Myasthenia gravis in the elderly.

OBJECTIVE: The objective of the study is to examine clinical, therapeutic and prognostic factors of myasthenia gravis (MG) in the elderly.

PATIENTS AND METHODS: We reviewed all MG files of patients who attended the neuro-immunology clinic at Rabin Medical Center, Petah Tikva, Israel from January 1995 until September 2011 for demographic data, MG presentation, and course and response to treatment. Patients were classified as elderly if disease onset was above 69years.

RESULTS: Out of 137 patients with MG, 29 developed MG after age 69. The 108 young onset patients had a male:female ratio of 0.9:1 whereas the eighth and ninth decade onset had a significant male predominance with ratios of 2.6:1 and 4.5:1 respectively. There was no difference in the presenting symptomatology and the rate of sero-negativity in the elderly patients when compared to the early onset patients was similar. The older patients had much less thymic pathology and their acetylcholine receptor (AChR) antibody titer was lower. This was associated with better response to therapy and a good prognosis.

CONCLUSION: MG onset in the elderly is not uncommon, is more prevalent in males, is associated with lower titer of AChR antibodies, is readily responsive to therapy and carries a good prognosis.