Post Dural Puncture Headache, Managed with Epidural Blood Patch, Is Associated with Subsequent Chronic Low Back Pain in Patients: a Pilot Study.

PURPOSE OF REVIEW: Post dural puncture headache (PDPH) is a relatively common complication which may occur in the setting of inadvertent dural puncture (DP) during labor epidural analgesia and during intentional DP during spinal anesthetic placement or diagnostic lumbar puncture. Few publications have established the long-term safety of an epidural blood patch (EBP) for the treatment of a PDPH. RECENT FINDINGS: The aim of this pilot study was to examine the association of chronic low back pain (LBP) in patients who experienced a PDPH following labor analgesia and were treated with an EBP. A total of 146 patients were contacted and completed a survey questionnaire via telephone. The EBP group was found to be more likely to have chronic LBP (percentage difference 20% [95% CI 6-33%], RR 2.6 [95% CI 1.3-5.2]) and also LBP < 6 (percentage difference 24% [95% CI 9- 37%], RR 2.3 [95% CI 1.3-4.1]). There were no significant differences in the severity and descriptive qualities of pain between the EBP and non-EBP groups. Our findings suggest that PDPH treated with an EBP is associated with an increased prevalence of subsequent low back pain in parturients. The findings of this pilot study should spur further prospective research into identifying potential associations between DP, EBP, and chronic low back pain.

Lumbar Epidural Contrast Spread Patterns for the Interlaminar Approach: Three-Dimensional Analysis Using Antero-Posterior, Lateral, and Contralateral Oblique Views.

OBJECTIVE: To describe and analyze lumbar epidural contrast spread patterns in antero-posterior (AP), lateral, and contralateral oblique (CLO) views. METHODS: Lumbar epidural contrast spread patterns after interlaminar injection were prospectively collected in AP, lateral, and several CLO views and analyzed for multiple variables; three-dimensional mapping was also performed. RESULTS: Epidural contrast patterns were prospectively analyzed in 28 subjects. The median volume of contrast injected was 2 mL; the AP view was more sensitive than the lateral view to detect foraminal uptake (13/28, 46%, 95% confidence interval [CI] = 27-66%, vs 7/28, 25%, 95% CI = 11-45% subjects). CLO view demonstrated the most consistent location for epidural contrast spread, with contrast contacting the ventral laminar margin in 28/28 (100%, 95% CI = 87-100%) patients. The most common location of contrast spread in the lateral view was at the facet joint lucency, with only 8/28 (29%, 95% CI = 13%-49%) subjects showing contrast contacting the spinolaminar junction. Lateral view was more sensitive than the CLO view in ventral epidural contrast spread detection. The extent and distribution of the spread did not bear any relationship to the volume injected or to the needle location in AP view. CONCLUSIONS: CLO view provides the most consistent landmark for lumbar epidural contrast spread, and lateral view is most suited to confirming ventral epidural spread. The AP view may be the most optimal for determining target access when considering access to the dorsal root ganglia; in an individual patient, the volume injected and needle location in AP view do not reliably predict target access. The volume to be injected and the need to re-access or obtain multisite access must be prospectively determined, based upon observation of the spread.

Cervical Epidural Contrast Spread Patterns in Fluoroscopic Antero-Posterior, Lateral, and Contralateral Oblique View: A Three-Dimensional Analysis.

Objective: To describe and to analyze cervical epidural contrast patterns seen in antero-posterior (AP), contralateral oblique (CLO), and lateral view. To identify factors that might help in predicting contrast distribution pattern and extent. Method: Spread of contrast in the cervical epidural space was prospectively studied in AP, lateral, and three CLO views. Results: CLO view showed contrast spread of variable thickness with its posterior margin overlying the ventral interlaminar line (VILL). In the lateral view, the spread was also of variable thickness, but the posterior margin of the contrast lay on the spinolaminar line in only 10 of 24 patients. Ventral contrast spread was not visualized in any patient. In the AP view, bilateral spread was seen in 14 of 24 subjects, and nerve root spread was seen in 16 of 24 subjects. No association of the pattern of spread or dispersion was seen to patient age, volume injected, or needle location. Conclusions: The CLO view provides a consistent radiological landmark for the posterior margin of contrast in the dorsal epidural space; the lateral view fails to provide such a consistent landmark. The thickness of the spread is variable, both in the CLO and in the lateral view. Thick spread extending into the foramen in the CLO view and over the articular pillars in the lateral view is frequent and should not be misconstrued as subdural or intrathecal spread. In contradistinction to previous studies, true ventral spread was not seen in any patient. When using low volumes, contrast spread is independent of patient age, volume injected, or needle tip location in the AP view.

