Diabetic Polyneuropathies, Other Polyneuropathies, Postherpetic Neuralgia
Conditions
Keywords
BOTULINUM TOXIN, NEUROPATHIC PAIN, RANDOMIZED CONTROLLED TRIAL
Brief summary
Pain due to peripheral nerve lesion remains extremely difficult to treat and current treatments have onl moderate efficacy and/or side effects. The investigators have previously demonstrated the long term efficacy of Botulinum toxin type A (BTX-A) in a small group of patients with post-traumatic/postherpetic neuralgia and allodynia. The present study aims to a/ confirm the efficacy of repeated applications of BTX-A in a larger group of patients with peripheral neuropathic pain with or without allodynia(primary outcome) ; b/ evaluate its mechanisms of action ; c/analyse the predictors of response ;d/analyse whether the second injection is associated with a therapeutic gain. This will be a randomized placebo controlled study. A total of 30 patients will be randomized to receive either BTX-A (subcutaneous injection in the painful area) or placebo. Each injection will be repeated within at least 3 months depending on the duration of efficacy. Skin punch biopsies will be performed before and 1 month after BTX-A administration. The investigators postulate that this study will confirm the clinical efficacy and good safety of repeated administrations of BTX-A in the treatment of peripheral neuropathic pain.
Interventions
DRUGbotulinum toxin type A
BTX A : 5 units/0.2 ml, maximum 300 units will be injected subcutaneous in the painful area ; this will be performed after randomization and within a minimum of 3 months interval depending on the duration of efficacy (maximum 6 months) Saline will be injected in the same volume in the painful area within the same frequency
Sponsors
Hospital Ambroise Paré Paris
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 85 Years
Healthy volunteers
No
Inclusion criteria
Men or women aged 18 to 85 years Spontaneous pain with a minimal intensity of 4/10 on numerical scle Pain present for at least 6 months Pain related to painful mononeuropathy or sensory polyneuropathy Able to understand the protocol and comply to the requirements of the study Written informed consent Painful area limited to a maximum of 240 cm2
Exclusion criteria
Facial pain Litigation (pending) Unstable condition responsible for neuropathic pain (ie, unstable immunological disease...) HIV or chemotherapy induced neuropathy Contraindications to BTX-A (neuromuscular disease, hypersensitivity, infection, coagulation disorder, pregnancy) Other pain more severe than neuropathic pain No compliance with the self diary Drug abuse or alcoholism Severe major depression Cognitive impairment Other research protocol within the last 30 days
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Average pain intensity on numerical scales in a self diary by the patient | every day from baseline for up to 6 months | Numerical scales (0-10) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Efficacy of treatment on neuropathic symptoms | at each visit | Neuropathic Pain Symptom Inventory will be used to assess symptoms |
| Quality of life VAS | at each visit | This will be assessed using the EuroQol questionnaire |
| Intensity of allodynia to brush | at each visit | This will performed using a brush |
| assessment of effects of BTX-A on substance P and CGRP | at baseline and 1 month after BTX-A or placebo | This will be performed using skin punch biopsies in the painful area |
| Detection and pain thresholds to mechanical and thermal stimuli and responses to suprathreshold stimuli | at each visit | this will use quantitative sensory testing (thermotest, Von Frey filaments) |
| Predictors of the response | Up to 6 months | We will assess the predictors of the response to BTX-A based on baseline pain thresholds, presence and severity of allodynia, skin punch biopsy and catastrophizing |
| Side effects | throughout the study and each each visit | side effects of BTX-A will be assessed |
Other
| Measure | Time frame | Description |
|---|---|---|
| Evaluate the therapeutic gain of the second injection | Throughout the study up to 6 months | Evaluate whether the second injection is associated with significant therapeutic gain on average pain intensity over 6 months |
| Evaluate pain relief at 24 weeks | 24 weeks | pain relief scale |
Countries
Brazil, France
Outcome results
None listed