I85PREP
⌘ K
CSHK Part 1 MCQ study materials
CSHK Part 1 MCQ study resources

CSHK Part 1 MCQ: Neurosurgery: Raised ICP, Herniation and Neurotrauma

CSHK Part 1 MCQ · Work through your exam, one topic at a time.

All guide sections

Neurosurgery: Raised ICP, Herniation and Neurotrauma

Neurosurgery in Part 1 focuses on traumatic brain injury, raised intracranial pressure, herniation syndromes, hydrocephalus, subarachnoid haemorrhage and spinal cord compression. Stems frequently ask for the next step in a deteriorating patient.

Core rules

  • Glasgow Coma Scale: eye 1 to 4, verbal 1 to 5, motor 1 to 6. In an intubated patient the verbal component is recorded as T, not given a number; the motor score carries most prognostic weight.
  • Monro-Kellie doctrine: brain, blood and CSF occupy a fixed volume. Compensation is limited, after which intracranial pressure rises exponentially.
  • Cerebral perfusion pressure: CPP = MAP − ICP. In traumatic brain injury, target ICP below 22 mmHg and CPP 60 to 70 mmHg.
  • Uncal herniation: ipsilateral blown pupil from CN III compression, contralateral hemiparesis from cerebral peduncle compression, and declining consciousness. Kernohan notch compression can rarely cause ipsilateral hemiparesis.
  • Haematomas: extradural haematoma is biconvex and arterial, often with a lucid interval; subdural haematoma is crescentic and venous.
  • Subarachnoid haemorrhage: thunderclap headache. CT is highly sensitive within 6 hours; if CT is negative after 12 hours, lumbar puncture for xanthochromia is considered. Nimodipine and early coiling or clipping are standard.
  • Spinal cord compression: give dexamethasone and arrange urgent MRI; lumbar puncture is contraindicated.

Worked example

A 32-year-old motorcyclist has GCS 7 (E1, V2, M4), a right pupil 6 mm and non-reactive, and left-sided weakness. CT shows a right extradural haematoma.

Reasoning: the right blown pupil indicates right uncal herniation, compressing the right CN III and the right cerebral peduncle, which causes left hemiparesis. Management is intubation, normocapnia (PaCO2 35 to 40 mmHg), head-up positioning, avoidance of hypotension, hypertonic saline or mannitol, and urgent craniotomy.

Traps

  • Steroids are contraindicated in traumatic brain injury.
  • The Cushing triad of hypertension, bradycardia and irregular breathing is a late sign.
  • Lumbar puncture is dangerous with raised intracranial pressure.
  • Prophylactic anticonvulsants are not continued long term after traumatic brain injury.