General Rehabilitation Unit
UPMC Physical Medicine and Rehabilitation
University of Pittsburgh Medical Center
MT declares that she has no competing interests.
Dr Luke C. Henry and Dr Maria Twichell would like to gratefully acknowledge Dr Jeffrey Bazarian and Dr Maryse Lassonde, previous contributors to this topic.
JB has been reimbursed by Roche, the manufacturer of an automated assay for serum S-100B, to attend a conference, and has been reimbursed by Banyan Biomarkers and Neuren Pharmaceuticals to help develop their research protocols. JB is also an author of a reference cited in this topic. ML is an author of several references cited in this topic.
Eirik Helseth, MD, PhD
Professor and Consultant
Department of Neurosurgery
Ulleval University Hospital
EH declares that he has no competing interests.
Margot Putukian, MD
Director of Athletic Medicine
MP is an author of a reference cited in this topic.
- Moderate/severe traumatic brain injury
- General trauma or injury to the body not involving the head
- Head injury: assessment and early management
- Living guideline for diagnosing and managing pediatric concussion
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