Overview of Concussion

Concussion, also called concussion injury, closed head injury, or mild traumatic brain injury (MTBI), is a temporary brain injury that occurs as a result of head trauma. Motor vehicle accidents, falls, collisions during recreational sports, and child abuse are common causes for concussion.

Concussion is characterized by a brief period of unresponsiveness or loss of consciousness, disturbances in vision and/or balance, confusion, and short-term memory loss. Although concussions are not life threatening, any head injury can cause serious complications (e.g., bleeding or swelling in the brain) and can have long-term effects on health.

The brain controls all body functions and processes. It is located inside the skull (cranium) and is surrounded by cerebrospinal fluid (CSF), which cushions and helps to protect the brain. Concussion occurs when a blow, jolt, or other type of impact forces the brain against the skull and causes an injury that briefly impairs brain function.

Types of Concussion

Concussions can be categorized as simple or complex. Simple concussions, which are mild and relatively common in children and adolescents, gradually resolve within a week to 10 days. As long as another head injury is not sustained, mild concussions usually do not result in complications or long-term health risks.

Complex concussions result in persistent symptoms and can affect brain function. Complex concussions increase the risk for complications, such as swelling or bleeding in the brain, seizures, and post-concussion syndrome (e.g., persistent headache, dizziness, or blurred vision). Severe concussions and multiple concussions are characterized as complex.

Concussions also can be classified according to grade. Grade 1 concussion is mild; grade 2 is moderate; and grade 3 is severe. Grade 1 concussion does not result in a loss of consciousness. People who sustain grade 1 concussions may be confused or dazed for a short time (less than 15 minutes) after the injury, but recover completely within 20 minutes.

Grade 2 concussion does not result in a loss of consciousness, but symptoms (e.g., confusion) last longer than 20 minutes. People who sustain grade 2 concussions may not remember the injury (called post-traumatic amnesia).

Grade 3 concussion is the most severe type. A person who sustains a grade 3 concussion loses consciousness (usually for a brief period of time) and often does not remember what occurred just before or just after the injury.

Incidence and Prevalence of Concussions in Children

According to the American Academy of Pediatrics (AAP), concussion is one of the most common injuries requiring medical care in children and adolescents in the United States. The Centers for Disease Control and Prevention (CDC) reports that concussion and other types of traumatic brain injury (TBI) account for about 435,000 emergency room visits each year in children 14 years of age and younger.

The highest childhood concussion rates occur in children under the age of 5 and in adolescents 15–19 years of age. Boys sustain concussion injuries about twice as often as girls.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 27 Aug 2008

Last Modified: 08 Sep 2015