Edward C. Covington

Failed back surgery: etiology and diagnostic evaluation

BACKGROUND CONTEXT This is a synopsis of a symposium presented to the North American Spine Society Annual Meeting in Montreal, Canada, 2002. PURPOSE To provide the reader with a distillation of the material presented regarding the diagnosis of failed back surgery syndrome (FBSS). METHODS Panel presentation. RESULTS The proper treatment of patients with FBSS depends on a precise and accurate diagnosis. With a careful history, examination, imaging studies, psychological evaluation and diagnostic injections, a diagnosis can be reached in over 90% of patients. The most common diagnoses are foraminal stenosis (25% to 29%), painful disc (20% to 22%), pseudarthrosis (14%), neuropathic pain (10%), recurrent disc herniation (7% to 12%), facet joint pain (3%) and sacroiliac joint (SIJ) pain (2%). Psychological factors are always present and may help or hinder. Common psychological diagnoses include depression, anxiety disorder and substance abuse disorder. Diagnostic injections are very useful for facet joint pain, SIJ pain and discogenic pain; they may also be used to confirm a putative neural compression as a cause of pain. CONCLUSIONS Spine surgeons must be aware of the common causes of FBSS in order to be able to thoroughly evaluate their patients and to minimize the occurrence of this problem.

Long-term intraspinal infusions of opioids in the treatment of neuropathic pain

Long-term intraspinal infusions of opioid drugs are being increasingly utilized in patients with noncancer pain. Despite this, there is a lack of long-term information, including success and failure rates for pain relief and technical problems. During a 5-year period, 18 noncancer patients underwent implantation of programmable infusion pumps for long-term intrathecal opioid infusion. Patients had (a) neuropathic pain, (b) had failed or been ineligible for noninvasive treatments, and (c) obtained greater than 50% pain relief with intrathecal trial infusions of morphine sulfate or sufentanil citrate. A disinterested third-party reviewer evaluated patients at the most recent follow-up. Sixty-one percent (11/18) of patients had good or fair pain relief with mean follow-up 2.4 +/- 0.3 years (0.8-4.7 years). Average numeric pain scores decreased by 39% +/- 4.3%. Five of the 11 responders required lower opioid doses (12-24 mg/day morphine) and the remaining six patients required higher opioid doses (> 34 mg/day morphine). Failure of long-term pain relief occurred in 39% (7/18) despite good pain relief in trial infusions and the use of both morphine and sufentanil. Technical problems developed in 6/18 patients but appeared to be preventable with further experience. Long-term intrathecal opioid infusions can be effective in treatment of neuropathic pain but might require higher infusion doses.

Sufentanil citrate and morphine/bupivacaine as alternative agents in chronic epidural infusions for intractable non-cancer pain.

Intraspinal narcotic (usually intrathecal morphine) infusions with implanted pumps are increasingly used in patients with intractable chronic pain not caused by cancer. In some patients, pain control is difficult with infusions of morphine. Seven patients with diagnoses of arachnoiditis, epidural scarring, and/or vertebral body compression fracture were treated with alternative solutions in an epidural route. For maximal flexibility, Medtronic implanted programmable infusion pumps with catheters to T6-T10 were used, and pain was monitored by verbal pain scales. In three patients, epidural infusions of morphine in 0.5% bupivacaine (MS-MARC) resulted in little or no pain relief without significant side effects (e.g., headache, nausea, or vomiting). In these same patients, epidural infusions of sufentanil citrate resulted in pain scale reductions of 92%, 82%, and 40%, respectively, with no side effects. Four other patients found more effective pain relief when switched from initial sufentanil citrate infusions to MS-MARC. Pain scale reductions (with no side effects) were 92%, 76%, 59%, and 47% in these patients. Pain relief and minimal side effects with sufentanil citrate is theorized to result from its higher lipophilicity promoting local transdural diffusion to spinal cord and limiting upward diffusion to the brain stem. Sufentanil citrate is also advantageous for programmable pumps because it is 100 times more potent than morphine and therefore allows longer pump refill times and higher infusion doses. Although this study was done on a limited number of patients, sufentanil citrate and MS-MARC in epidural infusions using programmable infusion pumps for non-cancer patients provide significant alternative drug combinations and routes.

