The Effect of Peripheral Neuromodulation on Pain From the Sacroiliac Joint: A Retrospective Cohort Study.

OBJECTIVE: To report a retrospective review of the longer-term results of peripheral neuromodulation in 12 patients with significant chronic sacroiliac joint pain who had previously failed multiple conservative and interventional pain therapies. METHODS: To allow for the assessment of meaningful longer-term outcome, implants for all 12 patients had been in place for a minimum of 18 months to a maximum of 36 months prior to the formal review. RESULTS: Compared to the preimplantation baseline, the longer-term follow-up revealed a significant and sustained reduction in visual analog scale pain scores from 8.7T 1.1 to 1.1T 1.0 (p < 0.001), with a 75% reduction in analgesia requirement, and improvement in pain impact on daily function from 94.1% T 5.9% to 5.8% T 6.0% (p < 0.001). CONCLUSION: This initial case series has highlighted that SIJ neuromodulation results in the reduction in pain intensity and improved functionality in patients who have already failed conventional medical management and interventional techniques, including RF denervation. These preliminary results merit a prospective randomized trial of peripheral neuromodulation.

The Effect of Peripheral Neuromodulation on Pain from the Sacroiliac Joint: A Retrospective Cohort Study.

We report here a retrospective review of the longer-term results of peripheral neuromodulation in 12 patients with significant chronic sacroiliac joint pain who had previously failed multiple conservative and interventional pain therapies. To allow for the assessment of meaningful longer-term outcome, implants for all 12 patients had been in place for a minimum of 18 months to a maximum of 36 months prior to the formal review. Compared to the preimplantation baseline, the longer-term follow-up revealed a significant and sustained reduction in visual analog scale pain scores from 8.7 ± 1.1 to 1.1 ± 1.0 (P < 0.001), with a 75% reduction in analgesia requirement, and improvement in pain impact on daily function from 94.1% ± 5.9% to 5.8% ± 6.0% (P < 0.001). These preliminary results merit a prospective randomized trial of peripheral neuromodulation.

Peripheral neuromodulation: a review.

Peripheral nerve stimulation (PNS) is likely the most diverse and rapidly expanding area of neuromodulation. Its expansion has become possible due to both technological and clinical advances in pain medicine. The first implantable systems were surgically placed. However, it is currently commonplace to use percutaneous leads, as this approach has become instrumental in its expansion. The first percutaneous peripheral nerve stimulators were reported in 1999. Cylindrical leads were implanted to stimulate the greater occipital nerve to manage intractable headache. It has been expanded into other individual nerves or nerve plexuses to treat neuropathic, visceral, cardiac, abdominal, low back and facial pain. The use of PNS in modulating organ function in treatment of syndromes such as epilepsy, incontinence and obesity with vagal, tibial and gastric stimulation is under extensive investigation. New technologies that allow easier and safer electrode placement are expected to further expand the uses of PNS. A noninvasive stimulation will open this treatment modality to more clinicians of varying backgrounds.

Subcutaneous target stimulation-peripheral subcutaneous field stimulation in the treatment of refractory angina: preliminary case reports.

Spinal cord stimulation is now established as an effective treatment for refractory angina. We present the use of an alternative approach to neuromodulation of anginal pain using subcutaneous leads placed at the site of pain. In this case series, five patients with refractory angina received successful treatment with subcutaneous target stimulation-peripheral subcutaneous field stimulation. This technique was able to provide good analgesia in two patients that had had poor pain relief from existing spinal cord stimulators. All five patients achieved significant pain relief with a reduction in symptoms and a decrease in the use of pain medication.

Permanent percutaneous splanchnic nerve neuromodulation for management of pain due to chronic pancreatitis: a case report.

