October 2013 References  Devin J. Starlanyl   for http://www.sover.net/~devstar

Akdeniz S, Kelsaka E, Guldogus F. 2013. [Retrospective evaluation of the patients with chronic pain admitted to the algology polyclinic between 2000-2010.] Agri. 25(3):115-122 [Article in Turkish].  Patients in this pain clinic during the 11-year period between January 2000 and December 2010 were evaluated as to the cause of their pain.  These 6647 patients included those with malignancies as well as non-cancer conditions.  “66.9% of the patients were between the ages of 19 and 64. There was no significant difference between genders. The most common causes of pain were myofascial pain, neuropathic pain, low back pain and headache. Among malignancy related cases the most common sources were gastrointestinal system, lung and breast regions. In 83.4% of patients, pharmacological and invasive treatments were utilized. The most common invasive treatment modalities were, trigger point injection, dry needle application and epidural catheter application. Conclusion: In conclusion, pain treatments with multidisciplinary approach applied by the increasing number of pain clinics provide favorable results and patients quality of life is also increased. We hope our retrospective study may provide helpful data for future studies on chronic pain with its comprehensive base of patient data which covers an eleven years period.”

Baron R, Hans G, Dickenson A. 2013. Peripheral input and its importance for central sensitization. Ann Neurol. [Sep 10 Epub ahead of print]. “Many pain states begin with damage to tissue and/or nerves in the periphery, leading to enhanced transmitter release within the spinal cord and central sensitization. Manifestations of this central sensitization are wind-up and long-term potentiation. Hyperexcitable spinal neurons show reduced thresholds, greater evoked responses, increased receptive field sizes and ongoing stimulus-independent activity; these changes probably underlie the allodynia, hyperalgesia and spontaneous pain seen in patients. Central sensitization is maintained by continuing input from the periphery, but also modulated by descending controls, both inhibitory and facilitatory, from the midbrain and brainstem. The projections of sensitized spinal neurons to the brain, in turn, alter the processing of painful messages by higher centers. Several mechanisms contribute to central sensitization. Repetitive activation of primary afferent C-fibers leads to a synaptic strengthening of nociceptive transmission. It may also induce facilitation of non-nociceptive Aβ-fibers and nociceptive Aδ-fibers, giving rise to dynamic mechanical allodynia and mechanical hyperalgesia. In post-herpetic neuralgia and complex regional pain syndrome, for example, these symptoms are maintained and modulated by peripheral nociceptive input. Diagnosing central sensitization can be particularly difficult. In addition to the medical history, quantitative sensory testing and functional magnetic resonance imaging may be useful, but diagnostic criteria which include both subjective and objective measures of central augmentation are needed. Mounting evidence indicates that treatment strategies which desensitize the peripheral and central nervous systems are required. These should generally involve a multimodal approach, so that therapies may target the peripheral drivers of central sensitization and/or the central consequences.” 

Bastos JL, Pires ED, Silva ML et al. 2013. Effect of acupuncture at tender points for the management of fibromyalgia syndrome: a case series.  J Acupunct Meridian Stud. 6(3):163-168. Dry needling with acupuncture needles once a week for 2 months was done at 5 tender points (occiput, trapezius, rhomboid, upper chest and lateral epicondyle) on 8 female fibromyalgia patients.  There was a reduction in pain sensitivity and improvement in anxiety and depression and quality of life with the Fibromyalgia Impact Questionnaire, the Beck Depression Inventory, the Beck Anxiety inventory, but not the Health Assessment Questionnaire.

Batheja S, Nields JA, Landa A et al. 2013. Post-treatment Lyme syndrome and central sensitization. J Neuropsychiatry Clin Neurosci. 25(3):176-186. “Central sensitization is a process that links a variety of chronic pain disorders that are characterized by hypersensitivity to noxious stimuli and pain in response to non-noxious stimuli. Among these disorders, treatments that act centrally may have greater efficacy than treatments acting peripherally. Because many individuals with post-treatment Lyme Syndrome (PTLS) have a similar symptom cluster, central sensitization may be a process mediating or exacerbating their sensory processing. This article reviews central sensitization, reports new data on sensory hyperarousal in PTLS, explores the potential role of central sensitization in symptom chronicity, and suggests new directions for neurophysiologic and treatment research.”

