Limb Pain, Phantom
Conditions
Brief summary
This research is being done to determine if an anesthetic like Lidocaine, may be effective when injected around the sciatic nerve of the intact limb in patients with limb loss pain on the contralateral side.
Interventions
DRUGLidocaine
2 teaspoons of 2% lidocaine injection
DRUGPlacebo
Saline injection
Sponsors
Mayo Clinic
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Lower extremity amputation performed more than 12 months before study enrollment * PLP/RLP in affected amputated limb \> 4 on NRS26 * 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) * Willingness to undergo image guided diagnostic nerve block
Exclusion criteria
* Refusal / inability to participate or provide consent * Contraindications to diagnostic nerve block * Non-neurogenic source of PLP/RLP * Current opioid use \> 50 morphine milligram equivalents per day * Any interventional pain treatment in the residual limb within the last 30 days * Severe uncontrolled medical condition (i.e., hypertensive crisis, decompensated hypothyroidism) * Use of investigational pain drug within past 30 days or other concurrent clinical trial enrollment
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in pain | Baseline, 60 minutes post injection | Measured using self-reported Numerical Rating Scale (NRS) where 0=no pain and 10=worst pain. |
| Change in Functional Improvement | Baseline, 5 days post-injection | Measured using self-reported 20-item Orthotic and Prosthetics User's Survey (OPUS) Lower Extremity Functional Status Measurement survey. Total scores range from 0-100 scale with higher scores indicating a better outcome. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in disability | Baseline, 5 days post-injection | Measured using self-reported 18-item The Groningen Activity Restriction Scale (GARS) that is a general disease independent instrument for measuring disability. Total scores range from 18-72. The higher the score the greater the disability. |
| Change in Pressure-Pain Algometry | Baseline, 5 days post-injection | Qualified study personnel will measure pain pressure threshold three times at each visit with an algometer on the participant's residual limb at the point of a maximal pain as indicated by the participant during pre-block physical examination, reported in kilopascal (kPa). |
| Step Count | 5 days post-injection | Number of daily steps recorded by Modus StepWatch™ or Evolution EvoWalk™ fitted to the participant's prostheses |
Countries
United States
Outcome results
None listed