Harvard Mental Health Letter

Postconcussion syndrome

Why this diagnosis is controversial and what treatments may help

More than one million Americans suffer head injuries each year that are serious enough to send them to hospitals. The vast majority of these injuries — anywhere from 75% to 90% — are concussions. Although bicycle accidents and other sports injuries are often to blame for concussions in children, the most common causes in adults are falls and motor vehicle accidents.

Defined broadly, the term concussion is used to describe an injury that results from a blow or other impact to the head. The person may briefly become dazed or lose consciousness. Dizziness or headache may follow. Other symptoms include neck pain, nausea or vomiting, sensory disturbances (problems with hearing, vision, or taste), fatigue, and confusion. Concussions can also cause either anterograde amnesia (inability to remember new information) or retrograde amnesia (forgetting what happened just before or during the accident).

These symptoms develop because a head impact that significantly jolts the brain can disrupt brain cell function. Most people recover within a few hours, although headache and irritability may persist for a day or more.

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