Spinal Cord Stimulation Versus Spinal Infusion for Low Back and Leg Pain

The relative roles of spinal cord stimulation and the spinal infusion of opioids in the treatment of chronic, non-cancer lower body pain remains unclear. This report contains a retrospective analysis of patients with chronic lower body, neuropathic pain and treated over a 5 year period. Unilateral leg and/or buttock pain was treated initially with spinal stimulation and bilateral leg or mainly low back pain was treated initially with spinal infusions. 26 patients received spinal stimulation. Pain relief was > or = 50% in 16 (62%) with increased activity levels. Stimulator coverage was most difficult or failed in patients with buttock pain. 16 patients received long-term spinal infusions. Pain relief was > or = 50% in 2 (13%) but 25-49% in another 8 (50%) with stable infusion doses and was best in patients requiring low-dose (< 1 mg/h morphine intrathecal) infusions in the trial period. The review indicates that spinal infusions may be best for bilateral or axial pain that has not responded to spinal stimulation. Clonidine appears to be an alternative in high-dose morphine patients. New diamond-shaped electrode and dual quadripolar arrays appear to be very helpful for back, buttock, and/or bilateral leg pain patterns.

Trigeminal cisternal injection of glycerol for treatment of chronic intractable cluster headaches.

Medical treatment of chronic cluster headaches (cluster headaches that occur frequently without remission) can be very difficult. In many patients, the pain remains severe despite all medication trials. For these patients, previous reports recommend radiofrequency trigeminal rhizotomy, which risks corneal anesthesia and subsequent corneal decompensation. As a safer, yet effective, treatment, retro-Gasserian injections of glycerol were given to eight patients having intractable chronic cluster headaches. Needle penetration into the trigeminal cistern, glycerol amount (0.55 ml), and length of patient elevation after the procedure (80-90 degrees upright for 10 h) were modified for maximal exposure of the V1 division. Three patients required one additional injection, and one patient required two additional injections. Verbal pain scales (means +/- 1 standard error of the mean) were: 9.1 +/- 0.30 (preoperative), 2.6 +/- 1.10 (1 mo postoperative), and 2.1 +/- 0.64 (1 yr postoperative). Daily headache frequency decreased from 6.0 +/- 2.0 (preoperative) to 0.2 +/- 0.09 (i.e., one headache every 5 days) (1 yr postoperative). Three of the eight patients had no headaches after 1 year. There were no instances of corneal or facial anesthesia. One year postoperatively, five patients required no medication, and three remained on low doses of medication for headache treatment. In contrast to previous limited reports of glycerol injections for cluster headaches, results with these patients having chronic cluster headaches support the use of glycerol injections as a viable treatment alternative, with significant pain relief and corneal safety.

Opioid Use 12 Months Following Interdisciplinary Pain Rehabilitation with Weaning

OBJECTIVES To examine the frequency of and factors predicting opioid resumption among patients with chronic non-cancer pain (CNCP) and therapeutic opioid addiction (TOA) treated in an interdisciplinary chronic pain rehabilitation program (CPRP) incorporating opioid weaning. DESIGN Longitudinal retrospective treatment outcome study. Only those with addiction were counseled to avoid opioids for non-acute pain. SETTING Large academic medical center. PARTICIPANTS One hundred twenty patients, 32.5% with TOA. Participants were predominately married (77.5%), females (66.7%). Mean age was 49.5 (±13.7). 29.2% had lifetime histories of non-opioid substance use disorders. METHODS TOA was diagnosed using consensus definitions developed by American Academy of Pain Medicine, American Pain Society and American Society of Addiction Medicine to supplement Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision (DSM-IV-TR) criteria. Non-opioid substance use disorders were diagnosed using DSM-IV-TR. Data, including pain severity, depression and anxiety, were collected at admission, discharge and 12 months. Opioid use during treatment was based on medical records and use at 12 months was based on self-report. RESULTS Only 22.5% reported resuming use at 12 months. Neither patients with TOA nor patients with non-opioid substance use disorders were more likely to resume use than those without substance use disorders. Only posttreatment depression increased the probability of resumption. CONCLUSIONS CNCP and co-occurring TOA can be successfully treated within a CPRP. Patients report low rates of resumption regardless of addiction status. This is in marked contrast to reported outcomes of non-medically induced opioid addictions. Prolonged abstinence may depend upon the successful treatment of depression.

Immediate Benefits of a Brief 10-Minute Exercise Protocol in a Chronic Pain Population: A Pilot Study

OBJECTIVE Determining the acute effects of a brief, 10-minute exercise protocol on pain, mood, and perceived exertion. PATIENTS Twenty-eight subjects who were admitted to the Cleveland Clinic Chronic Pain Rehabilitation Program (CPRP), and who were capable of completing an experimenter-designed and controlled treadmill protocol were included in this pilot study. METHODS A within-group repeated measure analysis was used to compare 28 subjects admitted to the Cleveland Clinic CPRP. Measures of heart rate were obtained using the Nellcor Oximax, pulse oximeter; measures of mood and pain were obtained using a 0-10 Likert scale, and perceived exertion measured with a visual analog scale. Each measure was taken pre- and post-10-minute exercise protocol. RESULTS The brief exercise protocol was associated with self-report of immediate antidepressant and anxiolytic effects. Additionally, after the 3-week CPRP, self-reports in perceived exertion decreased. Brief exercise was not found to have an acute analgesic effect. CONCLUSION This preliminary research revealed a temporal association of improvement in self-rated anxiety and depression, following a brief exercise protocol, and over the course of 3 weeks leads to decreased perceived exertion. Therefore suggesting that brief exercise is a safe, nonpharmacologic strategy for immediately improving mood, and has further implications for mortality risk.

