Publications by Year: 2009


Shen YF, Younger J, Goddard G, Mackey S. Randomized clinical trial of acupuncture for myofascial pain of the jaw muscles. J. Orofac. Pain. 2009;23(4):353-359.
AIMS: To evaluate the effectiveness of acupuncture in treating symptoms associated with myofascial pain of the jaw muscles. METHODS: Twenty-eight subjects over the age of 18 and diagnosed with chronic myofascial pain of the jaw muscles were randomized to receive real (n = 16) or sham (n = 12) acupuncture. Prior to treatment, each subject clenched his or her teeth for 2 minutes. Acupuncture or sham acupuncture was then administered at the Hegu large intestine 4 (LI4) acupoint for 15 minutes. Real acupuncture was given by penetrating the needle through a sticky foam pad at the acupoint. Sham acupuncture was conducted by pricking the skin, without penetration, with a shortened, blunted acupuncture needle through a foam pad placed away from the acupoint. General head and neck pain ratings were obtained before and after treatment on a numerical rating scale. A mechanical pain stimulus on the masseter muscle was given before and after treatment and rated on a visual analog scale to measure pain tolerance level. Paired t tests were performed to detect significant changes in pain levels. RESULTS: Subjects receiving real acupuncture experienced a significant reduction in jaw pain (P = .04), jaw/face tightness (P = .04), and neck pain (P = .04), and a significant increase in pain tolerance of the masseter muscle (P = .001). Subjects were not able to determine whether they received real or sham acupuncture (P = .69). No significant pain reductions were observed in the sham acupuncture group. CONCLUSION: A single acupuncture session using one acupoint at Hegu large intestine 4 significantly reduced most myofascial pain endpoints when compared to sham acupuncture.
Wang CK, Gowda A, Barad M, Mackey SC, Carroll IR. Serratus muscle stimulation effectively treats notalgia paresthetica caused by long thoracic nerve dysfunction: a case series. J. Brachial Plex. Peripher. Nerve Inj. 2009;4(1):17.
Currently, notalgia paresthetica (NP) is a poorly-understood condition diagnosed on the basis of pruritus, pain, or both, in the area medial to the scapula and lateral to the thoracic spine. It has been proposed that NP is caused by degenerative changes to the T2-T6 vertebrae, genetic disposition, or nerve entrapment of the posterior rami of spinal nerves arising at T2-T6. Despite considerable research, the etiology of NP remains unclear, and a multitude of different treatment modalities have correspondingly met with varying degrees of success. Here we demonstrate that NP can be caused by long thoracic nerve injury leading to serratus anterior dysfunction, and that electrical muscle stimulation (EMS) of the serratus anterior can successfully and conservatively treat NP. In four cases of NP with known injury to the long thoracic nerve we performed transcutaneous EMS to the serratus anterior in an area far lateral to the site of pain and pruritus, resulting in significant and rapid pain relief. These findings are the first to identify long thoracic nerve injury as a cause for notalgia paresthetica and electrical muscle stimulation of the serratus anterior as a possible treatment, and we discuss the implications of these findings on better diagnosing and treating notalgia paresthetica.
Younger J, Mackey S. Fibromyalgia symptoms are reduced by low-dose naltrexone: a pilot study. Pain Med. 2009;10(4):663-672.
OBJECTIVE: Fibromyalgia is a chronic pain disorder that is characterized by diffuse musculoskeletal pain and sensitivity to mechanical stimulation. In this pilot clinical trial, we tested the effectiveness of low-dose naltrexone in treating the symptoms of fibromyalgia. DESIGN: Participants completed a single-blind, crossover trial with the following time line: baseline (2 weeks), placebo (2 weeks), drug (8 weeks), and washout (2 weeks). PATIENTS: Ten women meeting criteria for fibromyalgia and not taking an opioid medication. INTERVENTIONS: Naltrexone, in addition to antagonizing opioid receptors on neurons, also inhibits microglia activity in the central nervous system. At low doses (4.5 mg), naltrexone may inhibit the activity of microglia and reverse central and peripheral inflammation. OUTCOME MEASURES: Participants completed reports of symptom severity everyday, using a handheld computer. In addition, participants visited the lab every 2 weeks for tests of mechanical, heat, and cold pain sensitivity. RESULTS: Low-dose naltrexone reduced fibromyalgia symptoms in the entire cohort, with a greater than 30% reduction of symptoms over placebo. In addition, laboratory visits showed that mechanical and heat pain thresholds were improved by the drug. Side effects (including insomnia and vivid dreams) were rare, and described as minor and transient. Baseline erythrocyte sedimentation rate predicted over 80% of the variance in drug response. Individuals with higher sedimentation rates (indicating general inflammatory processes) had the greatest reduction of symptoms in response to low-dose naltrexone. CONCLUSIONS: We conclude that low-dose naltrexone may be an effective, highly tolerable, and inexpensive treatment for fibromyalgia.
