Trial was not started due to lack of funding and nobody received an intervention.

Clinical trials organization in several neuromuscular disorders (NMD) has some specific issues. Nonambulant status and difficulties with transportation are among them. Moreover a lot of patients with NMD have so poor condition that even short transportation is able to worse it. Such situation forces researchers to limit a region of recruitment for clinical trials and to exclude from trials more severe subgroup of patients, which cause additional issues especially for rare diseases.

The purpose of this study is to prove hypothesis about possibility to reliably monitor patient condition remotely, without trial site visiting. Visit-free study design is potentially able to widen eligible patient population and to decrease patient dropout rate as well as burden of numerous assessments. Meanwhile assessment frequency could be increased enabling monitoring of short fluctuations in patients' condition.

Spinal muscular atrophy (SMA) is a rare neuromuscular condition to which all mentioned above issues are completely applicable. Direct current stimulation (DCS) of neural structures is well studied and safe intervention, however, its effects on SMA patients' strength and durability has not been reported for today. The investigators suppose that investigation of DCS action in SMA patient population is an adequate model for visit-free design feasibility, reliability and sensitivity evaluation.

Inclusion Criteria:

• Signed informed consent
• 5q SMA confirmed by molecular testing

Exclusion Criteria:

• Need for ventilation
• Hypersensitivity (pain or allergic reaction) to current stimulation