Curriculum · Neurology
Raised intracranial pressure after head injury
What it is
Raised ICP is the thing to worry about after a head injury, and head injury survival is dependent on cerebral perfusion pressure. Cerebral perfusion pressure is the mean arterial pressure minus the intracranial pressure: CPP = MAP - ICP. CPP should be 60-70 mmHg. Two ways follow from that, and they are the whole of management: reduce ICP, or increase MAP.
How it presents
Signs of raised ICP are:
- Pupillary dilatation
- Hypertension
- Bradycardia
- Papilledema
Cushing's triad is what to look for. Rapid intracranial expansion under systemic arterial pressure ends in transtentorial herniation with a CN III palsy, and the epidural hematoma that does this is the one that follows a lucid interval.