NCT07359677

High-frequency Alternating Current Stimulation for Neurophatic Pain in Spinal Cord Injury

Effectiveness and Safety of Transcutaneous Electrical Stimulation With 40 kHz Alternating Currents in People With Spinal Cord Injury and Neuropathic Pain. A Randomised, Double-blind, Parallel Pilot Study With Placebo Control

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 30 (actual)
• Sponsor: University of Castilla-La Mancha · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

To investigate the safety and effectiveness of transcutaneous electrical stimulation with 40 kHz alternating currents combined with standard treatment compared to placebo electrical stimulation plus standard treatment for neuropathic pain in people with spinal cord injury.

Detailed description

Neuropathic pain affects more than a third of people with spinal cord injuries, reducing their quality of life, and the effectiveness of current treatments is limited. The latest research on healthy volunteers has shown that transcutaneous electrical stimulation with high-frequency blocking currents could have a potential effect on pain, proving to be a safe intervention. To investigate the safety and effectiveness of transcutaneous electrical stimulation with 40 kHz alternating currents combined with standard treatment compared to placebo electrical stimulation plus standard treatment for neuropathic pain in people with spinal cord injury. Design: Parallel, randomised, double-blind, placebo-controlled pilot clinical trial. Participants and location: People with spinal cord injury over the age of 18, with a history of more than three months, neuropathic pain at the level of injury and/or below the level of injury, and pain intensity ≥ 30 mm on the visual analogue scale (VAS) for pain. Participants with any contraindications for the application of transcutaneous electrical stimulation will be excluded. The study will be conducted at the National Hospital for Paraplegics in Toledo. Intervention: Participants will be randomly assigned to two intervention groups: Active group (n=15) transcutaneous electrical stimulation with 40kHz alternating currents and Placebo group (n=15) simulated stimulation. The duration of the session in both interventions will be 20 minutes, 10 sessions, over two weeks (5 sessions/week). Main variables and measurement instruments: The main variable will be the Spanish version of the Neuropathic Pain Symptom Inventory. Secondary variables will be pain perception, which will be assessed using a daily record of spontaneous pain with the VAS scale. The intensity of pain evoked by mechanical stimuli will be assessed using the VAS scale, and pain evoked by thermal stimuli will be assessed using a quantitative sensory test with a Peltier thermode. An ad hoc questionnaire has been designed to assess adverse effects. The assessments will be carried out at four time points: before the intervention, during the intervention, immediately after the intervention, and one week after the intervention.

Conditions

• Neuropathic Pain
• Spinal Cord Injuries (SCI)

Interventions

Type	Name	Description
DEVICE	Active group 40 kHz	For experimental electrical stimulation, two stainless steel electrodes with conductive gel will be applied over the bilateral spinal roots with a separation between electrodes of at least 2 cm and a distance between the medial edge of each electrode and the spinous process of at least 1 cm. The upper third of the electrode will be placed above the level of spinal cord injury where the participant will have preserved sensitivity, and the remaining two thirds in the lesion and/or infralesional area. An unmodulated rectangular alternating or biphasic electrical current with a frequency of 40 kHz will be applied. The intensity of the current will be adjusted individually, increasing it until the participant reports a sensation of 'strong but comfortable tingling' just below the motor threshold. Every two minutes, the intensity of the current will be adjusted if the tingling sensation decreases. The electrical current will be applied for 20 minutes in two 10-minute phases.
DEVICE	Sham intervention	Placebo stimulation will be performed using the same electrical current device, the same electrode placement, and the same stimulation parameters as in the experimental stimulation, but the current intensity will be increased only during the initial 30 initial seconds and the final 30 seconds of the session, with the current intensity set to 0 mA for the rest of the intervention (20 minutes).

Timeline

• Start date: 2026-01-30
• Primary completion: 2026-04-07
• Completion: 2026-04-07
• First posted: 2026-01-22
• Last updated: 2026-04-13

Locations

1 site across 1 country: Spain