A Diagnostic Crossroads: Bulbar Weakness Mimicking ALS in a Seropositive Myasthenia Gravis Patient— A Case Report

Bulbar-onset Amyotrophic Lateral Sclerosis (ALS) and Myasthenia Gravis (MG) may present with overlapping clinical features, complicating early diagnosis. We report the case of a 30-year-old woman with progressive dysarthria, dysphagia, and tongue fasciculations initially suggestive of bulbar-onset ALS. However, positive anti-acetylcholine receptor (anti-AChR) antibodies and a dramatic clinical response to anticholinesterase therapy and corticosteroids confirmed a diagnosis of bulbar-predominant MG. This case underscores the diagnostic challenge of differentiating bulbar MG from ALS and emphasizes the critical role of serologic evaluation and treatment response in avoiding misdiagnosis.