Researchers at the Oxford CMS Highly Specialist Service, studied 49 people with congenital myasthenic syndromes (CMS) over two years. Their goal was to find better ways to track symptoms, since the tools currently used were designed for a different condition (myasthenia gravis, MG) and may not be accurate enough for CMS.

They found different patterns of symptoms and muscle weakness depending on the type of CMS people have, including:

• People with AChR deficiency CMS often had droopy eyelids.
• Those with DOK7 CMS mainly had weakness in the shoulders, hips, and neck.
• People with COLQ CMS had severe fatigue in many areas of the body and breathing weakness.
• Across all CMS types, limb weakness was symmetrical (same on left and right side)

They also tested whether the current symptom scales (QMG and MG-ADL) worked well for CMS patients. The results showed that some parts of these tools do not capture CMS symptoms well, since symptoms for CMS are often subtle and under-reported, compared to patients with MG. Whilst the QMG and MG-ADL measure slightly different things (and so provide complementary insights), a sit to stand test and a six-minute walking test seem to measure similar aspects, with sit to stand test being simpler to use in clinics for both children and adults.

This study shows that fatigue in CMS varies a lot depending on the subtype, and the current scoring tools do not always capture those differences. The researchers suggest adding extra measurements, which focus on the symptoms that matter most for patients with CMS will make these tools more accurate.

The study began in February 2022.

For more information you can contact the project team by:

Email: [email protected] or call: 01865 231915

Research