Faculty Bibliography

Background Marijuana- both medical and recreational- is often used to manage pain and nausea. Some advocate for its use over traditional opioid therapy noting that it may be a safer and more effective alternative for treating chronic pain1,2. However, there is emerging evidence that marijuana may have adverse effects on pain and nausea. Activation of cannabinoid receptors inhibits GABAergic synaptic transmission in a number of central nervous system regions. The interneurons stop releasing the inhibitory neurotransmitters GABA and glycine3. Without these inhibitory signals, pain signaling to the brain intensifies3. This suggests cannabinoids can control the interneurons and potentially facilitate the transition of acute pain into chronic pain. Moreover, it appears cannabis can not only suppress nausea in certain situations, but also cause it in vulnerable patients. THC activates cannabinoid receptors in the enteric nervous system, which mediate nausea and vomiting4. Accumulation of THC in fatty tissues leads to enteric stimulation which can also lead to nausea4. Cannabinoid hyperemesis syndrome (CHS) is a disorder characterized by recurrent nausea, vomiting and abdominal pain5. It associated with chronic cannabis use. The short-term treatment of CHS is supportive care. Longterm treatment is aimed at discontinuing cannabis use. Objective To assess the potential link between myofascial pain affecting the abdominal musculature and marijuana use. To raise awareness about cannabinoid hyperemesis syndrome in patients with chronic pain who are not requesting opioid therapy. Case Presentation This is the case of a 22-year-old male who presented with acute on chronic abdominal pain and recurrent vomiting for over two years. He would vomit between one and seven times per day. He had developed multiple trigger points in the rectus abdominis, internal and external obliques, and transverse abdominis muscles. Diagnostically, the patient had a CT scan of the abdomen/ pelvis, which was unremarkable. He also had an endoscopy that was non-specific. He had multiple evaluations by various gastroenterologists and psychiatrists with no specific cause found for his symptoms. The patient had previously tried zofran, hydroxyzine, and sertraline without benefit. He reported smoking marijuana on a daily basis to address the pain and nausea. Over the treatment course, the patient received trigger point injections at the most painful areas. He returned three times over the course of six months to repeat the trigger point injections. It soon became apparent that the vomiting, which had caused the trigger points to form, was secondary to marijuana use. The patient was subsequently referred to a multidisciplinary Addiction Disorders clinic. The patient experienced > 50% relief of his chronic abdominal pain with a combination of trigger point injections and abstinence from marijuana. Conclusion Although many advocates suggest cannabis could be effective for relieving non-malignant chronic pain syndromes such as myofascial pain syndrome, there are some reports that pain may be increased with the use of this drug. To our knowledge, this is the first case in the literature of marijuana discontinuation, in combination with trigger point injections, leading to a greater than 50% improvement in myofascial pain symptoms in the abdomen and pelvis. Daily forceful vomiting can cause trigger points to form in the abdomen and pelvis. CHS can cause multiple episodes of vomiting per day5. Therefore, there may be a link between the two conditions. Patients with myofascial pain syndrome and CHS may present in the pain management office setting. Pain physicians treating patients with unexplained nausea and vomiting as well as abdominal myofascial pain should consider further assessing these patients for recreational drug use. CHS is a potential cause of chronic pain in a minority of patients. (Figure Presented)

