Efficacy and tolerability in patients with chronic facial pain of two consecutive treatment periods of rTMS applied over the facial motor cortex, using protocols differing in stimulation frequency, duration, and train pattern

One session of repetitive transcranial magnetic stimulation induces mild and transient analgesic effects among female individuals with painful temporomandibular disorders

OBJECTIVE

Temporomandibular disorders (TMD) are characterised by chronic pain and dysfunction in the jaw joint and masticatory muscles. Repetitive transcranial magnetic stimulation (rTMS) has emerged as a potential non-invasive treatment for chronic pain; however, its effectiveness in individuals with TMD has not been thoroughly investigated. This study aimed to evaluate the immediate and sustained (over seven consecutive days) effects of a single session of active rTMS compared to sham stimulation on pain intensity and pain unpleasantness in individuals with TMD.

METHODS

A randomised, double-blind, sham-controlled trial enrolled 41 female participants with chronic TMD. Pain intensity and pain unpleasantness were assessed immediately pre- and post-intervention, as well as twice daily for 21 days using electronic diaries. Secondary outcomes included pain interference, sleep quality, positive and negative affect and pain catastrophizing. Adverse effects were monitored. Repeated measures ANOVA and multilevel modelling regression analyses were employed for data analysis.

RESULT

Active rTMS demonstrated a significant immediate mild reduction in pain intensity and pain unpleasantness compared to sham stimulation. However, these effects were not sustained over the 7-day post-intervention period. No significant differences were observed between interventions for pain interference, sleep quality and negative affect. A minority of participants reported minor and transient side effects, including headaches and fatigue.

CONCLUSION

A single session of active rTMS was safe and led to immediate mild analgesic effects in individuals with TMD compared to sham stimulation. However, no significant differences were observed between interventions over the 7-day post-intervention period. Based on this study, rTMS stimulation appears to be a promising safe approach to be tested in TMD patients with longer stimulation protocols.

Brain stimulation for chronic pain management: a narrative review of analgesic mechanisms and clinical evidence

Chronic pain constitutes one of the most common chronic complaints that people experience. According to the International Association for the Study of Pain, chronic pain is defined as pain that persists or recurs longer than 3 months. Chronic pain has a significant impact on individuals' well-being and psychosocial health and the economy of healthcare systems as well. Despite the availability of numerous therapeutic modalities, treatment of chronic pain can be challenging. Only about 30% of individuals with non-cancer chronic pain achieve improvement from standard pharmacological treatment. Therefore, numerous therapeutic approaches were proposed as a potential treatment for chronic pain including non-opioid pharmacological agents, nerve blocks, acupuncture, cannabidiol, stem cells, exosomes, and neurostimulation techniques. Although some neurostimulation methods such as spinal cord stimulation were successfully introduced into clinical practice as a therapy for chronic pain, the current evidence for brain stimulation efficacy in the treatment of chronic pain remains unclear. Hence, this narrative literature review aimed to give an up-to-date overview of brain stimulation methods, including deep brain stimulation, motor cortex stimulation, transcranial direct current stimulation, repetitive transcranial magnetic stimulation, cranial electrotherapy stimulation, and reduced impedance non-invasive cortical electrostimulation as a potential treatment for chronic pain.