HD-tDCS in Amyotrophic Lateral Sclerosis: A Multicenter Randomized Controlled Trial

A multicenter, randomized controlled clinical trial will be conducted. Participants will be randomized into two groups: the HD-tDCS group (gTDCS) and the sham tDCS group (gSham). The intervention protocol will assess the effects of HD-tDCS on respiratory parameters and ALS progression. The study will include individuals of both sexes, aged 18 to 80 years, with a clinical diagnosis of ALS, evaluated before, during, and after the home-based HD-tDCS protocol. The electrodes will be positioned in a circular arrangement over the primary diaphragmatic motor cortex, applying a continuous anodal current intensity. For placebo comparison, only an initial 30-second ramp stimulus will be applied, followed by a minimal current, resulting in no significant intervention. The intervention will be conducted at the participant's home, once daily, five days per week, for two weeks. Patients will undergo evaluations of lung function, cough peak flow, respiratory muscle strength, nasal respiratory pressures, functional capacity, muscle fatigue, cognitive function, as well as surface electromyography of respiratory muscles during active and assisted breathing curves using transcranial magnetic stimulation (TMS), cortical excitability, central tissue oxygenation, respiratory muscle tissue oxygenation, functionality and disease progression, motor control and muscle performance, fatigue and dyspnea, sleep analysis, quality of life, and adverse effects.