Concussion

Lore & Background

Concussion occurs when external forces act on the head, either through a direct blow or forces transmitted from elsewhere on the body. The mechanism involves linear, rotational, or angular movement of the brain, with rotational force thought to be a major component in severity. The injury disrupts normal cellular activities, particularly in the reticular activating system, midbrain, and diencephalon, leading to temporary neuron dysfunction due to increased glucose requirements without sufficient blood supply. Signs and symptoms typically appear within minutes to hours of injury, most commonly within 72 hours, though they may be delayed by 1–2 days. Physical symptoms include headache, dizziness, nausea, balance problems, and visual disturbances. Cognitive symptoms include confusion, disorientation, difficulty focusing, and post-traumatic amnesia. Emotional changes such as crankiness, loss of interest, and inappropriate emotions may also occur. Loss of consciousness occurs in fewer than 10% of sports-related concussions among children and is not necessarily correlated with severity if brief. Diagnosis requires a thorough evaluation by a qualified medical provider to rule out life-threatening head injuries, cervical spine injuries, and neurological conditions. Glasgow coma scale score 13 to 15, loss of consciousness for less than 30 minutes, and memory loss for less than 24 hours help rule out moderate or severe traumatic brain injuries. Diagnostic imaging such as CT or MRI may be used to rule out severe head injuries, but routine imaging is not required and is by definition normal after concussion.

Reader's Guide

Concussion is significant as the most common form of traumatic brain injury, with outcomes generally good but varying by individual. The severity of initial symptoms is the strongest predictor of recovery time in adults. Up to one-third of people experience persisting symptoms lasting beyond 14 days in adults or 4 weeks in children, known as post-concussion syndrome. Another concussion before prior symptoms resolve is associated with worse outcomes, and repeated concussions may increase the risk of chronic traumatic encephalopathy, Parkinson's disease, and depression later in life. Prevention includes helmet and mouth guard use in sports, seatbelt use in vehicles, and following rules on body contact in organized sport. Treatment involves relative rest for no more than 1–2 days, as prolonged rest may slow recovery and increase depression and anxiety. Aerobic exercise and gradual return to activities are recommended. Paracetamol or NSAIDs may help with headache, and physiotherapy may aid persisting balance problems or whiplash. Cognitive behavioral therapy may help with mood changes and sleep problems. Evidence for hyperbaric oxygen therapy and chiropractic therapy is lacking. The condition affects more than 3.5 per 1,000 people annually worldwide, with males and young adults most commonly affected.

Did You Know?

• Fewer than 10% of sports-related concussions among children are associated with loss of consciousness.
• Concussive convulsions occur in about one in seventy concussions and are not predictive of epilepsy.
• Symptoms may be delayed by 1–2 days after the accident.
• Prolonged periods of rest may slow recovery and result in greater depression and anxiety.