[Study of an ocular ptosis in a 13th century illuminated manuscript].

Introduction: The finding of an eyelid ptosis in a manuscript of the xiii century raises the differential diagnosis of injury to the third cranial nerve. This nerve was not differentiated from the other oculomotors until the xvi century and only in the xix century a clinicopathological correlation was established for its paralysis.

Aim: Describe the characteristics and differential diagnoses of an eyelid ptosis illustrated in the Book of Divine Works (1173) by Hildegard of Bingen.

Development: In the mentioned work the nun Richardis of Stade is portrayed with her left eyelid drooping. Two conspicuous signs are described, ptosis and corresponding raising of the eyebrow. The deviation of the eye downward and outward is inferred from the shape that adopts the eyelid by the position of the eye and the curvature of the cornea. The picture is consistent with an isolated paralysis of the oculomotor nerve. The causes of ptosis are discussed: aponeurotic due to levator palpebrae dehiscence; myogenic, congenital and acquired; of the neuromuscular junction, and neuropathic, the latter being the most probable in this case and of a compressive mechanism. The nun's unexpected natural death suggests a ruptured brain aneurysm.

Conclusions: Richardis of Stade's portrait shows an oculomotor paralysis centuries before its anatomy, function, and clinicopathological expression were known. Credit for this original description must go to Hildegard, whose medical vocation has long been recognized.