(BA) Neuro-ophthalmology Fellow, University of Miami, Bascom Palmer Eye Institute; (HJ) Associate Professor of Clinical Neuro-ophthalmology & Neurology, University of Miami, Department of Neurology, Bascom Palmer Eye Institute
Subject
Myasthenia GravIs; Clinical Signs
Description
This is a 78-year-old male patient who presented with diplopia, right eyelid ptosis, and ophthalmoplegia. He had severe ptosis OD and pseudo-proptosis (lid retraction) OS at baseline, but when the right eyelid was manually elevated, there was marked enhanced ptosis of the left eyelid (Video). He was diagnosed with seronegative Myasthenia graves with a negative thyroid lab and normal Orbital MRI. He responded well to pyridostigmine. This curtain sign (enhanced ptosis) is one of the signs of myasthenia gravis. Hering's law of reciprocal innervation states that the extraocular muscles receive equal bilateral innervation. Thus, manually elevating the more ptotic lid sends a signal to the less ptotic lid that it can relax and increase ptosis(enhanced ptosis). See associated images: MRI Orbit With Contrast: https://collections.lib.utah.edu/details?id=2116680 MRI Orbit With Contrast 768x711: https://collections.lib.utah.edu/details?id=2116681 Imaging: MRI Orbit With Contrast: https://collections.lib.utah.edu/details?id=2116680 MRI Orbit With Contrast 768x711: https://collections.lib.utah.edu/details?id=2116681