Younger J, McCue R, Mackey S. Pain outcomes: a brief review of instruments and techniques. Curr. Pain Headache Rep. 2009;13(1):39-43.
Pain is a difficult outcome to measure due to its multifaceted and subjective nature. The need for selecting proper outcome measures is high because of the increasing demand for scientifically valid demonstrations of treatment efficacy. This article discusses some basic topics in the measurement of pain outcomes and addresses issues such as statistical versus clinical significance, daily home data collection, appropriate length of outcome measurement packets, and the possibility of objective pain measurements. This article also reviews some of the more commonly used tools for measuring pain and pain-related disability. By selecting the proper tools and employing them correctly, we can obtain highly reliable and valid measures of pain outcomes in research and clinical care.
Barad M, Greicius MD, Mackey S. IMAGING THE CNS CORRELATES OF NEUROPATHIC PAIN. CONTINUUM: Lifelong Learning in Neurology. 2009;15(5):30.
In recent years, there has been considerable growth in the use of imaging to understand, define, and-to a lesser extent, treat-neuropathic pain. This review seeks to summarize the newfound focus on neuroimaging and to put this research in the context of the existing definitions of neuropathic pain and the pain matrix. The research described herein is leading to an expanded definition of neuropathic pain at a time when some in the scientific community have sought to narrow the definition. The research also is helping us understand the role of central neural systems in the development, diagnosis, and treatment of chronic neuropathic pain. However, much of this early research on imaging has been based on relatively small studies and/or heterogenous patient populations, suggesting that further research needs to be done to validate them.Relationship Disclosure: Dr Barad has nothing to disclose. Dr Greicius has received personal compensation from Forest Laboratories, Inc., for serving on a patient safety monitoring panel. Dr Mackey has received personal compensation from Pfizer Inc for serving as a consultant and speaker.Unlabeled Use of Products/Investigational Use Disclosure: Drs Barad, Greicius, and Mackey have nothing to disclose.
Carroll I, Clark D, Mackey S. Sympathetic block with botulinum toxin to treat complex regional pain syndrome. Ann. Neurol. 2009;65(3):348-351.
Complex regional pain syndrome is a refractory pain condition with few tested therapies. We hypothesized that botulinum toxin A (BTA) would prolong analgesia after sympathetic blocks in patients with complex regional pain syndrome. We compared the duration of standard lumbar sympathetic block (LSB) with bupivacaine to LSB with bupivacaine and BTA in nine patients with refractory complex regional pain syndrome. Median time to analgesic failure was 71 (95% confidence interval, 12-253) days after LSB with BTA compared with fewer than 10 days (95% confidence interval, 0-12) after standard LSB (log-rank, p \textless 0.02). BTA profoundly prolonged the analgesia from sympathetic block in this preliminary study.
Neugebauer V, Galhardo V, Maione S, Mackey SC. Forebrain pain mechanisms. Brain Res. Rev. 2009;60(1):226-242.
Emotional-affective and cognitive dimensions of pain are less well understood than nociceptive and nocifensive components, but the forebrain is believed to play an important role. Recent evidence suggests that subcortical and cortical brain areas outside the traditional pain processing network contribute critically to emotional-affective responses and cognitive deficits related to pain. These brain areas include different nuclei of the amygdala and certain prefrontal cortical areas. Their roles in various aspects of pain will be discussed. Biomarkers of cortical dysfunction are being identified that may evolve into therapeutic targets to modulate pain experience and improve pain-related cognitive impairment. Supporting data from preclinical studies in neuropathic pain models will be presented. Neuroimaging analysis provides evidence for plastic changes in the pain processing brain network. Results of clinical studies in neuropathic pain patients suggest that neuroimaging may help determine mechanisms of altered brain functions in pain as well as monitor the effects of pharmacologic interventions to optimize treatment in individual patients. Recent progress in the analysis of higher brain functions emphasizes the concept of pain as a multidimensional experience and the need for integrative approaches to determine the full spectrum of harmful or protective neurobiological changes in pain.