A nonspecific term used to describe transient alterations or loss of consciousness following closed head injuries. The duration of UNCONSCIOUSNESS generally lasts a few seconds, but may persist for several hours. Concussions may be classified as mild, intermediate, and severe. Prolonged periods of unconsciousness (often defined as greater than 6 hours in duration) may be referred to as post-traumatic coma (COMA, POST-HEAD INJURY). (From Rowland, Merritt's Textbook of Neurology, 9th ed, p418)

Synonyms: Severe Concussions, Concussion, Cerebral, Cerebral Concussion, Cerebral Concussions, Concussion, Severe, Severe Concussion, Intermediate Concussion, Commotio Cerebri, Concussion, Mild, Mild Concussions, Concussion, Intermediate, Brain Concussions, Concussion, Brain, Mild Concussion, Intermediate Concussions, Mild Traumatic Brain Injury, Brain Concussion