Bruce Mitchell

Peripheral nerve field stimulation for chronic pain: 100 cases and review of the literature.

OBJECTIVE To evaluate the clinical outcomes of 100 consecutive patients receiving peripheral nerve field stimulation (PNFS) for the treatment of chronic intractable pain. DESIGN Prospective, observational study. SETTING A private interventional pain specialty referral practice. PATIENTS One hundred consecutive private practice patients receiving PNFS for the treatment of chronic craniofacial, thorax, lumbosacral, abdominal, pelvic, and groin pain conditions. OUTCOME MEASURES Pain (11-point numerical rating scale), complications, changes to analgesic use and employment status, disability (Oswestry or Neck Disability Indexes), depression (Zung Depression Index), and patient satisfaction. RESULTS We demonstrate an average pain reduction of 4.2 ± 2.5 pain scale points on an 11-point scale following PNFS (preimplant pain score of 7.4 ± 1.7 to a follow-up average of 3.2 ± 2.3 pain scale points) (P≤0.00). At a follow-up period of 8.1 ± 4.7 months (range 1-23 months), an overall 72% of patients reduced their analgesic use following PNFS. Patients receiving a lumbosacral PNFS for chronic low back pain reported a significant reduction in disability following treatment, as determined by the Oswestry Disability Index. Of the 100 cases, no long-term complications were reported. CONCLUSIONS This prospective 100 consecutive PNFS patient outcome study demonstrates that PNFS can be a safe and effective treatment option for, otherwise, intractable chronic pain conditions. PNFS has the potential to fundamentally change the way we think about pain management.

Peripheral Nerve Stimulation: A Treatment for Chronic Low Back Pain and Failed Back Surgery Syndrome?

Objective.  This study aims to evaluate the usefulness of peripheral nerve stimulation as a treatment option for patients with chronic low back pain.

The incidence of intravascular penetration in medial branch blocks: cervical, thoracic, and lumbar spines.

Study Design. Clinical observational study. Objective. To quantify the incidence of inadvertent intravascular injections in spinal medial branch blocks in a clinical setting. Summary of Background Data. Previous research established the rate of inadvertent intravascular injection in lumbar medial branch blocks at 8%. The incidence of intravascular injection in cervical and thoracic medial branch blocks has not been reported previously. This study establishes the rate of inadvertent intravascular injection in patients receiving medial branch blocks of the cervical and thoracic spines. Further, this study reports a significantly lower rate of inadvertent intravascular injection for lumbar medial branch blocks than previously reported. Methods. Patients were originally referred to the clinic, for diagnosis and treatment of chronic spinal origin somatic pain. Medial branch blocks were then performed as diagnostic procedures to confirm the zygapophysial joint(s) as the suspected source of pain. Blocks were performed by experienced practitioners on nonidentified patients over a 3-year period. Clinical observations were recorded for 14,312 separate medial branch block levels. The level of the spine and the incidence of inadvertent intravascular injections were recorded. Results. This study demonstrates that the overall incidence of intravascular penetration in medial branch blocks is rare, with an overall rate of 3.5%. This study also establishes the rate of intravascular injection for levels within the spine: the cervical spine is likely to be intravascular 3.9% of the time and the lumbar spine 3.7%, whereas the thoracic spine is significantly lower, with just 0.7% injections reported as intravascular. Significant differences were also observed between individual vertebral levels. Conclusion. The false-negative rate for medial branch blocks is likely to be lower than previously reported. The rate of inadvertent intravascular injection for thoracic medial branch blocks is 0.7%. Cervical and lumbar medial branch blocks are associated with an overall rate of 3.9% and 3.7%, respectively. Although these rates are lower than previously reported, the incidence of false-negative blocks still justifies the use of contrast to confirm nonvascular injection.

Peripheral Nerve Field Stimulation for Chronic Headache: 60 Cases and Long‐Term Follow‐Up

The objective of this study is to evaluate the efficacy of peripheral nerve field stimulation (PNFS) for the treatment of chronic headache conditions.

