Contusion of Central Nervous System

• "Contusion" is the term used to indicate focal haemorrhage within the brain.
  • Two further terms are used to describe the location of the contusive injury:
    • Coup
    • Contrecoup

Coup and Contrecoup

• The brain is smaller than the cranial vault, and so is free to move inside the skull.
• Before trauma occurs, the head is moving.
  1. The first point of impact is where a solid object hits the head. This suddenly stops the head's movement.
     • The force of impact stops the head moving, but the brain does not stop so quickly.
  2. The brain strikes the inside of the skull at the first point of impact.
     • This point is called the coup lesion.
  3. The brain has moved away from the centre of the cranium, towards the side of the coup lesion. This causes stretching and tearing of vessels and nerves on the opposite side to the original impact
     • This is the contrecoup lesion.