Machine-Learning Based EEG Biomarkers for Personalized Interventions

Inclusion Criteria: * 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. Exclusion Criteria: * 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. * Subjects with substance abuse. * Subjects with any other chronic medical condition where transcranial tDCS is relatively contraindicated, such as pregnancy or epilepsy.