<unk>  <unk>  is defined as bleeding into the<unk>  space (the space between the arachnoid membrane and the pia mater of the brain or spinal cord).  This consists of:
Aneurysmal<unk> 
Non-aneurysmal<unk> 
Time of onset is defined as when the patient was last awake and symptom-free or known to be “normal".
Subarachnoid hemorrhage
Subdural hematoma
Migraine
Intracerebral hemorrhage
Ischemic stroke
Hemorrhagic stroke
Arachnoiditis
Stroke