INTRODUCTION: The management of pain in chronic benign pancreatitis is complex. Celiac plexus neurolysis provides pain relief of variable duration. Neuromodulation of splanchnic nerves with electrodes and an implantable pulse generator system is an alternative to producing long-term pain relief with minimal complications in selected cases. METHODS: A 36-year-old lady with intractable abdominal pain for five years from chronic benign pancreatitis presented to our pain clinic. Multiple pharmacotherapy regimens, surgery, and interventions produced temporary pain relief of variable duration and intensity. Following a successful trial of celiac plexus stimulation, neuromodulation of the splanchnic nerves was achieved with two permanently implanted octopolar leads at the T11/T12 area connected to an implantable pulse generator. RESULTS: Eighteen months following the implant, the patient continues to derive satisfactory pain relief without any device related complications. Her opiate use is significantly reduced from 225 (486 mg morphine per day) to 12.5 (27 mg morphine per day) micrograms/h fentanyl patches and the fentanyl lozenges were stopped with an increase in appetite and of more than 8 kg in weight gain. The initial pain score visual analogue scale (VAS) 8-9/10 was reduced to VAS 0/10 since implantation. DISCUSSION: The pain of chronic pancreatitis has both visceral and somatic components as evidenced by the lack of complete pain relief from celiac plexus block alone and the knowledge that in chronic disease, the pathology extends to extra pancreatic somatic tissues, particularly the retro-peritoneum. We postulate that the electrical field generated by the dual octrode system extends to include splanchnic nerves and other somatic innervation of the pancreas. CONCLUSION: In our opinion, this is the first case of a successful long-term neuromodulation of splanchnic nerves with a permanently implanted device. The potential exists for its use in visceral abdominal pain of varied etiology, once more experience is obtained with this technique.

Peripheral nerve stimulation of the thoracic paravertebral plexus for chronic neuropathic pain.

Persistent post surgical pain is reported in 70% of patients following thoracotomy and mastectomy. This pain is often neuropathic in nature and occasionally it is refractory to traditional medical and interventional management. Neurostimulation of peripheral nerves can be a highly effective clinical modality for the management of neuropathic pain. The placement of a percutaneously sited electrode in the thoracic paravertebral plexus offers a new and novel mode of managing refractory thoracic neuropathic pain. We present 2 cases that demonstrate the effectiveness of this intervention in the long-term management of this clinical dilemma. The first case presented is that of a 61-year-old female, with unilateral neuropathic pain for 6 years following mastectomy refractory to traditional interventions. Targeted field stimulation of the thoracic paravertebral plexus resulted in significant improvement for 12 years. The second case is that of a 65-year-old male, with Type II diabetes with neuropathic thoracic pain for 6 years following multiple rib fractures (T4-T7) who responded positively to neurostimulation of the thoracic paravertebral plexus. Both of these cases demonstrate a relative reduction in pain intensity (> 80%), the elimination of oral analgesics, and improved functionality directly related to the novel use of this intervention. Effective and reproducible pain relief is achieved by specifically using a low frequency (10 Hz) and low amplitude (2 mA) stimulation technique. Equally important is that these cases highlight the increased risk of inadvertent pleural puncture with the development of a pneumothorax that can be associated with this intervention. Possible clinical, investigative and equipment modifications that need to be considered are discussed. The limitations include only 2 case reports, considered as the lowest level of evidence available in the era of evidence-based medicine, and lack of utilization of multiple other modalities of treatments utilized in managing neuropathic pain. In conclusion, these cases demonstrate the effectiveness of peripheral nerve stimulation of the thoracic paravertebral plexus in the long-term management of refractory neuropathic pain. They also serve to underline the importance of clinical awareness in order to improve patient safety.

Lumbar sympathetic chain neuromodulation with implanted electrodes for long-term pain relief in loin pain haematuria syndrome.

Introduction. Loin pain-hematuria syndrome (LPHS) is a rare clinical entity causing unilateral or bilateral intractable flank and loin pain with hematuria. The etiology is poorly understood, and the diagnosis is made by exclusion of urological and nephrological conditions. The management is mainly symptomatic aiming for pain relief with nonopioid and opioids analgesics, and interventions such as capsaicin infusion into the renal pelvis, percutaneous regional nerve blocks, and laparoscopic or open surgical procedures, none of them providing lasting pain relief. Methods. We describe four cases of LPHS in which long-term pain relief was achieved successfully by neuromodulation of lumbar sympathetic plexus with implanted electrodes. All patients underwent an initial successful trial of neuromodulation with Stimulong monoelectrode (Pajunk, GmbH, Geisingen, Germany) inserted percutaneously to lie adjacent to L3-L4 vertebral bodies followed by permanent implantation of the stimulation system using four contact electrodes (Medtronic Inc, Minneapolis, Minnesota, USA) in two patients with excellent long-term pain relief. Results. All our patients had significant reductions in visual analog scale scores and analgesic consumption for the duration of the monoelectrode trial and in one patient beyond six months. Of the two patients who had full implants, pain relief is excellent with minimal analgesic consumption and one has resumed employment. There were no complications. Discussion. LPHS is very difficult to treat with some experts maintaining it is mainly psychological. Conservative treatments are often unsatisfactory and radical measures not reliable. Peripheral stimulation of nerves and plexuses has been successful as shown from case reports. All our patients preferred low-frequency stimulation although its precise mode of action is uncertain. Conclusion. Our experience shows that lumbar sympathetic chain neuromodulation in intractable LPHS not amenable to conservative therapy is a reasonable alternative before radical interventions. More experience is needed in multiple centers before its recommendation for refractory LPHS.

