Neurosurgery
What the exam tests
This domain covers head injury, raised intracranial pressure, hydrocephalus, subarachnoid haemorrhage, spinal cord compression and neurosurgical emergencies.
Core rules
- Record GCS and pupillary responses serially. A GCS of 8 or less warrants intubation and airway protection.
- Urgent CT head is indicated after head injury with reduced GCS, focal deficit, seizure, vomiting, anticoagulation or a dangerous mechanism.
- Reverse anticoagulation in intracranial haemorrhage according to agent and local protocol.
- Raised intracranial pressure is managed with head-up positioning, normocapnia, adequate sedation, osmotherapy and, in selected cases, decompressive craniectomy; avoid hypotonic fluids.
- Suspected spinal cord compression from malignancy is an emergency: give dexamethasone and obtain urgent MRI.
- Subarachnoid haemorrhage is confirmed by CT; if CT is negative and suspicion persists, lumbar puncture for xanthochromia is considered.
Worked example
A 35-year-old is brought in after a road traffic collision with GCS 7, unequal pupils and a boggy scalp haematoma. He is intubated, ventilated to normocapnia and taken for urgent CT, which shows an extradural haematoma with midline shift. He undergoes craniotomy and evacuation, then ICU care with ICP monitoring.
Traps
Attributing a low GCS to alcohol; failing to reverse anticoagulation; missing a cervical spine injury; and treating a fixed dilated pupil as a late finding rather than an emergency.