BACKGROUND: Epidural injections have been used since 1901 in managing low back pain and sciatica. Spinal pain, disability, health, and economic impact continue to increase, despite numerous modalities of interventions available in managing chronic spinal pain. Thus far, systematic reviews performed to assess the efficacy of epidural injections in managing chronic spinal pain have yielded conflicting results. OBJECTIVE: To evaluate and update the clinical utility of the efficacy of epidural injections in managing chronic spinal pain. STUDY DESIGN: A systematic review of randomized controlled trials of epidural injections in managing chronic spinal pain. METHODS: In this systematic review, randomized trials with a placebo control or an active-control design were included. The outcome measures were pain relief and functional status improvement. The quality of each individual article was assessed by Cochrane review criteria, as well as the Interventional Pain Management Techniques - Quality Appraisal of Reliability and Risk of Bias Assessment (IPM-QRB). Best evidence synthesis was conducted based on the qualitative level of evidence (Level I to V). Data sources included relevant literature identified through searches of PubMed for a period starting in 1966 through August 2015; Cochrane reviews; and manual searches of the bibliographies of known primary and review articles. RESULTS: A total of 52 trials met inclusion criteria. Meta-analysis was not feasible. The evidence in managing lumbar disc herniation or radiculitis is Level II for long-term improvement either with caudal, interlaminar, or transforaminal epidural injections with no significant difference among the approaches. The evidence is Level II for long-term management of cervical disc herniation with interlaminar epidural injections. The evidence is Level II to III in managing thoracic disc herniation with an interlaminar approach. The evidence is Level II for caudal and lumbar interlaminar epidural injections with Level III evidence for lumbar transforaminal epidural injections for lumbar spinal stenosis. The evidence is Level II for cervical spinal stenosis management with an interlaminar approach. The evidence is Level II for axial or discogenic pain without facet arthropathy or disc herniation treated with caudal or lumbar interlaminar injections in the lumbar region; whereas it is Level II in the cervical region treated with cervical interlaminar epidural injections. The evidence for post lumbar surgery syndrome is Level II with caudal epidural injections and for post cervical surgery syndrome it is Level II with cervical interlaminar epidural injections. LIMITATIONS: Even though this is a large systematic review with inclusion of a large number of randomized controlled trials, the paucity of high quality randomized trials literature continues to confound the evidence. CONCLUSION: This systematic review, with an assessment of the quality of manuscripts and outcome parameters, shows the efficacy of epidural injections in managing a multitude of chronic spinal conditions. KEY WORDS: Chronic pain, spinal pain, epidural injections, local anesthetic, steroids, interlaminar epidural injections, caudal epidural injections, transforaminal epidural injections.

BACKGROUND: The sacroiliac joint is well known as a cause of low back and lower extremity pain. Prevalence estimates are 10% to 25% in patients with persistent axial low back pain without disc herniation, discogenic pain, or radiculitis based on multiple diagnostic studies and systematic reviews. However, at present there are no definitive management options for treating sacroiliac joint pain. OBJECTIVE: To evaluate the diagnostic accuracy and therapeutic effectiveness of sacroiliac joint interventions. STUDY DESIGN: A systematic review of the diagnostic accuracy and therapeutic effectiveness of sacroiliac joint interventions. METHODS: The available literature on diagnostic and therapeutic sacroiliac joint interventions was reviewed. The quality assessment criteria utilized were the Quality Appraisal of Reliability Studies (QAREL) checklist for diagnostic accuracy studies, Cochrane review criteria to assess sources of risk of bias, and Interventional Pain Management Techniques - Quality Appraisal of Reliability and Risk of Bias Assessment (I

OBJECTIVE: To assess the validity of fluoroscopically guided diagnostic intra-articular injections of local anesthetic and effectiveness of intra-articular steroid injections in treating sacroiliac joint (SIJ) pain. DESIGN: Systematic review INTERVENTIONS: Ten reviewers independently assessed 45 publications on diagnostic validity or effectiveness of fluoroscopically guided intra-articular SIJ injections. OUTCOME MEASURES: For diagnostic injections, the primary outcome was validity; for therapeutic injections, analgesia. Secondary outcomes were also described. RESULTS: Of 45 articles reviewed, 39 yielded diagnostic data on physical exam findings, provocation tests, and SIJ injections for diagnosing SIJ pain, and 15 addressed therapeutic effectiveness. When confirmed by comparative local anesthetic blocks with a high degree of pain relief, no single physical exam maneuver predicts response to diagnostic injections. When at least three physical exam findings are present, sensitivity, and specificity increases significantly. The prevalence of SIJ pain is likely 20-30% among patients that have suspected SIJ pain based on history and physical examination. This estimate may be higher in certain subgroups such as the elderly and fusion patients. Two randomized controlled trials and multiple observational studies supported the effectiveness of therapeutic sacroiliac joint injections. CONCLUSIONS: Based on this literature, it is unclear whether image-guided intra-articular diagnostic injections of local anesthetic predict positive responses to therapeutic agents. The overall quality of evidence is moderate for the effectiveness of therapeutic SIJ injections.

