subarachnoid and subdural haemorrhage Flashcards
causes of subarachnoid haemorrhage
Aneurysm rupture
Traumatic
Arteriovenous malformations (unusual link between artery and vein)
Ctyptogenic
Presentation of. SAH
A severe global headache that reaches maximum intensity with seconds
May lose consciousness or vomit at onset
Over time photophobia and neck stiffness
What are the signs of SAH
What happens if a posterior communicating artery aneurysm
May have a low GCS score (low consciousness)
-Third nerve palsy with dilated pupil if posterior communicating artery aneurysm. (this means they have a completely closed eyelid and eye looks down and outwards. Pupil is also fixly dilated and doesn’t react to light)
Neck stiffness
Sub hyaloid haemorrhage seen in pupil
how to diagnose a SAH
-What if first investigation fails
Very urgent CT
-If CT scan normal, do lumbar puncture after 12 hours to look for xanthochromia
how to manage SAH
Urgent neurosurgical referral for definitive treatment
- OFten interventional near-radiology
- IV nimodipine to stop spasms of artery
Complications of SAH
Rebleed Seizures Vasospasm Hydrocephalus Electrolyte abnormalities ECG abnormalities (ST depression, T wave inversion) Pulmonary oedema
Symptoms of meningism
headache
Photophobia
Nausea
Signs of meningism
Nuchal rigidity: neck resists passive flexion
Kernig’s sign-passive knee extension in supine patient elicits neck and hamstring pain and further resistance to further extension
Brudzinski sign-passive flexion of the neck while the patient is in a supine position results in flexion of the hips and knees
Causes of meningism
Meningitis
SAH
cause of subdural haemorrhage
-What risk factors
rupture of bridging cortical veins
- More likely to tear in older patients with fragile veins and more space between brain and dura
- Anticoagulants increase risk
Features of a subdural haemorrhage
Slower rate of bleeding
Cause of of hemiparesis (weakness in one side of body) with third nerve palsy and drowsiness
-Why
Haematoma
Haematoma compresses hemisphere (hemiparesis cause) then that compresses posterior communicating artery (third nerve palsy) and the drowsiness is because of problems with both hemispheres or the brainstem
What are the causes of a third nerve palsy with a fixed dilated pupil
Haematoma
POsterior communicating artery aneurysm
features of acute SDH
Loss of consciousness, low gCS, anisocoria (difference in pupil size), motor deficit
Lucid interval–> after the injury where the patient appears relatively well and normal but subsequently deteriorates and loses consciousness as the haematoma forms
hyper dense on CT
Requires surgical evacuation
features of a chronic SDH
> 2 weeks
Subtle signs, weakness, hemiparesis
Isodense or hypodese to parenchyma
Management can be surgical vs conservative