Optimize the Effects of Repetitive Transcranial Magnetic Stimulation on Neuropathic Pain

Zhejiang University

Status: Completed

Conditions: Neuropathic Pain; Repetitive Transcranial Magnetic Stimulation

Treatments: Device: Repetitive transcranial magnetic stimulation

Study type: Interventional

Funder types: Other

Identifiers

NCT05338554

2021-0752

Details and patient eligibility

About

Neuropathic pain (NP) is one type of refractory chronic pain condition,medical treatments for NP is limited because of its poorly response.Repetitive transcranial magnetic stimulation (rTMS) can induce neuroplastic changes which has been used to manage chronic pain conditions. Indeed, high-frequency (≥ 5 Hz) rTMS over the primary motor cortex (M1) is suggested to be able to reduce neuropathic pain in randomized controlled studies. Overall, the clinical application of rTMS in chronic pain is still limited by the response rate, whereby it is close to moderate and far from being excellent at its best. Therefore this project designed a series of clinical trials to optimize the analgesic efficacy of rTMS. According to the research results of investigators previous project, patients with neuropathic pain were divided into responders and non-responders after 5 consecutive days of 10HZ rTMS or pcTBS intervention (see project ID:2021-0751)according to the change of pain intensity, and then different trials will be applied to responders and non-responders to optimize the analgesic effect of rTMS.

Full description

For non-responders (whose visuo-analogic scale (VAS) decreased less than 20 mm or T1-T0/T0×100%<30%), a feasible method is to switch stimulation targets. So the investigator will change the stimulation target from M1 to dorsolateral prefrontal cortex (DLPFC), and then delivered another 5 days consecutive interventions to assess the efficacy.

For responders (whose VAS decreased an average of 20 mm or more or T1-T0/T0×100%≥30%), the investigator further investigate the long-lasting effect of rTMS. the patients will participate a continuous trials (2 sessions weekly for 2 weeks) and 4 weeks follow up.

Enrollment: 40 patients

Sex: All

Ages: 18 to 85 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• （1）woman or man over 18 years and under 85 years; （2）Clinical diagnosis of neuropathic pain (3) pain for at least 3 months, at least moderate intensity (≥ 4/10 assessed by VAS) ; (4) stable pharmacological treatment for pain at least 2 weeks before inclusion; (5) able to cooperate in completing questionnaire.

Exclusion criteria

• (1)Any clinically significant or unstable ongoing medical or psychiatric disorder including major depression; (2) History of substance abuse (alcohol, drugs); (3) Past treatment with repetitive transcranial magnetic stimulation (rTMS); (4) Contraindications to rTMS (previous severe head trauma or neurosurgical intervention, past or current epilepsy, active brain tumor, intracranial hypertension, implanted ferromagnetic devices, e.g., cardiac pacemaker, neurostimulator, or cochlear implants); (5) other type of pain more severe than neuropathic pain; (6) Any difficulty to fill out questionnaires (due to language or cognitive problems); (7) impossibility to be followed during the time course of the study;

Trial design

Primary purpose: Prevention

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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40 participants in 2 patient groups

pcTBS

Experimental group

Description:

The protocol is same as the previous study: pcTBS was administered to the left M1 at 80% resting motor threshold (RMT), consisting of a burst of 3 pulses given at 50 Hz repeated every 5 Hz using repetitive transcranial magnetic stimulation device . A total of 1,200 pulses were delivered with the TMS coil positioned in a posterior-anterior (PA) direction parallel to the midline.

Treatment:

Device: Repetitive transcranial magnetic stimulation

Device: Repetitive transcranial magnetic stimulation

10HZ rTMS

Experimental group

Description:

The protocol is same as the previous study: 10HZ rTMS included 15 trains of 10-second stimulation given at 10 Hz to the left M1 at 80% resting motor threshold (RMT) using repetitive transcranial magnetic stimulation device , with the inter-train interval being set to 50 seconds (1500 pulses)

Treatment:

Device: Repetitive transcranial magnetic stimulation

Device: Repetitive transcranial magnetic stimulation