Predictors of analgesic efficacy of neurolytic celiac plexus block in patients with unresectable pancreatic cancer: the importance of timing.

BACKGROUND: Neurolytic celiac plexus block (NCPB) is a safe and effective method for reducing abdominal cancer pain. However, the analgesic efficacy of NCPB is not always guaranteed. The aim of this retrospective study was to identify predictors for the analgesic efficacy of NCPB in patients with unresectable pancreatic cancer. METHODS: Patients with unresectable pancreatic cancer who underwent NCPB from 2006 to 2015 were enrolled. Good analgesia after NCPB was defined as ≥ 50% reduction in pain score at day 30. Patient demographics, cancer characteristics, and pain-related factors were evaluated using a logistic regression analysis to identify predictors for good analgesia after NCPB. Additionally, survival outcomes were compared between patients with poor and good analgesia after NCPB. RESULTS: A total of 112 patients satisfied the study protocol requirements. Forty-seven patients (41.9%) showed good analgesia after NCPB. Better performance status, lower serum CA 19-9 level, shorter pain duration, and lower opioid dose were observed in patients with good analgesia after NCPB. Good performance status (ECOG performance status 1 vs. 2 or 3, OR = 2.737, 95% CI = 1.149 to 6.518, P = 0.023) and low daily opioid use (< 150 vs. ≥ 150 mg, OR = 2.813, 95% CI = 1.159 to 6.831, P = 0.022) before NCPB were independent predictors of good analgesia after NCPB. The median survival was significantly lower for patients with poor analgesia after NCPB (68 vs. 150 days, P < 0.001). CONCLUSION: NCPB should be offered early to selected patients to improve its analgesic efficacy in advance of deterioration from disease and pain in this population.

Botulinum Toxin Treatment for Nocturnal Calf Cramps in Patients With Lumbar Spinal Stenosis: A Randomized Clinical Trial.

OBJECTIVES: To evaluate the clinical effectiveness of botulinum toxin (BTX) injection into the gastrocnemius muscles in patients with lumbar spinal stenosis (LSS) who have frequent nocturnal calf cramps (NCCs). DESIGN: Prospective, randomized clinical trial. SETTING: Outpatient department for interventional pain management. PARTICIPANTS: Patients (N=50) with LSS who have NCCs at least once per week were enrolled. INTERVENTION: Patients were randomly allocated to receive either conservative treatments plus gabapentin (group GPN) or BTX injection (group BTX). MAIN OUTCOME MEASURES: We assessed back/leg pain intensity, the frequency and severity of NCCs, insomnia severity, and functional disability at baseline and after 2 weeks, 1 month, and 3 months. Additionally, Patient Global Impression of Change was assessed. RESULTS: Forty-five patients completed all assessments (group GPN, n=21; group BTX, n=24). Compared with group GPN, leg pain intensity, cramp frequency, and cramp severity were significantly decreased in group BTX at all follow-up visits (all, P<.01). Also, insomnia significantly improved in group BTX at the 2-week (P=.018) and 1-month follow-up (P=.037). Functional disability significantly improved in group BTX at 2 weeks' follow-up (P=.041). At the 3-month follow-up, patients in group BTX reported a higher impression of improvement for NCC symptoms than did those in group GPN (P<.001). A mean dose of 642.8mg of gabapentin was given daily in group GPN, but 7 patients (33.3%) reported systemic side effects. There were no serious complications related to BTX use. CONCLUSIONS: BTX treatment appears to be effective and safe for NCCs in symptomatic LSS patients receiving conservative care.

Factors Associated with Increased Risk for Clinical Insomnia in Patients with Postherpetic Neuralgia: A Retrospective Cross-Sectional Study.

