Effect of Multitarget tDCS for Neuropathic Pain

Effect of Multitarget Transcranial Direct Current Stimulation (tDCS) in Patients With Neuropathic Pain

This study aims to conduct a randomized controlled trial to evaluate the effect of multitarget transcranial direct current stimulation (tDCS) on pain, depression, anxiety, quality of life and sleep, in patients with neuropathic pain.

The present multicenter, randomized, double-blind, sham-controlled, parallel-group trial aims to evaluate the effect of multitarget transcranial direct current stimulation (tDCS) in patients with neuropathic pain.

The patients will be randomized to receive one of 3 treatment arms: multitarget stimulation, single-target stimulation and sham stimulation. All patients received 20 minutes of active or sham tDCS once a day for 10 consecutive weekdays. In multitarget group, subjects will receive 2mA tDCS applied to M1 and DLPFC alternately, with each target stimulated for 5 sessions. In single-target group, 2mA tDCS will target M1 only. In sham group, subjects will receive sham tDCS. Ramps up and down will be applied for 15 seconds each at the beginning and end of the session. The current will be 0 mA during the interval between the initial and final ramps.

Inclusion Criteria:

1. Female or males aged between 18 and 75 years.
2. Pain fulfilling the criteria for probable or definite neuropathic pain and scoring ≥4/10 at Douleur Neuropathique 4 Questions.
3. Pain duration of at least 3 months and average pain intensity scoring ≥4/10 at Numeric Rating Scale.
4. Stable pharmacological treatment for at least 4 weeks prior to the study and throughout the trial.
5. Informed consent obtained.

Exclusion Criteria:

1. Pregnancy or lactation.
2. Active central nervous system diseases including but not limited to brain tumour, intracranial hypertension, past or current epilepsy.
3. Unable to complete the questionnaire due to language abilities or reduced cognitive functioning.
4. Alcohol or substance abuse.
5. Common contraindications for transcranial direct current stimulation including but not limited to skull defect, implanted device or metal in the brain, severe cardiopulmonary, renal or hepatic diseases.
6. Unwilling to comply with the treatment or follow-up assessments.
7. Participating in another clinical trial within 3 months prior to enrollment of this clinical trial.
8. Any patient deemed unsuitable for enrollment by the investigators.