[Chronic myasthenia gravis mimicking muscular dystrophy, in eastern Colombia].

INTRODUCTION. Myasthenia gravis is an apparently well-defined neuromuscular disease with some variants, including one recently described as chronic myasthenia gravis. CASE REPORT. We present a 22 year old Columbian woman who complained of progressive weakness for the previous four years, affecting her pelvic and shoulder girdles but with no clinical involvement of the extra-ocular muscles. Repetitive stimulation of the neuro-muscular junction of the abductor digiti quinti muscle was negative, but positive for myasthenia gravis in the trapezius muscle and the right orbital eye muscles. Her symptoms improved and the clinical neurophysiological studies were normal again after treatment with pyridostigimine, which confirmed the diagnosis.