Effects of Percutaneous Peripheral Nerve Stimulation on Neck and Low Back Pain

Study Overview
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Brief Summary
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Percutaneous Peripheral Nerve Stimulation (pPNS) is a physical therapy technique, whose main objective is to treat neuro-musculo-skeletal signs and symptoms by applying a current to a peripheric nerve with a blunt dry needle. Despite its clinical use being already stablished, its use in pathologic subjects is still unknown and, thus, so is its optimal parameterization. The present study proposes to perform two different protocols of peripheral nerve stimulation on neck and low back pain subjects to answer those questions and compared it towards a control group receiving a standard intervention.

Detailed Description
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Intervention will be performed on the Spinal Nerve (for neck pain subjects) and Inferior Gluteal Nerve and Tibial Nerve (for low back pain subjects), using ultrasonography to guide the needle insertion, without risk of affecting any adjacent structure. The theoretical basis of the technique is to produce analgesia by making controlled changes in the somatosensory system using synaptic plasticity, to ultimate affect the perception of pain through reduction of nociception afference. The protocols will be the following: Intervention Group 1: Sensory Threshold, high frequency in trains (ST-bHF). 5 trains of 5 seconds, separated by 55 seconds from each other, at a frequency of 100 hertz (Hz), making 5 minutes of total treatment. The intensity will be set at patient's sensory threshold, ensuring a non-painful perception. Intervention Group 2: Theta-Burst Stimulation (TBS). 40 trains separated 10 seconds apart, where each train contains 5 trains separated by 200ms, at a frequency of 5 hertz, resulting in 6 minutes and 45 seconds of total intervention. The intensity will be set at patient's motor threshold, ensuring a non-painful stimulation. Intervention Group 3: Transcutaneous electrical nerve stimulation (TENS), at a frequency of 80 hertz and a pulse width of 250 microseconds, for 15 minutes. The intensity will be set at the detection threshold of each patient, generating a sensitive but not painful sensory but not painful. The study will be a randomised quadruple-blind clinical trial. Two pPNS protocols (ST-bHF, TBS) and a third TENS protocol (TENS) will be compared. To study the effects of these protocols on pain, strength, functionality and electromyographic activity, three measurements will be performed: pre-intervention (Numerical Pain Scale (NRS), NRS for induced pain, Maximal strength + EMG), during the intervention (EMG) and immediately post-intervention (NRS, NRS for induced pain, Maximal strength + EMG). In addition, one week later, subjects will be asked for a pain NRS to assess the mid-term treatment effect.

Official Title
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Effects of Percutaneous Peripheral Nerve Stimulation on Neck and Low Back Pain: a Quadruple-blinded, Randomized Clinical Trial

Conditions
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Neck Pain, Low Back Pain

Intervention / Treatment
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* Other: Sensory Thresold, Burst High Frecuency
* Other: Theta-Burst Stimulation
* Other: Transcutaneous Electrical Nerve Stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adults (+18 years) Patients with non-specific/mechanical/articular neck pain. Patients with non-specific/mechanical/articular low back pain and/or low back pain accompanied by radicular symptomatology or sciatica. Exclusion Criteria: Pregnancy. Severe illnesses: diabetes, cancer, neurological diseases, depression, etc... Balanophora (needle phobia). Professional athlete. Other concomitant physiotherapy treatment for this pathology. Patients with neck or low back pain associated with severe bone damage such as fractures or vertebral fissures.

