Seizures
6-18%
- May indicate a re-bleed and should be treated aggressively
- Perform an EEG in patients with neurological deterioration or those who fail to recover to exclude non-convulsive status epilepticus (NCSE)
- Routine seizure prophylaxis is not recommended
Re-bleeding
<72 hours
5-10%
- Highest risk immediately following primary bleed, and in patients with high clinical grade or larger aneurysms
- May occur following rapid reduction in ICP, e.g. following EVD insertion in a patient with an unsecured aneurysm
- Unlikely to occur following securing of the aneurysm
Hydrocephalus
Day 1-3
20-30%
- More common in those with high clinical grade or large amounts of sub-arachnoid and/or intraventricular blood
- Should be suspected in patients with a neurological deterioration within the first three days (although 25% will present later)
- CT is diagnostic and treatment is with placement of an EVD
Vasospasm & Delayed Cerebral Ischaemia
Day 4-14
70%
- Delayed cerebral ischaemia is a neurological deficit that lasts > 1 hour that is due to ischaemia and has no other cause
- Vasospasm is thought to be the cause of most cases and occurs between day 4 and 14 (although maximally between day 7 and 10) and lasts for several days.
- Only about half of all episodes are associated with neurological deficit.
- Transcranial Doppler ultrasonography can be used to detect vasospasm by measuring flow velocities in the cerebral arteries
Systemic Conditions
- Neurological decline can also occur secondary to systemic complications:
- Hypoxia
- Hypotension
- Pyrexia and infection
- Electrolyte disturbance