Treatment of Erosive Digital Osteoarthritis by Transcutaneous Auricular Nerve Stimulation

Study Overview
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Brief Summary
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Erosive hand osteoarthritis (EHOA) is a subtype of had osteoarthritis characterized by inflammation and pain, with subsequent burden. Few symptomatic treatments are available in EHOA, while this population with EHOA has frequently comorbidities. Stimulation of the vagus nerve (VN), belonging to parasympathetic system, dampens pro-inflammatory cytokines production by splenic macrophages, through to the binding of acetylcholine neurotransmitter to α7nicotinic receptor on macrophages: this is the cholinergic anti-inflammatory pathway (CAP). Beyond its anti-inflammatory effects, VNS is analgesic in chronic pain disorders (headache, fibromyalgia). Beside implantable devices, VNS may be performed using transcutaneous stimulation of the ascendant auricular branch of the VN (tVNS) at the left ear localized on the cymba conchae tVNS is well-tolerated therapy avoiding invasive neurosurgery. The investigator do the hypothesis that auricular tVNS using a transcutaneous electrical nerve stimulation (TENS) device could be a novel, simple and well-tolerated analgesic and anti-inflammatory treatment of symptomatic EHOA.

Detailed Description
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In symptomatic and inflammatory EHOA patients, we will apply tNVNS using device from Schwa-Medico (TENSeco2 + auricular electrode + conductive gel) 25 Hz stimulation will be applied, intensity escalated up to 15 mA or below if tingling sensation. tVNS will be performed 1 hour daily for 1 month and we will assess EHOA symptoms (pain and function) at 1 month (end of the study)

Official Title
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Transcutaneous Auricular Vagus Nerve Stimulation in Erosive Hand Osteoarthritis

Conditions
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Erosive Osteo-Arthritis, Hand Osteoarthritis

Intervention / Treatment
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* Device: active tVNS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age≥18 years Symptomatic HOA (1990 American College of Rheumatology criteria) EHOA according to hand radiographs with ≥1 erosive digital joints of proximal or distal interphalangeal joint (phases E or R of Verbruggen-Veys score) Visual Analogic Scale (VAS) for hand pain ≥ 40/100 at inclusion -≥1 interphalangeal joints symptomatic ≥ 3 months despite analgesics or non-steroidal anti-inflammatory drugs (NSAIDs) (or contraindicated) ≥1 symptomatic interphalangeal joint with clinical palpable synovitis at inclusion Informed written consent Exclusion Criteria: Isolated thumb-base OA (ie, rhizarthrosis) Hand osteoarthritis secondary to other known causes (eg gout, psoriatic arthritis) Psoriasis Current skin disease of the ear Ear canal not adapted to apply the auricular electrode History of severe cardiac disease (coronary artery disease, rhythm disturbance, heart failure, valvulopathy) Conduction or rhythm disturbances on electrocardiogram Symptomatic orthostatic hypotension or vasovagal syncope history History of vagotomy Pregnancy Fibromyalgia Use of other electrically active medical devices (eg pacemaker) Documented sleep apnea Use of corticosteroid (oral, intramuscular, intra-articular or intravenous), immunosuppressive agents, hyaluronic acid injection in interphalangeal joint within the last 3 months Hand surgery planned during the study period Pregnancy or breastfeeding if applicable Oral NSAIDs consumption during the last 48 hours before inclusion

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: active arm with active tVNS for 1 month<br> | Device: active tVNS<br>* tVNS using TENS device from Schwa-Medico (TENSeco2) + auricular electrode applied on the left ear (Schwa-Medico) + conductive gel class I; 25 Hz stimulation 1 hour daily for 1 month<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Measure of Pain | Self-reported hand pain in the previous 48h measured on a 100 mm visual analogic scale (VAS). Scoring system: 0= No pain 5= Moderate pain 10= Worst pain | 1 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Function | questionnaire Functional Index for Hand OsteoArthritis (FIHOA): scale minimum 0 , and maximum 30. Scoring system of the FIHOA: 0 = possible without difficulty = possible with slight difficulty = possible with important difficulty = impossible | 1 month | 
| Side effect | Safety : report of side effects during the study period | 1 month | 
| Mean time of daily use and cumulative time of use from the device's tracker | Observance : Mean time of daily use and cumulative time of use during the 30 days before the 1 month visit collected from the device's tracker | 1 month | 
| Dose of daily consumption of paracetamol | Measure of Pain by daily consumption of paracetamol | 1 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Erosive hand osteoarthritis, pain, inflammation, vagus nerve stimulation