A case of successful treatment of neuropathic pain after a scapular fracture using subcutaneous targeted neuromodulation.

Subcutaneous targeted neuromodulation is one part of the wider new peripheral neuromodulation development in the treatment of neuropathic pain. Although it has not received wider acceptance, there are many reports in the literature of successful use of this technique.

Co-injection of clonidine prolongs the anesthetic effect of lidocaine skin infiltration by a peripheral action.

BACKGROUND: The addition of clonidine to local anesthesia prolongs the local anesthetic action, but in humans, the contribution of a peripheral mechanism remains unclear. METHODS: We investigated clonidine's peripheral effect in 20 healthy volunteers undergoing double-blind, subcutaneous infiltration of 0.5% lidocaine with normal saline to one forearm and then, immediately, of lidocaine with 10 mug clonidine to the contralateral arm. Pinprick sensation was tested every 15 min for 6 h. RESULTS: Median time to return of normal sensation was 3.5 h for lidocaine alone, but at least 6 h if combined with clonidine (P < 0.001). CONCLUSIONS: Clonidine has a significant peripheral action in enhancing duration of local anesthesia on superficial co-infiltration with lidocaine.

Percutaneous implantation of a brachial plexus electrode for management of pain syndrome caused by a traction injury.

Introduction. Intractable pain in the affected arm is a common sequel to severe traction lesions of the brachial plexus. Its management presents a challenge. Existing interventional therapies are not effective for the intractable pain from brachial plexus traction lesions, in the long term. Spinal cord stimulation is indicated for the relief of pain following peripheral nerve injury, but has its limitations and, in the UK, is restricted only to specialized centers. Peripheral neuromodulation is widely practiced noninvasively as transcutaneous electrical nerve stimulation and more recently, both as external neuromodulation and, invasively, using a surgical procedure with restricted indications. Methods. We report here a single case report of the successful management of intractable pain of uncertain pathology following traction injury of the shoulder and brachial plexus with the percutaneous implantation of a permanent stimulating electrode via a stimulating needle to the brachial plexus using the posterior route at the interscalene level. Results. Stimulation of the brachial plexus in this one patient has resulted in excellent pain control and unexpected beneficial sensory and motor changes in the arm of the patient. Conclusions. We cautiously conclude that percutaneous implantation of a stimulating electrode to the brachial plexus via a stimulating needle is a relatively simple procedure when compared to surgical implantation and, as shown in our case, very effective.

Subcutaneous neuromodulating implant targeted at the site of pain.

INTRODUCTION: Primary afferent stimulation for the control of chronic pain frequently offers the optimal compromise for the control of intractable pain. We describe a new access route directly to the site of pain (target) in the form of subcutaneous targeted neurostimulation (STN) via a percutaneous permanent neurostimulating implant. CASE REPORT: We present 3 cases with chronic intractable pain where STN via a permanent neurostimulating implant was introduced successfully. STN for 1-2 hours daily produced pain relief lasting between 12 to 24 hours, which argues that subcutaneous neurostimulation instead of stimulation of peripheral nerves is sufficient in selected cases. The effects of subcutaneous stimulation do not correlate with transcutaneous electrical nerve stimulation applied externally over the same area. CONCLUSION: The introduction of an STN directly to painful areas, therefore bypassing the spinal cord and peripheral nerves, is a novel and simple procedure that is effective, in this small series, for control of intractable pain consistent with neuropathic pain.