<unk>  <unk>  is bleeding into the<unk>  space surrounding the brain, i.e., the area between the arachnoid membrane and the pia mater. It may arise due to trauma or spontaneously,  and is a medical emergency which can lead to death or severe disability even if recognized and treated in an early stage. Treatment is with close observation, medication and early neurosurgical investigations and treatments.<unk>  causes 5% of all strokes. 10-15% die before arriving in hospital, and average survival is 50%.
Subarachnoid hemorrhage
Subdural hematoma
Migraine
Intracerebral hemorrhage
Ischemic stroke
Hemorrhagic stroke
Arachnoiditis
Stroke