OBJECTIVE: To determine the risk factors associated with clinical insomnia in postherpetic neuralgia (PHN) patients. DESIGN: A retrospective cross-sectional study. SETTING: Outpatient department for interventional pain management at a university hospital. SUBJECTS: A total of 111 patients with PHN satisfied the study inclusion criteria and were included in the analyses. METHODS: The Insomnia Severity Index (ISI) was used to determine the presence of clinical insomnia (ISI score ≥ 15). Patient demographics, pain-related factors, and rash severity and location were evaluated with logistic regression analysis to identify risk factors of clinical insomnia among patients with PHN. RESULTS: In total, 50.5% of patients reported mild to severe insomnia symptoms (ISI score ≥ 8) after pain development. Moderate to severe clinical insomnia (ISI score ≥ 15) was observed in 30.6% of PHN patients. Multivariate logistic regression analyses revealed that high pain intensity was the strongest predictor of clinical insomnia (odds ratio (OR) = 12.417, 95% confidence interval (CI): 2.990-51.561, P = 0.001). However, presence of mechanical allodynia (OR = 4.263, 95% CI: 1.040-17.481, P = 0.034) and high anxiety and depression level (OR = 4.452, 95% CI: 1.201-16.508, P = 0.026; OR = 6.975, 95% CI: 1.425-34.138, P = 0.017) were also significantly associated with clinical insomnia after adjusting for pain score. Clinical insomnia was not significantly related to age, gender, rash severity, or location of skin lesion. CONCLUSIONS: Insomnia should be addressed as an important part of pain management in PHN patients with these risk factors, especially in patients with severe pain.

Cross-cultural Adaptation and Linguistic Validation of the Korean Version of the Leeds Assessment of Neuropathic Symptoms and Signs Pain Scale.

Distinction between neuropathic pain and nociceptive pain helps facilitate appropriate management of pain; however, diagnosis of neuropathic pain remains a challenge. The aim of this study was to develop a Korean version of the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) pain scale and assess its reliability and validity. The translation and cross-cultural adaptation of the original LANSS pain scale into Korean was established according to the published guidelines. The Korean version of the LANSS pain scale was applied to a total of 213 patients who were expertly diagnosed with neuropathic (n = 113) or nociceptive pain (n = 100). The Korean version of the scale had good reliability (Cronbach's α coefficient = 0.815, Guttman split-half coefficient = 0.800). The area under the receiver operating characteristic curve was 0.928 with a 95% confidence interval of 0.885-0.959 (P < 0.001), suggesting good discriminate value. With a cut-off score ≥ 12, sensitivity was 72.6%, specificity was 98.0%, and the positive and negative predictive values were 98% and 76%, respectively. The Korean version of the LANSS pain scale is a useful, reliable, and valid instrument for screening neuropathic pain from nociceptive pain.

Clinical effectiveness of the obturator externus muscle injection in chronic pelvic pain patients.

BACKGROUND: Because of its anatomical location and function, the obturator externus (OE) muscle can be a source of pain; however, this muscle is understudied as a possible target for therapeutic intervention in pain practice. In this retrospective observational study, we evaluated the clinical effectiveness of the OE muscle injection with a local anesthetic in chronic pelvic pain patients with suspected OE muscle problems. METHODS: Twenty-three patients with localized tenderness on the inferolateral side of the pubic tubercle accompanied by pain in the groin, anteromedial thigh, or hip were studied. After identifying the OE with contrast dye under fluoroscopic guidance, 5 to 8 mL of 0.3% lidocaine was injected. Pain scores were assessed before and after injection; patient satisfaction was also assessed. RESULTS: Mean pain score decreased by 44.7% (6.6 ± 1.8 to 3.5 ± 0.9, P < 0.001) 2 weeks after OE muscle injection as compared with pain score before injection. In addition, 82% of patients (19 of 23 patients) reported excellent or good satisfaction during 2 weeks after injection. No patients reported complications from OE muscle injection. CONCLUSIONS: Fluoroscopy-guided injection of the OE muscle with local anesthetic reduced pain scores and led to a high level of satisfaction at short-term follow-up in patients with suspected OE muscle problem. The results of this study suggest that OE muscle injection may be a valuable therapeutic option for a select group of chronic pelvic pain patients who present with localized tenderness in the OE muscle that is accompanied by groin, anteromedial thigh, or hip pain.