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
Allocation: Randomized
Intervention Model: Factorial Assignment
Interventional Model Description: Randomised quadruple-blind clinical trial, with three intervention groups
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sensory Threshold, Burst High Frequency<br>The technique consists of percutaneous peripheral electrical stimulation on the Spinal or Inferior Gluteal and Tibial Nerve through a ultrasound-guided needle. | Other: Sensory Thresold, Burst High Frecuency<br>* The ultrasound guided percutaneous peripheral nerve stimulation will be applied to the Spinal or Inferior Gluteal and Tibial Nerve. The parameters will be 5 trains of 5 seconds, 55 seconds apart, at a frequency of 100Hz, making 5 minutes of total treatment. The intensity will be set 200 microamperes (μA) above the detection threshold for each patient, guaranteeing a sensitive but not painful perception.<br>|
| Experimental: Theta-Burst Stimulation<br>The technique consists of percutaneous peripheral electrical stimulation on the Spinal or Inferior Gluteal and Tibial Nerve through a ultrasound-guided needle. | Other: Theta-Burst Stimulation<br>* The ultrasound guided percutaneous peripheral nerve stimulation will be applied to the Spinal or Inferior Gluteal and Tibial Nerve. The parameters will be 40 trains separated by 7 seconds from each other, where each train contains 5 trains separated by 200ms, at a frequency of 5Hz, resulting in 6 minutes and 45 seconds of total treatment. The intensity will be set at the motor threshold of the patient, ensuring a non-painful stimulation.<br>|
| Active Comparator: Transcutaneous Electrical Nerve Stimulation<br>The technique consists of transcutaneous electrical nerve stimulation on the trapezius or low back and internal calf muscles through surface electrodes. | Other: Transcutaneous Electrical Nerve Stimulation<br>* The transcutaneous electrical nerve stimulation will be applied on the trapezius or low back and internal calf muscles at a frequency of 80Hz and a pulse width of 250 microseconds, for 15 minutes. The intensity will be set at the detection threshold of each patient generating a sensitive but non-painful perception.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Pain | The subject will verbally report the pain intensity suffered along the last week according to the Numeric rate scale (NRS): 0 will be any pain and 10 will be the maximal perception of pain. | Pre-intervention and immediately after the intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Demographic questionnaire | Patients will fill a demographic data questionnaire with descriptive variables such as age, sex, work, time with pain, concomitant pathologies, level of sporting activity, toxic habits and drugs. | Pre-intervention | 
| Change in pain | The subject will verbally report a mean of the last week pain intensity according to the Numeric rate scale (NRS) from 0 to 10: 0 will be any pain and 10 will be the maximal perception of pain. One week after the intervention, and after having received a conventional physiotherapy treatment, subjects will verbally report a mean of the last week pain intensity according to the Numeric rate scale (NRS). | Pre-intervention and one week after the intervention | 
| Change in pain evoked with movement | Participants will be asked to perform a motion that evokes pain related to their pathology. After performing the movement, the pain perception will be obtained from 0 to 10 according to the NRS scale: 0 will be any pain and 10 will be the maximal perception of pain. | Pre-intervention and immediately after the intervention | 
| Change in maximum strength during muscle contraction with dynamometer | The maximum strength achievable given the condition will be assessed by means of a dynamometry test. Neck pain subjects will stand up and perform a maximum voluntary trapezius contraction by raising the shoulder towards the ceiling. Low back pain subjets will be in prone position, resting the trunk on the bed, but no the lower limbs, that will be resting on the floor. They will perform a maximum voluntary unilateral hip extension with the homolateral leg extended and the other leg resting on the floor. In order to not influence the measurement, all subjects will receive the same instructions on how to perform the contraction: fast and hard, and will be encouraged during the task. Three test will be performed, and a first familiarisation test will be discarded. The rest between measurements will be 1 minute. | Pre-intervention and immediately after the intervention | 
| Change in surface electromyography signal during muscle contraction | Electrical activity of trapezius muscle (descending fibres) or gluteus maximus muscle will be measured synchronously with strength. Electromyography measurement will be performed in order to collect the muscle excitation signal during the muscle contraction. For the trapezius, electrodes will be placed in the middle of an imaginary line joining prominences of the acromion and C7's spinous apophysis. For the gluteus maximus, the electrodes will be placed in the middle of an imaginary line joining prominences of the sacrum and trochanter. | Pre-intervention and immediately after the intervention | 
| Surface electromyography signal during stimulation | Electrical activity of trapezius muscle (descending fibres) or gluteus maximus and internal calf muscle will be measured synchronously with treatment application. Electromyography measurement will be performed in order to collect the muscle excitation signal during the electrical stimulation. For the trapezius, the electrodes will be placed in the middle of an imaginary line joining prominences of the acromion and C7's spinous apophysis. For the gluteus maximus, the electrodes will be placed in the middle of an imaginary line joining prominences of the sacrum and trochanter. For the inner calf, a plantar flexion will be requested to the subject to visualize the center of the muscle belly, where the electrodes will be placed. | During intervention | 
| Treatment-evoked perceptions questionnaire | After the stimulation, subjects will be asked about their perceptions related to sensations during stimulation (pleasant- displeasing- indifferent), contraction of the area during the treatment (increasingly- decreasingly- equal), and changes in the strength of the treated area (more- less- equal). | Immediately after the intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Percutaneous peripheral nerve stimulation, Sensorimotor effects, Neck pain, Transcutaneous electrical nerve stimulation, Theta burst stimulation, Low back pain