Ricardo Vallejo

Novel 10-kHz High-frequency Therapy (HF10 Therapy) Is Superior to Traditional Low-frequency Spinal Cord Stimulation for the Treatment of Chronic Back and Leg PainThe SENZA-RCT Randomized Controlled Trial

Background:Current treatments for chronic pain have limited effectiveness and commonly known side effects. Given the prevalence and burden of intractable pain, additional therapeutic approaches are desired. Spinal cord stimulation (SCS) delivered at 10 kHz (as in HF10 therapy) may provide pain relief without the paresthesias typical of traditional low-frequency SCS. The objective of this randomized, parallel-arm, noninferiority study was to compare long-term safety and efficacy of SCS therapies in patients with back and leg pain. Methods:A total of 198 subjects with both back and leg pain were randomized in a 1:1 ratio to a treatment group across 10 comprehensive pain treatment centers. Of these, 171 passed a temporary trial and were implanted with an SCS system. Responders (the primary outcome) were defined as having 50% or greater back pain reduction with no stimulation-related neurological deficit. Results:At 3 months, 84.5% of implanted HF10 therapy subjects were responders for back pain and 83.1% for leg pain, and 43.8% of traditional SCS subjects were responders for back pain and 55.5% for leg pain (P < 0.001 for both back and leg pain comparisons). The relative ratio for responders was 1.9 (95% CI, 1.4 to 2.5) for back pain and 1.5 (95% CI, 1.2 to 1.9) for leg pain. The superiority of HF10 therapy over traditional SCS for leg and back pain was sustained through 12 months (P < 0.001). HF10 therapy subjects did not experience paresthesias. Conclusion:HF10 therapy promises to substantially impact the management of back and leg pain with broad applicability to patients, physicians, and payers.

Novel Spinal Cord Stimulation Parameters in Patients with Predominant Back Pain

To examine the feasibility of novel high‐frequency spinal cord stimulation therapy in a cohort of patients with chronic predominant back pain during a four day, percutaneous trial.

Comparison of 10-kHz High-Frequency and Traditional Low-Frequency Spinal Cord Stimulation for the Treatment of Chronic Back and Leg Pain: 24-Month Results From a Multicenter, Randomized, Controlled Pivotal Trial

BACKGROUND: Pain relief with spinal cord stimulation (SCS) has focused historically on paresthesias overlapping chronically painful areas. A higher level evidence supports the use of SCS in treating leg pain than supports back pain, as it is difficult to achieve adequate paresthesia coverage, and then pain relief, in the low back region. In comparison, 10-kHz high-frequency (HF10 therapy) SCS therapy does not rely on intraoperative paresthesia mapping and remains paresthesia-free during therapy. OBJECTIVE: To compare long-term results of HF10 therapy and traditional low-frequency SCS. METHODS: A pragmatic randomized, controlled, pivotal trial with 24-month follow-up was conducted across 11 comprehensive pain treatment centers. Subjects had Visual Analog Scale scores of ≥5.0/10.0 cm for both back and leg pain, and were assigned randomly (1:1) to receive HF10 therapy or low-frequency SCS. The primary end point was a responder rate, defined as ≥50% back pain reduction from baseline at 3 months with a secondary end point at 12 months (previously reported). In this article, 24-month secondary results are presented. Non-inferiority was first assessed, and if demonstrated the results were tested for superiority. RESULTS: In the study, 198 subjects were randomized (101 HF10 therapy, 97 traditional SCS). One hundred seventy-one subjects (90 HF10 therapy, 81 traditional SCS) successfully completed a short-term trial and were implanted. Subjects averaged 54.9 ± 12.9 years old, 13.6 ± 11.3 years since diagnosis, 86.6% had back surgery, 88.3% were taking opioid analgesics. At 3 months, 84.5% of implanted HF10 therapy subjects were responders for back pain and 83.1% for leg pain, and 43.8% of traditional SCS subjects were responders for back pain and 55.5% for leg pain (P < .001 for both back and leg pain comparisons, non-inferiority and superiority). At 24 months, more subjects were responders to HF10 therapy than traditional SCS (back pain: 76.5% vs 49.3%; 27.2% difference, 95% CI, 10.1%-41.8%; P < .001 for non-inferiority and superiority; leg pain: 72.9% vs 49.3%; 23.6% difference, 95% CI, 5.9%-38.6%; P < .001 for non-inferiority and P = .003 for superiority). Also at 24 months, back pain decreased to a greater degree with HF10 therapy (66.9% ± 31.8%) than traditional SCS (41.1% ± 36.8%, P < .001 for non-inferiority and superiority). Leg pain also decreased to a greater degree with HF10 therapy (65.1% ± 36.0%) than traditional SCS (46.0% ± 40.4%, P < .001 for non-inferiority and P = .002 for superiority). CONCLUSION: This study demonstrates long-term superiority of HF10 therapy compared with traditional SCS in treating both back and leg pain. The advantages of HF10 therapy are anticipated to impact the management of chronic pain patients substantially. ABBREVIATIONS: IPG, implantable pulse generator MCID, minimal clinically important difference PI, permanent implant ODI, Oswestry Disability Index SCS, spinal cord stimulation VAS, Visual Analog Scale

Opioids in chronic noncancer pain

Chronic noncancer pain is highly prevalent with associated negative effects on function and quality of life of the individuals involved. Opioids have been shown to decrease pain and improve function in some patients with chronic noncancer pain, but they are not always effective and are associated with multiple complications, including drug misuse, abuse and diversion. Furthermore, the effectiveness of opioids in decreasing pain and improving function has not been proven conclusively, resulting in continued uncertainty about long-term benefits of opioids for chronic noncancer pain. Ideally, in modern medicine, clinical decisions are made based on information derived from high quality evidence. Since no such evidence exists for chronic opioid therapy in chronic noncancer pain, this review describes various aspects of opioid therapy in chronic noncancer pain, including adherence monitoring, along with a ten-step process outlining the principles of effective and safe opioid use.

