Percutaneous Disc Decompression for Lumbar Radicular Pain: A Review Article.

BACKGROUND: Open discectomy remains the standard of treatment for patients with lumbar radicular pain secondary to a prolapsed intervertebral disc. Open discectomy performed in patients with small, contained herniations may result in poor outcomes. The various techniques of percutaneous disc decompression (PDD) have been developed to address this population. METHODS: A literature search was conducted on articles, which address PDD for lumbar radicular pain. Published techniques include chymopapain chemonucleolysis, percutaneous laser disc decompression (PLDD), automated percutaneous lumbar discectomy (APLD), Dekompressor, nucleoplasty, and targeted disc decompression (TDD). In addition, the rationale of provocative discography, selective nerve root injections, and intra-op discograms before performing PDD is discussed in detail. RESULTS: Dekompressor and nucleoplasty have the best level of evidence with a score of 2B+. The chymopapain chemonucleolysis has the most publications, but it is also accompanied by the most significant adverse complications and so it is scored as a 2B+/-. The other techniques are supported mainly by observational studies and thus their scores range between 0 and 2B+/-. There is no supporting evidence for provocative discography in patients with lumbar radicular pain. The evidence for a positive selective nerve root injection as an inclusion criteria or the need for an intra-op discogram shows mixed results. CONCLUSIONS: Nucleoplasty and Dekompressor have a weak positive recommendation for the treatment of patients with lumbar radicular pain. There is no role for provocative discography in this group of patients, although the evidence for a selective nerve root injection or an intra-op discogram is inconclusive.

The long-term efficacy and safety of percutaneous cervical nucleoplasty in patients with a contained herniated disk.

BACKGROUND: Percutaneous cervical nucleoplasty (PCN) is a safe and effective treatment in symptomatic patients with contained cervical herniated disks. It provides simple and efficient disk decompression, using a controlled and highly localized ablation, but evidence regarding long-term efficacy is limited. We conducted a retrospective study to investigate the long-term efficacy and safety of PCN, and the influence of ideal selection settings. METHODS: A total of 27 patients treated with PCN fulfilling ideal selection criteria (Group A) were studied and compared to 42 patients not meeting these criteria (Group B). Outcomes were assessed using the Visual Analogue Scale (VAS) and a four-level Likert item for perceived pain and satisfaction, the Neck Disability Index (NDI), and the Short Form 36 (SF-36). Additional relevant outcomes were retrieved from medical records. RESULTS: The postoperative mean VAS pain for Group A was 29.9 (SD ± 32.6) at a mean follow-up of 24 months (range: 2-45). Only 10% of these patients reported mild transient adverse events. There was a trend, but no difference between both groups in pain scores; however, treatment satisfaction was higher for Group A (74.1 ± 27.2-55.5 ± 31.4, P = 0.02). Group A also reported better physical functioning based on the Physical Component Summary (43.6 ± 10.6-37.3 ± 12.0, P = 0.03) and showed a larger proportion of patients no longer using any medication postoperatively (63-26%, P = 0.01). CONCLUSION: These results show long-term effectiveness and safety of PCN in patients with a one-level contained cervical herniated disk, and the reliance of selecting patients meeting ideal criteria for successful PCN.

Comparing the analgesia effects of single-injection and continuous femoral nerve blocks with patient controlled analgesia after total knee arthroplasty.

We compared the analgesic effects of single-injection or continuous femoral nerve block (FNB) with intravenous patient controlled analgesia (PCA) opioids. Two hundred patients undergoing knee arthroplasty were randomized to one of the three regimens. Significant knee pain on movement at postoperative 24h was reduced with single-injection (OR 0.30; 95% CI 0.12 to 0.74; P=0.009) or continuous (OR 0.21; 95% CI 0.08 to 0.51; P=0.001) FNB, compared with PCA. Allocation to FNBs also resulted in significantly less opioid consumption, fewer episodes of nausea and vomiting, and achieved knee flexion 90° earlier than allocation to PCA. Compared to single-injection FNB, patients with continuous FNB had lower pain scores on movement at 24h (mean difference -0.57; 95% CI -1.14 to -0.01; P=0.045), consumed less opioid, and had fewer incidences of nausea and vomiting. The analgesic efficacy of single-injection and continuous FNBs was superior to PCA in the immediate postoperative period; with continuous FNB providing better analgesia than single-injection FNB.

