About this trial
The goal of this observational study is to develop a machine learning model to predict the outcome of a transcranial direct current stimulation (tDCS) treatment in patients suffering from neuropathic pain derived from a spinal cord injury. The main question it aims to answer is:
• Can electroencephalography (EEG) and clinical assessment data predict the success of tDCS treatment in neuropathic pain patients?
Participants will:
* Undergo EEG recording sessions to collect brain activity data before treatment. * Complete clinical assessments, including medical diagnostics and questionnaires focused on factors related to neuropathic pain before and after treatment.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Age: Over 18 years old.
Neuropathic Pain (NP): Subacute NP at or below the lesion level for at least 1 month following spinal cord injury or disease. Persistent NP is defined as pain in an area of sensory abnormality corresponding to the spinal cord injury according to international criteria (Bryce et al. 2012). The pain should not be primarily related to spasms or any other movement.
Pain Intensity: At least 4 out of 10 on the Numerical Rating Scale (NRS) at the time of screening (rated during the previous 24 hours).
Pharmacological Treatment: Stable treatment including antiepileptic, antidepressant, or antispastic drugs (Gabapentin (GBP) with a minimum dose of 900 mg/day, Pregabalin (PGB) with a minimum dose of 150 mg/day, Amitriptyline with a minimum dose of 25 mg/day). No dose changes for at least 2 weeks prior to treatment and no additional antiepileptic medication. The pharmacological regimen must be maintained without changes during the 10-day stimulation period and until the electrophysiological measurement. It is recommended to keep the regimen stable until the completion of the following two evaluations (4 and 12 weeks after the end of treatment). Only paracetamol or anti-inflammatory drugs are allowed as rescue treatment.
Disqualifiers
Patients with severe pain (NRS > 7) from other sources, such as musculoskeletal pain, inflammatory pain, or cancer-related pain.
Subjects with traumatic brain injury.
Subjects with alcohol abuse.
Subjects with neurological diseases other than the specified spinal cord injury.
Trial population
Patients with spinal cord injury (SCI) suffering from neuropathic pain (NP).
Trial design
Cohort
Prospective
Treatments tested in this trial
transcranial Direct Current Stimulation
DeviceThe treatment follows an approved neuromodulation protocol at our center (approved on Nov. 4 2021, valid until Nov. 4 2024). tDCS will be administered with a battery-powered DC stimulator (Sooma tDCS, Helsinki, Finland), using saline-saturated circular electrodes with a diameter of 6 cm². The anode will be positioned over C3 to stimulate the primary motor cortex (M1), and the cathode over the contralateral supraorbital area (FP2). For asymmetric pain, stimulation targets the M1 contralateral to the more painful side, and for symmetric pain, the dominant hemisphere (C3) is stimulated. The maximum current is 2 mA (current density: 0.06 mA/cm²). Each session lasts 30 minutes, conducted daily for two weeks (Monday to Friday), totaling 10 sessions. All stimulation parameters adhere to general safety guidelines for transcranial electrical stimulation (Bikson et al., 2016).
Electroencephalography
Diagnostic test64-channel active-electrode EEG with impedances kept \~5KOhm
Treatment groups
Trial outcomes
Primary outcomes
Patient Improvement as assessed by a composite score
Composite Score Breakdown: Neuropathic Pain Symptom Inventory (NPSI) Items: * Constant pain intensity: Questions 1, 2, 3, 11, 12 (sum) * Constant pain persistence/frequency: Question 4 * Pain crisis intensity: Questions 5, 6 (sum) * Pain crisis frequency: Question 7 * Allodynia: Questions 8, 9, 10 (sum) Criteria: * Numerical NPSI items are only used where pre-treatment pain ratings are 4/10 or higher. * Responder: Any NPSI item shows a 50% or larger reduction. Brief Pain Inventory (BPI) Items: * Pain Interference: Questions 3a - 3g (average) Criteria: * Responder: 30% improvement or more. Summary: A subject is considered a responder if BOTH of these conditions are met: 1. Improvement of 50% or more in pain intensity or frequency (NPSI). 2. Improvement of 30% or more in pain interference (BPI).
Sponsors and contacts
Click on the lead sponsor to view all of their trials.
Institut Guttmann
Lead sponsor
Castellers de la Vila de Gràcia
Collaborator