Temporomandibular joint disorder (TMJD) is known for its mastication-associated pain. TMJD is medically relevant because of its prevalence, severity, chronicity, and “therapy-refractoriness” of its pain, and its largely elusive pathogenesis. Against this background we sought to investigate pathogenetic contributions of the calcium-permeable TRPV4 ion channel, robustly expressed in the trigeminal ganglion sensory neurons, to TMJ inflammation and pain behavior. We demonstrate here that TRPV4 is critical for TMJ-inflammation evoked pain behavior in mice, and that trigeminal ganglion pro-nociceptive changes are Trpv4-dependent. As a quantitative metric, bite force was recorded as evidence of masticatory sensitization, in keeping with human translational studies. In Trpv4−/− mice with TMJ-inflammation, attenuation of bite force was significantly less than in WT mice. Similar effects were seen with systemic application of a specific TRPV4 inhibitor. TMJ-inflammation and mandibular bony changes were apparent after CFA injections, but remarkably independent of Trpv4 genotype. Intriguingly, as a result of TMJ-inflammation, WT mice exhibited significant up-regulation of TRPV4 and phosphorylated ERK in TMJ-innervating trigeminal sensory neurons, absent in Trpv4−/− mice. Mice with genetically-impaired MEK/ERK phosphorylation in neurons showed a similar resistance to reduction of bite-force as Trpv4−/− mice. Thus, TRPV4 is necessary for masticatory sensitization in TMJ-inflammation, and likely functions up-stream of MEK/ERK phosphorylation in trigeminal ganglion sensory neurons in-vivo. TRPV4 therefore represents a novel pro-nociceptive target in TMJ inflammation, and should be considered a target-of-interest in human TMJD.

BackgroundChronic low back pain (CLBP) has a significant effect on quality of life and imposes a great economical burden on society. In a number of studies, validated questionnaires had been given to CLBP patients to determine their health-associated quality of life, sleep disturbance, and psychological status. However, such outcome studies had not been performed previously in Korea.MethodsWe used self-report questionnaires to compare CLBP patients with an age- and sex-matched healthy control group. Between September 2012 and August 2013, we enrolled 47 patients who had CLBP for more than 3 months (group P) and 44 healthy age- and sex-matched controls (group C), who completed the following self-report questionnaires: 36-Item Short Form Health Survey (SF-36), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Oswestry Disability Index (ODI), and Pittsburgh Sleep Quality Index (PSQI).ResultsThe scores from the ODI, BDI, and BAI were significantly higher in group P than in group C. The SF-36 scores were significantly lower in group P than in group C, suggesting lower quality of life in group P. The incidence of depression and anxiety was significantly higher in group P than in group C. However, neither the PSQI score nor the incidence of sleep disturbance was significantly different between the groups.ConclusionsPatients with CLBP showed considerable functional disability and significant impairment of psychological status with a low quality of life. Hence, it is important to evaluate CLBP patients to provide adequate psychological support.

As the treatment of chronic non-cancer pain gradually increases, clinicians have more opportunities to encounter opioid prescription. However, guidelines for prescribing opioids for chronic non-cancer pain have never been published in Korea. The present guidelines were prepared by reviewing various research data. In cases in which the data were insufficient, recommendations were presented following discussion among experts affiliated with the Opioids Research Group in the Korean Pain Society. The present guidelines may need to be continuously revised and amended as more clinical evidence is acquired.

Temporomandibular joint (TMJ) disorder is clinically important because of its prevalence, chronicity, and therapy-refractoriness of the pain. In this study, we investigated the effect of infliximab in a mouse model of TMJ pain using a specially-engineered transducer for evaluating the changes in bite force (BF). The mice were randomly divided into three groups (7 mice per group): the control group, the complete Freund's adjuvant (CFA) group, and the infliximab group. BF was measured at day 0 (baseline BF). After measuring the baseline BF, CFA or incomplete Freund's adjuvant was injected into both TMJs and then the changes in BF were measured at days 1, 3, 5, 7, 9, and 13 after the TMJ injection. For measuring the BF, we used a custom-built BF transducer. Control, CFA, and infliximab groups showed similar baseline BF at day 0. From day 1, a significant reduction in BF was observed in the CFA group, and this reduction in BF was statistically significant compared to that in the control group (P < 0.05). This reduction in BF was maintained until day 7, and BF started to recover gradually from day 9. In the infliximab group also, the reduction in BF was observed on day 1, and this reduction was maintained until day 7. However, the degree of reduction in BF was less remarkable compared to that in the CFA group. The reduction in BF caused by injection of CFA into the TMJ could be partially alleviated by the injection of anti-tumor necrosis factor alpha, infliximab.Graphical Abstract

Spontaneous intracranial hypotension (SIH) is considered to be a very rare disorder. It is characterized by an orthostatic headache that is aggravated with the patient in the upright position and it is relieved by the patient assuming the supine position. SIH is caused by a spontaneous spinal cerebrospinal fluid leakage without the patient having undergone trauma, surgery or dural puncture or having any other significant medical history. An autologous epidural blood patch (EBP) is effective in relieving SIH. We report here on a case of SIH with cerebrospinal fluid leakage at the upper cervical vertebral level and the middle thoracic vertebral level. The points of leakage were identified by radionuclide cisternography, and this patient was successfully managed by injecting an EBP at each level of leakage.

Inadvertent intradiscal injection during TFESI is not rare. Physicians who perform interventional pain procedures should increase their awareness of related potential complications. The aspiration test and static image of fluoroscope often fail to detect the intravascular injection during the TFESI. Real-time fluoroscopy should be the gold standard for confirming intravascular injection.

BackgroundTo investigate and analyze MRI findings in relation to visual analogue scale (VAS), Oswestry Disability Index (ODI), psychological-factor, sleep-quality, and Short-Form Health Survey (SF-36) scores among patients with central lumbar spinal stenosis (LSS) for the purpose of elucidating a correlation.MethodsFrom July 2013 to May 2014, 117 consecutive patients with central LSS were included in this study. All of the MRIs were evaluated by one of the authors, and the evaluated items were the dural sac cross-sectional area (DSCSA), the number of stenotic levels, and the presence and levels of spondylolisthesis. The ODI, VAS, 36-item SF-36, Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), and Pittsburgh Sleep Quality Index (PSQI) questionnaires were used to evaluate the participants.ResultsThere are no correlations between the ODI, VAS, BDI, BAI, PSQI, and SF-36 scores and the minimum DSCSA; however, a significant correlation was found between the ODI scores and multilevel LSS. The BDI, BAI, and PSQI scores are higher for multilevel LSS compared with single-level LSS, but the difference of this mean value is not statistically significant.ConclusionsA significant correlation was shown between those patients with multilevel LSS and the ODI scores; however, significant correlations were not found between the MRI findings and the psychological factors pertaining to sleep and life qualities.

A 64-year-old woman visited our pain clinic with the pain of right lateral side of thigh for one year. Her pain always started from knee and was radiated to buttock area when symptom was severe. She showed significant tenderness at knee lateral side and local tightness at lateral thigh. Magnetic resonance image of the knee was performed and we could identify high signal intensity of iliotibial band through coronal and axial view. In spite of medication and physical stretching exercise of iliotibial band for one month, she did not show any improvement of pain. To alleviate her symptom, ultrasound guided local corticosteroid injection targeting beneath the iliotibial band was performed. After the procedure, the reduction of pain was significant and there was no need for further management.