Diagnosis of myasthenia gravis: Comparison of anti-nicotinic acetyl choline receptor antibodies, repetitive nerve stimulation and Neostigmine tests at a tertiary neuro care centre in India, a ten year study

Anti-nicotinic AChR antibodies (Anti-nAChR antibodies), Repetitive Nerve Stimulation (RNS) and Neostigmine test are used for diagnosis of myasthenia gravis (MG). We compared their diagnostic agreement in a cohort of 486 MG patients over a period of ten years. Anti-nAChR antibodies, RNS and Neostigmine test showed positivity of 57.36%, 51.78%, and 93.4% respectively in ocular myasthenia and 93.77%, 82.35%, and 97.92% respectively in generalized myasthenia group. Neostigmine test showed higher positivity than anti-nAChR antibodies and RNS test in both groups. A marginal to fair agreement was observed between these tests highlighting their significance in the diagnosis of the disease.