Drop FootNCT06919289
The Investigators Are Comparing Lidocaine and Papaverine Nerve Blocks to Determine Which Improves Blood Flow Better, Making the "Phoenix Sign" Clearer on Imaging. This Helps Accurately Diagnose Nerve Compression, Improving Patient Care
A study testing Infiltration of papaverine and Lidocaine infiltration in people with Drop Foot, run by US Neuropathy Centers at 1 site in United States.
Trial summary
This pilot study aims to investigate the effects of nerve blocks in patients with diabetic peripheral neuropathy through a double-blinded, randomized trial involving 4 patients. Each participant will receive bilateral peripheral nerve blocks using either lidocaine or papaverine. Read more about this study
- Who is it for?
- Any ageHealthy volunteers can take part
- Conditions the study is for
- Drop Foot
- What is being tested?
- Infiltration of papaverine and Lidocaine infiltration
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 4 participants
- Where
- 1 siteUnited States
- Study dates
- 7 Mar 2024to 1 Jul 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- subjects were included if they were diabetic and neuropathic.
Who cannot join
- Patients with Trypanophobia
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Quantifying the Phoenix Sign: A Comparative, Randomized Control Trial Analysis of Lidocaine and Papaverine-Induced Vascular Enhancement After Common Peroneal (Fibular) Nerve Blocks for the Diagnosis of a Focal Peripheral Nerve Entrapment
This pilot study aims to investigate the effects of nerve blocks in patients with diabetic peripheral neuropathy through a double-blinded, randomized trial involving 4 patients. Each participant will receive bilateral peripheral nerve blocks using either lidocaine or papaverine. Following randomization, each patient will receive one medication in one leg and the alternate medication in the contralateral leg. Researchers will measure parameters including motor strength, sensory function (two-point discrimination), arterial blood flow via Doppler ultrasound, and microvascular perfusion using near-infrared spectroscopy both prior to and following nerve block administration. This research seeks to explore potential diagnostic and therapeutic applications for peripheral nerve entrapment, a common yet challenging clinical condition.
Read the detailed description
Detailed Analysis of the Phoenix Sign and Vascular Changes Following Nerve Blocks in Diabetic Neuropathy
Study Background and Purpose
This study investigates the vascular and neurological phenomena associated with peripheral nerve blocks in patients with diabetic neuropathy. The primary aim is to assess whether observed changes following nerve block administration can be attributed to vasodilatory effects of lidocaine or neurological mechanisms.
Common peroneal nerve (CPN) entrapment is the third most common nerve entrapment pathology in humans and frequently results in foot drop, characterized by difficulty lifting the front part of the foot.
Study Design and Methodology
This pilot study is a double-blinded, randomized trial involving 4 diabetic patients presenting bilateral anterior compartment weakness affecting dorsiflexion. All participants will have confirmed diabetic neuropathy with severe sensory impairment.
Key methodological elements:
Randomized administration of 0.5 cc of papaverine HCL (30 mg/ml) or 0.5 cc of 1% lidocaine without epinephrine.
Initial randomization of the first leg via coin toss, with the contralateral leg receiving the alternate medication.
Double-blinded design, ensuring neither patients nor evaluating physicians are aware of medication allocation for each leg.
Ultrasound-guided perineural injection at the fibular neck level.
Comprehensive pre- and post-injection assessments.
Study assessments include:
Macrovascular assessment:
Ultrasound Doppler waveform analysis.
Measurement of blood flow velocity in dorsalis pedis and posterior tibial arteries.
Microvascular assessment:
Kent Snapshot Near-Infrared (NIR) imaging of dorsal and plantar foot surfaces.
Measurement of hemoglobin, deoxyhemoglobin, oxygen saturation (SpO2), and total hemoglobin.
Imaging scheduled pre-injection, at 4 minutes post-injection, and at 10 minutes post-injection.
Motor function assessment:
Movement Against Manual Resistance (MAMR) scored from 1-5 (normalized to 0.2-1.0).
Evaluation of three muscles: extensor hallucis longus (EHL), tibialis anterior (TA), and extensor digitorum longus (EDL).
Dynamometer measurements of EHL muscle strength (Newtons, N).
Sensory assessment:
Two-point discrimination testing
- Conditions
- Drop Foot
- Being tested
- Infiltration of papaverine, Lidocaine infiltration
- Keywords
- Nerve entrapment, Drop foot
- Medical subject headings
- Peroneal Neuropathies, Nerve Compression Syndromes
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Infiltration of papaverineDrug
The study was randomized and double blinded. For randomization, the first extremity had either an infiltration of 0.5 cc of papaverine HCL (30mg/ml) for a 15mg perineural infiltration, or .5 cc of 1% lidocaine without epinephrine determined by a coin toss application.
