A Phase 2/3 interventional study of Active HD-tDCS and Simulated HD-tDCS in Amyotrophic Lateral Sclerosis (ALS), sponsored by Universidade Federal do Rio Grande do Norte. Recruiting at 4 sites in 2 countries. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-07-20.
Sponsored by Universidade Federal do Rio Grande do Norte · Phase 2/3, Interventional, and Treatment
Amyotrophic Lateral Sclerosis (ALS) is a nervous system disease that causes muscle weakness and rapidly progresses to the loss of mobility and functionality. Studies suggest that High-Definition Transcranial Direct Current Stimulation (HD-tDCS) is a technique for modulating motor cortical hyperexcitability. However, evidence on the use of HD-tDCS as a neuromodulator of the diaphragmatic motor cortex in people with ALS is inconclusive.
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.
978 studies on the registry are indexed under Amyotrophic Lateral Sclerosis; 277 are open to participants now.
This study's planned enrollment of 80 is above the median of 38 across 662 interventional studies indexed under Amyotrophic Lateral Sclerosis.
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Exclusion Criteria:
Patients randomly included in this group will receive 10 sessions of anodal HD-tDCS stimulation. The intervention will take place at the participant's home, with electrodes positioned in a circular arrangement-one central electrode and four peripheral electrodes-over the cortical representation zone of the left primary diaphragmatic motor cortex, with a continuous current applied
Device: Active HD-tDCS
Patients randomly included in this group will receive 10 sessions of sham HD-tDCS stimulation. The intervention will take place at the participant's home, with electrodes positioned in a circular arrangement-one central electrode and four peripheral electrodes-over the cortical representation zone of the left primary diaphragmatic motor cortex. Only an initial 30-second ramp stimulus will be applied, followed by a non-effective current
Device: Simulated HD-tDCS
10 sessions of anodal HD-tDCS stimulation (neurostimulator coupled with a 4x1 HD-tDCS multichannel adapter) with a defined electrical current intensity over the cortical representation zone of the left diaphragmatic motor cortex
10 sessions of sham anodal HD-tDCS stimulation (neurostimulator coupled with a 4x1 HD-tDCS multichannel adapter) over the cortical representation zone of the left diaphragmatic motor cortex. The device will provide a 30-second ramp and then maintain a minimal, non-effective continuous current
Cortical excitability assessed via TMS
Cortical excitability assessed by means of Transcranial Magnetic Stimulation measuring motor evoked potentials, cortical inhibition and duration of the cortical silent period
Time frame: From the date of randomization (1 week before the start of the intervention) up to 6 months (follow-up)
Cortical tissue oxygenation
Assessment of cortical tissue oxygenation using brain coupled near-infrared spectroscopy technique coupled to the brain to monitor cerebral oxygenation and regional cerebral oxygen saturation.
Time frame: From the date of randomization (1 week before the start of the intervention) up to 6 months (follow-up)
Electromyographic activity of specific respiratory muscles
This outcome will be assessed through Electromyography of the sternocleidomastoid, scalene, parasternal, hemidiaphragm and rectus abdominis muscles
Time frame: From the date of randomization (1 week before the start of the intervention) up to 6 months (follow-up)
Respiratory function assessed by spirometry
This outcome will be assessed using spirometry
Time frame: From the date of randomization (1 week before the start of the intervention) up to 6 months (follow-up)
Maximum Inspiratory and Expiratory Pressure
This outcome will be assessed by assessing maximum inspiratory and expiratory pressure, Sniff Nasal Inspiratory Pressure and Sniff Nasal Expiratory Pressure curves
Time frame: From the date of randomization (1 week before the start of the intervention) up to 6 months (follow-up)
Cough Peak Flow
This outcome will be assessed through Cough Peak Flow values
Time frame: From the date of randomization (1 week before the start of the intervention) up to 6 months (follow-up)
Respiratory muscle oxygenation via near-infrared spectroscopy
This outcome will be assessed using the near-infrared spectroscopy technique coupled to the scalene and parasternal muscles
Time frame: From the date of randomization (1 week before the start of the intervention) up to 6 months (follow-up)
Peripheral upper limb muscle activity assessed via electromyography
This outcome will be assessed through a protocol for assessing muscle activity positioned in the Lower Trapezius, Anterior Deltoid, Biceps Brachii (medial head), Triceps Brachii (lateral head), Brachioradialis, Extensor Carpi Radialis Longus, Abductor Pollicis Brevis and Upper Trapezius muscles, bilaterally
Time frame: From the date of randomization (1 week before the start of the intervention) up to 6 months (follow-up)
Functionality and disease progression
This outcome will be assessed using the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised which has 12 items with a score from zero to 4, and its total score can range from zero to 48, where 48 means normal functionality and zero, severe disability
Time frame: From the date of randomization (1 week before the start of the intervention) up to 6 months (follow-up)
Fatigue Severity
This outcome will be assessed using the Fatigue Severity Scale comprises nine statements ranging from 1 to 7, with 7 being the maximum level of agreement with the statement, with a minimum score of 9 and a maximum of 63, with values equal to or greater than 28 indicating fatigue
Time frame: From the date of randomization (1 week before the start of the intervention) up to 6 months (follow-up)
Dyspnea assessed via Modified Borg Scales
The Modified Borg scale is numbered from 0 to 10, with each number referring to a textual description of the degree of respiratory fatigue, with 0 as the minimum and 10 as the maximum respiratory discomfort
Time frame: From the date of randomization (1 week before the start of the intervention) up to 6 months (follow-up)
Quality of sleep assessment
This outcome will be assessed using the Mini-Sleep Questionnaire
Time frame: From the date of randomization (1 week before the start of the intervention) up to 6 months (follow-up)
Quality of life assessed using the Brief ALS-specific Quality of Life Questionnaire
This outcome will be assessed using the Brief Specific Quality of Life Questionnaire for ALS Patients
Time frame: From the date of randomization (1 week before the start of the intervention) up to 6 months (follow-up)
Subjective assessment of stimulation-related effects
This outcome will be assessed through a questionnaire about effects such as itching, tingling, redness of the skin, drowsiness, concentration problems, headache, fatigue, dizziness and others, indicating the intensity of these sensations on a scale of 1 to 4 (1 being none, 2 being mild, 3 being moderate and 4 being strong) and whether these effects are related to the stimulation, using a Likert scale from 1 (no relation) to 5 (strongly related)
Time frame: From the date of randomization (1 week before the start of the intervention) up to 6 months (follow-up)
Plan to share: Undecided
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