PROGRESSIVE MUSCULAR DYSTROPHY INVOLVING THE EXTRAOCULAR MUSCLES

Abstract

THE DIAGNOSIS of palsy of an extraocular muscle usually signifies to the ophthalmologist a lesion of its nerve supply. For example, a paralysis of the external rectus muscle is accepted as indicating a lesion of the sixth nerve or of its nucleus. This is so common that there is a great tendency to forget the rarer occurrence of a primary muscular disorder as a cause of impairment. Many such errors appear in the literature; a critical review of the published reports since 1890 indicated that in some of the cases of ophthalmoplegia the paralysis was due not to the nerve lesions to which it was ascribed, but probably to myasthenia gravis or one of the types of muscular dystrophy. In 1890 Fuchs¹ reported 5 isolated cases of bilateral ptosis in female patients. In 3 of these cases the ptosis developed late in life; in the other 2 it either