Influence of Centrally Mediated Symptoms on Postoperative Pain in Osteoarthritis Patients Undergoing Total Knee Arthroplasty: A Prospective Observational Evaluation.

BACKGROUND: Central sensitization plays an important role in the chronic pain experienced by osteoarthritis (OA) patients. In this prospective observational study, we investigated the influence of the level of preoperative centrally mediated symptoms measured by the Central Sensitization Inventory (CSI) on pain intensity after total knee arthroplasty (TKA) for OA. METHODS: Ninety-eight female OA patients undergoing TKA were enrolled in this study. We assessed CSI scores, pain-related data, and other clinical data preoperatively. All patients received spinal anesthesia and postoperative epidural analgesia. Pain intensity (at rest and on movement) and rescue meperidine requirements were assessed during postoperative days 1 and 2. Also, pain intensity and patient satisfaction were assessed 1 month and 3 months after surgery. After the completion of all postoperative assessments, we separated the study population into a preoperative CSI score ≥40 and <40 group. We assessed pain-related data between the 2 groups at each assessment time. RESULTS: Ninety-one patients completed the postoperative assessments (a preoperative CSI ≥40 group; n = 44, CSI <40 group; n = 47). Patients with preoperative CSI ≥40 complained of a greater pain intensity (P = 0.001) during postoperative days 1 and 2 and required a higher dose of meperidine rescue (P = 0.003) than those with a preoperative CSI <40. The high CSI score group also showed a less favorable outcome in terms of pain relief on follow-up at 1 month (P = 0.006) and 3 months (P = 0.002) after surgery. In multivariate analysis, a preoperative CSI score ≥40 was the strongest determinant with 5.091 of the highest odds ratio (95% CI 1.324 to 19.523, P = 0.016) for predicting a persistent pain 3 months after surgery among demographic and pain-related variables. CONCLUSIONS: OA patients with high levels of comorbid centrally mediated symptoms showed severe pain and increased analgesic requirements after TKA in the early postoperative period. Moreover, these patients seemed to be at higher risk of persistent pain, and a high CSI score was predictive of low patient satisfaction in terms of pain relief after surgery.

Comparison of NSAID patch given as monotherapy and NSAID patch in combination with transcutaneous electric nerve stimulation, a heating pad, or topical capsaicin in the treatment of patients with myofascial pain syndrome of the upper trapezius: a pilot study.

OBJECTIVE: This study compared the therapeutic effect of monotherapy with a nonsteroidal anti-inflammatory drug (NSAID) patch vs an NSAID patch combined with transcutaneous electric nerve stimulation (TENS), a heating pad, or topical capsaicin in the treatment of patients with myofascial pain syndrome (MPS) of the upper trapezius. DESIGN: A randomized, single-blind, controlled study of combination therapy for patients with MPS was performed. METHODS: Ninety-nine patients were randomly assigned to one of four different self-management methods for treatment: NSAID patch (N = 25), NSAID patch + TENS (N = 24), NSAID patch + heating pad (N = 25), and NSAID patch + topical capsaicin (N = 25). The NSAID patch used in this study was a ketoprofen patch. All treatment groups were observed for 2 weeks, and the numeric rating scale (NRS) pain score, cervical active range of motion, pressure pain threshold, and Neck Disability Index were assessed. RESULTS: There was no significant difference between the NSAID patch alone group and the three combination therapy groups with respect to decrease in NRS score from baseline (day 0) to each period of observation. In covariate analysis, although there was no difference among the groups in most of the periods, the data at day 14 indicated a trend (P = 0.057). There were no significant differences in the other variables. CONCLUSIONS: We did not observe a statistical difference in improvements to the clinical variables among the four different methods. However, further studies regarding the effectiveness of a mixture of topical capsaicin and ketoprofen in patients with MPS should be considered.

