Amyotrophic Lateral Sclerosis and Myasthenia Gravis: Comorbidities and Differential Diagnosis

Amyotrophic lateral sclerosis (ALS) and myasthenia gravis (MG) are both characterized by primarily motor deficit, and their differential diagnosis may be sometimes challenging. We present a case report of a patient with late-onset ALS, which was initially misdiagnosed for anti-acetylcholine (anti-AChR) antibody-positive MG. In some cases, ALS has been thought to be triggered by MG. In the presented case report, elevated anti-AChR antibody titers (positive anti-AchR Ab) had no clinical significance and possibly indicated an immune response to structural changes in the postsynaptic membrane of the neuromuscular synapse in the ALS patient.