Intra-axial<unk> c stroke (Spontaneous intracerebral<unk> 
Traumatic intracerebral<unk> 
Extra-axial
Epidural<unk> 
Subdural<unk> <unk>  (aneurysmal intracranial<unk> <unk> c stroke (Spontaneous intracerebral<unk> 
Traumatic intracerebral<unk> 
Epidural<unk> 
Subdural<unk> <unk>  (aneurysmal intracranial<unk> 
Drug toxicity
Ischemic Stroke
Meningitis
Encephalitis
Intracranial tumor
Intracranial hypotension
Metabolic derangements
Cerebral venous thrombosis
Primary headache syndromes (benign thunderclap headache, Migraine, Cluster Headache)
Subarachnoid hemorrhage
Intra-axial
Subdural hemorrhage
Hemorrhagic stroke 
Ischemic stroke
Traumatic intracerebral hemorrhage
Hemorrhagic stroke
Extra-axial