An evaluation of contrast medium spread on caudal epidurography with the needle positioned toward the affected side in patients with unilateral lumbosacral radiculopathy.

OBJECTIVE: We used caudal epidurography to compare the spread of contrast medium when the needle was inserted toward the affected side in patients with unilateral radiculopathy undergoing caudal steroid injection. MATERIALS AND METHODS: We enrolled 24 patients with unilateral radiculopathy. A block needle was positioned toward the affected side in the sacral epidural space. After 5 mL of iodinated contrast medium was injected, a standardized anteroposterior view was imaged. Using Adobe Photoshop software, contrast medium spread was assessed by counting pixels within the areas spread on the affected side and on the opposite side, and the pixel counts of the two sides were compared. Spinal nerve root filling was also assessed. RESULTS: The pixel count within the area of contrast medium spread on the side with the needle was significantly greater than that of the opposite side (mean [SD] 41,368.6 [13,143.1] vs 15,165.3 (10,698.1), P < 0.001]. However, 13.6% of the study patients had greater spread on the opposite side. The rates of L5 and S1 nerve root filling in the affected side were 18.2% and 36.4% respectively. CONCLUSIONS: When a needle was intentionally inserted toward the side with radiculopathy, the spread of contrast medium and number of delineated roots tended to be greater on the side with the needle, compared with those on the opposite side. However, the pattern of contrast medium spread in the sacral epidural space varied and some patients even had greater spread on the opposite side.

Identification of the correct cervical level by palpation of spinous processes.

BACKGROUND: The ability to identify the correct vertebral level through examination is an important skill for clinicians who are performing nerve blocks without fluoroscopy. The conventional palpation method, which identifies the most prominent cervical spinous process as the seventh cervical (C7) spinous process is unreliable in many cases. We compared the accuracy of 2 different palpation methods used for identifying C7. METHODS: Ninety-six patients scheduled for cervical spine procedures under fluoroscopy guidance were randomized into either the control group or the flexion-extension group. The control group was examined with the conventional method, and the flexion-extension group was examined through assisted flexion and extension of the patient's cervical spine and identifying the lowest freely moving spinous process as C6 and the following stationary cervical spinous process as C7. A single anesthesiologist attempted to identify the C7 spinous process by using either the conventional method or the flexion-extension method and marked the presumed C7 spinous process with a radiopaque indicator. The actual vertebral level was then confirmed by fluoroscopy. The accuracy of the 2 different palpation techniques was compared, and the influence of patients' age, gender, and body mass index (BMI) was also examined. RESULTS: The C7 spinous process was correctly identified in 77.1% of patients in the flexion-extension group, compared with 37.5% in the control group (P<0.001). The C6 spinous process was identified as the most prominent cervical spinous process instead of C7 in 47.9% of patients in the control group, showing that errors are more common in the cephalad direction with the conventional method. The accuracy of the flexion-extension method was significantly higher than the conventional method regardless of the patient's age, gender, and BMI. Particularly, this difference in accuracy was seen not only in patients with a BMI <25 kg/m(2), but also in those with a BMI ≥25 kg/m(2) (BMI <25 kg/m(2), P=0.006 vs BMI ≥25 kg/m(2), P=0.008). CONCLUSIONS: The flexion-extension method is more accurate than the conventional method when identifying cervical vertebral level.

Sonographic estimation of needle depth for cervical epidural blocks.

