Brain Functional Changes and Duloxetine Treatment Response in Fibromyalgia: A Pilot Study
Laboratory of Brain, Behavior, and Pharmacology, Semel Institute for Neuroscience and Human Behavior at the University of California, Los Angeles, CA, USA. Pain Medicine
(Impact Factor: 2.3).
05/2009; 10(4):730-8. DOI: 10.1111/j.1526-4637.2009.00614.x
Serotonin-norepinephrine reuptake inhibitor (SNRI) antidepressant medications may have efficacy in relieving pain associated with fibromyalgia syndrome (FMS), even in the absence of major depressive disorder (MDD). Current practice is to use a trial-and-error treatment strategy, often requiring 8-12 weeks to determine the effectiveness of a given pharmacological intervention. The ability to predict response to antidepressant medications would facilitate clinical management of FMS. Prior work in MDD has shown that the quantitative electroencephalographic (QEEG) cordance biomarker of brain functional changes early in the course of antidepressant treatment is related to later clinical response. We hypothesized that cordance might also predict response to antidepressant medications for symptoms of FMS.
Twelve adults (9 females) meeting American College of Rheumatology criteria for FMS participated in a double-blind placebo-controlled treatment trial utilizing duloxetine 60 mg. QEEG cordance changes were examined over the first week of treatment. Primary clinical outcomes included change in average pain severity on the Brief Pain Inventory (BPI) and global improvement in pain on the Patient's Global Impressions of Improvement (PGI-I) scale at 12 weeks.
Changes in left frontal QEEG cordance after the first week of duloxetine treatment significantly predicted BPI pain improvement (regression coefficient = 2.9, R(2) = 0.93, P = 0.008) and PGI-I global improvement (regression coefficient = 0.94, R(2) = 0.81, P = 0.04).
This pilot study suggests that QEEG biomarkers may prove useful for predicting improvement in painful symptoms during SNRI treatment in FMS. Larger studies are needed to confirm this finding.
Figures in this publication
Available from: Audrey J Brooks
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ABSTRACT: Electroencephalography (EEG) offers psychophysiologic tools to improve sensitivity for detecting objective effects in complementary and alternative medicine. This current investigation extended prior clinical research studies to evaluate effects of one of two different homeopathic remedies on resting EEG cordance after an olfactory activation protocol on healthy young adults with remedy-relevant, self-perceived characteristics.
Ninety-seven (7) young adults (N=97, mean age 19 years, 55% women) with good self-rated global health and screened for homeopathic constitutional types consistent with one of two remedies (either Sulphur or Pulsatilla) underwent three weekly laboratory sessions. At each visit, subjects had 5-minute resting, eyes-closed EEG recordings before and after a placebo-controlled olfactory activation task with their constitutionally relevant verum remedy. One remedy potency (6c, 12c, or 30c) used per week, was presented in a randomized order over the 3 sessions. Prefrontal resting EEG cordance values at Fp1 and Fp2 were computed from artifact-free 2-minute EEG samples from the presniffing and postsniffing rest periods. Cordance derives from an algorithm that incorporates absolute and relative EEG values.
The data showed significant two-way oscillatory interactions of remedy by time for ß, α, θ, and δ cordance, controlling for gender and chemical sensitivity.
EEG cordance provided a minimally invasive technique for assessing objective nonlinear physiologic effects of two different homeopathic remedies salient to the individuals who received them. Time factors modulated the direction of effects. Given previous evidence of correlations between cordance and single-photon emission computed tomography, these findings encourage additional neuroimaging research on nonlinear psychophysiologic effects of specific homeopathic remedies.
Available from: Anne Brokjær
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ABSTRACT: AIMS: To assess centrally mediated analgesic mechanisms in clinical trials with pain patients, objective standardized methods such as electroencephalography (EEG) has many advantages. The aim of this review is to provide the reader with an overview of present findings in analgesics assessed with spontaneous EEG and evoked brain potentials (EPs) in humans. Furthermore, EEG methodologies will be discussed with respect to translation from animals to humans and future perspectives in predicting analgesic efficacy. METHODS: We searched PubMed with MeSH terms "analgesics", "electroencephalography" and "evoked potentials" for relevant articles. Combined with a search in their reference lists 15 articles on spontaneous EEG and 55 papers on EPs were identified. RESULTS: Overall, opioids produced increased activity in the delta band in the spontaneous EEG, but increases in higher frequency bands were also seen. The EP amplitudes decreased in the majority of studies. Anticonvulsants used as analgesics showed inconsistent results. The N-Methyl-D-aspartate receptor antagonist ketamine showed an increase in the theta band in spontaneous EEG and decreases in EP amplitudes. Tricyclic antidepressants increased the activity in the delta, theta and beta bands in the spontaneous EEG while EPs were inconsistently affected. Weak analgesics were mainly investigated with EPs and a decrease in amplitudes was generally observed. CONCLUSIONS: This review reveals that both spontaneous EEG and EPs are widely used as biomarkers for analgesic drug effects. Methodological differences are common and a more uniform approach will further enhance the value of such biomarkers for drug development and prediction of treatment response in individual patients.
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ABSTRACT: Abstract This review provides a scientific comment on the welfare of ruminants slaughtered by ventral-neck incision without stunning. Evidence is derived from studies of calves, sheep and goats. Reference is also made to findings in other mammals including humans. Pain is an inherently subjective experience and only indirect indices are available in animals. Neurophysiological tools are widely used in humans to assess pain and have demonstrated that electroencephalographic (EEG) variables correlate well with subjective evaluations of pain. These neurophysiological tools have also been applied in animal studies. In humans pain is associated with major cutting injuries and it is widely accepted that farm animals also experience pain due to such injuries. Overwhelming international scientific opinion has long been that slaughter by neck incision of conscious animals causes pain. A series of studies in calves demonstrated that slaughter by ventral-neck incision is likely to be perceived as painful. It is proposed that, as in cattle, non-stunned sheep and goats would experience pain in a similar manner. The precise assessment of the point after slaughter at which non-stunned animals become insensible remains a major methodological challenge. In sheep it is at least 2-8 seconds, but may be 8-20 seconds in duration. In cattle the mean duration is similar, but can commonly be extended to longer than 60 seconds with occasional instances of even greater durations. Taken together, these findings indicate that because the slaughter of cattle, sheep and goats by ventral-neck incision without prior stunning is likely to cause pain, this poses a risk to animal welfare.
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