VON GRAEFE, in 1868,1 was the first to describe a condition consisting of paresis of all the extraocular muscles which resembled internuclear progressive bulbar palsy, and which he therefore called "Ophthalmoplegia Externa Chronica Progressiva Internuclearis." Hutchinson,2 in 1879, described 17 similar cases and called the disease External Ophthalmoplegia. In 1888, Gowers3 postulated degeneration of the nuclei of the ocular muscles as the direct cause and site of the disease. Fuchs,4 in 1890, reported the same condition in five women; he included a histopathological study of the levator palpebrae which showed signs of muscular atrophy, suggesting that the ptosis is of muscular origin. Since then, both the site of the primary lesion and the nomenclature of the disease have been controversial. One group of ininvestigators5-8 suggested a nuclear degeneration as the primary cause and accordingly named the disease Progressive Nuclear Ophthalmoplegia. A second group-9-11