Occurrence of Guillain-Barre syndrome and Myasthenia Gravis in an elderly male

Introduction The occurrence of both Guillain-Barre syndrome(GBS) and myasthenia gravis (MG) in the same individual is rare. The underlying pathophysiology was assumed to be autoimmune humoral mechanisms and molecular mimicry with a cross-reaction between autoantibodies and myelin sheath of peripheral nerves and acetylcholine receptors of the neuromuscular junction (NMJ). Case description A 68-year-old male known diabetic and hypertensive with good drug compliance presented with acute onset quadriparesis with bulbar involvement for 1 day. On examination, he had mild neck flexion weakness and bulbar weakness. He had flaccid quadriparesis with absent deep tendon reflexes and negative Babinski. The rest of the neurological examination was normal. Discussion and evaluation Blood and electrophysiological studies showed evidence of demyelinating polyradiculoneuropathy with temporal dispersion suggestive of Guillain-Barre syndrome. He was treated with intravenous immunoglobin and complete resolution of symptoms. Two months later, he presented with new-onset asymmetrical ptosis and bulbar symptoms for 3 days. On further evaluation, repetitive nerve stimulation showed postsynaptic neuromuscular disorder pattern typical of myasthenia gravis, which was further confirmed by positive acetylcholinesterase receptor antibodies (AChR). Thymoma was ruled out by imaging. He was treated with anticholinesterases, low dose steroids, and immunosuppressants (azathioprine) following which he had improvement of symptoms. Conclusion Our patient, who was initially diagnosed with Guillain-Barre syndrome and recovered, presented 2 months later with a new-onset illness suggestive of myasthenia gravis. This existence of two different neurological entities in the same individual is a rarity, and early recognition is essential for treatment decision and prognostic strategies.