 Some argue that Nietzsche was afflicted with a syphilitic infection (this was the original diagnosis of the doctors in Basel and Jena) contracted either while he was a student or while he was serving as a hospital attendant during the Franco-Prussian War; some claim that his use of chloral hydrate, a drug which he had been using as a sedative, undermined his already-weakened nervous system; some speculate that Nietzsche’s collapse was due to a brain disease he inherited from his father; some maintain that a mental illness gradually drove him insane; some maintain that he suffered from a slow-growing, frontal cranial base tumor; some maintain that he suffered from CADASIL syndrome, a hereditary stroke disorder; some maintain that Nietzsche suffered from a tumor on the surface of the brain growing behind his right eye. The exact cause of Nietzsche’s incapacitation remains unclear. That he had an extraordinarily sensitive nervous constitution and took an assortment of medications is well-documented as a more general fact. To complicate matters of interpretation, Nietzsche states in a letter from April 1888 that he never had any symptoms of a mental disorder.