Blankenfield A. 2013. Kynurenine pathway pathologies: Do nicotinamide and other pathway co-factors have a therapeutic role in reduction of symptom severity, including chronic fatigue syndrome (CFS) and fibromyalgia (FM). Int J Tryptophan Res. 6(Suppl 1):39-45. “The up-regulation of the kynurenine pathway by physical illness can cause neuropathic and immunological disorders associated with secondary neuropsychiatric symptoms. Tryptophan and nicotinamide deficiencies fall within the protein energy malnutrition (PEM) spectrum. They can arise if the kynurenine pathway is stressed by primary or secondary inflammatory conditions and the consequent imbalance of available catabolic/anabolic substrates may adversely influence convalescent phase efficiency.  The replacement of depleted or reduced NAD+ levels and other cofactors can perhaps improve the clinical management of these disorders. Chronic fatigue syndrome (CFS) and fibromyalgia (FM) appear to meet the criteria of a tryptophan-kynurenine pathway disorder with potential neuroimunological sequelae.”  [Actually, FM and CFS have been shown to be different conditions.  A subset of FM patients does utilize the kynurenine alternative metabolic pathway, producing the neurotoxic quinolinic acid rather than serotonin.  The release of this neurotoxin may be more causative of symptoms than what is here proposed.  DJS]

Coluzzi F, Valensise H, Sacco M et al.  2013. Chronic pain management in pregnancy and lactation. Minerva Anestesiol. [Jul 15 Epub ahead of print.]  Chronic pain management during pregnancy and lactation is a challenge to clinicians and patients.  This paper reviews safety profiles of possible medications.

Crettaz B, Marziniak M, Willeke P et al. 2013. Stress-induced allodynia-evidence of increased pain sensitivity in healthy humans and patients with chronic pain after experimentally induced psychosocial stress.  PLoS One. 8(8):e69460.  This study provides:  “…evidence for stress-induced allodynia/hyperalgesia in humans for the first time and suggest differential underlying mechanisms determining response to stressors in healthy subjects and patients suffering from chronic pain.”

Duschek S, Werner NS, Winkelmann A et al. 2013. Implicit memory function in fibromyalgia syndrome. Behav Med. 39(1):11-16. “The study investigated implicit memory function in fibromyalgia syndrome (FMS) and its association with clinical parameters. Implicit memory refers to the influence of past experience on current behavior without conscious awareness of these experiences. Eighteen FMS patients and 25 healthy individuals accomplished a word-stem completion task. As possible factors mediating the expected impairment, pain severity, emotional disorders, and medication were taken into the expected impairment, pain severity, emotional disorders, and medication were taken into account. The patients displayed markedly reduced task performance and higher levels of depression and anxiety. Among the clinical features, pain severity was most closely associated with performance, whereas depression, anxiety, and medication showed only a minor impact. The study documented reduced implicit memory function in FMS. In contrast to former findings on impaired performance of FMS patients on classical memory tests, lower implicit memory function cannot be ascribed to motivational deficits. Instead, the aberrances may relate to functional inference between central nervous nociceptive activity and cognitive processing.”

Fields RD, Araque A, Johansen-Berg H et al. 2013. Glial Biology in Learning and Cognition.

Neuroscientist. 2013 Oct 11. [Epub ahead of print] “Neurons are exquisitely specialized for rapid electrical transmission of signals, but some properties of glial cells, which do not communicate with electrical impulses, are well suited for participating in complex cognitive functions requiring broad spatial integration and long-term temporal regulation. Astrocytes, microglia, and oligodendrocytes all have biological properties that could influence learning and cognition. Myelination by oligodendrocytes increases conduction velocity, affecting spike timing and oscillations in neuronal activity. Astrocytes can modulate synaptic transmission and may couple multiple neurons and synapses into functional assemblies. Microglia can remove synapses in an activity-dependent manner altering neural networks. Incorporating glia into a bicellular mechanism of nervous system function may help answer long-standing questions concerning the cellular mechanisms of learning and cognition.”

