A randomized placebo-controlled study of noninvasive cortical electrostimulation in the treatment of fibromyalgia patients.

OBJECTIVE: The aim of this multicenter study was to evaluate the efficacy, safety, and tolerability of noninvasive cortical electrostimulation in the management of fibromyalgia (FM). DESIGN: A prospective, randomized, double-blind, placebo-controlled design was used. Setting. Subjects received therapy at two different outpatient clinical locations. PATIENTS: There were 77 subjects meeting the American College of Rheumatology 1990 classification criteria for FM. Intervention. Thirty-nine (39) active treatment (AT) FM patients and 38 placebo controls received 22 applications of either noninvasive cortical electrostimulation or a sham therapy over an 11-week period. OUTCOME MEASURES: The primary outcome measures were the number of tender points (TePs) and pressure pain threshold (PPT). Secondary outcome measures were responses to the Fibromyalgia Impact Questionnaire (FIQ), Symptom Checklist-90 (SCL-90), Beck Depression Inventory-II, and a novel sleep questionnaire, all evaluated at baseline and at the end of treatment. RESULTS: Intervention provided significant improvements in TeP measures: compared with placebo, the AT patients improved in the number of positive TePs (-7.4 vs -0.2, P<0.001) and the PPT (19.6 vs -3.2, P<0.001). Most secondary outcomes also improved more in the AT group: total FIQ score (-15.5 vs -5.6, P=0.03), FIQ pain (-2.0 vs -0.6, P=0.03), FIQ fatigue (-2.0 vs -0.4, P=0.02), and FIQ refreshing sleep (-2.1 vs -0.7, P=0.02); and while FIQ function improved (-1.0 vs -0.2), the between-group change had a 14% likelihood of occurring due to chance (P=0.14). There were no significant side effects observed. CONCLUSIONS: Noninvasive cortical electrostimulation in FM patients provided modest improvements in pain, TeP measures, fatigue, and sleep; and the treatment was well tolerated. This form of therapy could potentially provide worthwhile adjunctive symptom relief for FM patients.

Quantitative electroencephalographic abnormalities in fibromyalgia patients.

There is increasing acceptance that pain in fibromyalgia (FM) is a result of dysfunctional sensory processing in the spinal cord and brain, and a number of recent imaging studies have demonstrated abnormal central mechanisms. The objective of this report is to statistically compare quantitative electroencephalogram (qEEG) measures in 85 FM patients with age and gender matched controls in a normative database. A statistically significant sample (minimum 60 seconds from each subject) of artifact-free EEG data exhibiting a minimum split-half reliability ratio of 0.95 and test-retest reliability ratio of 0.90 was used as the threshold for acceptable data inclusion. FM subject EEG data was compared to EEGs of age and gender matched healthy subjects in the Lifespan Normative Database and analyzed using NeuroGuide 2.0 software. Analyses were based on spectral absolute power, relative power and coherence. Clinical evaluations included the Fibromyalgia Impact Questionnaire (FIQ), Beck Depression Inventory and Fischer dolorimetry for pain pressure thresholds. Based on Z-statistic findings, the EEGs from FM subjects differed from matched controls in the normative database in three features: (1) reduced EEG spectral absolute power in the frontal International 10-20 EEG measurement sites, particularly in the low- to mid-frequency EEG spectral segments; (2) elevated spectral relative power of high frequency components in frontal/central EEG measurement sites; and (3) widespread hypocoherence, particularly in low- to mid-frequency EEG spectral segments, in the frontal EEG measurement sites. A consistent and significant negative correlation was found between pain severity and the magnitude of the EEG abnormalities. No relationship between EEG findings and medicine use was found. It is concluded that qEEG analysis reveals significant differences between FM patients compared to age and gender matched healthy controls in a normative database, and has the potential to be a clinically useful tool for assessing brain function in FM patients.

New views of myofascial trigger points: etiology and diagnosis.