Lidocaine infiltrationDrug
The study was randomized and double blinded. For randomization, the first extremity had either an infiltration of 0.5 cc of papaverine HCL (30mg/ml) for a 15mg perineural infiltration, or .5 cc of 1% lidocaine without epinephrine determined by a coin toss application.
| Study group | Role | What they receive |
|---|---|---|
| Lidocaine group | Active comparator | This arm is randomized to the laterality of the subject for either lidocaine or papaverine Receives: Drug: Lidocaine infiltration |
| Papavarine | Active comparator | This arm is randomized to the laterality of the subject for either lidocaine or papaverine, for the first infiltration. The contralateral extremity will then receive the agent that was not administered on the first side from randomization. Receives: Drug: Infiltration of papaverine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Manual Motor Strength Testing of Anterior Compartment
Movement Against Manual Resistance (MAMR) was evaluated using a scale of 1-5 out of 5. This was normalized so that 1/5 = 0.2, and 5/5=1.0. This was performed on three muscles of the anterior compartment, extensor hallusis longus (EHL), tibialis anterior (TA), and extensor digitorum longus (EDL) and the result for three muscles were averaged. In addition, the EHL was evaluated with a dynamometer, in Newtons (N) separately.
Measured: From enrollment to 1 day of testing
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Apr 2025
- Study start7 Mar 2024
- Primary completion7 Mar 2024
- Study completion1 Jul 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Drop FootStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 4 participants (actual)
Sponsor and investigators
- Lead sponsor
- US Neuropathy Centers
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Stephen Barrett, US Neuropathy Centers
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06919289
- Sponsor's protocol ID
- JIN-2025-0326
- Other IDs
- USNC-2025-3
- Status last verified
- Apr 2025
- First submitted
- 27 Mar 2025
- Last updated
- 9 Apr 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Barrett SL, Boyd B, DuCasse S, Nassier W, Mitchell N, Nagra AP, Dalmau-Pastor M, Yamasaki DS, Nickerson S. 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. BMC Musculoskelet Disord. 2024 Oct 23;25(1):840. doi: 10.1186/s12891-024-07972-3.
PubMed 39443927Barrett SL, Rader A, DuCasse S, Nagra A, Anderson K, Dalmau Pastor M, Yamasaki DS, Nickerson S. Quantifying the Phoenix Sign: A Double-Blind Pilot Study on Lidocaine and Papaverine-Induced Vascular and Motor Changes After Common Peroneal Nerve Block in Diabetic Neuropathy. J Am Podiatr Med Assoc. 2026 May 22;116(3):35. doi: 10.3390/japma116030035.
PubMed 42200998
Study at a glance
From the registry record, last updated by the sponsor on 9 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Quantifying the Phoenix Sign: A Comparative, Randomized Control Trial Analysis of Lidocaine and Papaverine-Induced Vascular Enhancement After Common Peroneal (Fibular) Nerve Blocks for the Diagnosis of a Focal Peripheral Nerve Entrapment
- ClinicalTrials.gov ID
- NCT06919289
- Acronym / sponsor ID
- JIN-2025-0326
- Conditions
- Drop Foot
- Keywords
- Nerve entrapment, Drop foot
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 4 participants (actual)
- Lead sponsor
- US Neuropathy CentersUniversity, hospital or other
- Study start
- 7 Mar 2024 (actual)
- Primary completion
- 7 Mar 2024 (actual)
- Study completion
- 1 Jul 2024 (actual)
- First posted
- 9 Apr 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This pilot study aims to investigate the effects of nerve blocks in patients with diabetic peripheral neuropathy through a double-blinded, randomized trial involving 4 patients. Each participant will receive bilateral peripheral nerve blocks using either lidocaine or papaverine. Following randomization, each patient will receive one medication in one leg and the alternate medication in the contralateral leg. Researchers will measure parameters including motor strength, sensory function (two-point discrimination), arterial blood flow via Doppler ultrasound, and microvascular perfusion using near-infrared spectroscopy both prior to and following nerve block administration. This research seeks to explore potential diagnostic and therapeutic applications for peripheral nerve entrapment, a common yet challenging clinical condition.
Detailed description
Detailed Analysis of the Phoenix Sign and Vascular Changes Following Nerve Blocks in Diabetic Neuropathy
Study Background and Purpose
This study investigates the vascular and neurological phenomena associated with peripheral nerve blocks in patients with diabetic neuropathy. The primary aim is to assess whether observed changes following nerve block administration can be attributed to vasodilatory effects of lidocaine or neurological mechanisms.
