A 45 year old hypertensive male patient presented in the casualty with two hours history of sudden onset of severe headache associated with nausea and vomiting. On clinical examination the patient had necks stiffness and right sided ptosis. Rest of the neurological examination was normal. What is the clinical diagnosis -
Hypertensive brain haemorrhage
Migraine
Aneurysmal subarachnoid haemorrhage
Arteriovenous malformation haemorrhage