Contralateral Oblique View Is Superior to the Lateral View for Lumbar Epidural Access.

OBJECTIVE: The purpose of this study was to perform a comparative analysis of the contralateral oblique (CLO) view and the lateral view for lumbar interlaminar epidural access. DESIGN: After the epidural space was accessed, fluoroscopic images at eight different angles (antero-posterior view, multiple CLO, and lateral view) were prospectively obtained. Visualization and location of needle tip relative to bony landmarks were analyzed. The epidural location of the needle was subsequently confirmed by contrast injection and analysis in multiple views. RESULTS: Visualization of the needle tip and the relevant radiologic landmarks was superior in the CLO view. The needle tip location in the epidural space was most consistent at a CLO angle of 45°. CONCLUSION: This study shows that the CLO view for lumbar interlaminar epidural access offers clear advantages over the lateral view on many clinically important grounds: the needle tip visualization is better, the important radiological landmarks are better visualized, and the needle tip when placed in the epidural space presents a more precise relationship to these landmarks. All of these differences were highly significant. Thus, when using this view, the needle may be directly placed in very close vicinity to the epidural space and true loss of resistance expected soon thereafter. In addition, this view provides the ability to plot the cranio-caudad needle trajectory. The combination of these factors is likely to improve the ease and efficiency of epidural access. The crisp visualization of the final moments of epidural access could also translate to improved safety and accuracy. In light of this, it is suggested that a CLO view at 45° be considered the preferred view for gauging needle depth during interlaminar lumbar epidural access.

Contralateral oblique view is superior to lateral view for interlaminar cervical and cervicothoracic epidural access.

OBJECTIVE: The purpose of this study was to compare the reliability of the lateral fluoroscopic view and several contralateral oblique (CLO) views at different angles in visualizing and accurately predicting the position of the needle tip at the point of access in the posterior cervical and cervicothoracic epidural space. DESIGN: After the epidural space was accessed but before confirmation with contrast fluoroscopy, we prospectively obtained fluoroscopic images at eight different angles. Subsequent contrast injection confirmed epidural spread. Needle tip visualization and location of needle relative to bony landmarks were analyzed. RESULTS: The needle tip was clearly visualized in all CLO projections in all 24 subjects. CLO view at 50 degrees and at obliquity measured on magnetic resonance imaging (MRI) images provided the most consistent needle tip location. In these views, the epidural space was accessed at or just beyond the ventral laminar margin at the ventral interlaminar line or within the proximal half of the predefined CLO area in all patients. The needle tip was poorly visualized in the lateral view and the location of the needle tip was less well defined and independent of the needle location in the anteroposterior (AP) view. CONCLUSIONS: This study provides evidence that during cervical and cervicothoracic epidural access, the CLO view at 50 degrees and at MRI-measured obliquity is superior to the lateral view for the purpose of needle tip visualization and in providing a consistent landmark for accessing the epidural space. This article also introduces the concept of zones to describe needle position in the cervical and cervicothoracic spine in AP, lateral, and oblique views.

Percutaneous radiofrequency lesioning of the suprascapular nerve for the management of chronic shoulder pain: a case series.

