Study: Understanding The Clinical Course of MuSK-positive Myasthenia Gravis

In order to create treatments and diagnostic methods for rare diseases, it’s necessary to have a thorough understanding of said disease. A recent study aimed to do just this. Titled “Spotlight on MuSK positive myasthenia gravis: clinical characteristics, treatment and outcomes,” this paper was published in BMC Neurology and aimed to better explain myasthenia gravis (MG) resulting from antibodies against muscle-specific kinase (MuSK).

About the Study

Three scientists reviewed the data of 21 MuSK-positive MG patients (81% female), all of whom had received treatment at their clinic over the past ten years. They looked at criteria like disease progression time, therapy, and clinical characteristics. The median time to follow-up was a little more than three years. From this analysis, they derived the following results:

  • Of the 21 patients, the average age of disease onset was just under 52 years old
  • 47.6% of study participants were originally diagnosed with ocular MG
    • Their symptoms were most commonly double vision and/or drooping eyelids
    • All of these patients progressed to have generalized MG
      • The mean time to progression was a little more than four months
  • Slightly under 43% of participants were initially diagnosed with bulbar MG
    • Their symptoms were most commonly speech impairment and issues with breathing and/or swallowing
  • 9.5% of participants had generalized MG
  • Just under 29% of patients experienced an MG crisis, which sees the muscles necessary for breathing impacted
    • 7.76 months was the median time from disease onset to MG crisis
  • 81% of the participants were treated with pyridostigmine
  • Over 90% of the participants were treated with an immune-suppressing medication of some kind, such as corticosteroids
    • These patients were also treatment with other medications; however, this was a much less common occurrence
      • For example, three patients were being treated with traditional Chinese herbal remedies, all of whom remained generally stable
  • The majority of patients were treated with more than one therapy throughout their patient journey
  • Long-term data (which was collected slightly over three years after the initial study) was available for 18 of 21 patients
    • 42.9% of participants had minimal disease manifestation
    • 19% of participants experienced improved conditions
    • Only one patient saw little to no change in their clinical status
    • Two patients passed away due to MG-related complications

In the end, the researchers came away with two major conclusions, one related to clinical course and one related to treatment. The first provides us with a better understanding of the clinical course of MG; many patients first present with ocular symptoms before progressing to the generalized form of the disease. In terms of the treatment-related conclusion, the researchers determined that combination treatment can be helpful in many cases. However, it is important to note that some patients do not respond and should be given more effective treatments earlier following diagnosis.

About MG

Myasthenia gravis (MG) is the most common autoimmune neuromuscular disorder. Those affected experience weakness in the voluntarily controlled muscles. Physical activity worsens the symptoms, whereas periods of rest can improve them. Throughout the world, about 20 of every 100,000 people have MG. It is an autoimmune condition, meaning the body attacks itself, specifically the proteins that are necessary for communication between the brain and muscles. This causes symptoms like drooping eyelids, issues with chewing and swallowing, fatigue and weakness in the skeletal muscles, slurred speech, double vision, and a changed gait. For a small percentage of those with MG, weakness in the chest could lead to life-threatening respiratory issues.

Doctors diagnose this condition through a physical exam, evaluation of patient history, blood tests, and EMGs. Like many rare disorders, a diagnosis is not always easy to obtain. The similarity of symptoms to other conditions often results in a misdiagnosis. After doctors have confirmed that one has MG, treatment consists of steroids, plasmapheresis, or surgery to remove the thymus gland. While there is no cure, some medications can greatly improve symptoms or even induce remission.

Find the source article here.

Follow us