BACKGROUND: The therapeutic spinal facet joint interventions generally used for the treatment of axial spinal pain of facet joint origin are intraarticular facet joint injections, facet joint nerve blocks, and radiofrequency neurotomy. Despite interventional procedures being common as treatment strategies for facet joint pathology, there is a paucity of literature investigating these therapeutic approaches. Systematic reviews assessing the effectiveness of various therapeutic facet joint interventions have shown there to be variable evidence based on the region and the modality of treatment utilized. Overall, the evidence ranges from limited to moderate. OBJECTIVE: To evaluate and update the clinical utility of therapeutic lumbar, cervical, and thoracic facet joint interventions in managing chronic spinal pain. STUDY DESIGN: A systematic review of therapeutic lumbar, cervical, and thoracic facet joint interventions for the treatment of chronic spinal pain. METHODS: The available literature on lumbar, cervical, and thoracic facet joint interventions in managing chronic spinal pain was reviewed. The quality assessment criteria utilized were the Cochrane Musculoskeletal Review Group criteria and Interventional Pain Management Techniques - Quality Appraisal of Reliability and Risk of Bias Assessment (I

BACKGROUND: Spinal zygapophysial, or facet, joints are a source of axial spinal pain and referred pain in the extremities. Conventional clinical features and other noninvasive diagnostic modalities are unreliable in diagnosing zygapophysial joint pain. STUDY DESIGN: A systematic review of the diagnostic accuracy of spinal facet joint nerve blocks. OBJECTIVE: To determine the diagnostic accuracy of spinal facet joint nerve blocks in chronic spinal pain. METHODS: A methodological quality assessment of included studies was performed using Quality Appraisal of Reliability Studies (QAREL). Only diagnostic accuracy studies meeting at least 50% of the designated inclusion criteria were utilized for analysis. The level of evidence was classified as Level I to V based on the grading of evidence utilizing best evidence synthesis. Data sources included relevant literature identified through searches of PubMed and other electronic searches published from 1966 through March 2015, Cochrane reviews, and manual searches of the bibliographies of known primary and review articles. OUTCOME MEASURES: Studies must have been performed utilizing controlled local anesthetic blocks. The criterion standard must have been at least 50% pain relief from baseline scores and the ability to perform previously painful movements. RESULTS: The available evidence is Level I for lumbar facet joint nerve blocks with the inclusion of a total of 17 studies with dual diagnostic blocks, with at least 75% pain relief with an average prevalence of 16% to 41% and false-positive rates of 25% to 44%. The evidence for diagnosis of cervical facet joint pain with cervical facet joint nerve blocks is Level II based on a total of 11 controlled diagnostic accuracy studies, with significant variability among the prevalence in a heterogenous population with internal inconsistency. The prevalence rates ranged from 36% to 67% with at least 80% pain relief as the criterion standard and a false-positive rate of 27% to 63%. The level of evidence for the diagnostic accuracy of thoracic facet joint nerve blocks is Level II with 80% or higher pain relief as the criterion standard with a prevalence ranging from 34% to 48% and false-positive rates ranging from 42% to 48%. LIMITATIONS: The shortcomings of this systematic review include a paucity of literature related to the thoracic spine, continued debate on an appropriate gold standard, appropriateness of diagnostic blocks, and utility. CONCLUSION: The evidence is Level I for the diagnostic accuracy of lumbar facet joint nerve blocks, Level II for cervical facet joint nerve blocks, and Level II for thoracic facet joint nerve blocks in assessment of chronic spinal pain. KEY WORDS: Chronic spinal pain, lumbar facet or zygapophysial joint pain, cervical facet or zygapophysial joint pain, thoracic facet or zygapophysial joint pain, facet joint nerve blocks, medial branch blocks, controlled comparative local anesthetic blocks.

BACKGROUND: Lumbar discogenic pain without pain mediated by a disc herniation, facet joints, or the sacroiliac joints, is common and often results in chronic, persistent pain and disability. After conservative treatment failure, injection therapy, such as an epidural injection, is frequently the next step considered in managing discogenic pain. The objective of this systematic review is to determine the efficacy of lumbar epidural injections in managing discogenic pain without radiculopathy, and compare this approach to lumbar fusion or disc arthroplasty surgery. METHODS: A systematic review of randomized trials published from 1966 through October 2014 of all types of epidural injections and lumbar fusion or disc arthroplasty in managing lumbar discogenic pain was performed with methodological quality assessment and grading of evidence. The level of evidence was based on the grading of evidence criteria which, was conducted using 5 levels of evidence ranging from levels I to V. RESULTS: Based on a qualitative assessment of the evidence for both approaches, there is Level II evidence for epidural injections, either caudal or lumbar interlaminar. CONCLUSIONS: The available evidence suggests fluoroscopically directed epidural injections provide long-term improvement in back and lower extremity pain for patients with lumbar discogenic pain. There is also limited evidence showing the potential effectiveness of surgical interventions compared to nonsurgical treatments.

