Background: Fibromyalgia (FM) is a chronic disease, with no effective treatments for this disorder. The origin is suspected to be a misprocessing of signals in the central nervous system. One of the experimental treatments is very low intensity transcranial magnetic stimulation (LITMS) used to perform central neuromodulation.
Objectives: The main objective was to characterize the differences in oscillatory brain processing before and after LITMS in FM and compare the results with healthy controls.
Study design: This is an interventional study with control group, which shows how the treatment with LITMS could modify brain oscillatory activity and be useful for the improvement of symptoms in FM patients.
Methods: Thirty-three women with FM and 14 healthy controls are studied using magnetoencephalography recording, and mechanical stimuli are applied before and after treatment with transcranial magnetic stimulation. Changes in different brain areas and a specific brain frequency are studied, and the results are analyzed within and between patients, before and after treatment.
Results: In the FM group, an increase in alpha brain oscillatory activity was observed mainly in the dorsolateral prefrontal cortex (DLPFS), and more pronounced in the left hemisphere (P = 0.03). In addition, there was a significant improvement in the FM impact questionnaire in the patients (P < 0.01). When comparing patients with controls, it is observed that the differences in alpha frequency in this brain area disappear between groups.
Limitations: Age difference between patients and controls. Replicating the long-term results.
Conclusions: This treatment improves the patients' symptomatology, and also produces statistical changes in alpha brain activity in the DLPFS. Furthermore, a normalization was observed in this frequency and in this area, similar to that of the controls.
Keywords: central nervous system; chronic pain; cingulum; insula; magnetoencephalography; mechanical stimuli; oscillatory brain activity; prefrontal cortex; transcranial magnetic stimulation; Fibromyalgia.