The historians Plutarch and Suetonius described Caesar as suffering from convulsions and sudden fainting fits, which Shakespeare interprets as the 'falling sickness'. It has been widely accepted that this was epilepsy. However, two doctors are now arguing that he might have been afflicted by cerebrovascular disease, a series of mini-strokes that would have impaired his judgement and might account for his reckless behaviour in his final years. See their arguments here.