PURPOSE: The objective of this study was to retrospectively evaluate the analgesic effects of continuous radiofrequency lesioning of the suprascapular nerve (SSN) for chronic shoulder pain. The authors sought to obtain insight into the time-sensitive analgesic success and complications of this therapy. PATIENTS AND METHODS: This study was a retrospective case series involving patients with unremitting shoulder pain that had lasted for at least 12 months. Patients were selected if they showed a reduction of at least 50% in pain intensity during the anesthetic phase after SSN block, no additional motor weakness of the shoulder, and pain relief lasting for less than 2 months after separate treatments of the SSN with depot corticosteroids and pulsed radiofrequency. Nine patients were referred to the Arnold Pain Management Center. Of these nine patients, six patients who had significant chronic shoulder pain unresponsive to oral medications and intra-articular injections and who were not considered surgical candidates were selected. These patients were treated with a single radiofrequency lesion of the SSN at 80°C for 60 seconds. The primary outcome was a reduction in pain intensity by 50%, as determined by the numeric rating scale, and duration of this effect. The secondary outcome was improvement in either the passive or the active range of motion (ROM). Patients were also monitored for adverse effects such as weakness or increased pain. RESULTS: The pooled mean numeric rating scale score before the procedure was 7.2 ± 1.2; this fell to 3.0 ± 0.9 at 5-7 weeks post procedure. The duration of pain relief ranged from 3 to 18 months, and all patients underwent at least one additional treatment. The change in baseline ROM improved from an average of 60° ± 28° (flexion) and 58° ± 28° (abduction) to 99° ± 46° (flexion) and 107° ± 39° (abduction). No adverse side effects were observed. CONCLUSION: Continuous radiofrequency lesioning of the SSN seems to be an effective treatment for chronic shoulder pain. There can be improved ROM of the shoulder following this treatment. More formal, controlled studies are required to confirm these observations.

Retrospective review of the efficacy and safety of repeated pulsed and continuous radiofrequency lesioning of the dorsal root ganglion/segmental nerve for lumbar radicular pain.

BACKGROUND: Chronic lumbosacral radicular pain is a common source of radiating leg pain seen in pain management patients. These patients are frequently managed conservatively with multiple modalities including medications, physical therapy, and epidural steroid injections. Radiofrequency has been used to treat chronic radicular pain for over 30 years; however, there is a paucity of literature about the safety and efficacy of repeat radiofrequency lesioning. OBJECTIVES: To determine the safety, success rate, and duration of pain relief of repeat pulsed radiofrequency (PRF) and continuous radiofrequency (CRF) lesioning of the dorsal root ganglion (DRG)/ sacral segmental nerves (SN) in patients with chronic lumbosacral radicular pain. STUDY DESIGN: Retrospective chart review SETTING: Outpatient multidisciplinary pain center METHODS: Medical record review of patients who were treated with pulsed and continuous radiofrequency lesioning of the lumbar dorsal root ganglia and segmental nerves and who reported initial success were evaluated for recurrence of pain and repeat radiofrequency treatment. Responses to subsequent treatments were compared to initial treatments for success rates, average duration of relief, and adverse neurologic side-effects. LIMITATIONS: Retrospective chart review without a control group. RESULTS: Twenty-six women and 24 men were identified who received 50% pain relief or better after PRF and CRF of the lumbar DRG/ sacral SN for lumbosacral radicular pain. The mean age was 62 years (range, 25-86). The mean duration of relief for the 40 patients who had 2 treatments was 4.7 months (range 0-24; Se [standard error] 0.74). Twenty-eight patients had 3 treatments with an average duration of relief of 4.5 months (range 0-19 months; Se 0.74). Twenty patients had 4 treatments with a mean duration of relief of 4.4 months (range 0.5-18; Se 0.95) and 18 patients who had 5 or more treatments received an average duration of relief of 4.3 months (range 0.5-18; Se 1.03). The average duration of relief and success frequency remained constant after each subsequent radiofrequency treatment. Of the 50 total patients, there was only 1 reported complication, specifically, transient thigh numbness which resolved after one week. CONCLUSIONS: Repeated pulsed and continuous radiofrequency ablation of the lumbar dorsal root ganglion/segmental nerve shows promise to be a safe and effective long-term palliative management for lumbosacral radicular pain in some patients.

Low and therapeutic doses of antidepressants are associated with similar response in the context of multimodal treatment of pain.

