Effects of Percutaneous Neuromodulation on Plasticity in the Somatosensory System in Healthy Subjects
Condition: Healthy
Study type: Interventional

Summary: 
      Echography guided percutaneous neuromodulation is a physical therapy technique, whose main
      objective is the treatment of pain with direct stimulation of the peripheral nerves using a
      rome needle of acupuncture as an active electrode for applying currents of
      electrostimulation.

      The neurophysiological basis and the effects on the sensory and motor systems of this
      technique are not characterised. The present study proposes to perform the intervention on
      the area adjacent to the median nerve and to apply different stimulation protocols on healthy
      subjects to answer those questions.
    

Detailed description: 
      Intervention is going to be performed in the medial side of the arm, where the median nerve
      is accessible to the intervention. The theoretical basis of the technique is to produce
      specific controlled changes in the somatosensory system using synaptic plasticity, to
      ultimate affect the perception of pain through reduction of nociception afference.
      Subsequently, the protocols are based on synaptic physiology and the circuitry of the
      somatosensory system.

      The protocols are the following:

        1. - low-frequency and high-intensity of stimulation: 2hz during 16 min at an slightly
           annoying intensity, to induce synaptic depression on the c-fibers circuit, presumably
           carrying nociception.

        2. - high-frequency and low-intensity of stimulation: 100 hz in 5 second trains, separated
           by 1 min of no current with a perceptible but mild intensity, to induce potentiation of
           a-beta fibers, presumably englobing mechanoreceptors which inhibit nociception through
           gate control in the spinal cord.

        3. - placebo group has got the same intervention, but without current.

      The study design is an experimental clinical trial, with randomized order of intervention
      with repeated measurements. This means each subject is having the three protocols at
      randomized order, with a gap of at least two weeks between them. The study is triple-blinded.

      Somatomotor system variables, as sensory and pain pressure thresholds, grip strength, surface
      electromyographic activity and blood flow are evaluated on the hand of the subject. The arm
      to treat was also randomized for each subject The measurements are pre-intervention,
      post-intervention and 24 hours after the intervention for each protocol. Blood flow are
      measured only pre-intervention and post-intervention.
    

Intervention name(s): Ultrasound guided percutaneous neuromodulation
Intervention type(s): Other
Intervention description(s): It is a technique that consists in the electrical stimulation of peripheral nerve trunks, inserting an acupuncture needle in its path and using it as an electrode to apply electrical current
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Randomized intervention of repeated measures, quadruple-blinded
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Echography guided percutaneous neuromodulation; Plasticity; somatomotor system; Peripheral nerve stimulation; Pain