Fredheim OM, Borchgrevink PC, Mahic M et al. 2013. A pharmacoepidemiological cohort study of subjects starting strong opioids for nonmalignant pain: A study from the Norwegian Prescription Database. Pain. [Sep 24 Epub ahead of print]. “Clinical studies of short duration have demonstrated that strong opioids improve pain control in selected patients with chronic nonmalignant pain. However, high discontinuation rates and dose escalation during long-term treatment have been indicated. The aim of the present study was to determine discontinuation rates, dose escalation, and patterns of co-medication with benzodiazepines. The Norwegian Prescription Database provides complete national data at an individual level on dispensed drugs. A complete national cohort of new users of strong opioids was followed up for 5 years after initiation of therapy with strong opioids. Of the 17,248 persons who were new users of strong opioids in 2005, 7229 were dispensed a second prescription within 70 days and were assumed to be intended long-term users. A total of 1233 persons in the study cohort were still on opioid therapy 5years later. This equals 24% of the study cohort who were still alive. Of the participants, 21% decreased their annual opioid dose by 25% or more, whereas 21% kept a stable dose (±24%) and 34% more than doubled their opioid dose from the first to the fifth year. High annual doses of opioids were associated with high annual doses of benzodiazepines at the end of follow-up. It is an issue of major concern that large dose escalation is common during long-term treatment, and that that high doses of opioids are associated with high doses of benzodiazepines. These findings make it necessary to question whether the appropriate patient population receives long-term opioid treatment.”  [Benzodiazepines reduce the efficiency of opioids for pain control.  Are doctors not aware of this? DJS]

Gurvich C, Maller JJ, Lithgow B et al. 2013. Vestibular insights into cognition and psychiatry.  Brain Res. [Sep 6 Epub ahead of print]. “…emerging research suggests the vestibular system can be considered a potential window for exploring brain function beyond that of maintenance of balance, and into areas of cognitive, affective and psychiatric symptomology. Given the paucity of biological and diagnostic markers in psychiatry, novel avenues to explore brain function in psychiatric disorders are of particular interest and warrant further exploration.”

Harbeck B, Sufke S, Harten P et al. 2013. High prevalence of fibromyalgia-associated symptoms in patients with hypothalamic-pituitary disorders. Clin Exp Rheumatol. [Epub ahead of print.] “Our data suggest that patients with hypothalamic-pituitary disorders may be at increased risk of developing fibromyalgia-associated symptoms.”

Homann D, Louzeda FM, Goes SM et al. 2013. Acylated ghrelin: a potential marker for fibromyalgia?  Eur J Pain. 17(8):1216-1224. The findings in this study indicate that decreased acylated ghrelin levels in women with fibromyalgia are related to pain intensity.  [These patients were not assessed for co-existing insulin resistance, which may relate to the ghrelin finding. DJS]

Hong CZ. 2013. Needling therapy for myofascial pain control. Evid Based Complement Alternat Med. [Aug 26 Epub ahead of print].

Huber J, Lisiński P, Polowczyk A. 2013. Reinvestigation of the dysfunction in neck and shoulder girdle muscles as the reason of cervicogenic headache among office workers. Disabil Rehabil. 35(10):793-802. This study from Poland investigated: “Dysfunction of cervical and shoulder girdle muscles as reason of cervicogenic headache (CEH) was reinvestigated with clinical and neurophysiological studies….Forty office workers were randomized into two groups to verify efficiency of supervised kinesiotherapy (N = 20) aimed with improvement of muscle's activity and headache symptoms releasing. Headache intensity was evaluated with visual analog scale (VAS), range of cervical movement (ROM) with goniometer, trigger points (TrPs) incidence with palpation and muscle's strength with Lovett's scale. Reaction of patients for muscle's elongation was also evaluated. Surface electromyographical recordings were bilaterally analyzed at rest (rEMG) and during maximal contraction (mcEMG)….Deficits of cervical flexion and muscles strength were found in all patients. TrPs occurred predominantly in painful trapezius muscle. Incidence of trigger points coexisted with intensity of CEH. Results indicated on muscles dysfunction which improved only after supervised therapy. Positive correlations between increase in rEMG amplitudes and high VAS scores, high-amplitude rEMG recordings incidence and increased number of TrPs were found. Negative correlation was detected between amplitude in mcEMG and amplitude of rEMG recordings…Dysfunction of trapezius muscle was most responsible for CEH etiology. Proposed algorithm of kinesiotherapy was effective as complementary method of the CEH patients’ treatment.”

