Sciatic Block in Contralateral Limb Phantom and Residual Limb Pain

Phase 4TerminatedNCT05046639

Northwestern University1 enrolled

Overview

Participants with chronic, refractory phantom limb pain (PLP) or residual limb pain (RLP) for more than 6 months will be enrolled in this clinical trial. Aim: Define the attributable pain relief and functional improvement in participants with PLP/RLP after contralateral limb sciatic nerve block. Also, contribute to the basic science understanding of the crossed-withdraw reflex by demonstrating a known animal model phenomenon in human participants. Hypothesis: Contralateral limb sciatic nerve anesthetic block with 2% lidocaine provides immediate clinically meaningful pain reduction, defined as the proportion of patients with at least 50% improvement in numeric rating scale (NRS) pain score in PLP/RLP when compared to sham.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Enrollment

Conditions

Pain Amputation

Interventions

10 mL preservative free salineDRUG

Image guided sciatic nerve anesthetic block of the contralateral limb with an injection of 10 mL preservative free saline. Crossover treatment 5 days later using Image guided sciatic nerve anesthetic block of the contralateral limb with an injection of 10 mL 2% lidocaine.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * 1\. Age greater than 18 years of age at day of enrollment * 2\. Lower extremity amputation performed more than 12 months before study enrollment * 3\. PLP/RLP in affected amputated limb \> 4 on numeric rating scale 26 (NRS26) * 4\. Pain duration of more than 6 months despite a trial of conservative therapies for at least 2 months, including oral medications, topical medicines, physical therapy, and physical modalities (i.e., heat, cold, transcutaneous electrical nerve stimulation, phonophoresis) * 5\. Willingness to undergo image guided diagnostic nerve block Exclusion Criteria: * 1\. Refusal / inability to participate or provide consent * 2\. Contraindications to diagnostic nerve block * 3\. Non-neurogenic source of PLP/RLP * 4\. Current opioid use \> 50 morphine milligram equivalents per day * 5\. Any interventional pain treatment in the residual limb within the last 30 days * 6\. Severe uncontrolled medical condition (i.e., hypertensive crisis, decompensated hypothyroidism) * 7\. Use of investigational pain drug within past 30 days or other concurrent clinical trial enrollment

Outcomes

Primary Outcomes

Number of Participants Reporting ≥ 50% Improvement in NRS Pain Score

Proportions of Participants Reporting ≥ 50% Improvement in NRS pain score on a scale of 0 (no pain) to 10 (worst pain imaginable) from baseline at 15 minutes in treatment and sham groups.

Time frame: 15 minutes after treatment