The Effect of Transcutaneous Posterior Tibial Nerve Stimulation in Patients With Fibromyalgia

The Effect of Transcutaneous Posterior Tibial Nerve Stimulation on Pain and Quality of Life in Patients With Fibromyalgia: a Single-blind, Randomized Controlled Trial

This study aimed to investigate the effectiveness of posterior tibial nerve stimulation (PTNS) in reducing pain, improving quality of life, and decreasing disease severity in patients with fibromyalgia.

This prospective, single-blind, randomized controlled trial included female patients newly diagnosed with fibromyalgia who had started duloxetine treatment (30 mg/day). Patients who met the inclusion criteria and agreed to participate in the study were randomized (1:1) into two groups. Group 1 (PTNS+duloxetine) underwent six sessions of posterior tibial nerve stimulation, twice weekly, 3-4 days apart, in addition to duloxetine (30 mg/day). Group 2 (duloxetine) received duloxetine only (30 mg/day). Randomization was performed manually, with assignments placed in opaque and sequentially numbered envelopes by off-site researchers who were not involved in patient care or follow-up. Outcome measures were assessed by two investigators who were blinded to each patient's group. The participants and nerve stimulators were not blinded to the group allocation. Patients were briefed to not disclose which group they were in during the assessment process.Patients in the study group received six sessions of posterior tibial nerve stimulation, twice weekly, 3-4 days apart, in addition to duloxetine; the controls received duloxetine only. The patients were evaluated three times (at baseline, 1st month, and 3rd month). Pain was evaluated using a numeric rating scale, the short-form McGill Pain Questionnaire, and quality of life with a 36-item Short-Form Health Survey (SF-36). Patient functional status and disease severity were evaluated using the fibromyalgia impact questionnaire (FIQ).

Posterior tibial nerve stimulation (PTNS), twice weekly, 3-4 days apart + Duloxetine 30 mg 1X1 p.o PTNS was applied using two 50 mm × 50 mm electrode pads per extremity. The live pad was placed superior to and medial to the medial malleolus. The ground pad was placed 5-10 cm proximal to the live pad. The PTNS was applied using biphasic square waves with a frequency of 10 Hz and pulse duration of 200 μs. The amplitude was adjusted to the level that produced painless paresthesia in each patient according to their tolerance. PTNS was applied for 30 minutes

PTNS was applied using two 50 mm × 50 mm electrode pads per extremity. The live pad was placed superior to and medial to the medial malleolus. The ground pad was placed 5-10 cm proximal to the live pad. The PTNS was applied using biphasic square waves with a frequency of 10 Hz and pulse duration of 200 μs. The amplitude was adjusted to the level that produced painless paresthesia in each patient according to their tolerance. PTNS was applied for 30 minutes Duloxetine 30 mg p.o 1X1 (daily)

NRS was used to evaluate the patients' general pain at rest and during activity (during activities of daily living). Patients were asked to rate their pain from 0 to 10, with 0 indicating no pain and 10 indicating the most severe pain

This questionnaire was used to assess the patients' pain. This questionnaire consisted of 15 descriptive words that evaluated the sensory (11) and affective (4) dimensions of pain. Pain intensity was evaluated as follows: 0=none, 1=mild, 2=moderate, and 3=severe. Three pain scores were obtained: sensory, affective, and total (both sensory and affective). The total present pain intensity index was evaluated using a 6-point Likert rating scale. (0 = no pain, 1 = mild, 2 = discomforting, 3 = distressing, 4 = horrible, and 5 = excruciating)

This questionnaire consists of 20 questions evaluating physical function, job status, depression, anxiety, sleep, pain, stiffness, fatigue, and well-being of patients with fibromyalgia. It was scored between 0 and 100. High scores indicate high disease severity and low functional status.

This scale is commonly used to evaluate the quality of life. It consists of eight subscales (physical function, physical role limitation, pain, general health, vitality, social function, social role limitation, and mental health) and a total of 36 items. Each subscale was scored between 0 and 100, with 100 points indicating the best health condition and 0 points indicating the worst health condition

Inclusion Criteria: Female patients aged between 18 and 65 years, newly diagnosed according to the American Rheumatology Association 2016 revised FMS diagnostic criteria Patients who come regularly to sessions for posterior tibial nerve stimulation. Exclusion Criteria: History of fracture/musculoskeletal surgery in the last 3 years Inflammatory joint disease, or neurological disease/neurological deficit with examination Receiving medical treatment for polyneuropathy Contraindications to PNS (pacemaker, epilepsy, diminished skin sensation in the area to be applied).

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