Sustained improvements in pain, mood, function and opioid use post interdisciplinary pain rehabilitation in patients weaned from high and low dose chronic opioid therapy.

Abstract Increased prescribing of opioids for chronic noncancer pain is associated with significant social costs, including overdose and addiction. In this context, there is interest in interdisciplinary chronic pain rehabilitation programs focusing on self-management and minimizing opioid use. This study examined outcomes of patients weaned from opioids in an ICPRP from 2007 to 2012. Participants included 413 patients on high dose chronic opioid therapy (COT; >100 mg), 528 on low dose COT, and 516 not on opioids (NO). Outcomes were assessed at discharge, 6, and 12 months posttreatment through self-report and chart review. One thousand one hundred ninety-four participants completed treatment (81.95%); 86.74% of those on opioids were weaned. High doses were less likely to complete (78.45%) than NO participants (85.27%; P < 0.05). Results showed immediate (P < 0.01) and sustained improvements (P < 0.05) in pain severity, depression, anxiety, and functional impairment with no group differences. Effect sizes ranged from medium to large (Cohen d values 0.57-1.96). Longitudinal medication use data were available for 319 no dose and 417 weaned participants; opioid resumption rates were 10.51% and 30.70% respectively. There were no differences in resumption between the high dose and low dose groups. Logistic regression analyses determined that opioid dose predicted neither treatment completion nor opioid resumption. Anxiety predicted completion, and functional impairment predicted opioid resumption within 1 year of discharge. Results suggest that patients on COT can be successfully weaned with long-term benefits in pain, mood, and function. Targeting anxiety and functional restoration may increase success rates.

The Forgotten Ones: Challenges and Needs of Children Living with Disabling Parental Chronic Pain

A qualitative study explored the challenges and needs of children living with parental chronic pain. Young adult children (n=30) of parents with chronic pain were interviewed. Parents (n=20) with chronic pain participated in four focus groups. Content analysis yielded five categories of child challenges: (a) understanding the big picture; (b) enduring hardships; (c) grieving losses; (d) communicating with parent, and; (e) isolating self from peers. Three categories of child needs emerged: (a) knowledge; (b) skills, and; (c) supervised interaction. Understanding these challenges and needs is a vital step in the process of developing evidence-based interventions for this at-risk group.

Variability in the Relationship Between Sleep and Pain in Patients Undergoing Interdisciplinary Rehabilitation for Chronic Pain

OBJECTIVE Chronic pain and sleep disturbance frequently coexist and often complicate the course of treatment. Despite the well-established comorbidity, there are no studies that have investigated concurrent changes in sleep and pain among patients participating in an interdisciplinary chronic pain rehabilitation program (ICPRP). The goal of this study was to investigate the daily changes in sleep and pain among patients participating in an ICPRP. METHODS Multilevel modeling techniques were used to evaluate the daily changes in total sleep time (TST) and pain among a sample of 50 patients with chronic noncancer pain participating in the ICPRP. RESULTS Increases in TST were predictive of less pain the following treatment day, although daily pain ratings were not predictive of that nights TST. Time in treatment was a significant predictor of both TST and pain reduction, even while controlling for age, gender, anxiety, and depression. Additional analyses revealed significant individual variability in the relationship between TST and next day pain. Individuals with stronger associations between previous nights TST and next day pain were found to experience the greatest treatment benefits overall, in terms of pain reduction and TST. CONCLUSIONS Our results provide compelling support for individual variability of the pain-sleep relationship in patients with intractable pain conditions participating in an ICPRP. Importantly, these findings suggest that when pain and sleep are comorbid, both must be addressed to reap the maximum response to treatment programs such as an ICPRP. PERSPECTIVE STATEMENT This study demonstrates the utility of treating sleep problems in patients participating in an interdisciplinary chronic pain rehabilitation program. Results highlight the benefits of accounting for individual variability in the pain-sleep relationship in a clinical setting and targeting sleep interventions for those individuals whose pain and sleep problems are comorbid.