ConcussionClaim Desk
Mechanics · file CON-01

What is a concussion?

A concussion is a mild traumatic brain injury caused by a bump, blow, or jolt that makes the brain move or twist inside the skull. The label does not require a visible lesion on routine imaging.

Reviewed October 15, 20265 minute read
01

Mechanism is not the same as a picture

Acceleration, deceleration, and rotation can disturb how brain systems work. Coup describes effects near the impact site; contrecoup describes effects on the opposite side after rebound. These are mechanisms, not a diagnosis from a diagram.

Concussion mechanism schematic: coup, contrecoup, and rotational shear
Fig. 1 — The mechanism plate: coup near the impact site, contrecoup on the opposite side after rebound, and shear from rotation. A schematic of mechanism, not a diagnostic image.
Use careful language.

A normal scan does not prove that symptoms are imaginary, and a symptom is not by itself proof of a particular mechanism. The clinical record supplies the context.

02

What belongs in the first record

  • What happened and what part of the head or body moved.
  • What was noticed immediately and what appeared later.
  • What activity, school, work, driving, or sleep changed afterward.