On Monday evening Dr. Ghazala Hayat of Saint Louis University Hospital gave an informative presentation on seronegative MG, leaving patients with additional knowledge to keep in their back pockets about this particular type of MG. In spite of living with MG for 15+ years, I definitely learned some new things and was reminded that there is always room for growth in better understanding myasthenia. Here are a few significant takeaways I thought were very interesting:
Sensitivity of Tests in MG
Those with MG know there are multiple tests that can be performed to achieve a proper diagnosis. Traditionally, diagnostic testing for MG can include pharmacological (response to a drug), serological (bloodwork analysis for associated antibodies), and/or electrodiagnostic testing (analysis of muscle/nerve functions). Although familiar with the various types, I was unaware of the sensitivity rates to such testing from people who exhibit myasthenic symptoms. For example, 90% of patients with generalized MG are sensitive to repetitive nerve stimulation, the most frequently used electrodiagnostic test for MG, compared to 30-60% of patients with ocular MG. Moreover, a single-fiber EMG may be conducted; a whopping 90-95% of patients with MG symptoms are sensitive to this particular test, indicating that there may be a myasthenia gravis diagnosis in order.
Regional Distribution of Muscle Weakness
Myasthenia Gravis is characterized by muscle weakness and fatigability, but what surprised me was how indicative the location of muscle weakness was when pinpointing an MG diagnosis. Did you know that 95% of muscle weakness in myasthenia gravis patients is located in the facial muscles? I wasn't necessarily astounded by the percentage but rather perplexed by the notion that if muscle weakness/fatigue in the face can be so imperative when diagnosing MG, why do some patients go for years without a diagnosis like myself?
Other Antibodies Playing a Role in MG
In all my years having myasthenia, I never knew there were other antibodies associated with MG other than AChR, MuSK, and LRP4. While I wasn't ignorant of the fact that research can, and most likely will reveal additional antibodies that play a role within MG, I was shocked to learn about newer ones I never heard of including Agrin, Titin, Cortactin, and Rapsyn.
Dr. Hayat's presentation not only allowed me to brush up on my knowledge of seronegative MG but reiterated the value in staying connected with each other in this tiny but mighty community of ours. While my MG is relatively stable, I know there are people out there who are struggling like I was 15 years ago, searching for answers and any sort of validation in their very real experiences. Now more than ever we have a better understanding and appreciation for signs of MG, diagnostic protocol, and extensive research, putting us one step closer to finding a cure for MG.
#MGA #MyastheniaGravisAssociation #MGADigest #MGStrong #MyastheniaGravis #IHaveHeardOfMG #SeronegativeMG #TypesofMG #ChronicIllness #Antibodies #DiagnosticTesting
This blog post was written by Meridith O'Connor, St. Louis Program Coordinator of the Myasthenia Gravis Association.