Does Blood Vessel Vasodilation, Caused by Focal Infiltration of Lidocaine Cause Temporary Nerve Functional Recovery for Patients with Common Peroneal Nerve Injury or Entrapment: Testing the 'Phoenix Sign' Effect Between Lidocaine (a Common Local Anesthetic) and Papaverine, a Know Vasodilator

Is the Phoenix Sign Phenomenon Due to Vasodilation? a Double-Blinded, Randomized Controlled Trial Comparing Motor Function Recovery After Diagnostic Common Fibular Nerve Block with Lidocaine and Papaverine

The goal of this clinical trial is to compare lidocaine without epinephrine to papaverine a known vasodilatory agent, in creating improved motor strength in patients with drop foot involving an entrapment of the Common Peroneal Nerve. This phenomenon has been named the Phoenix Sign and is a very specific peripheral nerve block.

Researchers will compare the effects of the above agent for pre and post infiltration changes in motor strength.

Participants will:

• Will be randomized to one of either agents already listed
• After receiving the ultrasound guided injection, motor testing will be evaluated in 4-6 minutes with manual motor strength testing of the anterior compartment muscles.
• No additional follow will be required

Study Overview

• Status: Completed
• Conditions: Drop Foot
• Intervention / Treatment: Diagnostic test: Diagnostic procedures; Diagnostic test: Lidocaine HCl

Detailed Description

A double-blinded, randomised, prospective controlled trial was conducted at US Neuropathy Centers in Marietta, GA, under the approval of the Kennesaw State University Institutional Review Board. Patients with weak dorsiflexion of the ankle or a drop foot were recruited from the existing clinical practice at US Neuropathy Centers. Cohort inclusion criteria also included a stable medical and medication status, ages 18-85, speaking English as the primary language, and ambulatory. Walking aids or ankle-foot orthosis were permitted.. Based on the inclusion criteria, only 20 patients were enrolled. Patients were recruited over a period of 1 year and two months from January 2021 to March 2022 with no requirement for follow-up. The enrolment phase was concluded as the study was originally designed as a pilot investigation, with recruitment limited to a single, small medical practice. A total of 20 patients were successfully enrolled within this setting.Participants were randomised by the throw of dice to injection of 0.3 cc of Papaverine HCl 10 mg/mL or 0.3 cc of 1% Lidocaine HCl adjacent to CFN in a room separate from patient room. Injection solutions were prepared by non-blinded assistants and were visually indistinguishable. Patients and physicians are blinded to drugs received. Motor strength of the Extensor Hallucis Longus (EHL), Tibialis Anterior (TA), and Extensor Digitorum Longus (EDL) muscles were tested. Strength was rated according to the Medical Research Council Manual Muscle Testing scale 0-5. The CFN at the fibular neck was identified under high-resolution ultrasound imaging. The injection site was prepared with alcohol, and ethyl chloride was used to anaesthetise the skin. A 30-gauge 1-inch needle was inserted adjacent to, but not within, the CFN. The infiltrate was delivered at the level of the fibular neck just proximal to where the CPN coursed beneath the deep fascia of the peroneus longus. This was immediately adjacent to the first known anatomical site of compression of the CPN. 0.3cc of the drug was delivered.

The investigator then waited approximately five minutes and re-tested motor strength of the Extensor Hallucis Longus (EHL), Tibialis Anterior (TA), and Extensor Digitorum Longus (EDL) muscles manually.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Georgia
    • Marietta, Georgia, United States, 30067
      • US Neuropathy Centers

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:Cohort inclusion criteria also included a stable medical and medication status, ages 18-85, speaking English as the primary language, and ambulatory. Walking aids or ankle-foot orthosis were permitted.

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Exclusion Criteria: Patients with normal motor strength of the anterior compartment of the leg.

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Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Lidocaine group; Patients randomized to this arm received less than a .5cc infiltration of plain lidocaine	Diagnostic test: Diagnostic procedures; A 30-gauge 1-inch needle was inserted adjacent to, but not within, the CFN. The infiltrate was delivered at the level of the fibular neck just proximal to where the CPN coursed beneath the deep fascia of the peroneus longus. This was immediately adjacent to the first known anatomical site of compression of the CPN. 0.3cc of the drug was delivered.; Diagnostic test: Lidocaine HCl; This study compares the vasodilatory effects of lidocaine to papaverine after diagnostic infiltration of the Common Peroneal Nerve in patients with demonstrated motor weakness of the EHL (extensor hallucis longus).; Other Names: Papaverine
Experimental: Papavarine; Patients randomized to this arm received less than a .5cc infiltration of 10mg/ml papaverine	Diagnostic test: Diagnostic procedures; A 30-gauge 1-inch needle was inserted adjacent to, but not within, the CFN. The infiltrate was delivered at the level of the fibular neck just proximal to where the CPN coursed beneath the deep fascia of the peroneus longus. This was immediately adjacent to the first known anatomical site of compression of the CPN. 0.3cc of the drug was delivered.; Diagnostic test: Lidocaine HCl; This study compares the vasodilatory effects of lidocaine to papaverine after diagnostic infiltration of the Common Peroneal Nerve in patients with demonstrated motor weakness of the EHL (extensor hallucis longus).; Other Names: Papaverine

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Manual Motor Strength Testing of Anterior Compartment	Motor strength of the Extensor Hallucis Longus (EHL), Tibialis Anterior (TA), and Extensor Digitorum Longus (EDL) muscles were tested. Strength was rated according to the Medical Research Council Manual Muscle Testing scale 0-5.	From enrollment to evaluation which is complete upon the first study visit after infiltration of the agents. The increased motor effect after infiltration is only apparent for 10 minutes or less

Collaborators and Investigators

• Sponsor: Stephen Barrett
• Collaborators: US Neuropathy Centers

Publications and helpful links

General Publications

• Bowley MP, Doughty CT. Entrapment Neuropathies of the Lower Extremity. Med Clin North Am. 2019 Mar;103(2):371-382. doi: 10.1016/j.mcna.2018.10.013. Epub 2018 Dec 3.

Study record dates

Study Major Dates

• Study Start (Actual): March 15, 2020
• Primary Completion (Actual): February 15, 2022
• Study Completion (Actual): November 1, 2023

Study Registration Dates

• First Submitted: October 7, 2024
• First Submitted That Met QC Criteria: October 9, 2024
• First Posted (Actual): October 15, 2024

Study Record Updates

• Last Update Posted (Actual): October 15, 2024
• Last Update Submitted That Met QC Criteria: October 9, 2024
• Last Verified: October 1, 2024

More Information

Terms related to this study

• Keywords: Drop Foot; Common Peroneal Nerve Palsy; Weakness of Anterior and Lateral Compartment of Leg
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Anti-Arrhythmia Agents; Vasodilator Agents; Central Nervous System Depressants; Peripheral Nervous System Agents; Urological Agents; Enzyme Inhibitors; Sensory System Agents; Anesthetics; Membrane Transport Modulators; Anesthetics, Local; Voltage-Gated Sodium Channel Blockers; Sodium Channel Blockers; Phosphodiesterase Inhibitors; Lidocaine; Papaverine
• Other Study ID Numbers: Study 20-391

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: Yes