A new study published in Neurosciences Journal reported on the outcomes and characteristics of different types of myasthenia gravis.

The retrospective cross-sectional study spanned over 10 years between 2010 and 2020 and found the most common initial presentation of the disease to be ocular weakness and the most frequently reported autoantibody to be against the acetylcholine receptors (AChR). It also reported that most patients with ocular and bulbar presentation developed generalized, but well-controlled, weakness during the follow-up period.

There are different types of myasthenia gravis based on the type of autoantibodies, epidemiology, clinical presentation, and comorbidities, and these different types respond differently to different treatments. Most studies do not consider the variations in therapeutic responses among myasthenia gravis types.

Read more about myasthenia gravis types

To investigate the distribution of muscle weakness and the therapeutic response in each type of myasthenia gravis, a team of researchers led by Reem S. Alenazi, MD, analyzed 147 patients with myasthenia gravis who presented to King Fahad Medical City in Riyadh, Saudi Arabia. Patients were between 17 to 51 years of age. The team collected electrophysiological, demographic, serological, clinical, histopathological, and radiological data about the patients. They also recorded the type of treatment they received.

More than half of patients (57.1%) had ocular myasthenia gravis. The researchers found no association between the type of myasthenia gravis a patient had and their gender. 

Almost all patients who had ocular myasthenia gravis (95.2%) had antibodies against AChR. These antibodies were also present in 87% of patients with generalized disease and 75% of those with bulbar myasthenia gravis, 20% of whom had antibodies against muscle-specific kinase. 

The majority of patients with ocular and bulbar myasthenia gravis (91.7% and 90%, respectively) developed generalized weakness. 

At the end of the follow-up period, 82.6% of patients with generalized myasthenia gravis had well-controlled weakness. This percentage was 70.2% for patients with ocular myasthenia gravis and 57.5% for those with bulbar disease.

Reference

Ali A, Almalki D, Kotb MS, Alenazi RS. Outcomes and characteristics of myasthenia gravis: a 10-year retrospective cross-sectional study at King Fahad Medical City. Neurosci J. Published online October 17, 2022. doi:10.17712/nsj.2022.4.20220038