P-5 Diagnosis and treatment of myasthenia gravis in Cyprus

This was a retrospective study of all patients treated for myasthenia gravis (MG) in Neurology Clinic E at the Cyprus Institute of Neurology and Genetics. Epidemiological data, antibody status and clinical severity using the MG Foundation of America score in relation to treatment were assessed. Results: 36 females and 24 males were included in the study (M:F ratio 1:1.5). Average age at onset in females was 41 years (range 12-75 years) and in males 43 years (range 16-67 years). Clinical diagnosis in the majority (95%) of patients was confirmed by single fiber EMG (SFEMG) and/or with repetitive nerve stimulation (13,3%). Onset was with ocular manifestations in 26.7% of patients, bulbar weakness in 61.7%, and limb weakness in 11.6%. At maximum disease severity 21.6% of patients had severe bulbar weakness, and 13.3% required intubation. Following various treatments the majority of patients are currently asymptomatic (23.3%) or have only ocular (41.6%) or mild generalized weakness (28.3%). Autoimmune thyroid disease, vitamin B12 deficiency and asthma are commonly associated disorders. 29.6% of generalized MG patients had AchR-Ab, 18.6% had MuSK-Ab, and 22.2% were double seronegative. 29,6% are seronegative for AchR-Ab but have not yet been tested for MuSK-Ab. MuSK Ab+ patients appear to have slightly more severe course than Ach-R Ab+ or seronegative patients. Thymectomy was performed in 24% of generalized MG patients and increased the chances of remission when done early and in the absence of neoplasm. Most patients were treated with combination of corticosteroids and steroid-sparing medications, mostly Azathioprine and mycophenolate preparations. Addition of mycophenolate in patients with moderate to severe disease significantly improved outcome and had a steroid sparing effect. Side effects occurred with all treatments. Conclusions: There is an unusual high proportion of seronegative MG patients in Cyprus. Further research on the auto-immune mechanisms is required. Most patients improve with combination of treatments currently available, but side effects remain problematic. Mycophenolate appears to be safe and effective for selected MG patients.