Chronic Neuropathic Pain EEG Raw data in EC (5 min) and EO (5 min)

Thirty six chronic neuropathic pain patients (8 men and 28 women) of Mexican nationality with a mean age of 44±13.98 were recruited for EEG signal recording in eyes open and eyes closed condition. Each condition was recorded for 5 min, with a total recording session time of 10 min. An ID number was given to each patient after singing up for the study, with which they answered the Pain Detect questionnaire. All patients had: (1) age above 18 years old, (2) chronic NP for more than 3 months, (3) long-term pharmacological treatment for at least 4 weeks prior to the EEG recording, (4) absence of a major psychiatric disorder (i.e., schizophrenia, major depressive disorder, bipolar disorder), (5) absence of a neurological disorder (i.e., epilepsy, tinnitus), and (6) Total Score >12 points of Pain Detect Questionnaire (the questionnaire outcome was confirmed by the clinical history of the patient). Patients were allowed to continue with their medication. The type and frequency of the pharmacological treatment was the following. Eighteen patients (n=18) were taking centrally acting drugs for over a year, twelve patients (n=12) were not taking medication, two patients (n=2) were on cannabidiol derivatives, and three (n=3) took nonsteroidal anti-inflammatory drugs for pain attacks. The causes for NP in the studied sample were spinal cord injury (31%), peripheral neuropathy (23%), diabetes (17%), trigeminal neuralgia (9%), CNS disorder (6%), and other (14%). None of these patients had any type of acute or chronic pain other than NP (e.g., arthritis, migraine, fibromyalgia), a severe mental disorder, neurological disorder (beside NP), head trauma, cerebral infarct, or CNS tumor. This study was approved by the Ethics Committee of CEIC TecSalud with the following number: P000369-DN-RespElectro-CI-CR005. Description and objective: Chronic neuropathic pain is defined as “pain arising as a direct consequence of a lesion or disease affecting the somatosensory system" according to the International Association for the Study of Pain. When neuropathic pain becomes chronic (has a duration greater than 3 months), the neurons in the spinal cord and the brain respond with neuroplastic changes. Currently, there is a significant gap in chronic neuropathic pain research and clinical management, because characterization relies only on the subjective perception of the patient. To address the characterization gap, the principal objective of this study was to characterize the neuroplastic changes in neuronal oscillations for the different degrees of neuropathic pain severity using linear and non linear dynamics. This could be a method to achieve an objective characterization and monitoring of neuropathic pain patients, and ultimately lead to a better management of their disease.