Interventional Neuromodulation in Fibromyalgia

This is a prospective double randomized controlled trial that was conducted in Tanta and Assiut University hospitals during the period from 1st October 2022 to the end of March 2023. Sixty four 64 patients with fibromyalgia were recruited from outpatient clinics of Physical Medicine, Rheumatology and Rehabilitation and Neuropsychiatry Departments, Tanta and Assiut University Hospitals. The diagnosis of fibromyalgia was done according to American College of Rheumatology criteria or other standard criteria.

Twenty two cases didn't meet the inclusion and exclusion criteria were excluded: 8 of them had systemic diseases, 5 patients refuse to participate, 4 had contraindication for magnetic stimulation, and 5 cases had primary psychiatric disorders. Forty two cases were eligible and allocated into one of the two groups (1:1 ratio) active rTMS group and sham rTMS group. One case from each group didn't complete the follow up study due to headache and the remaining 20 cases in each group completed the study.

Each patient was subjected to history taking including age of symptoms onset and duration, complete clinical and neurological examination neurological examinations. Fibromyalgia Impact Questionnaire (FIQ) was assessed at base line. Besides, baseline Sleep quality and sleep characteristics assessment using the Pittsburgh Sleep Quality Index (PSQI) and The Medical Outcomes Study Sleep Scale (MOS Sleep Scale) respectively .

Randomization All qualified members were haphazardly doled out to one of the two groups. Assignment concealment was done utilizing serially numbered closed, enigmatic envelopes. Each patient was given a serial number from a computer-created randomization table and was put within the suitable group after opening the congruent closed envelope. Counseling for participation was conducted before enrollment.

Procedure of repetitive transcranial magnetic stimulation (rTMS):

Forty two fibromyalgia patients who had regular appropriate trial of medical treatment for at least 3 months, underwent 20 sessions of 30 minutes duration for each session of low frequency real or active rTMS at a rate of 5 sessions per week over 4 consecutive weeks, they were carried out by a qualified expert in this field. The transcranial magnetic stimulation sessions were carried out using the MAGSTIM TMS equipment (Company Limited, Whitland, wales, UK). The apparatus consists of a stimulator and a coil connected to the stimulator by a thick , insulated cable. The investigators used the figure of eight or butterfly coil. It's constructed of two circular coils, about 7 cm in diameter, mounted next to each other.

The experimental group received real rTMS as follow: The intensity of the stimulus employed in treatment has used the motor threshold (MT) as the basic measure. To determine the MT, the coil is placed over the motor cortex and moved until the smallest possible impulse produces a visible movement of the thumb, wrist or fingers. The MT is used as a measurement index because the motor cortex is the only brain region which gives an easily detected signal [muscle twitch] when depolarized . The main stimulation parameters were 24 trains at120% of motor threshold for 60 seconds at 1 Hz and a 45-second interval between trains. The investigators subsequently provided a total of 1,200 pulses at each of the 20 sessions. The stimulation area was the right dorsolateral prefrontal area that was defined as the region 5 cm rostral in the same sagittal plane as the optimal site for MT production in the first dorsal interosseous .

The sham rTMS group received the same protocol of active group however the coil held perpendicular to the scalp. The investigator responsible for delivering rTMS had no contact with the patients, ensuring a double-blind procedure.

Polysomnography Evaluation:

All patients at baseline on medical ttt alone(before rTMS sessions), were subjected to one night Polysomnography:. PSG was performed by a Nihon Kohden corporation (1-31-4 Nishiochiai, Shinjuku-Ku, Tokyo 161-8560,Japan, SN: 04142: 2018). The PSG involved EEG channels montages (O1/A2, C3/A2, C4/A1 and O2/A1), electrooculography (LOC-A1/A2 and ROC-A1/A2), surface tibial and submental EMG(electromyography), and modified V2 lead ECG. Thermal airflow sensors (thermistors) were utilized for nasal and oral signals and the amplifier was connected for tracheal sound appraisal. Chest and abdominal endeavors were measured by double thoracoabdominal RIP (respiratory inductance plethysmography) belts. PSG parameters (Sleep latency, Apnea hypopnea index, Sleep efficiency , Arousal index , Total sleep time(TST), Wake after sleep onset, Wake % TST, N1 % TST, N2%TST, N3%TST, REM(rapid eye movement) %TST, PLMs(periodic limb movements) index) were scored by a PSG technician and interpreted by a trained, expert sleep medicine physician according to The American Academy of Sleep Medicine guidelines . Apneas and hypopneas were defined according to standard methods .