Taste disorders in myasthenia gravis: A multicenter cooperative study

Background and purpose: The purpose of the present study was to investigate the prevalence and clinical characteristics of taste disorders in patients with myasthenia gravis (MG). Methods: We studied 371 Japanese patients with MG (127 men and 244 women; mean age, 56.6±16.9years) consecutively evaluated between May and September 2010 in six neurological centers comprising the East Japan MG Study Group. Ninety-three patients (25%) had thymoma. We interviewed all patients to determine whether they had taste disorders during the clinical course of MG and then further evaluated the patients with MG, who reported having taste disorders, using a questionnaire. Results: Taste disorders were observed in 16 (4.3%) of the 371 patients with MG. We concluded that taste disorders in 2.4% of patients with MG excluding other factors were associated with MG itself. All patients had thymoma with seropositivity for anti-acetylcholine receptor antibodies. Thymoma tended to be advanced, and four patients with Masaoka stage IVa required radiation therapy or chemotherapy. Five patients noticed taste disorders 2-3months before the onset of MG. Sweet taste loss was more common than salty, bitter, and sour taste loss. Conclusions: This was the first systematic survey of taste disorders in patients with MG by a multicenter study. Taste disorders were more common in the present sample of patients with MG than in the general population.