Common peroneal nerve (CPN) entrapment is the third most common nerve entrapment pathology in humans and frequently results in foot drop, characterized by difficulty lifting the front part of the foot.
Study Design and Methodology
This pilot study is a double-blinded, randomized trial involving 4 diabetic patients presenting bilateral anterior compartment weakness affecting dorsiflexion. All participants will have confirmed diabetic neuropathy with severe sensory impairment.
Key methodological elements:
Randomized administration of 0.5 cc of papaverine HCL (30 mg/ml) or 0.5 cc of 1% lidocaine without epinephrine.
Initial randomization of the first leg via coin toss, with the contralateral leg receiving the alternate medication.
Double-blinded design, ensuring neither patients nor evaluating physicians are aware of medication allocation for each leg.
Ultrasound-guided perineural injection at the fibular neck level.
Comprehensive pre- and post-injection assessments.
Study assessments include:
Macrovascular assessment:
Ultrasound Doppler waveform analysis.
Measurement of blood flow velocity in dorsalis pedis and posterior tibial arteries.
Microvascular assessment:
Kent Snapshot Near-Infrared (NIR) imaging of dorsal and plantar foot surfaces.
Measurement of hemoglobin, deoxyhemoglobin, oxygen saturation (SpO2), and total hemoglobin.
Imaging scheduled pre-injection, at 4 minutes post-injection, and at 10 minutes post-injection.
Motor function assessment:
Movement Against Manual Resistance (MAMR) scored from 1-5 (normalized to 0.2-1.0).
Evaluation of three muscles: extensor hallucis longus (EHL), tibialis anterior (TA), and extensor digitorum longus (EDL).
Dynamometer measurements of EHL muscle strength (Newtons, N).
Sensory assessment:
Two-point discrimination testing
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Lidocaine group | Active comparator | Drug: Lidocaine infiltrationThis arm is randomized to the laterality of the subject for either lidocaine or papaverine |
| Papavarine | Active comparator | Drug: Infiltration of papaverineThis arm is randomized to the laterality of the subject for either lidocaine or papaverine, for the first infiltration. The contralateral extremity will then receive the agent that was not administered on the first side from randomization. |
Who may qualify
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (1 listed)
- subjects were included if they were diabetic and neuropathic.
Key exclusion criteria (1 listed)
- Patients with Trypanophobia
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Infiltration of papaverineThe study was randomized and double blinded. For randomization, the first extremity had either an infiltration of 0.5 cc of papaverine HCL (30mg/ml) for a 15mg perineural infiltration, or .5 cc of 1% lidocaine without epinephrine determined by a coin toss application. | Drug | Papavarine |
| Lidocaine infiltrationThe study was randomized and double blinded. For randomization, the first extremity had either an infiltration of 0.5 cc of papaverine HCL (30mg/ml) for a 15mg perineural infiltration, or .5 cc of 1% lidocaine without epinephrine determined by a coin toss application. | Drug | Lidocaine group |
Primary outcome
Manual Motor Strength Testing of Anterior Compartment
Time frame: From enrollment to 1 day of testing
Movement Against Manual Resistance (MAMR) was evaluated using a scale of 1-5 out of 5. This was normalized so that 1/5 = 0.2, and 5/5=1.0. This was performed on three muscles of the anterior compartment, extensor hallusis longus (EHL), tibialis anterior (TA), and extensor digitorum longus (EDL) and the result for three muscles were averaged. In addition, the EHL was evaluated with a dynamometer, in Newtons (N) separately.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Apr 2025.
- Background: PubMed 39443927Barrett SL, Boyd B, DuCasse S, Nassier W, Mitchell N, Nagra AP, Dalmau-Pastor M, Yamasaki DS, Nickerson S. 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. BMC Musculoskelet Disord. 2024 Oct 23;25(1):840. doi: 10.1186/s12891-024-07972-3.
- Derived from this study: PubMed 42200998Barrett SL, Rader A, DuCasse S, Nagra A, Anderson K, Dalmau Pastor M, Yamasaki DS, Nickerson S. Quantifying the Phoenix Sign: A Double-Blind Pilot Study on Lidocaine and Papaverine-Induced Vascular and Motor Changes After Common Peroneal Nerve Block in Diabetic Neuropathy. J Am Podiatr Med Assoc. 2026 May 22;116(3):35. doi: 10.3390/japma116030035.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Infiltration of papaverine and Lidocaine infiltration in people with Drop Foot, run by US Neuropathy Centers at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 9 Apr 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Manual Motor Strength Testing of Anterior Compartment (time frame: From enrollment to 1 day of testing). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06919289, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Apr 2025.