Im SH, Han EY. 2013. Improvement in anxiety and pain after whole body whirlpool hydrotherapy among patients with myofascial pain syndrome. Ann Rehabil Med. 37(4):534-540. This study found whirlpool therapy to be more effective than conventional hydrocollator packs for the treatment of myofascial pain. 

Jensen KB, Sriniasan P, Spaeth R et al. 2013. Overlapping structural and functional brain changes in patients with long-term exposure to fibromyalgia. Arthritis Rheum. [Aug 27 Epub ahead of print]. “FM patients displayed a distinct overlap between decreased cortical thickness, brain volumes and measures of functional regional coherence in the rostral anterior cingulate cortex. The morphometric changes were more pronounced with longer exposure to FM pain. In addition, we found associations between structural and functional changes in the mesolimbic areas of the brain and comorbid depressive symptoms in FM patients. Conclusion: The combined integration of structural and functional measures allowed for a unique characterization of the impact of FM pain on the brain. Our data may lead to the identification of early structural and functional brain alterations in response to pain, which could be used to develop markers to predict the development of FM and other pain disorders.”

Ji RR, Berta T, Nedergaard M. 2013. Glia and pain: Is chronic pain a gliopathy?  Pain.Jun 20.  [Epub ahead of print] “Activation of glial cells and neuro-glial interactions are emerging as key mechanisms underlying chronic pain. Accumulating evidence has implicated 3 types of glial cells in the development and maintenance of chronic pain: microglia and astrocytes of the central nervous system (CNS), and satellite glial cells of the dorsal root and trigeminal ganglia. Painful syndromes are associated with different glial activation states: (1) glial reaction (ie, upregulation of glial markers such as IBA1 and glial fibrillary acidic protein (GFAP) and/or morphological changes, including hypertrophy, proliferation, and modifications of glial networks); (2) phosphorylation of mitogen-activated protein kinase signaling pathways; (3) upregulation of adenosine triphosphate and chemokine receptors and hemichannels and downregulation of glutamate transporters; and (4) synthesis and release of glial mediators (eg, cytokines, chemokines, growth factors, and proteases) to the extracellular space. Although widely detected in chronic pain resulting from nerve trauma, inflammation, cancer, and chemotherapy in rodents, and more recently, human immunodeficiency virus-associated neuropathy in human beings, glial reaction (activation state 1) is not thought to mediate pain sensitivity directly. Instead, activation states 2 to 4 have been demonstrated to enhance pain sensitivity via a number of synergistic neuro-glial interactions. Glial mediators have been shown to powerfully modulate excitatory and inhibitory synaptic transmission at presynaptic, postsynaptic, and extrasynaptic sites. Glial activation also occurs in acute pain conditions, and acute opioid treatment activates peripheral glia to mask opioid analgesia. Thus, chronic pain could be a result of "gliopathy," that is, dysregulation of glial functions in the central and peripheral nervous system. In this review, we provide an update on recent advances and discuss remaining questions.”

Kim JY, Kim SH, Seo J et al. 2013. Increased power spectral density in resting-state pain-related brain networks in fibromyalgia. Pain. 154(9):1792-1797. “Fibromyalgia (FM), characterized by chronic widespread pain, is known to be associated with heightened responses to painful stimuli and atypical resting-state functional connectivity among pain-related regions of the brain. Previous studies of FM using resting-state functional magnetic resonance imaging (rs-fMRI) have focused on intrinsic functional connectivity, which maps the spatial distribution of temporal correlations among spontaneous low-frequency fluctuation in functional MRI (fMRI) resting-state data. In the current study, using rs-fMRI data in the frequency domain, we investigated the possible alteration of power spectral density (PSD) of low-frequency fluctuation in brain regions associated with central pain processing in patients with FM. rsfMRI data were obtained from 19 patients with FM and 20 age-matched healthy female control subjects. For each subject, the PSDs for each brain region identified from functional connectivity maps were computed for the frequency band of 0.01 to 0.25Hz. For each group, the average PSD was determined for each brain region and a 2-sample t test was performed to determine the difference in power between the two groups. According to the results, patients with FM exhibited significantly increased frequency power in the primary somatosensory cortex (S1), supplementary motor area (SMA), dorsolateral prefrontal cortex, and amygdale. In patients with FM, the increase in PSD did not show an association with depression or anxiety. Therefore, our findings of atypical increased frequency power during the resting state in pain-related brain regions may implicate the enhanced resting-state baseline neural activity in several brain regions associated with pain processing in FM.”

