Concussion

A concussion is often the result of a mishap during sports or recreational activities. Falls or motor vehicle crashes may also cause concussion. (See also Overview of Head Injuries.)

In concussion, no brain damage can be detected on imaging tests, such as computed tomography (CT) or magnetic resonance imaging (MRI). However, brain cells are temporarily damaged or dysfunctional, and the person has noticeable symptoms.

Symptoms of a concussion, which are temporary, include 1 or more of the following:

• Confusion: Appearing dazed or stunned and/or answers slowly

• Memory loss: Being unable to recall events that occurred just before the injury or just afterward

• Double vision

• Sensitivity to light

• Dizziness, clumsy movements, and problems with balance

• Headache

• Nausea and vomiting

• Ringing in the ears (tinnitus)

• Loss of smell or taste

Consciousness may be lost for a brief time, rarely for more than 15 minutes. Some people may not realize they have had a concussion.

Postconcussion syndrome refers to certain symptoms that sometimes occur for up to a few weeks after a concussion. These symptoms include 1 or more of the following:

• Headaches

• Difficulty sleeping

• Fatigue

• Problems with short-term memory

• Difficulty concentrating

• Sensitivity to light or noise

• Personality changes, such as irritability or mood swings

Postconcussion syndrome symptoms are common during the week after concussion and commonly resolve during the second week. However, sometimes, symptoms persist for months or, rarely, years.

People who have had a concussion also seem to be more susceptible to another one, particularly if the new injury occurs before symptoms from the previous concussion have completely gone away.

To diagnose a concussion, doctors do a physical examination and take a history of the trauma. Computed tomography (CT) or magnetic resonance imaging (MRI) is not needed to diagnose a concussion, but imaging may be done if a more serious brain injury (a hematoma or contusion) is suspected.

For pain due to concussion, acetaminophen is the preferred pain medication. Rest of both the body and the brain is the best treatment for a concussion.

Treatment for postconcussion syndrome is based on the severity of the symptoms. Rest and close observation are important. If symptoms worsen, people who have had a concussion should be taken to the doctor or hospital for evaluation. Athletes who have had concussions should return to play gradually, after specific steps in their rehabilitation.

People should not return to contact sports after a concussion until all ill effects have resolved and medical evaluation has been completed. (See also Sports-Related Concussion.)

Repeated concussions may increase a person’s risk of Parkinson disease, depression or chronic traumatic encephalopathy (CTE) in later life. CTE is a chronic progressive degenerative neurological disease.