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': 'In normal pressure hydrocephalus, all are seen except- \nSelect and explain. \nA. Convulsion, B. Ataxia, C. Dementia, D. Incontinence', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Normal Pressure Hydrocephalus\xa0is an uncommon syndrome consisting of\xa0\n\nan abnormal gait (ataxia or apractic)\ndementia (usually mild to moderate)\nurinary incontinence\n\n\nThis is a communicating hydrocephalus with patent aqueduct of Sylvius.\nNPH is presumed to be caused by obstruction to normal flow of CSF over the cerebral convexity and delayed absorption into the venous system. The indolent nature of process results in an enlarged lateral ventricles but\xa0 relatively little increase in CSF pressure.\nFollowing conditions have been seen to cause NPH by producing scarring of basilar meninges (blocking upwards flow of CSF)\n\n\nmeningitis\nsubarachnoid haemorrhage\nhead injury\n\n\nApprox 30-50% of the patients of NPH will show improvement with a ventricular shunting procedure.', 'role': 'assistant'}]