BACKGROUND: Cervical epidural steroid injections are often used to treat acute and chronic pain syndromes involving the face, neck, and upper extremities. Ultrasound has evolved as a valuable tool for performing neuraxial blocks, providing useful prepuncture information on the structure. Our goal was to evaluate the accuracy and precision of ultrasound by comparing skin to dura distance from ultrasound with the actual skin to epidural depth. METHODS: We enrolled 50 patients undergoing cervical epidural blocks at the pain clinic. Ultrasound images with transverse and longitudinal median views of the C6/7 area were taken. The epidural needle was inserted, reproducing the direction of the ultrasound beam on the longitudinal median view. Measured distances from skin to dura on each ultrasound view were compared with the actual needle depth. Additionally, we examined ultrasound visibility, the number of puncture attempts, and any complications related to the procedure. RESULTS: Concordance correlation coefficients between the measured distances on ultrasound and actual needle depth were 0.9272 and 0.9268 on transverse and longitudinal median view, respectively. The cervical epidural block was successfully performed on 48 patients (96%). There were two incidents (4%) of dural puncture. No bloody taps, postprocedure complications, or hemodynamic instability related to cervical epidural blocks occurred. CONCLUSIONS: Ultrasound provides very accurate information on the skin to dura distance for epidural blocks in the cervical spine. Knowledge of skin to dura distance and a preview of spinal anatomy before puncture can more safely identify the epidural space.

Predictors of the analgesic efficacy of pulsed radiofrequency treatment in patients with chronic lumbosacral radicular pain: a retrospective observational study.

BACKGROUND: Pulsed radiofrequency (RF) targeting the adjacent dorsal root ganglion (DRG) is one treatment option for lumbosacral radicular pain. However, the analgesic efficacy of this procedure is not always guaranteed. The aim of this retrospective study was to identify the predictors of the analgesic efficacy of pulsed DRG RF treatment in patients with chronic lumbosacral radicular pain. METHODS: Patients who underwent pulsed DRG RF treatment from 2006 to 2017 at our clinic were enrolled. Positive response was defined as a ≥50% reduction in pain score from baseline at day 30. Patient demographics, pain-related factors, and clinical factors were evaluated using logistic regression analysis to identify the predictors of a positive response to the treatment. RESULTS: A total of 60 patients satisfied the study protocol requirements. Twenty-eight patients (46.7%) had a positive outcome. Multivariate logistic regression analysis revealed that the absence of comorbid musculoskeletal pain (OR=0.518, 95% CI=0.029-0.858, P=0.033) and positive response to previous epidural steroid injection (OR=3.269, 95% CI=1.046-10.215, P=0.042) were independent predictors of the analgesic efficacy of pulsed DRG RF treatment. CONCLUSION: Comorbid musculoskeletal pain and previous epidural injection response appear to affect the outcome of pulsed DRG RF treatment in patients with chronic lumbosacral radicular pain.

Comparison of Incidences of Intravascular Injection between Medial and Lateral Side Approaches during Traditional S1 Transforaminal Epidural Steroid Injection.

Purpose. Intravascular injection rates are higher during traditional S1 transforaminal epidural steroid injection (TFESI) compared with lumbar transforaminal injection. We compared the incidences of intravascular injection between the medial and lateral approaches to the S1 foramen during S1 TFESI. Materials and Methods. A total of 139 patients underwent one or more TFESIs (170 total injections). The patients received S1 TFESI by either medial or lateral side of S1 foramen under fluoroscopic anteroposterior view using digital subtraction method. The intravascular injection rates, epidural spread patterns, and contrast volumes required to reach the superior aspect of the L5-S1 intervertebral disc (SIVD) were compared between groups. Results. Intravascular injection rates during S1 TFESI were significantly lower in the medial approach compared with the lateral approach patients (4.9% versus 38.6%, resp., P < 0.001). The medial approach group had more epidural spread to the L5-S1 SIVD than the lateral group (82.1% versus 58.8%, resp.); lower contrast volume amounts were required to extend the L5-S1 SIVD (1.46 ± 0.48 versus 1.90 ± 0.62, resp.). Conclusion. During S1 TFESI, approaching the needle towards the medial part of the S1 foramen may reduce intravascular injection risk.

The Effect of Skin Pressure on Needle Entry Point Accuracy During Fluoroscopically Guided Lumbar Transforaminal Epidural Injections: A Randomized Clinical Trial.

