Ultrasound-Guided Pulsed Radiofrequency Versus Phenol Neurolysis for Post-Stroke Hemiplegic Shoulder Pain

August 6, 2026 updated by: Salwa Omar Mohamed, Assiut University

Ultrasound-Guided Pulsed Radiofrequency Neuromodulation Versus Ultrasound -Guided Phenol Neurolysis in Post-Stroke Hemiplegic Shoulder Pain: A Randomized Controlled Trial

Post-stroke hemiplegic shoulder pain is a common complication that negatively affects upper limb function and quality of life. This randomized controlled trial aims to compare the efficacy and safety of ultrasound-guided pulsed radiofrequency neuromodulation versus ultrasound-guided phenol neurolysis targeting the suprascapular, axillary, and lateral pectoral nerves in patients with post-stroke hemiplegic shoulder pain. The primary outcome is pain reduction, while secondary outcomes include shoulder function, spasticity, range of motion, quality of life, analgesic consumption, and adverse events during follow-up.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Hemiplegic shoulder pain (HSP) is a common complication following stroke. It may lead to withdrawal from rehabilitation programs, reduced upper-limb movement and poorer functional recovery; therefore, timely pain control is relevant to rehabilitation participation and long-term outcome. [1] A systematic review reported wide variation in incidence and prevalence; pooled/meta-analytic estimates included incidence ranges around 10-22% and prevalence ranges around 22-47%, while individual studies varied more widely because of differences in timing, definitions and clinical settings. Risk factors include increased tone, impaired motor function, sensory impairment, shoulder subluxation, abnormal shoulder examination, hemispastical neglect and prior shoulder pain. [1,2] The cause of post-stroke HSP is often multifactorial. The mechanisms can be grouped into: (a) impaired motor control and tone changes; (b) soft-tissue lesions and (c) altered peripheral and central nervous activity, Because these mechanisms may overlap in the same patient, baseline clinical and ultrasound phenotyping will be used to document the dominant pain/spasticity pattern and to exclude structural shoulder pathology requiring surgical management. [1,3,4] Central sensitization, defined as increased responsiveness of nociceptive neurons in the central nervous system to normal or subthreshold afferent input, may contribute to persistent HSP. [4] Pulsed radiofrequency delivers radiofrequency current in intermittent pulses consisting of short periods of electrical stimulation, typically 20 ms, followed by longer silent phases, approximately 480 ms. This intermittent delivery allows heat dissipation and keeps target tissue temperature below approximately 42 degrees Celsius, thereby reducing the risk of thermal nerve injury. For this reason, the intervention is described in this enhanced protocol as PRF rather than conventional thermal radiofrequency ablation. This correction improves technical accuracy because the submitted synopsis described a PRF technique rather than destructive thermal ablation. [5] PRF stimulation may reduce pain through long-term depression of C-fiber-mediated spinal sensitization and several neuromodulatory effects on inflammatory and descending inhibitory pathways. The exact mechanism remains elucidated; therefore, the study will measure both pain and function rather than assuming a single mechanism of benefit. [5,6] Phenol is a neurolytic agent used to manage focal spasticity. Immediately after injection, phenol may produce a transient local anesthetic effect by reversibly blocking nerve conduction. At neurolytic concentrations, commonly around 5-6%, phenol causes protein denaturation with segmental demyelination, axonal degeneration, and Wallerian degeneration of exposed nerve fibers, interrupting nerve conduction and reducing overactivity. Because phenol can cause dysesthesia, pain, inflammation, hypotension or unintended motor/sensory effects, the protocol specifies ultrasound guidance, aspiration before injection, limited per-nerve volumes according to institutional SOP, post-procedure monitoring, and structured AE recording.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
70

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults aged 18 years or older. History of ischemic or hemorrhagic stroke confirmed clinically and/or by neuroimaging when available.

Post-stroke shoulder pain on the hemiplegic side with VAS pain intensity >=4/10 during rest, passive movement or functional use.

Spasticity of target shoulder-girdle muscles with MAS score >=2. Stable medical condition allowing outpatient or inpatient interventional procedure.

Ability to provide written informed consent; if the patient has a communication impairment, consent will follow institutional ethics-approved procedures involving legally authorized representatives when appropriate.

Expected ability to attend scheduled follow-up visits through 6 months

Exclusion Criteria:

  • Previous radiofrequency treatment or phenol neurolysis to the affected shoulder within the previous 6 months.

Botulinum toxin injection to the target shoulder muscles within the previous 3-6 months.

Shoulder fracture, dislocation or rotator cuff tear requiring surgery. Active infection at the injection site. Known allergy or contraindication to phenol, local anesthetic, antiseptic solution or other procedure-related medication.

Coagulopathy, platelet disorder or anticoagulant/antiplatelet treatment that cannot be safely managed according to local anesthesia/interventional-pain policy.

Severe uncontrolled medical illness, unstable cardiopulmonary disease, uncontrolled diabetes with active infection risk, or any condition judged by investigators to increase procedural risk.

Severe cognitive, behavioral, or communication impairment preventing reliable pain/outcome assessment unless a validated caregiver-assisted assessment approach is approved by the ethics committee.

Pregnancy or lactation, when applicable, because of procedural medication exposure and safety monitoring requirements.

Concurrent participation in another interventional trial that may affect shoulder pain, tone or function.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Ultrasound-guided pulsed radiofrequency
Procedure: Pulsed radiofrequency neuromodulation
Ultrasound-guided pulsed radiofrequency will be applied to radicular branch of suprascapular, axillary and lat pectoral nerves
Experimental: Ultrasound-guided phenol neurolysis
Other: Ultrasound-guided phenol neurolysis
Ultrasound-guided phenol injection will be applied to radicular branch of suprascapular, axillary and lat pectoral nerves

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in shoulder pain intensity measured from baseline to 3 months
Time Frame: 3months
Change in shoulder pain intensity measured by 0-10 cm/point VAS from baseline to 3 months. The 3-month endpoint is selected as the primary endpoint because it is clinically meaningful for rehabilitation planning and allows comparison of medium-term response between neuromodulatory PRF and neurolytic phenol treatment.
3months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Pain intensity by VAS at 1 week, 1 month, and 6 months.
Time Frame: 6 months
Pain intensity by VAS at 1 week, 1 month, and 6 months.
6 months
Patient Global Impression of Change (1-7)at 1, 3, and 6 month
Time Frame: 6 months
6 months
Functional outcomes using SPADI.
Time Frame: 6 months
6 months
Neuromuscular/shoulder ultrasound findings, including bursitis, tendinopathy, effusion, subluxation or other relevant pathology when assessed.
Time Frame: 6 months
6 months
Technical success
Time Frame: 6 months
Technical success is defined as successful ultrasound-guided identification of all predefined target nerves, correct needle placement, and complete delivery of the assigned intervention to all target nerves. The outcome will be reported as the proportion of participants in whom all criteria are achieved
6 months
Analgesic/rescue medication consumption during follow-up.
Time Frame: 6 months
6 months
Shoulder ROM measured by goniometer using a standardized method and side-positioning protocol. [14
Time Frame: 6 months
6 months
Shoulder spasticity using MAS, with predefined target muscle groups documented at baseline. [12]
Time Frame: 6 months
6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Assiut University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 1, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 30, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 6, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 7, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 7, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 6, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ASU-HSP-PRF-PHENOL-1

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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