 It appeared to be a severe episode of bronchitis.Caruso's physician, Philip Horowitz, who usually treated him for migraine headaches with a kind of primitive TENS unit, diagnosed "intercostal neuralgia" and pronounced him fit to appear on stage, although the pain continued to hinder his voice production and movements.During a performance of "L'elisir d'amore" by Donizetti at the Brooklyn Academy of Music on December 11, 1920, he suffered a throat haemorrhage and the performance was canceled at the end of Act 1.