Mehul J. Desai

Biochemicals Associated With Pain and Inflammation are Elevated in Sites Near to and Remote From Active Myofascial Trigger Points

OBJECTIVES To investigate the biochemical milieu of the upper trapezius muscle in subjects with active, latent, or absent myofascial trigger points (MTPs) and to contrast this with that of the noninvolved gastrocnemius muscle. DESIGN We used a microanalytic technique, including needle insertions at standardized locations in subjects identified as active (having neck pain and MTP), latent (no neck pain but with MTP), or normal (no neck pain, no MTP). We followed a predetermined sampling schedule; first in the trapezius muscle and then in normal gastrocnemius muscle, to measure pH, bradykinin, substance P, calcitonin gene-related peptide, tumor necrosis factor alpha, interleukin 1beta (IL-1beta), IL-6, IL-8, serotonin, and norepinephrine, using immunocapillary electrophoresis and capillary electrochromatography. Pressure algometry was obtained. We compared analyte concentrations among groups with 2-way repeated-measures analysis of variance. SETTING A biomedical research facility. PARTICIPANTS Nine healthy volunteer subjects. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Preselected analyte concentrations. RESULTS Within the trapezius muscle, concentrations for all analytes were higher in active subjects than in latent or normal subjects (P<.002); pH was lower (P<.03). At needle insertion, analyte concentrations in the trapezius for the active group were always higher (pH not different) than concentrations in the gastrocnemius muscle. At all times within the gastrocnemius, the active group had higher concentrations of all analytes than did subjects in the latent and normal groups (P<.05); pH was lower (P<.01). CONCLUSIONS We have shown the feasibility of continuous, in vivo recovery of small molecules from soft tissue without harmful effects. Subjects with active MTPs in the trapezius muscle have a biochemical milieu of selected inflammatory mediators, neuropeptides, cytokines, and catecholamines different from subjects with latent or absent MTPs in their trapezius. These concentrations also differ quantitatively from a remote, uninvolved site in the gastrocnemius muscle. The milieu of the gastrocnemius in subjects with active MTPs in the trapezius differs from subjects without active MTPs.

A Critical Appraisal of the Evidence for Botulinum Toxin Type A in the Treatment for Cervico‐Thoracic Myofascial Pain Syndrome

Myofascial pain syndrome (MPS) is a musculoskeletal condition characterized by regional pain and muscle tenderness associated with the presence of myofascial trigger points (MTrPs). The last decade has seen an exponential increase in the use of botulinum toxin (BTX) to treat MPS. To understand the medical evidence substantiating the role of therapeutic BTX injections and to provide useful information for the medical practitioner, we applied the principles of evidence‐based medicine to the treatment for cervico‐thoracic MPS. A search was conducted through MEDLINE (PubMed, OVID, MDConsult), EMBASE, SCOPUS and the Cochrane database for the period 1966 to 2012 using the following keywords: myofascial pain, muscle pain, botulinum toxin, trigger points, and injections. A total of 7 trials satisfied our inclusion criteria and were evaluated in this review. Although the majority of studies found negative results, our analysis identified Gobel et al.s as the highest quality study among these prospectively randomized investigations. This was due to appropriate identification of diagnostic criteria, excellent study design and objective endpoints. The 6 other identified studies had significant failings due to deficiencies in 1 or more major criteria. We conclude that higher quality, rigorously standardized studies are needed to more appropriately investigate this promising treatment modality.

