Atypical Myasthenia Gravis Presentation with Limb-Girdle Weakness

Abstract

Myasthenia Gravis is a disorder characterized by autoantibodies targeting different proteins across the neuromuscular junction. The typical presentation of Myasthenia Gravis involves oculobulbar weakness, classically ptosis that may or may not be symmetric. Patients may also present with a more dramatic presentation of generalized weakness or even in myasthenic crisis requiring respiratory support for oxygenation. While these are the common presentations, our patient, a 63 year old male, presented with an atypical presentation of what is described as Limb-Girdle Myasthenia Gravis. This patient presented with proximal arm and leg weakness that rapidly progressed and lead to loss of reflexes, appearing to be a myelopathy prior to obtaining an electromyography/nerve conduction study which demonstrated decrement of 21% in ulnar, 22% in median, and 59% of radial nerves during 2Hz repetitive stimulation. Our patient improved with plasmapheresis and prednisone with full recovery of strength.