BACKGROUND: Antidepressants are prescribed in a wide range of doses to treat both depression and chronic pain, with optimal psychopharmacology individualized for each patient. In the past decade more antidepressants from different chemical classes have become available and are being used for the treatment of both chronic pain and depression. OBJECTIVE: To review the utilization pattern changes and compare response rates of different classes and doses of antidepressants for various pain conditions in the context of multimodal therapies. DESIGN: Chart review. METHODS: We reviewed 5,916 records at an outpatient multidisciplinary pain center. Of these, 379 records were for patients diagnosed with cancer pain. Because the mechanisms and treatment approaches to cancer pain can differ greatly from non-cancer chronic pain, these records were excluded from the analysis. We assessed 1,506 medical records for patients with chronic non-caner pain who had used at least one antidepressant, with the main outcome measure being the Numeric Rating Pain Scale, 0-10. RESULTS: Of the 5,916 charts reviewed, 1,506 (25.4%) chronic non-cancer pain charts recorded the prescription of at least one antidepressant. Most patients received a combination of medications and procedures. Of the 450 patients receiving secondary amines, favorable responses were recorded for 340 (76%) patients, while 103 (23%) did not respond and 7 had unknown responses. Of the 492 patients receiving tertiary amines, favorable responses were recorded for 375 (76%) patients, while 113 (23%) did not respond, and 4 had unknown responses. Of the 533 patients receiving SSRI/SNRIs, favorable responses were recorded for 382 (72%) patients, while 147 (28%) did not respond, and 4 had unknown responses. Of the 369 patients receiving atypical antidepressants, favorable responses were recorded for 272 (74%) patients, while 94 (25%) did not respond, and 3 had unknown responses. LIMITATIONS: A retrospective study design and the use of antidepressants as a part of multimodal treatment of pain. CONCLUSION: The data suggest that in the context of multimodal treatment for chronic pain, antidepressant therapy at both low and therapeutic doses demonstrates similar response rates. Tricyclic antidepressants (TCAs), which include secondary and tertiary amines, as well as SSRI/SNRIs and atypicals, all appear to show similar favorable response rates.

Response to pulsed and continuous radiofrequency lesioning of the dorsal root ganglion and segmental nerves in patients with chronic lumbar radicular pain.

OBJECTIVES: We aimed to prospectively evaluate the response and safety of pulsed and continuous radiofrequecy lesioning of the dorsal root ganglion/segmental nerves in patients with chronic lumbosacral radicular pain. METHODS: Seventy-six patients with chronic lumbosacral radicular pain refractory to conventional therapy met the inclusion criteria and were randomly assigned to one of 2 types of treatment, pulsed radiofrequency lesioning of the dorsal root ganglion/segmental nerve or pulsed radiofrequency followed immediately by continuous radiofrequency. Patients were carefully evaluated for neurologic deficits and side effects. The response was evaluated at 2 months and was then tracked monthly. A Kaplan-Meier analysis was used to illustrate the probability of success over time and a Box-Whisker analysis was applied to determine the mean duration of a successful analgesic effect. RESULTS: Two months after undergoing radiofrequency treatment, 70% of the patients treated with pulsed radiofrequency and 82% treated with pulsed and continuous radiofrequency had a successful reduction in pain intensity. The average duration of successful analgesic response was 3.18 months (+/- 2.81) in the group treated with pulsed radiofrequency and 4.39 months (+/-3.50) in those patients treated with pulsed and continuous radiofrequency lesioning. A Kaplan-Meier analysis illustrated that in both treatment groups the chance of success approached 50% in each group at 3 months. The vast majority of patients had lost any beneficial effects by 8 months. There was no statistical difference between the 2 treatment groups. No side effects or neurological deficits were found in either group. CONCLUSION: Pulsed mode radiofrequency of the dorsal root ganglion of segmental nerves appears to be a safe treatment for chronic lumbosacral radicular pain. A significant number of patients can derive at least a short-term benefit. The addition of heat via continuous radiofrequency does not offer a significant advantage. A randomized controlled trial is now required to determine the effectiveness of pulsed radiofrequency.