This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'A patient presents with sudden headache and vomiting and unconsciousness. The diagnosis is \nSelect and explain. \nA. Subarachnoid hemorrhage -, B. Intracerebral hemorrhage, C. Subdural hemorrhage, D. Extradural hemorrhage', 'role': 'user'}, {'content': 'Answer: A \nExplanation: • MC cause: Trauma >Spontaneous rupture of Berry aneurysm\nClinical Features\n• Sudden transient loss of consciousness\xa0(occurs in nearly half of the patients)\n• Excruciating severe headache: presenting complaint in 45% of cases (worst headache of patients life) more common upon regaining consciousness when loss of consciousness is associated\n• Neck stiffness and vomiting: are common associations\n• Focal neurological deficit: uncommon.\n• Sudden headache in the absence of focal neurological deficit is the hallmark of aneurysmal rupture.\n• Associated prodromal symptoms (suggest location of progressively enlarging unruptured aneurysm):\n−− Third cranial nerve palsy: Aneurysm at junction of PCA and ICA\n−− Sixth nerve palsy: Aneurysm in cavernous sinus\n−− Occipital and posterior cervical pain: Inferior cerebellar artery aneurysm\n−− Pain in or behind the eye: MCA aneurysm\nDiagnosis\n• Non contrast CT scan: Investigation of choice (Lumbar puncture is not indicated prior to an imaging procedure)\n• CSF picture: Hallmark of aneurysmal rupture is blood in CSF (Xanthochromic spinal fluid)', 'role': 'assistant'}]