Improved Pain Relief With Burst Spinal Cord Stimulation for Two Weeks in Patients Using Tonic Stimulation: Results From a Small Clinical Study

Conventional spinal cord stimulation (SCS) delivers a tonic waveform with consistent stream of pulses; burst delivers groups of pulses separated by short pulse‐free periods. The current study compared the short‐term safety and efficacy of burst with tonic stimulation in subjects already receiving SCS.

New Therapy for Refractory Chronic Mechanical Low Back Pain-Restorative Neurostimulation to Activate the Lumbar Multifidus: One Year Results of a Prospective Multicenter Clinical Trial: RESTORATIVE NEUROSTIMULATION FOR CLBP

The purpose of the international multicenter prospective single arm clinical trial was to evaluate restorative neurostimulation eliciting episodic contraction of the lumbar multifidus for treatment of chronic mechanical low back pain (CMLBP) in patients who have failed conventional therapy and are not candidates for surgery or spinal cord stimulation (SCS).

Peripheral Nerve Field Stimulation: Is Age an Indicator of Outcome?

Objective.  This study aims to assess peripheral nerve field stimulation as a treatment option for chronic pain and test for indicators of outcome.

Peripheral Nerve Field Stimulation Therapy for Patients With Thoracic Pain: A Prospective Study.

Relative to the number of patients suffering chronic lumbar and cervical pain, fewer patients suffer persistent thoracic pain. Consequently there is less literature, with smaller sample sizes, reporting treatment of this cohort. Here, we assess peripheral nerve field stimulation (PNfS) as a potential treatment for chronic thoracic pain.

The efficacy of hip arthroscopy

Aim: The purpose of this study was to determine if pain and disability associated with hip pathology improve following hip arthroscopy, and to determine if certain types of hip pathology lead to a more successful outcome following arthroscopy, as rated using patient administered questionnaires. Methods: Prior to undergoing hip arthroscopy, 15 patients (15 hips) filled out three questionnaires, Hip and Back Assessment questionnaire (HABAQ), modified Harris Hip Score (HHS) and the Oswestry Disability Questionnaire (OSW). Following surgery, subjects again filled out the three questionnaires at 6 week and 12 week postsurgery. Immediately following each arthroscopy, the surgeons completed a standardized form detailing the pathology found at arthroscopy. Results: No complications were reported at surgery. There was a statistically significant mean improvement across all three questionnaires, from baseline to 6 week follow up; HABAQ p=0.030, HHS p=0.010, OSW p=0.004. Whilst there was a further mean improvement from 6 week follow up to 12 week follow up, this was not statistically significant. Two patients did not improve or became worse than baseline at 12 weeks. There was no statistically significant difference between the mean change score from baseline to 6 week follow up determined from HABAQ and HHS, and the type of pathology found at surgery. Conclusion: In most cases, for patients with hip pathology, arthroscopy is a useful tool in relieving or reducing patient pain and disability. Owing to the small number of subjects enrolled in this study, this may account for the non-significant finding of change scores and pathology type.

Correlation of hip arthroscopy findings and different MRI techniques. A review of 99 cases

MR arthrography has been claimed to have a very high sensitivity and specificity for diagnosing intraarticular hip joint pathology. This claim has not been supported by clinical experience in Australia. (Mitchell et al 03) In an attempt to improve the performance of MRI, 2 new techniques were developed. This paper compares the 2 new techniques and traditional MR arthrography to hip arthroscopic findings. Further, intra and intertester reliability studies were completed for the new technique. These results are presented. Methodology: Details of patients who had undergone hip arthroscopy in the last 4 years were kept by the author. Those who were still contactable and signed consent forms were included in the study. The MRI and operative reports were compared. 3 different MRI techniques were used over this period of time. MR arthrography, FSE PD spins in traditional planes and FSE PD spins with a new plane at a right angle to the plane of the acetabulum. Results: Radial tears of the labrum were the best detected pathology overall, with 54% deected overall. Synovitis, however, (present in 48% of hips) was only detected 4% of the time. All 11 flap labral tears were missed.: For detecting pathology on the edge of the hip joint, MR arthrography had. a sensitivity of 45%, PD FSE in traditional planes 67% and the new technique with cuts in the plane of the hip joint had a sensitivity of 86%. Conclusion: MR arthrography is not as accurate as previously thought. PD FSE MR appears to have a far superior sensitivity.