Sodium Content in Lower Leg Muscle in Patients with ME/CFS

Project description

Background: Muscle pain and muscular fatigue are among the main symptoms of ME/CFS. Although the causes of the neuroimmunological disease are not yet fully understood, there are numerous studies that indicate autoantibody-mediated dysregulation of the autonomic nervous system. The resulting disruption of vascular regulation and reduced blood flow can lead to electrolyte disorders and consequently a Sodium overload in the muscles The aim of this study was to measure the sodium content of the lower leg muscles in female patients with ME/CFS and to compare it with that of healthy controls.

Method: 6 patients with ME/CFS and 6 healthy control subjects of the same gender, age and BMI underwent sodium magnetic resonance imaging of the left lower leg. A special sodium coil was inserted into a clinical 3 Tesla MRI scanner. Before and after the imaging, all subjects performed a 3-minute exercise. The lower leg muscles were subjected to imaging stress before and for a period of 40 minutes after the exercise in order to observe the progression of the sodium content. Using a program for medical image viewing, the muscles were marked and, after converting the signal intensities into sodium concentrations, the sodium content of the muscles was recorded over time.

Results: The sodium content at rest was higher in ME/CFS in all 5 compartments of the lower leg muscles than in the controls. The largest difference at rest was found in the extensor muscles. Directly after exertion of the lower leg muscles, there was an increase in the sodium content in the muscle tissue of the triceps surae in both groups, with an increase of +30% in ME/CFS and +24% in controls in the medial gastrocnemius muscle.

Interpretation: The sodium content of the lower leg muscles was higher in patients with ME/CFS than in healthy controls both at rest and after muscle strain. Muscular sodium overloads may play a role in the development of symptoms in patients with ME/CFS and possibly - with the help of further studies - enable targeted therapy in the future.

(Description adapted from project website: see link above)