Kim SA, Oh KY, Choi WH et al. 2013. Ischemic compression after trigger point injection affect the treatment of myofascial trigger points. Ann Rehabil Med. 37(4):541-546. “This study demonstrated the effectiveness of ischemic compression for myofascial trigger point. Trigger point injections combined with ischemic compression shows better effects on treatment of myofascial trigger points in the upper trapezius muscle than the only trigger point injections therapy. But the duration of ischemic compression did not affect treatment of myofascial trigger point.”

Kofler M, Halder W. 2013. Alterations in excitatory and inhibitory brainstem interneuronal circuits in fibromyalgia: Evidence of brainstem dysfunction. Clin Neurophysiol. [Sept 21 Epub ahead of print]. In this small studyundefined10 women with fibromyalgia and 26 healthy controlsundefinedfound the blink reflex to be the same in FM patients and healthy controls. The blink reflex excitability recovery was enhanced in FM, and the blink reflex prepulse inhibition reduced.  This is suggestive of brainstem functional changes in FM patients.  Reduced blink reflex prepulse inhibition is common in patients with altered sensory gating, suggesting that FM patients have dysfunctional ability to filter stimuli. This can lead to sensory overload.

Kosharskyy B, Almonte W, Shaparin N et al. 2013. Intravenous infusions in chronic pain management. 16(3):231-249. This review covers general information on the use of lidocaine, ketamine, phentolamine, dexedetomidine, and bisphosphonates for chronic pain, without providing guidelines for their use.

Langevin HM, Nedergaard M, Howe AK. 2013.  Cellular control of connective tissue matrix tension. J Cell Biochem. Aug;114(8):1714-9. “The biomechanical behavior of connective tissue in response to stretching is generally attributed to the molecular composition and organization of its extracellular matrix. It also is becoming apparent that fibroblasts play an active role in regulating connective tissue tension. In response to static stretching of the tissue, fibroblasts expand within minutes by actively remodeling their cytoskeleton. This dynamic change in fibroblast shape contributes to the drop in tissue tension that occurs during viscoelastic relaxation. We propose that this response of fibroblasts plays a role in regulating extracellular fluid flow into the tissue, and protects against swelling when the matrix is stretched. This article reviews the evidence supporting possible mechanisms underlying this response including autocrine purinergic signaling. We also discuss fibroblast regulation of connective tissue tension with respect to lymphatic flow, immune function, and cancer.”

Latina R, Sansoni J, D'Angelo D et al. 2013. [Etiology and prevalence of chronic pain in adults: a Narrative Review.]  Prof Inferm. 66(3):151-158. [Article in Italian]  “The chronic nonmalignant pain is an underestimated epidemiologic health problem. It is a disease in its own right. It is one of the major reasons because patients use health service. The magnitude of chronic pain is in terms of human suffering and costs to society. The aim of this review is to identify the diagnosis and the prevalence of nonmalignant chronic pain in the adults….Excluding topics of headache, pain for pediatric and geriatric groups, cancer pain and disease-specific items. … We have obtained 7 articles. These epidemiological studies conducted in different part of the world, reported prevalence rates of chronic pain ranging from 16-53%. They show a high heterogeneity of results concerning diagnosis and methods. Although limited the number of articles, show the high complexity of the phenomenon.”

Lee MJ, Chung YS. 2013. Spinal subarachnoid hematoma as a complication of an intramuscular stimulation: case report and a review of literatures. J Korean Neurosurg Soc. 54(1):58-60.

“Intramuscular stimulation (IMS) is widely used to treat myofascial pain syndrome. IMS is a safe procedure but several complications have been described. To our knowledge, spinal subarachnoid hematoma has never been reported as a complication of an IMS. The authors have experienced a case of spinal subarachnoid hematoma occurring after an IMS, which was tentatively diagnosed as intracranial subarachnoid hemorrhage because of severe headache. Patient was successfully treated with surgery.” 

Liston MB, Bamiou DE, Martin F et al. 2013. Peripheral vestibular dysfunction is prevalent in older adults experiencing multiple non-syncopal falls versus age-matched non-fallers: a pilot study. Age Ageing. [Sep 15 Epub ahead of print]. “Vestibular dysfunction is significantly more prevalent in older adult fallers versus non-fallers. Individuals referred to a falls clinic are older, more impaired and report more falls than those referred to a neuro-otology department. A greater awareness of vestibular impairments may lead to more effective management and treatment for older adult fallers.”