BACKGROUND: The high prevalence of chronic persistent neck pain not only leads to disability but also has a significant economic, societal, and health impact. Among multiple modalities of treatments prescribed in the management of neck and upper extremity pain, surgical, interventional and conservative modalities have been described. Cervical epidural injections are also common modalities of treatments provided in managing neck and upper extremity pain. They are administered by either an interlaminar approach or transforaminal approach. OBJECTIVES: To determine the long-term efficacy of cervical interlaminar and transforaminal epidural injections in the treatment of cervical disc herniation, spinal stenosis, discogenic pain without facet joint pain, and post surgery syndrome. METHODS: The literature search was performed from 1966 to October 2014 utilizing data from PubMed, Cochrane Library, US National Guideline Clearinghouse, previous systematic reviews, and cross-references. The evidence was assessed based on best evidence synthesis with Level I to Level V. RESULTS: There were 7 manuscripts meeting inclusion criteria. Of these, 4 assessed the role of interlaminar epidural injections for managing disc herniation or radiculitis, and 3 assessed these injections for managing central spinal stenosis, discogenic pain without facet joint pain, and post surgery syndrome. There were 4 high quality manuscripts. A qualitative synthesis of evidence showed there is Level II evidence for each etiology category. The evidence is based on one relevant, high quality trial supporting the efficacy of cervical interlaminar epidural injections for each particular etiology. There were no randomized trials available assessing the efficacy of cervical transforaminal epidural injections. LIMITATIONS: Paucity of available literature, specifically conditions other than disc herniation. CONCLUSION: This systematic review with qualitative best evidence synthesis shows Level II evidence for the efficacy of cervical interlaminar epidural injections with local anesthetic with or without steroids, based on at least one high-quality relevant randomized control trial in each category for disc herniation, discogenic pain without facet joint pain, central spinal stenosis, and post surgery syndrome.

BACKGROUND: The efficacy of epidural and facet joint injections has been assessed utilizing multiple solutions including saline, local anesthetic, steroids, and others. The responses to these various solutions have been variable and have not been systematically assessed with long-term follow-ups. METHODS: Randomized trials utilizing a true active control design were included. The primary outcome measure was pain relief and the secondary outcome measure was functional improvement. The quality of each individual article was assessed by Cochrane review criteria, as well as the criteria developed by the American Society of Interventional Pain Physicians (ASIPP) for assessing interventional techniques. An evidence analysis was conducted based on the qualitative level of evidence (Level I to IV). RESULTS: A total of 31 trials met the inclusion criteria. There was Level I evidence that local anesthetic with steroids was effective in managing chronic spinal pain based on multiple high-quality randomized controlled trials. The evidence also showed that local anesthetic with steroids and local anesthetic alone were equally effective except in disc herniation, where the superiority of local anesthetic with steroids was demonstrated over local anesthetic alone. CONCLUSION: This systematic review showed equal efficacy for local anesthetic with steroids and local anesthetic alone in multiple spinal conditions except for disc herniation where the superiority of local anesthetic with steroids was seen over local anesthetic alone.

OBJECTIVES: This study's objective was to determine if the literature supports use of the Minimally Invasive Lumbar Decompression (mild(R)) procedure (Vertos Medical, Aliso Viejo, CA, USA) to reduce pain and improve function in patients with symptomatic degenerative lumbar spinal stenosis. DESIGN/SETTINGS: The study was designed as an evidence-based review of available data. Studies were identified from PubMed, Embase, and the Cochrane Library. Articles were evaluated using the Grading of Recommendations Assessment, Development and Evaluation Working Group system. Results were compiled assessing short- (4-6 weeks), medium- (3-6 months), and long-term (>1 year) outcomes. The primary outcomes evaluated were pain, measured by the visual analog scale (VAS), and function, measured by the Oswestry Disability Index (ODI). Secondary outcomes included pain and patient satisfaction, measured by the Zurich Claudication Questionnaire, adverse effects/complications, and changes in utilization of co-interventions. RESULTS: The literature search revealed one randomized controlled trial (RCT) and 12 other studies (seven prospective cohort, four retrospective, and one case series) that provided information on the use of mild(R) in patients with degenerative lumbar spinal stenosis. All studies showed statistically significant improvements in VAS and ODI scores at all time frames compared with preprocedure levels; the RCT showed improvement over controls. Categorical data were not provided; thus, the proportion of patients who experienced minimal clinically meaningful outcomes is unknown. CONCLUSION: The current body of evidence addressing mild(R) is of low quality. High-quality studies that are independent of industry funding and provide categorical data are needed to clarify the proportions of patients who benefit from mild(R) and the degree to which these patients benefit. Additional data at up to 2 years are needed to determine the overall utility of the procedure.