YOu are talking of Gauguin, right? He had syphilis.
I have not read that of Van Gogh.
Too much Digoxin causes death by cardiac arhythmia. And I have not heard of Digoxin as a treatment for seizures.
Actually it was digitalis the active ingredient in Digoxin. It was used in Van Gogh's time for epilepsy. It may not have been effective but it was used. Yes Van Gogh did have syphilis. http://www.doctorsreview.com/node/56 "A couple of years later Vincent moved to Antwerp in Belgium, where big city life lifted his spirits somewhat, but also introduced him to a new problem: absinthe. Van Gogh drank heavily during this time, smoked like a fiend and led a generally debauched lifestyle, enjoying the company of prostitutes and badly neglecting his health. Though in Antwerp he received inspiration and further training, his time in the city also left him with syphilis"