The study with that finding, “Is high-frequency repetitive transcranial magnetic stimulation of the left primary motor cortex superior to the stimulation of the left dorsolateral prefrontal cortex in fibromyalgia syndrome?,” was published recently in Somatosensory & Motor Research.
Fibromyalgia is a complex condition characterized by widespread muscle pain, fatigue, sleep disturbance, and memory and mood issues. Although the specific causes underlying the development of fibromyalgia are still not clear, scientists believe the condition arises from a disturbance of the nervous system that changes the way the brain interprets sensations, especially painful stimuli.
Although there is no cure, and there is no so-called “gold standard” therapy for fibromyalgia, recent studies have shown that rTMS — a non-invasive technique in which nerve cells in the brain are stimulated with magnetic pulses — may be indicated to alleviate pain and depression associated with several neurological and psychiatric disorders.
“High-frequency rTMS of the prefrontal cortex (…) was found to be effective on pain reduction as well as improvement of depressive symptoms in fibromyalgic patients. It was suggested in a meta-analysis that [motor cortex] stimulation may be better in pain reduction and the dorsolateral prefrontal cortex may be better in depression improvement,” the investigators wrote.
Of note, the prefrontal cortex is a region responsible for higher thought processes, such as decision-making, planning and reasoning; the motor cortex is a region responsible for the control of voluntary movements.
In this study, a group of researchers from institutions in Turkey set out to test the therapeutic effectiveness of two different high-frequency rTMS methods on pain, fatigue, depression and quality of life in a group of women with fibromyalgia. One involved the pre-central motor cortex (left M1), and the other involved the dorsolateral prefrontal cortex (DLPFC).
The study enrolled 30 women with fibromyalgia who were randomly divided into three groups:
- The M1 group (10 women who completed 15 sessions of high-frequency rTMS [1,200 pulses of 10 Hz] applied to the left primary motor cortex);
- The DLPFC group (10 women who completed 15 sessions of high-frequency rTMS [1,200 pulses of 10 Hz] applied to the left dorsolateral prefrontal cortex);
- And the sham (control) group (10 women who completed 15 sessions of sham rTMS over three weeks).
Patients’ quality of life was determined based on the scores of the Fibromyalgia Impact Questionnaire (FIQ) and on the Short-form 36 (SF-36). All parameters were assessed at baseline (before intervention) and at the end of the study by a blinded (unknowing) expert.
Results showed significant improvements in perceived pain, depression and patients’ quality of life in women from all groups. However, improvements in depression, physical functioning and overall health were higher in women who received high-frequency rTMS, compared to those who were treated with sham rTMS.
Improvements in emotional functioning were observed only among women from the M1 group. Reduction in VAS scores associated with improvements in perceived pain were significantly higher in group M1 compared to the control group.
Conversely, improvements in physical functioning were higher among women from the DLPFC group, compared to those from the M1 group.
“To conclude, significant improvements in physical role functioning, physical functioning, depression and general health perceptions were achieved in active rTMS groups. We assume that further clinical studies on larger samples involving both the sexes and longer follow-up durations are needed to clarify the efficacy of different rTMS protocols on pain, fatigue, QoL [quality of life], and depression in patients with FMS [fibromyalgia syndrome],” the scientists concluded.