Associated conditions in myasthenia gravis: response to thymectomy.

To compare the response of thymectomy in patients with associated conditions (PWAC) and without associated conditions (PWOAC). Comparative, retrospective. 198 patients with the established diagnosis of myasthenia gravis who had a thymectomy between 1987 and 2000, and who were folowed up for at least 3 years. We formed two groups, one with associated conditions and the second without associated conditions. The patients were divided into four groups: (i) patients in remission, (ii) patients with improvement, (iii) patients without changes, and (iv) patients whose condition worsened. Associated conditions (AC) were found in 49 patients (26%). The main associated conditions were hyperthyroidism in 16 patients (33%) hypothyroidism in seven (14%), rheumatoid arthritis in five (10%) and hypothyroidism and Sjogren syndrome in three (6%). Concerning the response of thymectomy, 13 patients WAC showed remission (27%), vs. 54 patients WOAC (39%). Twenty patients WAC showed improvement (41%) vs. 46 WOAC (33%). Thirteen patients WAC had no changes (27%) vs. 37 WOAC (26%). Finally, in three patients WAC their condition worsened (6%) vs. three WOAC (2%). The response to thymectomy was high (69%) in both groups. We did not identify significant differences.