Myopathy

WiTNNess is designed to accurately document the natural course and variation of muscle disease caused by pathogenic changes of the TNNT1 gene. The primary aim of the study is to specify meaningful outcome measures for future clinical trials. WiTNNess is open to children and adults worldwide. Participants can choose to include their information once (cross-sectional cohort) or every few months (prospective cohort).

This study is being done to further develop a device, the mScan, to measure muscle health as compared to measurements of muscle health using MRI (magnetic resonance imaging). This device is held against the skin and uses Electrical Impedance Myography (EIM). EIM uses a very small, noninvasive (e.g. no needles), brief (about 6 seconds), and painless electrical current to measure the muscle. The investigators will look at how the mScan predicts the muscle measurements seen on MRI in people with and without muscle disease. The investigators hope that this can be used in the future as a quick, convenient and less time-consuming way than MRI to assess muscle health. This could be used to measure how well treatments for different muscle disorders are working over a period of time.

The investigators are researching families with inherited inclusion body myopathy (IBM) and/or Paget disease of bone (PDB) and/or dementia (FTD) which is also called IBMPFD. IBMPFD is caused by mutations in the VCP gene. Our main goal is to understand how changes in the VCP gene cause the muscle, bone and cognitive problems associated with the disease. The investigators are collecting biological specimen such as blood and urine samples, family and medical histories, questionnaire data of patients with a personal or family history of VCP associated disease. Participants do not need to have all symptoms listed above in order to qualify. A select group of participants may be invited to travel to University of California, Irvine for a two day program of local procedures such as an MRI and bone scan. Samples are coded to maintain confidentiality. Travel is not necessary except for families invited for additional testing.

The repeated bout effect (RBE) refers to the adaptation whereby a single bout of eccentric exercise protects against muscle damage from subsequent eccentric bouts. This effect has been shown in many muscle groups using both serum biomarkers, muscle soreness and imaging techniques. Though the effect is well described in healthy, it has never been studied in patients with neuromuscular diseases (NMDs). In healthy, the RBE is only described using eccentric exercise, but unlike healthy persons, patients with NMDs can experience significant muscle damage with concentric exercise. This raises the question, if patients with NMDs could also show RBE when performing concentric exercise.

Systemic autoimmune myopathies are rheumatic diseases that affect the striatum skeletal muscles. The transcranial direct current stimulation technique has been frequent, for example, in patients with ischemic stroke or for the optimization of muscular performance in athletes. However, to date, there are no studies evaluating this technique in patients with systemic autoimmune myopathies. Therefore, the main objective of the present prospective, randomized, double-blind, placebo-controlled study is to evaluate the safety and efficacy of the application of chronic transcranial direct current stimulation sessions - associated with aerobic exercises - in the patients with systemic autoimmune myopathies.

Systemic autoimmune myopathies are a heterogeneous group of rheumatic diseases that primarily affect the skeletal muscles. The transcranial direct current stimulation technique has been frequent, for example, in patients with ischemic stroke or for the optimization of muscular performance in athletes. However, to date, there are no studies evaluating this technique in patients with systemic autoimmune myopathies. Therefore, the main objective of the present prospective, randomized, double-blind, placebo-controlled study is to evaluate the safety and efficacy of the application of acute transcranial current stimulation session in patients with systemic autoimmune myopathies.