Dorsal Root Ganglion Stimulation: Assessment of Analgesic Efficacy in Postherpetic Neuropathy Based on Pain Phenotype
试验速览
- 阶段
- 不适用
- 状态
- Enrolling By Invitation
- 入组人数
- 75
- 试验地点
- 1
- 主要终点
- Analgesic efficacy identifying the pathogenetic cluster with the greatest therapeutic response
研究概览
简要总结
This is a prospective, multicenter observational study evaluating the efficacy of ganglion stimulation (medical device) in cases of post-herpetic neuropathy.
This study introduces recent methods of phenotypic stratification of postherpetic neuropathy into the field of interventional pain therapy. The aim is to identify which clinical expression of this diverse pathology can derive the greatest benefits from an otherwise effective but expensive therapy such as ganglion stimulation.
The study protocol includes the application of a common clinical practice, already in use for several years at the promoting center and participating centers (as well as internationally scientifically codified). It is supported by an innovative stratification of clinical expression (phenotype of the disease), recently introduced in the literature.
The study aims to identify, through careful clinical evaluation, predictive indices of the greatest success in invasive ganglion stimulation therapy, a treatment associated with significant system costs and considerable inconvenience for the patient.
The results of the experimentation will allow the codification of evaluative clinical pathways to predict a higher success index in certain clinical expressions of postherpetic neuropathy compared to others. This will help reduce the costs of implant trials and enable defining the real objective of the proposed therapy in consultation with the patient.
详细描述
During the manifestation of varicella, the varicella-zoster virus (VZV) localizes in the ganglia of dorsal roots or cranial nerves and remains latent until it can reactivate in conditions of reduced immunity, such as old age or certain diseases. Infection control is linked to cell-mediated immunity, which tends to decrease with age but can be periodically stimulated by exposure to chickenpox or silent reactivations..
Epidemiological studies demonstrate that herpes zoster affects 5.23 cases per 1000 persons/year, with 13.7% showing signs of postherpetic neuralgia (PHN) after three months. In individuals over 80 years, the PHN percentage rises to 80%. PHN is a very challenging-to-treat painful syndrome with diverse manifestations in patients.
During reactivation, the virus travels along the central and peripheral dendrites of the first neuron, reaching the skin where it causes vesicles, usually affecting a dermatome but sometimes more than one. Post-mortem histological studies have shown atrophy of the dorsal horns of the spinal cord and loss of cells, axons, and myelin in the dorsal root ganglion (DRG) of patients with long-lasting PHN; histopathological changes were confined to a single ganglion per patient. The loss of axons and myelin in sensory roots and nerves was also present in patients without pain. In some patients, a prolonged cell-mediated inflammatory process was evident .
Skin biopsy in PHN patients demonstrated a significant reduction in terminals of small-caliber fibers, more evident in the epidermis than in the dermis. The innervation of affected areas shows great variability among patients and is not correlated with pain intensity or the degree of allodynia.
At the molecular level, increased expression of voltage-sensitive Na+ channels, alterations in K+ channels, and an increase in transient receptor potential vanilloid 1 (TRPV1) have been demonstrated. These modifications alter the threshold for the generation of action potentials at the nerve terminals and can generate action potentials at the site of injury along the fiber or at the level of the DRG. There is also a postulated loss of inhibitory GABAergic interneurons in the dorsal horns and descending inhibition.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 75 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Subjects of both genders aged between 18 and 75 years;
- •Patients with postherpetic neuralgia (PHN) for at least 6 months who have tried the topical and systemic pharmacological therapies recommended in the neuropathic pain guidelines
- •Distribution of neuropathic pain in a region between C6 and L5;
- •Individuals capable of adequately adhering to the study protocol and responding to the administered questionnaires;
- •Signed informed consent.
排除标准
- •Subjects with a history of major depression or other psychiatric conditions that, in the investigator's opinion, may interfere with study participation;
- •Patients in presumed/confirmed pregnancy;
- •Patients for whom the placement of spinal/ganglion stimulation systems is contraindicated due to systemic pathological conditions.
结局指标
主要结局
Analgesic efficacy identifying the pathogenetic cluster with the greatest therapeutic response
时间窗: at 6 months
Average minimum and maximum pain with the NRS scale (0-10) DN4 (neuropathic pain) in the validated Italian version; SF12 (short form health questionnaire) in the validated Italian version• EQ5 (Euro QOL 5) in the validated Italian version.
次要结局
未报告次要终点