Louter MA, Bosker JE, van Oosterhout WP et al. 2013. Cutaneous allodynia as a predictor of migraine chronification. Brain. [Sep 29 Epub ahead of print]. “Cutaneous allodynia is a risk factor for migraine chronification and may warrant preventive treatment strategies.”

Martinez-Jauand M, Sitges C, Femenia J et al. 2013. Age-of-onset of menopause is associated with enhanced painful and non-painful sensitivity in fibromyalgia. Clin Rheumatol. 32(7):975-981. “Fibromyalgia (FM) is a chronic pain condition characterized by high prevalence in women. In particular, estrogen deficit has been considered as a potentially promoting factor of FM symptoms. This study was aimed to examine the relationship between age-of-onset of menopause and pain sensitivity in FM. For this purpose, pain sensitivity was assessed in 74 FM and 32 pain-free control women. All participants were postmenopausal and underwent a detailed semi-structured clinical interview, including data about menopause transition, previous history of hysterectomy or ovariectomy, and menses time. Participants were divided into two groups depending on age-of-onset of menopause: early menopause [<49 years] vs. late menopause [>49 years]. Pain and non-pain thresholds were assessed by using cold, heat, mechanical, and electrical stimulation. FM women showed higher overall pain sensitivity as compared with healthy subjects. FM women with early age-of-onset of menopause displayed greater pain and non-pain sensitivity than women with late age-of-onset of menopause, whereas no differences were observed in healthy women due to age-of-onset of menopause. These results suggest that an early transition to menopause (shortening the time of exposure to estrogens) may influence pain hypersensitivity and could be related to aggravation of FM symptoms.”

Meeus M, Nijs J, Hermans L et al. 2013. The role of mitochondrial dysfunctions due to oxidative and nitrosative stress in the chronic pain or chronic fatigue syndromes and fibromyalgia patients: peripheral and central mechanisms as therapeutic targets? Expert Opin Ther Targets. 17(9):1081-1089. “Introduction: Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are characterized by persistent pain and fatigue. It is hypothesized that reactive oxygen species (ROS), caused by oxidative and nitrosative stress, by inhibiting mitochondrial function can be involved in muscle pain and central sensitization as typically seen in these patients. Areas covered: The current evidence regarding oxidative and nitrosative stress and mitochondrial dysfunction in CFS and FM is presented in relation to chronic widespread pain. Mitochondrial dysfunction has been shown in leukocytes of CFS patients and in muscle cells of FM patients, which could explain the muscle pain. Additionally, if mitochondrial dysfunction is also present in central neural cells, this could result in lowered ATP pools in neural cells, leading to generalized hypersensitivity and chronic widespread pain. Expert opinion: increased ROS in CFS and FM, resulting in impaired mitochondrial function and reduced ATP in muscle and neural cells, might lead to chronic widespread pain in these patients. Therefore, targeting increased ROS by antioxidants and targeting the mitochondrial biogenesis could offer a solution for the chronic pain in these patients. The role of exercise therapy in restoring mitochondrial dysfunction remains to be explored, and provides important avenues for future research in this area.”

Menzies V, Lyon DE, Archer KJ et al. 2013. Epigenetic alterations and an increased frequency of micronuclei in women with fibromyalgia. Nurs Res Pract. [Aug 22 Epub ahead of print].

The frequency of spontaneously occurring micronuclei and genome-wide methylation patterns in 10 women with FM were compared. There were significant alterations in methylation patterns at 69 sites compared with those in 42 healthy controls of similar ages. “Genes associated with DM (differently methylated) sites whose function has particular relevance to FM included BDNF, NAT15, HDAC4, PPKCA, RTN1, and PRKG1.”

Mu R, Li C, Zhu JX et al. 2013. National survey of knowledge, attitude and practice of fibromyalgia among rheumatologists in China. Int J Rheum Dis. 16(3):258-263. “The awareness and perception of FM are still low among Chinese rheumatologists. Continuing medical education on FM is needed for improving the quality of health care in China.”  [Much the same could be said of all countries. DJS]

  

Queme F, Taguchi T, Mizumura K et al. 2013. Muscular Heat and Mechanical Pain Sensitivity After Lengthening Contractions in Humans and Animals. J Pain. [Sep 21 Epub ahead of print].

