Very Late-Onset Myasthenia Gravis Presenting With Dysphagia and Gradual Decrease in Laryngeal Elevation During Repeated Swallowing: A Case Report

Abstract

Very late-onset myasthenia gravis (VLOMG) is rare myasthenia gravis (MG) that begins after the age of 65 years. Here, we describe a 72-year-old patient who presented with dysphagia. Upper gastrointestinal radiography revealed delayed initiation of swallowing in the pharynx and inadequate opening of the upper esophageal sphincter. Notably, there was a gradual decrease in laryngeal elevation, which strongly suggested MG. Additionally, the frequency of swallowing was reduced, and anti-acetylcholine receptor (anti-AChR) antibodies were positive. Due to type I respiratory failure, the patient required a tracheotomy and ventilator support. By the time of hospital discharge, the patient was able to walk out independently with a stomach tube and tracheotomy cannula. In conclusion, VLOMG should be considered in patients over 65 years old who present with sudden, isolated dysphagia or dysarthria, particularly when there is a gradual decrease in laryngeal elevation during swallowing as observed on upper gastrointestinal radiography.

Keywords: dysphagia; elderly; myasthenic crisis; upper gastrointestinal radiography; very late‐onset myasthenia gravis.

FIGURE 1

Insufficient laryngeal elevation and upper esophageal sphincter opening during swallowing.

FIGURE 2

Lung CT showed bronchiectasis and bilateral pneumonia.