OBJECTIVE: The aim of this study was to investigate the effect of skin pressure on needle entry point accuracy during fluoroscopically guided lumbar transforaminal epidural injection. DESIGN: This study is a prospective randomized clinical trial; 64 patients with a body mass index of 25 kg/m or greater were enrolled. For patients in the pressing group, the operator marked the needle entry point on the patient's back while pressing the patient's skin with the tip of an indicator. For patients in the nonpressing group, the tip of the indicator was gently positioned on the patient's skin. The data related to technical performance and radiation exposure during the procedure were compared. RESULTS: Sixty patients (nonpressing group, n = 30; pressing group, n = 30) were analyzed. There were more attempts to reposition the needle (n) and increased procedure time (in seconds) in the pressing group (median, 5 vs. 4 [P = 0.019]; 400.0 vs. 358.5 [P = 0.033]). The fluoroscopy time (in seconds) and the kerma-area product (in cGy cm) were also significantly longer and greater in the pressing group, respectively (median, 63.5 vs. 50.5 [P = 0.038]; 416.3 vs. 318.6 [P = 0.014]). CONCLUSIONS: This study shows that practitioners should not press the skin with a radiopaque indicator when determining the needle entry point by fluoroscopy during lumbar transforaminal epidural injection.

Ultrasound-guided lumbar medial-branch block: a clinical study with fluoroscopy control.

BACKGROUND AND OBJECTIVES: For diagnostic lumbar medial-branch blocks, fluoroscopic guidance is considered mandatory, but this technique comes with radiation exposure. The clinical feasibility of the ultrasound-guided lumbar medial-branch block has been demonstrated. We evaluated the success rate and validity of this new method by use of fluoroscopy controls in patients previously diagnosed with lumbar facet joint-mediated pain. METHODS: In 20 patients, 101 lumbar medial-branch blocks were performed under ultrasound guidance. The target point was the groove at the cephalad margin of the transverse process adjacent to the superior articular process. C-arm fluoroscopy was performed afterward to confirm the needle position. Pain scores were assessed by use of visual analog scale (VAS 0 to 100). RESULTS: All 101 needles were placed in the correct lumbar segment. Ninety-six of the 101 needletips were in the correct position with a success rate of 95%. Two needles were associated with intravascular spread of the contrast dye. VAS score was reduced from 52 to 16 after the block. CONCLUSIONS: Ultrasound-guided lumbar medial-branch blocks can be performed with a high success rate. However, to be completely independent from fluoroscopy controls, this technique requires further studies regarding the detection of intravascular spread.

Ultrasound-Guided Quadratus Femoris Muscle Injection in Patients with Lower Buttock Pain: Novel Ultrasound-Guided Approach and Clinical Effectiveness.

BACKGROUND: The quadratus femoris (QF) muscle is a possible source of lower buttock pain as evidenced by what is known about the pathophysiology of ischiofemoral impingement syndrome. However, there are few reports about the interventional management of the QF muscle as a pain generator. OBJECTIVE: To describe an ultrasound-guided QF muscle injection technique in patients with lower buttock pain suspected of QF muscle pathology and to report the result of treatment. STUDY DESIGN: Retrospective evaluation. SETTING: Outpatient department for interventional pain management at a university hospital. METHODS: We studied 14 patients who had deep tenderness localized to the lower buttock region at a point halfway between the lateral prominence of the greater trochanter and the ischial tuberosity corresponding to the location of the QF muscle belly. Under ultrasound guidance, 8 mL of 0.25% lidocaine was injected into the QF muscle. Pain scores were assessed prior to the first injection and 2 weeks after the last injection. Patient satisfaction was also assessed. RESULTS: When compared before and 2 weeks after last QF muscle injection, the mean pain score decreased by 49.3% (6.7 ± 2.3 to 3.4 ± 2.1, P < 0.001). Two weeks after the last injection, approximately 70% of patients (10 of 14 patients) expressed their satisfaction as excellent or good and the average frequency of injection was 2.5 times. There were no complications observed. LIMITATIONS: The results of this study should be considered preliminary owing to the small sample size and lack of a control group, and the retrospective characteristics of this study may have introduced a selection bias. CONCLUSIONS: Ultrasound-guided QF muscle injection with local anesthetic helps alleviate pain in patients with lower buttock pain attributed to the QF muscle, and leads to high levels of satisfaction for patients. A randomized placebo-controlled trial should be considered in the future.

