ABSTRACT 

Objective: There is no previous research on Myasthenia Gravis (MG) in Trinidad and Tobago. This study sought to determine the prevalence and to characterize MG in South Trinidad.

Methods: A cross-sectional study was performed over 30 months in South Trinidad to identify, interview and statistically analyse data on MG cases.

Results: Among 36 prevalent patients, female:male ratio was 1.6:1. Estimated MG point prevalence in South Trinidad on March 31, 2010 was 78 per million. Mean age of prevalent patients was 50.5 years. Mean age of onset was 35 years. A higher prevalence was detected in Africans than East Indians (178 vs 68 per million; p = 0.003). Ocular and extremity muscle weakness were the most common initial symptoms. Autoimmune conditions (mainly thyroid disease) co-existed in 25.7%. Treatment involved pyridostigmine and/or immunosuppressants for all except two that went into remission with just steroids. Generalized MG occurred in 60%; 42.9% expressed social and/or professional handicap. One case with suggestive clinical features tested positive for muscle specific tyrosine kinase antibody.

Conclusions: While many features of MG in South Trinidad were similar to international data, the unique, statistically significant higher prevalence in Africans than East Indians warrants further research, given the paucity of reports from Africa and India. Patients with MG suffered a diminished quality of life, necessitating improved health planning.