Chronic Neuropathic Pain: EEG data in eyes open (5 min) and eyes closed (5 min) with questionnaire reports

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, three patients (n=3) 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 (22%), diabetes (17%), trigeminal neuralgia (8%), CNS disorder (8%), 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.

本研究纳入了36名墨西哥籍慢性神经性疼痛患者（其中男性8名，女性28名，平均年龄为44±13.98岁），在睁眼和闭眼状态下进行了脑电图信号记录。每种状态下记录5分钟，总计记录时间为10分钟。每位患者在签署研究协议后均被赋予一个身份编号，并以此编号回答疼痛检测问卷。所有患者均符合以下条件：（1）年龄大于18岁，（2）慢性神经性疼痛持续时间超过3个月，（3）在脑电图记录前至少接受4周的长效药物治疗，（4）无重大精神疾病（如精神分裂症、重度抑郁症、双相情感障碍），（5）无神经系统疾病（如癫痫、耳鸣），以及（6）疼痛检测问卷总分超过12分（问卷结果由患者的临床病史证实）。患者被允许继续服用其药物。药物治疗类型和频率如下：18名患者（n=18）服用中枢作用药物已超过一年，12名患者（n=12）未服用任何药物，3名患者（n=3）服用大麻二酚衍生物，另有3名患者（n=3）在疼痛发作时服用非甾体抗炎药。所研究样本中神经性疼痛的原因包括脊髓损伤（31%）、周围神经病变（22%）、糖尿病（17%）、三叉神经痛（8%）、中枢神经系统疾病（8%）和其他（14%）。这些患者除神经性疼痛外，均无其他类型急性或慢性疼痛（如关节炎、偏头痛、纤维肌痛）、严重的精神疾病、神经系统疾病（除神经性疼痛外）、头部外伤、脑梗死或中枢神经系统肿瘤。本研究已获得CEIC TecSalud伦理委员会的批准，批准文号为P000369-DN-RespElectro-CI-CR005。

描述与目标：根据国际疼痛研究协会的定义，慢性神经性疼痛是指“由影响躯体感觉系统的损伤或疾病直接引起的疼痛”。当神经性疼痛发展为慢性（持续时间超过3个月）时，脊髓和大脑中的神经元会表现出神经可塑性变化。目前，慢性神经性疼痛的研究和临床管理存在显著差距，因为其特征化仅依赖于患者的主观感知。为了解决这一特征化差距，本研究的主要目标是利用线性和非线性动力学，对不同程度的神经性疼痛严重程度进行神经可塑性变化的特征化。这可能是实现神经性疼痛患者客观特征化和监测的方法，并最终有助于改善其疾病管理。