Single needle approach for multiple medial branch blocks: A new technique

Background and ObjectivesMedial branch blocks are an important tool for the diagnosis of facet joint arthropathy. The most commonly used technique involves multiple needle placements, one for each nerve blocked. This multiple needle technique may require a large amount of local anesthetic for anesthetizing the skin, thereby increasing the rate of false-positive blocks. TechniqueDiagnostic lumbar medial branch blocks are usually performed using multiple needles, one for each branch. The authors describe a different technique using a single needle for all levels. Initially, the needle is directed toward the medial branch located at the level of the affected facet joint in the antero–posterior view. After anesthetizing this nerve with local anesthetic, the same needle is withdrawn to the skin with the tip still in the subcutaneous tissue and repositioned to block the medial branch above, and thereafter below, while continuing to use only the antero–posterior view, thereby using only one entry site. ConclusionsWhen performed correctly, the single needle technique provides accuracy similar to the more conventional multiple needle approach during the performance of diagnostic facet joint nerve blocks. Because only one skin entry point is needed, however, this technique may afford several advantages over the multiple needle approach. These may include less patient discomfort, less time required and less radiation exposure since only one C-arm position is used, a smaller volume of local anesthetic, and possibly a lower incidence of false-positive blocks.

Seizures after a Bier block with clonidine and lidocaine.

A 47-yr-old man with history of complex regional pain syndrome type 1 underwent an IV Bier block with a mixture of lidocaine and clonidine. The tourniquet was deflated after 60 min, and approximately 10 min later he presented with complex partial seizures. The possible mechanisms for this are discussed, and the effects of clonidine, lidocaine, and the mixture of both are reviewed, as are four additional published cases reporting seizures after the administration of clonidine.

Carpal Tunnel Syndrome

Abstract:u2003 Carpal tunnel syndrome (CTS) is a common disorder. In the majority of cases, patients with CTS can be diagnosed by means of appropriate history taking. Nerve conduction examination of the nervus medianus is the most important additional diagnostic test and is the best predictor of symptom severity and functional status in idiopathic CTS. Treatment option depends on the severity of the symptoms and the degree of functional daily limitations. If few limitations are present, splinting or corticosteroid injections are preferred. Surgical interventions are reserved for the more severe conditions resulting in significant disability.

Prospective, Multicenter, Randomized, Double‐Blinded, Partial Crossover Study to Assess the Safety and Efficacy of the Novel Neuromodulation System in the Treatment of Patients With Chronic Pain of Peripheral Nerve Origin

Currently available central nervous system treatment strategies are often insufficient in management of peripheral neuropathic pain, prompting a resurgence of neuromodulation focused on peripheral pain. A new peripheral nerve stimulation device was investigated in a prospective, randomized, double blind, crossover study, looking specifically at efficacy and safety, with Food and Drug Administration oversight.

Percutaneous cement injection into a created cavity for the treatment of vertebral body fracture: preliminary results of a new vertebroplasty technique.

Objectives:Vertebral body fractures (VBFs) are the most common complication of osteoporosis. Minimally invasive placement of cement to stabilize VBFs results in significant pain reduction and improved performance of daily activities. The authors describe a modified percutaneous vertebroplasty (PV) procedure during which a cavity is created manually in the VBF, allowing the cement to be injected with less resistance. Methods:Data were gathered from a retrospective chart review from 15 consecutive patients with acute compression VBFs who underwent 33 PV procedures with the Cavity Creation System. Mean follow-up was 30 weeks. Oral opiate intake, quality of life improvement, and visual analog pain scores (VAS) were measured before and 1 month after the procedure. Results:All 15 patients exhibited a reduction in pain VAS (mean reduction 5.9 ± 2.5). Improvement in quality of life was demonstrated by lower (improved) FACIT scores in the General Activity, Enjoyment of Life, Mood, Normal Work Routine, and Sleep subscales. In addition, opioid use decreased in 10 of the 12 (83%) patients who were taking opioids before surgery. In eight (67%) patients, opioid use decreased by over 50%. Complications included extrusion of cement in two patients (an incidence of 5.7% of the levels operated) and two patients with intraoperative rib fractures. No postoperative neurologic deficits were noted. Conclusions:The Cavity Creation System is a safe, cost-effective treatment of VBF resulting in good/excellent pain relief and an improved quality of life.

19. Carpal Tunnel Syndrome

Abstract:u2003 Carpal tunnel syndrome (CTS) is a common disorder. In the majority of cases, patients with CTS can be diagnosed by means of appropriate history taking. Nerve conduction examination of the nervus medianus is the most important additional diagnostic test and is the best predictor of symptom severity and functional status in idiopathic CTS. Treatment option depends on the severity of the symptoms and the degree of functional daily limitations. If few limitations are present, splinting or corticosteroid injections are preferred. Surgical interventions are reserved for the more severe conditions resulting in significant disability.