A Prospective, Randomized, Multicenter, Open-label Clinical Trial Comparing Intradiscal Biacuplasty to Conventional Medical Management for Discogenic Lumbar Back Pain

Study Design. This study was a prospective, randomized, crossover, multicenter trial for the evaluation of comparative effectiveness of intradiscal biacuplasty (IDB) versus conventional medical management (CMM) in the treatment of lumbar discogenic pain. Objective. The objective was to demonstrate the superiority of IDB over CMM in the treatment of discogenic pain with respect to the primary outcome measure. Summary of Background Data. Current therapeutic options for the treatment of chronic low back pain of discogenic origin are limited. CMM is often unsatisfactory with regard to the treatment of discogenic pain. IDB offers a minimally invasive treatment that has been demonstrated to be superior to placebo in the past. Methods. A total of 63 subjects with lumbar discogenic pain diagnosed via provocation discography were randomized to IDB + CMM (n = 29) or CMM-alone (n = 34). At 6 months, patients in the CMM-alone group were eligible for crossover if desired. The primary outcome measure was the change in visual analog scale (VAS) from baseline to 6 months. Secondary outcome measures included treatment “responders,” defined as the proportion of subjects with a 2-point or 30% decrease in VAS scores. Other secondary measures included changes from baseline to 6 months in (1) short form (SF) 36-physical functioning, (2) Oswestry Disability Index, (3) Beck Depression Inventory, (4) Patient Global Impression of Change, (5) EQ-5D VAS, and (6) back pain-related medication usage. Results. In the IDB cohort, the mean VAS score reduction exceeded that in the CMM cohort (−2.4 vs. −0.56; P = 0.02), and the proportion of treatment responders was substantially greater (50% vs. 18%). Differences in secondary measures favored IDB. No differences in opioid utilization were noted between groups. Conclusion. Superior performance of IDB with respect to all study outcomes suggests that it is a more effective treatment for discogenic pain than CMM-alone. Level of Evidence: 2

Demonstration of Lesions Produced by Cooled Radiofrequency Neurotomy for Chronic Osteoarthritic Knee Pain: A Case Presentation

This case presentation demonstrates radiographic evidence of lesions created following cooled radiofrequency (cRF) neurotomy of the knee. A 67‐year‐old man presented with chronic left knee osteoarthritis, pain, and disability. After a failed trial of conservative treatments, the patient underwent diagnostic genicular nerve blocks and subsequent cRF neurotomy of the left knee. Shortly after cRF, magnetic resonance imaging (MRI) of the left knee was performed. On MRI, lesions created by cRF ablation were identified. The images presented in this case offer a visual explanation for the success of cRF in the treatment of knee osteoarthritis.

Poster 171 Associations between Low Back Pain and Movement Patterns (B-PAM): A Prospective Registry Protocol

Results or Clinical Course: Based on the MRI findings, she was referred to neurosurgery and underwent L5/S1 laminectomy. Intraoperatively, these lesions were associated with several nerve roots. The extramedullary lesion was sent to pathology and was found to be positive for S100 protein immunostain, strongly indicative of a tumor derived from Schwann cells. At 2 month follow up, the patient noted significant improvement of her function and radicular pain. Discussion: Schwannomas are slow growing benign nerve sheath tumors. Schwannomatosis has been described as a distinct tumor syndrome separate from Neurofibromatosis. It is characterized by presence of Schwann cell hyperplasia. The dominant symptom is pain which worsens as the schwannoma enlarges, and compresses nerves and adjacent tissues. Conclusion: As in this case, the goal of surgery is to obtain a diagnosis as well as to provide symptomatic relief. However, complete surgical resection is generally not undertaken if there are multiple lesions throughout the spinal cord and/or cauda equina. Treatments for multiple progressive lesions primarily include radiation. The patient was also referred to medical genetics for further work-up.

Opioids in Abdominal Pain

The use of opioids in the setting of abdominal pain has nearly doubled in the last decade, making it a commonplace yet controversial practice. Although initially used predominantly for cancer pain and acute conditions, opioid use for chronic noncancerous pain has steadily increased along with the rates of abuse, misuse, and diversion. The variety of agents available have equally increased in recent years, giving the prescriber much to consider when weighing the drug’s properties with patient-related factors and special issues specific to opioids in the gastrointestinal tract. In light of the variables ultimately leading to the patient’s response, the opioid agent is often changed to a different type of formulation in order to maintain efficacy and minimize side effects. Overall, opioids must be prescribed on an individual basis with frequent monitoring for benefits as well as side effects and evidence of abuse.