Clinical Effectiveness of Ultrasound-guided Costotransverse Joint Injection in Thoracic Back Pain Patients.

Because of its anatomical location and function, the costotransverse (CTRV) joint can be a source of thoracic back pain. In this retrospective observational study, we evaluated the clinical effectiveness of the CTRV joint injection in thoracic back pain patients with suspected CTRV joint problems. We enrolled 20 thoracic back pain patients with localized tenderness that was provoked by the application of pressure on the affected CTRV joints. We injected it with 0.5 ml of a ropivacaine and triamcinolone mixture at each level. The mean pre-injection pain score decreased by 37.9% (7.2 ± 1.5 to 4.5 ± 1.7, P < 0.001) two weeks after CTRV joint injection. In addition, 70% of patients reported an excellent or good level of satisfaction. We demonstrated that an ultrasound-guided injection of the CTRV joint reduced patients' pain scores and led to a high level of satisfaction at short-term follow-ups in patients with suspected CTRV joint problems.

Factors Associated with Higher Reported Pain Levels in Patients with Chronic Musculoskeletal Pain: A Cross-Sectional, Correlational Analysis.

BACKGROUND: Chronic musculoskeletal pain is highly prevalent, disabling, and costly, and has many negative effects on quality of life. The aim of this study was to investigate factors associated with higher reported pain levels in patients with chronic musculoskeletal pain among demographic, clinical, and psychological factors, and to evaluate whether insomnia is independently associated with pain intensity in this population. METHODS: A total of 357 patients with chronic musculoskeletal pain (pain duration ≥ six months) satisfied the study inclusion criteria and were included in the analyses. Patient demographics, clinical, and psychological factors were evaluated with hierarchical multivariate logistic analysis to identify factors associated with severe pain (NRS [numeric rating scale] ≥ 7). Hierarchical linear regression analysis also performed to identify factors associated with pain intensity (0 to 10 NRS). RESULTS: Multivariate logistic analyses revealed older age (OR [odds ratio] = 1.017, 95% CI [confidence interval] 1.001-1.032, P = 0.034), high anxiety level (OR = 1.162, 95% CI 1.020-1.324, P = 0.024), high pain catastrophizing (OR = 1.043, 95% CI 1.007-1.081, P = 0.018), and severe insomnia (OR = 1.112, 95% CI 1.057-1.170, P<0.001) were significantly associated with severe pain. Hierarchical linear regression analysis showed age (ß = 0.106, P = 0.041), pain catastrophizing (ß = 0.249, P<0.001), and insomnia (ß = 0.286, P<0.001) were significantly associated with pain intensity. The variance in pain intensity explained by the final model was 32.2%. CONCLUSIONS: Older age, severe insomnia, and high pain catastrophizing were significantly associated with higher reported pain levels. Insomnia was independently associated with pain intensity, even after controlling for various demographic and clinical factors. These factors should be considered when devising pain management strategies for this population.

Factors associated with increased risk for pain catastrophizing in patients with chronic neck pain: A retrospective cross-sectional study.

