Muscle Elasticity Assessment of Postherpetic Neuralgia Using Elasticity Ultrasound

Preliminary Cohort Study on Muscle Elasticity Ultrasound Evaluation and Pathophysiological Changes in Postherpetic Neuralgia

Herpes zoster (HZ), also known as shingles, is caused by the varicella-zoster virus (VZV). Approximately 1/4 of the global population is affected by HZ, with statistics showing that about 90% of shingles patients experience acute neuralgia, and about 1/3 develop postherpetic neuralgia (PHN) after shingles. In PHN patients, about 30%-50% of the pain can persist for more than one year, and some cases can last for more than 10 years. PHN is a common complication of HZ characterized by intense pain in the area where the rash has healed, often described as burning, electric shock-like, or stabbing pain, severely affecting patients' sleep, emotions, work, and daily life. Additionally, approximately 43% of PHN patients exhibit symptoms of toxic anxiety or depression, significantly impacting their quality of life and increasing the societal burden. Due to the global aging population, the incidence of HZ and PHN is expected to significantly increase in the next 10 years, making effective prevention and treatment of PHN an urgent health issue. Although various treatments are available for PHN, a small number of patients remain unresponsive to multiple therapies, resulting in treatment-resistant chronic pain. The lack of a clear understanding of the underlying mechanisms contributes to the suboptimal treatment outcomes for PHN. Elastography, a technique that quantifies the mechanical properties of tissues by measuring their natural elasticity, trauma, degeneration, and healing processes, has shown promise as an innovative approach. Shear wave elastography (SWE) has been used to study the biomechanical characteristics of skeletal muscles by measuring the propagation speed of shear waves induced by ultrasound to quantify the shear elastic modulus, which characterizes the stiffness of soft tissues. In this study, the investigators intend to use elastography to observe the elasticity of muscle tissue in the lesions of PHN patients, with the unaffected side serving as a control. Elastography offers non-invasive, convenient, and straightforward advantages, further contributing to providing new directions for treatment and revealing the role of muscle tissue in PHN by offering new evidence. It also offers new treatment options and targets for PHN patients. While treatment of PHN is primarily focused on neural mechanisms due to HZ's neurotropism nature, recent evidence suggests that muscle tissues within the affected regions may also experience pathological changes, that contribute to the pain. These changes could reveal novel therapeutic targets and enhance patient prognosis. This study aims to investigate these muscular changes and explore myogenic pain mechanisms in PHN patients. It employs ultrasound elastography to compare muscle elasticity between the affected and unaffected sides and conduct muscle biopsies for pathophysiological analysis to uncover the underlying mechanisms.

Study Overview

• Status: Recruiting
• Conditions: Shear Wave Elastography
• Intervention / Treatment: Other: Interventional therapy

• Study Type: Observational
• Enrollment (Estimated): 30

Contacts and Locations

• Study Contact: Name: Heyu Ji, MD; Phone Number: +8618374808445; Email: jiheyu1929@163.com

Study Locations

• China
  • Beijing
    • Beijing, Beijing, China, 100730
      • Recruiting
      • Peking Union Medical College Hospital
      • Contact: Heyu Ji, MD; Phone Number: +8618374808445; Email: jiheyu1929@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Postherpetic neuralgia patients often experience unilateral symptoms, with lesions predominantly occurring on one side of the chest wall. Shear wave elastography (SWE) has been used to study the biomechanical characteristics of skeletal muscles by measuring the propagation speed of shear waves induced by ultrasound to quantify the shear elastic modulus, which characterizes the stiffness of soft tissues. Therefore, the investigators intend to use elastography to observe the elasticity of muscle tissue in the lesions of PHN patients, with the unaffected side serving as a control.

Description

Inclusion Criteria:

• Patients aged 18 years and older, diagnosed with PHN that affects the thoracic nerves and in need of surgical intervention, have been recruited. Written informed consent was obtained from all participants before inclusion. Exclusion Criteria:
• neuromuscular diseases; ongoing use of muscle relaxants and/or other medications that impact muscles; allergy to local anesthetic; a body mass index (BMI) over 30kg/m2; malignant tumors; and pregnancy. Patients who previously had surgery in the PHN-affected area or had another disease causing muscle changes

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

PHN Patients (Self-Controlled Design); This cohort comprises the affected and unaffected side muscles in postherpetic neuralgia (PHN) patients. These muscles will undergo elasticity ultrasound assessment at baseline and post-treatment. Additionally, muscle biopsies will be performed at specific time points during the treatment period, including during interventional therapy, to analyze pathological changes and elucidate the treatment's pathophysiological effects on the affected muscles.

Other: Interventional therapy; Interventional therapy for postherpetic neuralgia includes nerve blocks, pulsed radiofrequency therapy, etc

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Shear Wave Elastography	Shear-wave elastography has recently emerged as a promising assessment tool with the potential for diagnosing and monitoring muscle changes and as a noninvasive method to estimate muscle.	up to 1 month

Secondary Outcome Measures

Outcome Measure	Time Frame
A comparison of muscle elasticity between the affected and contralateral healthy sides across different PHN stages	up to 3 months
A comparison of the before and after the interventional therapy of SWE measurements	up to 3 months
A comparison SWE of measurements between groups receiving conventional treatment alone and those receiving conventional treatment plus targeted muscle relaxation therapy	up to 3 months
A comparison of the histopathological data of the muscle samples from the affected and the unaffected sides	up to 3 months
A comparison of the NRS pain scores before and after the treatment, document the number of treatment sessions, and analyze the duration of PHN	up to 3 months

Collaborators and Investigators

• Sponsor: Peking Union Medical College Hospital
• Investigators: Principal Investigator: Xulei Cui, Peking Union Medical College Hospital

Study record dates

Study Major Dates

• Study Start (Actual): August 14, 2023
• Primary Completion (Estimated): April 30, 2025
• Study Completion (Estimated): May 31, 2025

Study Registration Dates

• First Submitted: June 12, 2023
• First Submitted That Met QC Criteria: June 12, 2023
• First Posted (Actual): June 22, 2023

Study Record Updates

• Last Update Posted (Estimated): November 21, 2024
• Last Update Submitted That Met QC Criteria: November 18, 2024
• Last Verified: December 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Nervous System Diseases; Neuromuscular Diseases; Peripheral Nervous System Diseases; Neuralgia; Neuralgia, Postherpetic
• Other Study ID Numbers: UEL1

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No