Clinical profile of myasthenia gravis

Seventy three patients with myasthenia gravis were studied over 9 years period (1987-1995) in departments of neuromedicine, respiratory care unit, cardiothoracic unit of Institute of Postgraduate Medical Education and Research and Bangur Institute of Neurology, Calcutta, with reference to their clinical presentations, laboratory findings and various modes of treatment. Commonest age of presentation was 5th decade in men and 3rd decade in women. Fifty five percent of patients belong to type 2A myasthenia gravis (Osserman classification). Presentation was insidious (67.2%) and course was slowly progressive (65.7%) in majority of cases. Fatigability and ptosis were commonest clinical presentation and diurnal variation was noticed in 60% of cases. Edrophonium test was positive in 90.4% of cases and repetitive nerve stimulation showed 93.5% positivity in 30 cases. 27 patients (36.9%) underwent thymectomy and out of these, 89% of patients showed hyperplastic change and thymoma in 11% of cases. Mortality rate including both operated and nonoperated patients was recorded to be 9.6%. We observed earlier onset of myasthenia in male, higher incidence of oculo-bulbar involvement and lower incidence of respiratory problem and thymoma.