Pain catastrophizing is becoming increasingly recognized as a clinically important psychological factor in chronic musculoskeletal pain. In this retrospective cross-sectional study, we have identified factors associated with an increased risk for pain catastrophizing in chronic neck pain (CNP) patients. We obtained data from our medical database on 331 patients who were treated for neck pain as their chief complaint at our clinic. The Pain Catastrophizing Scale (PCS) was used to define a high pain catastrophizing state (PCS score ≥21) in this study. Patient demographics, pain-related factors, and psychological factors were evaluated with logistic regression analysis to identify risk factors of high pain catastrophizing among patients with CNP. A total of 256 patients with CNP satisfied the study inclusion criteria and were included in the analyses. The median PCS score was 16 (range, 0-45), and 86 of 256 patients (33.5%) reported a PCS score ≥21. In multivariate analysis, high pain intensity, clinical insomnia, and a high level of depression/anxiety were strongly associated with high pain catastrophizing in patients with CNP. Depression was the strongest predictor of high pain catastrophizing, with an odds ratio of 7.35 (95% confidence interval 2.23-24.22). High pain catastrophizing was not significantly related to age, gender, comorbidities, or neck pain-related physical symptoms. In conclusion, poor psychological states should be addressed as an important part of pain management in CNP patients who are susceptible to high pain catastrophizing.

The effects of myofascial trigger point injections on nocturnal calf cramps.

BACKGROUND: The purpose of this study was to elucidate the effects of injection at trigger points on pain and sleep disturbance in patients with nocturnal calf cramps (NCCs). METHODS: Patients with NCCs that occurred at least once per week and who had myofascial trigger points (MTrPs) on the gastrocnemius muscles were enrolled in the study for 9 months. At the first visit (T0), we measured the intensity of NCC pain on an 11-point numeric rating scale, recorded the frequency of NCCs, and calculated the Insomnia Severity Index (ISI). We then checked for MTrPs on the gastrocnemius muscles and injected 1-2 mL of 0.25% lidocaine into each of the trigger points. At 1 (T1), 2 (T2), and 4 (T3) weeks after the first visit, we repeated the process performed at T0. RESULTS: Twelve patients completed the treatment schedule and attended the follow-up visits. Mean values of the numeric rating scale pain score, frequency of cramps, and ISI declined significantly at T1, T2, and T3 compared with baseline (all P < .01). Of 12 patients, 10 had clinical insomnia before treatment, and this number decreased significantly to 3 patients at T2 and 1 patient at T3 (P = .012 and P = .001, respectively). CONCLUSIONS: These preliminary data show that injection at MTrPs in patients with NCCs not only alleviated pain and reduced the frequency of cramps but also lessened the severity of insomnia as measured by the ISI. A larger randomized controlled trial is needed to confirm these findings and determine whether the effect lasts over the long term.

Factors Associated with Increased Risk for Clinical Insomnia in Patients with Chronic Neck Pain.

BACKGROUND: Insomnia is highly prevalent among people with chronic pain conditions. Because insomnia has been shown to worsen pain, mood, and physical functioning, it could negatively impact the clinical outcomes of patients with chronic pain. OBJECTIVE: To determine the risk factors associated with clinical insomnia in chronic neck pain (CNP) patients. STUDY DESIGN: Retrospective analysis. SETTING: Outpatient department for interventional pain management at a university hospital. METHODS: Data from 218 CNP patients were analyzed in this study. The Insomnia Severity Index (ISI) was used to determine the presence of clinical insomnia (ISI score ≥ 15). Patient demographics and pain-related factors were evaluated with logistic regression analysis to identify risk factors of clinical insomnia in CNP. RESULTS: In total, 53.7% of patients reported mild to severe insomnia after neck pain development; 22.9% of patients met the criteria for clinically significant insomnia (ISI score ≥ 15). In multivariate analysis, high pain intensity, the presence of comorbid musculoskeletal pain, and a high level of depression were strongly associated with clinical insomnia in patients with CNP. Among these factors, a greater level of depression was the strongest predictor of clinical insomnia, with the highest odds ratio of 3.689 (95% CI 1.570-8.667). LIMITATIONS: This study was conducted in a single clinical setting including a selected study population with a homogeneous racial background. The ISI does not include several sleep-related variables, the roles of which are unknown in determining insomnia severity. CONCLUSIONS: Insomnia should be addressed as an indispensable part of pain management in CNP patients with these risk factors, especially depression. CLINICAL TRIAL: This study is a retrospective analysis. IRB No: 4-2014-0801.