Two studies appearing in Archives, one by Shah and colleagues and another one by Chen and colleagues, present groundbreaking findings that can reduce some of the controversy surrounding myofascial trigger points (MTPs). Both author groups recognize the ubiquity of this disease and the importance to patients of health care professionals becoming better acquainted with the cause and identification of MTPs. The integrated hypothesis is the most credible and most complete proposed etiology of MTPs. However, the feedback loop suggested in this hypothesis has a few weak links, and studies by Shah and colleagues in particular supply a solid link for one of them. The feedback loop connects the hypothesized energy crisis with the milieu changes responsible for noxious stimulation of local nociceptors that causes the local and referred pain of MTPs. Shah's reports quantify the presence of not just 1 noxious stimulant but 11 of them with outstanding concentrations of immune system histochemicals. The results also strongly place a solid histochemical base under the important clinical distinction between active and latent MTPs. The study by Chen on the use of magnetic resonance elastography (MRE) imaging of the taut band of an MTP in an upper trapezius muscle may open a whole new chapter in the centuries-old search for a convincing demonstration of the cause of MTP symptoms. MRE is a modification of existing magnetic resonance imaging equipment, and it images stress produced by adjacent tissues with different degrees of tension. This report seems to present an MRE image of the taut band that shows the chevron signature of the increased tension of the taut band compared with surrounding tissues.

Review of enigmatic MTrPs as a common cause of enigmatic musculoskeletal pain and dysfunction.

This article explores how myofascial trigger points (MTrPs) may relate to musculoskeletal dysfunction (MSD) in the workplace and what might be done about it. The cause of much MSD and pain is often enigmatic to modern medicine and very costly, just as the cause of MTrPs has been elusive for the past century, despite an extensive literature that is confusing because of restricted regional approaches and a seemingly endless variety of names. MTrPs are activated by acute or persistent muscle overload, which is characteristic of MSD in the workplace. MTrPs can involve any, and sometimes many, of the skeletal muscles in the body and are a major, complex cause of musculoskeletal pain. The clinical and etiological characteristics of MTrPs have been underexplored by investigators, leading to undertraining of health care professionals, underappreciation of their clinical importance. MTrPs have no gold standard diagnostic criterion, and no routinely available laboratory or imaging test. MTrPs require a specific non-routine examination and muscle-specific treatment for prompt relief when acute, and also resolution of perpetuating factors when chronic. After identifying a critical false assumption, electrodiagnostic studies are now making encouraging progress toward clarifying the etiology of MTrPs based on the 5- or 6-step positive-feedback model of the integrated hypothesis. Specific research needs are noted. MTrPs are treatable and they deserve increased attention and consideration by research investigators and clinicians.

Endplate potentials are common to midfiber myofacial trigger points.

OBJECTIVES: To compare the prevalence of motor endplate potentials (noise and spikes) in active central myofascial trigger points, endplate zones, and taut bands of skeletal muscle to assess the specificity of endplate potentials to myofascial trigger points. DESIGN: This nonrandomized, unblinded needle examination of myofascial trigger points compares the prevalence of three forms of endplate potentials at one test site and two control sites in 11 muscles of 10 subjects. The endplate zone was independently determined electrically. Active central myofascial trigger points were identified by spot tenderness in a palpable taut band of muscle, a local twitch response to snapping palpation, and the subject's recognition of pain elicited by pressure on the tender spot. RESULTS: Endplate noise without spikes occurred in all 11 muscles at trigger-point sites, in four muscles at endplate zone sites outside of trigger points (P = 0.024), and did not occur in taut band sites outside of an endplate zone (P = 0.000034). CONCLUSIONS: Endplate noise was significantly more prevalent in myofascial trigger points than in sites that were outside of a trigger point but still within the endplate zone. Endplate noise seems to be characteristic of, but is not restricted to, the region of a myofascial trigger point.

Focused review: myofascial pain.

Myofascial pain is defined as pain that originates from myofascial trigger points in skeletal muscle. It is prevalent in regional musculoskeletal pain syndromes, either alone or in combination with other pain generators. The appropriate evaluation and management of myofascial pain is an important part of musculoskeletal rehabilitation of regional axial and limb pain syndromes. This article reviews the current hypotheses regarding the pathophysiology of myofascial trigger points and muscle pain. A critical evidence-based review of the pharmacologic, nonpharmacologic, alternative medicine, and exercise treatments of myofascial pain is provided, as well as future research directions. OVERALL LEARNING OBJECTIVE: To review critically the state of the art knowledge of myofascial pain, including pathophysiology and comprehensive management. Areas of future research are identified.