Clinical Research Directory

Inclusion Criteria: * Patients over 18 years of age. * Unilateral pain radiating to the lower extremity (with or without lumbar pain), which clinically corresponds to the path of the corresponding dermatomes. * Correlation between clinical symptoms and lesion observed by magnetic resonance imaging (MRI). * Radicular syndrome of three months or more of evolution. * Normal or pathological electromyogram (EMG). * Pain with neuropathic characteristics confirmed by the DN4 neuropathic pain questionnaire. * Patients with a previous positive block diagnosis. * Patients who have signed the informed consent document. Exclusion Criteria: * Patients under 18 years of age. * Patients with non-radicular low back pain. * MRI not consistent with the patient\'s symptoms. * Patients with peripheral neuropathy of the lower extremities. * Patients with a history or current diagnosis of serious mental disorder. * Patients with moderate or severe cognitive impairment, or evidence of acute or subacute confusional syndrome. * Infection at the puncture site. * Coagulation disorders. * Pregnant patients. * Patients who refuse to sign the informed consent document. * Patients allergic to radiological contrast.