Multi-Coil Repetitive Transcranial Magnetic Stimulation Reduces Fibromyalgia Pain

Multi-Coil Repetitive Transcranial Magnetic Stimulation Reduces Fibromyalgia Pain

ProHealth.com • July 12, 2013

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Shaped magnetic field pulses by multi-coil repetitive transcranial magnetic stimulation (rTMS) differentially modulate anterior cingulate cortex responses and pain in volunteers and fibromyalgia patients.

By Alexander Tzabazis, et al.
Abstract:

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) has shown promise in the alleviation of acute and chronic pain by altering the activity of cortical areas involved in pain sensation. However, current single-coil rTMS technology only allows for effects in surface cortical structures. The ability to affect activity in certain deep brain structures may however, allow for a better efficacy, safety, and tolerability.

This study used PET imaging to determine whether a novel multi-coil rTMS would allow for preferential targeting of the dorsal anterior cingulate cortex (dACC), an area always activated with pain, and to provide preliminary evidence as to whether this targeted approach would allow for efficacious, safe, and tolerable analgesia both in a volunteer/acute pain model as well as in fibromyalgia chronic pain patients.
METHODS:

• Part 1: Different coil configurations were tested in a placebo-controlled crossover design in volunteers (N = 16). Tonic pain was induced using a capsaicin/thermal pain model and functional brain imaging was performed by means of H215O positron emission tomography -- computed tomography (PET/CT) scans. Differences in NRS pain ratings between TMS and sham treatment (NRSTMS-NRSplacebo) which were recorded each minute during the 10 minute PET scans.

• Part 2: 16 fibromyalgia patients were subjected to 20 multi-coil rTMS treatments over 4 weeks and effects on standard pain scales (Brief Pain Inventory, item 5, i.e. average pain NRS over the last 24 hours) were recorded.

RESULTS:

• A single 30 minute session using one of 3 tested rTMS coil configurations operated at 1 Hz consistently produced robust reduction (mean 70% on NRS scale) in evoked pain in volunteers.

• In fibromyalgia patients, the 20 rTMS sessions also produced a significant pain inhibition (43% reduction in NRS pain over last 24 hours), but only when operated at 10 Hz. This degree of pain control was maintained for at least 4 weeks after the final session.

CONCLUSION: Multi-coil rTMS may be a safe and effective treatment option for acute as well as for chronic pain, such as that accompanying fibromyalgia. Further studies are necessary to optimize configurations and settings as well as to elucidate the mechanisms that lead to the long-lasting pain control produced by these treatments.
Source: Molecular Pain, July 2, 2013. By Alexander Tzabazis, Carina Mari Aparici, Michael C Rowbotham, M Bret Schneider, Amit Etkin and David C Yeomans.

http://www.prohealth.com/library/showarticle.cfm?libid=18208

Pain Med. 2011 Aug 3. doi: 10.1111/j.1526-4637.2011.01203.x. [Epub ahead of print]

Safety and Efficacy of Vagus Nerve Stimulation in Fibromyalgia: A Phase I/II Proof of Concept Trial.

Lange G, Janal MN, Maniker A, Fitzgibbons J, Fobler M, Cook D, Natelson BH.

Source

Departments of Radiology Psychiatry Neuroscience, UMDNJ-New Jersey Medical School, Newark, New Jersey Department of Veterans Affairs, New Jersey Health Care System, East Orange, New Jersey Departments of Neurosurgery Pain Medicine & Palliative Care, Beth Israel Medical Center, New York, New York Department of Epidemiology and Health Promotion, College of Dentistry, New York University, New York, New York William S. Middleton Memorial Veterans Hospital and the Department of Kinesiology, University of Wisconsin, Madison, Wisconsin, USA.

Abstract

Objective.  We performed an open-label Phase I/II trial to evaluate the safety and tolerability of vagus nerve stimulation (VNS) in patients with treatment-resistant fibromyalgia (FM) as well as to determine preliminary measures of efficacy in these patients. Methods.  Of 14 patients implanted with the VNS stimulator, 12 patients completed the initial 3-month study of VNS; 11 patients returned for follow-up visits 5, 8, and 11 months after start of stimulation. Therapeutic efficacy was assessed with a composite measure requiring improvement in pain, overall wellness, and physical function. Loss of both pain and tenderness criteria for the diagnosis of FM was added as a secondary outcome measure because of results found at the end of 3 months of stimulation. Results.  Side effects were similar to those reported in patients treated with VNS for epilepsy or depression and, in addition, dry mouth and fatigue were reported. Two patients did not tolerate stimulation. At 3 months, five patients had attained efficacy criteria; of these, two patients no longer met widespread pain or tenderness criteria for the diagnosis of FM. The therapeutic effect seemed to increase over time in that additional participants attained both criteria at 11 months. Conclusions.  Side effects and tolerability were similar to those found in disorders currently treated with VNS. Preliminary outcome measures suggested that VNS may be a useful adjunct treatment for FM patients resistant to conventional therapeutic management, but further research is required to better understand its actual role in the treatment of FM.
Wiley Periodicals, Inc.

PMID:

21812908

[PubMed - as supplied by publisher]

http://www.ncbi.nlm.nih.gov/pubmed/21812908