Understanding cervicogenic headache.

The purported mechanism underlying the development and progression of cervicogenic headache (CEH) is the convergence of sensory inputs at the trigeminocervical nucleus. This mechanism explains the radiation of pain from the neck or the occipitonuchal area and its spread to the oculo-fronto-temporal region; it also explains the recurrent headaches caused by improper neck postures or external pressure to the structures in the neck and the occipital region. These neural connectivity mechanisms involving the trigeminal nucleus are also evident from the eyeblink reflex and findings of quantitative sensory testing (QST). Understanding the mechanisms underlying the development of CEH is important because it will not only provide a better treatment outcome but will also allow practitioners to appreciate the variability of symptomatic presentations in these patients.

Do diagnostic blocks have beneficial effects on pain processing?

BACKGROUND AND OBJECTIVES: Diagnostic blocks of cervical zygapophysial joints have been used as part of the management strategy for patients with chronic neck pain. Little information is available regarding the sensory processing changes that occur after these common procedures. In a hypothesis-generating prospective study, the pressure-pain thresholds, electrical pain thresholds, and descending inhibitory modulation response using the conditioned pain modulation paradigm are described for 9 patients with cervical zygapophysial joint pain that underwent successful comparative diagnostic blocks. METHODS: The study was designed as a prospective cross-sectional study in 9 patients with cervical zygapophysial joint pain with positive comparative diagnostic blocks using lidocaine and bupivacaine. Each patient underwent baseline Quantitative Sensory Testing (QST) measurement (QST 1) after inclusion. Subsequent QST measurements (QST 2 and 3) were performed only after comparative blocks proved positive and only after the neck pain returned after each diagnostic block. RESULTS: Despite the return of their neck pain after the local anesthetic agents wore off, the patients exhibited (1) less focal pressure hyperalgesia, (2) generalized electrical hypoalgesia, and (3) significantly reduced conditioned pain modulation responses. CONCLUSIONS: Our preliminary evidence suggests that the perturbations to the sensory processing system from effective diagnostic blocks affect the tonic inhibitory system in a positive manner. Conditioned pain modulation, however, needs to be interpreted in the context of altered pain thresholds, and future studies should aim to investigate the shift in the nociceptive balance between facilitatory and inhibitory control after therapeutic interventions.

Differences in sensory processing between chronic cervical zygapophysial joint pain patients with and without cervicogenic headache.

BACKGROUND: It is not known why some patients with underlying chronic nociceptive sources in the neck develop cervicogenic headache (CEH) and why others do not. This quantitative sensory testing (QST) study systematically explores the differences in sensory pain processing in 17 CEH patients with underlying chronic cervical zygapophysial joint pain compared to 10 patients with chronic cervical zygapophysial joint pain but without CEH. METHODS: The QST protocol comprises pressure pain threshold testing, thermal detection threshold testing, electrical pain threshold testing and measurement of descending inhibitory modulation using the conditioned pain modulation (CPM) paradigm. RESULTS: The main difference between patients with or without CEH was the lateralization of pressure hyperalgesia to the painful side of the head of CEH patients, accompanied by cold as well as warm relative hyperesthesia on the painful side of the head and neck. DISCUSSION: From this hypothesis-generating study, our results suggest that rostral neuraxial spread of central sensitization, probably to the trigeminal spinal nucleus, plays a major role in the development of CEH.

Percutaneous thoracic intervertebral disc nucleoplasty: technical notes from 3 patients with painful thoracic disc herniations.

