Clinical trial NCT06637046: 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
Official title: 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
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Drop Foot
Keywords: Drop Foot
Common Peroneal Nerve Palsy
Weakness of Anterior and Lateral Compartment of Leg
Lead sponsor: US Neuropathy Centers
Sponsor class: OTHER
Collaborators: name: US Neuropathy Centers
First posted: 2024-10-15
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Maximum age (years): 85
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: OTHER

Brief summary: 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

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.

Eligibility criteria: 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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Primary outcomes:
measure: Manual Motor Strength Testing of Anterior Compartment
timeFrame: 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
Secondary outcomes:
Other outcomes:
Locations:
city: Marietta
country: United States
facility: US Neuropathy Centers
state: Georgia
Study officials:
References:
citation: 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.