Which statement best defines a concussion?

• A. violent shaking up or jarring of the brain resulting in disruption of neurons inside the brain
• B. temporary loss of consciousness due to dehydration
• C. minor muscle strain of the neck
• D. headache due to stress

Answer: (D)

Concussion is a mild traumatic brain injury caused by a blow to the head or a sudden jolt that makes the brain move within the skull, briefly disrupting how brain cells communicate. This disruption to brain function is the defining feature, so a statement that describes the brain being jarred and neurons functioning abnormally best captures what a concussion is. While headaches can occur with a concussion, a headache from stress or other non-traumatic causes is not an injury to the brain itself. Likewise, temporary loss of consciousness from dehydration or a minor neck strain are not brain injuries from impact, so they don’t define concussion.