Symptomatic thoracic disc herniation is an uncommon condition and early surgical approaches were associated with significant morbidity and even mortality. We are the first to describe the technique of percutaneous thoracic nucleoplasty in three patients with severe radicular pain due to thoracic disc herniation. Two of the patients experienced more than 75% pain relief and one patient experienced more than 50% pain relief. Post-procedural pain relief was maintained up to an average of 10 months after nucleoplasty. One patient with preoperative neurological signs improved postoperatively. There were no reported complications in all three patients. In view of the reduced morbidity and shorter operating time, thoracic intervertebral disc nucleoplasty can be considered in patients with pain due to thoracic disc herniation, with no calcification of the herniated disc, and in patients who may be otherwise be unfit for conventional surgery.

Quantitative sensory testing may predict response to sphenopalatine ganglion pulsed radiofrequency treatment in cluster headaches: a case series.

Pulsed radiofrequency treatment has been described as a nonablative alternative to radiofrequency thermocoagulation for the management of certain chronic pain syndromes. We present our first three patients with long-standing cluster headaches who were treated with pulsed radiofrequency to the sphenopalatine ganglion. All three patients have had cluster headaches for more than 10 years' duration and experienced minimal relief with conservative treatment. An excellent midterm effect was achieved in two of the three patients and a partial effect in one. No neurological side effects or complications were reported. Quantitative sensory testing consisting of allodynia testing, pressure-pain thresholds, electrical pain thresholds, and conditioned pain modulation (CPM) response testing were used to monitor their sensory processing changes before and after the procedure. From this case series, it might be that cluster headache patients with an impaired CPM response with or without signs of allodynia will respond less favorably to interventional treatment. Further studies are required to validate this hypothesis.

Pulsed radiofrequency treatment in interventional pain management: mechanisms and potential indications-a review.

BACKGROUND: The objective of this review is to evaluate the efficacy of Pulsed Radiofrequency (PRF) treatment in chronic pain management in randomized clinical trials (RCTs) and well-designed observational studies. The physics, mechanisms of action, and biological effects are discussed to provide the scientific basis for this promising modality. METHODS: We systematically searched for clinical studies on PRF. We searched the MEDLINE (PubMed) and EMBASE database, using the free text terms: pulsed radiofrequency, radio frequency, radiation, isothermal radiofrequency, and combination of these. We classified the information in two tables, one focusing only on RCTs, and another, containing prospective studies. Date of last electronic search was 30 May 2010. The methodological quality of the presented reports was scored using the original criteria proposed by Jadad et al. FINDINGS: We found six RCTs that evaluated the efficacy of PRF, one against corticosteroid injection, one against sham intervention, and the rest against conventional RF thermocoagulation. Two trials were conducted in patients with lower back pain due to lumbar zygapophyseal joint pain, one in cervical radicular pain, one in lumbosacral radicular pain, one in trigeminal neuralgia, and another in chronic shoulder pain. CONCLUSION: From the available evidence, the use of PRF to the dorsal root ganglion in cervical radicular pain is compelling. With regards to its lumbosacral counterpart, the use of PRF cannot be similarly advocated in view of the methodological quality of the included study. PRF application to the supracapular nerve was found to be as efficacious as intra-articular corticosteroid in patients with chronic shoulder pain. The use of PRF in lumbar facet arthropathy and trigeminal neuralgia was found to be less effective than conventional RF thermocoagulation techniques.

Long-term pain relief in patients with cervicogenic headaches after pulsed radiofrequency application into the lateral atlantoaxial (C1-2) joint using an anterolateral approach.

The lateral atlantoaxial joint has long been reported as a source of cervicogenic headache. We present a retrospective study, including 86 patients who had undergone lateral C1-2 joint pulsed radiofrequency application, for cervicogenic headache in a single pain center from March 2007 to December 2008. The percentage of patients who had >or=50% pain relief at 2 months, 6 months, and 1 year were 50% (43/86), 50% (43/86), and 44.2% (38/86), respectively. Long-term pain relief at 6 months and 1 year were predicted reliably by >or=50% pain relief at 2 months (P < 0.001). Apart from 1 patient that complained of increased severity of occipital headache lasting several hours, we had no other reported complications.