Effect of Thymectomy on Outcomes of Myasthenia Gravis Patients: A Case-Control Study at a Tertiary Care Hospital

Background and objective Myasthenia gravis (MG) is an acquired autoimmune disease mediated by antibodies affecting the neuro-muscular junction on the postsynaptic membrane, resulting in neuromuscular transmission obstruction and, consequently, muscle weakening. It is believed that the thymus gland plays a critical role in the production of these antibodies. Screening patients for thymoma and surgical excision of the thymus gland is a crucial part of the treatment. To compare the odds of good outcomes in Myasthenia Gravis patients with or without thymectomy. Material and methods A retrospective case-control study was conducted at the Department of Medicine and Neurology, Ayub Teaching Hospital, Abbottabad, Pakistan, from October 2020 to September 2021. A purposive sampling technique was employed. Thirty-two MG patients with thymectomy and 64 MG patients without thymectomy were selected for investigation. Controls and cases were matched on the basis of sex and age (1:2). A positive EMG study, acetylcholine receptor antibodies, and a pyridostigmine test were used to make the diagnosis of MG. Patients were called to the outpatient department for assessment of treatment outcomes. Primary outcome evaluation was done using the Myasthenia Gravis Foundation of America Post-Intervention Status (MGFA-PIS) tool at the last follow-up after one year. Results A sample of 96 patients was evaluated, of which 63 (65%) were females and 33 (34%) were males. The mean age for Group 1 (cases) was 35 years ±8.9 and for Group 2 (controls) was 37± 11.1. Age and Osserman stages were shown to be the two most crucial prognostic factors in our study. However, there are several other factors in our study that are linked to a poor response, such as a greater BMI, dysphagia, thymoma, older age, and a longer duration of disease. Conclusions Our findings indicate that none of the analysed groups had significantly worse outcomes as a result of the current clinical practice of thymectomy patient selection.