“Mechanical sensitivity of muscle nociceptors was previously shown to increase 2 days after lengthening contractions (LC), but heat sensitivity was not different despite nerve growth factor (NGF) being upregulated in the muscle during delayed-onset muscle soreness (DOMS). The discrepancy of these results and lack of other reports drove us to assess the heat sensitivity during DOMS in humans and to evaluate the effect of NGF on the heat response of muscle C-fibers. Pressure pain thresholds and pain intensity scores to intramuscular injection of isotonic saline at 48°C and capsaicin were recorded in humans after inducing DOMS. The response of single unmyelinated afferents to mechanical and heat stimulations applied to their receptive field was recorded from muscle-nerve preparations in vitro. In humans, pressure pain thresholds were reduced but heat and capsaicin pain responses were not increased during DOMS. In rats, the mechanical but not the heat sensitivity of muscle C-fibers was increased in the LC group. NGF applied to the receptive field facilitated the heat sensitivity relative to the control. The absence of facilitated heat sensitivity after LC, despite the NGF sensitization, may be explained if the NGF concentration produced after LC is not sufficient to sensitize nociceptor response to heat….This article presents new findings on the basic mechanisms underlying hyperalgesia during DOMS, which is a useful model to study myofascial pain syndrome, and the role of NGF on muscular nociception. This might be useful in the search for new pharmacologic targets and therapeutic approaches.”

Reiestad F, Kulkarni J. 2013. Role of myofascial trigger points in post-amputation pain: causation and management. Prosthet Orthot Int. 37(2):120-123. “Identification of myofascial trigger points in amputation stumps and their role in post-amputation pain, followed by appropriate intervention is an important facet of management of this complex chronic pain. Clinical relevance Myofascial trigger points in amputation stumps can lead to ongoing chronic post-amputation pain and our results indicate that identification and intervention of these trigger points does lead to notable resolution of this pain.”

Umeda M, Corbin LW, Maluf KS. 2013. Pain mediates the association between physical activity and the impact of fibromyalgia on daily function. Clin Rheumatol. [Sep 13 Epub ahead of print].

“These results indicate that the intensity of musculoskeletal pain, rather than depressive symptoms or body mass, mediates the association between physical activity and daily function among women with fibromyalgia.”

Wagner JS, Chandran A, DiBonaventura M et al. 2013. The costs associated with sleep symptoms among patients with fibromyalgia. Expert Rev Pharmacoecon Outcomes Res. 13(1):131-139. “Among the FM population, sleep symptoms were prevalent and associated with higher direct and indirect costs, suggesting improved management may have long-term cost savings.” [This leads one to wonder why Xyrem is not approved for deep-sleep-deprived patients with FM.  DJS]

Wallace LS, Wexler RK, Miser WF et al. 2013. Development and validation of the Patient Opioid Education Measure. J Pain Res. 6:663-681. “Although there are screening tools to aid clinicians in assessing the risk of opioid misuse, an instrument to assess opioid-related knowledge is not currently available. The purpose of this study was to develop a content-valid, understandable, readable, and reliable Patient Opioid Education Measure (POEM)….The POEM shows promise for rapidly identifying patients' opioid-related knowledge gaps and expectations. Correcting misunderstandings and gaps could result in safer use of opioids in a clinical care setting.”

Xie L, Kang H, Xu Q et al. 2013. Sleep drives metabolite clearance from the adult brain.

Science. 2013 Oct 18;342(6156):373-7.  “The conservation of sleep across all animal species suggests that sleep serves a vital function. We here report that sleep has a critical function in ensuring metabolic homeostasis. Using real-time assessments of tetramethylammonium diffusion and two-photon imaging in live mice, we show that natural sleep or anesthesia are associated with a 60% increase in the interstitial space, resulting in a striking increase in convective exchange of cerebrospinal fluid with interstitial fluid. In turn, convective fluxes of interstitial fluid increased the rate of β-amyloid clearance during sleep. Thus, the restorative function of sleep may be a consequence of the enhanced removal of potentially neurotoxic waste products that accumulate in the awake central nervous system.”