Pulsed Radiofrequency Under Ultrasound Guidance for Persistent Stump-Neuroma Pain

Management of Neuropathic Pain with Neurectomy Combined with Dermal Sensory Regenerative Peripheral Nerve Interface (DS-RPNI)

Neuropathic pain affects a large percentage of the U.S. population and leads to tremendous morbidity. Numerous nonsurgical and surgical treatments have been utilized to try and manage neuropathic pain with varying degrees of success. Recent research investigating ways to improve prosthetic control have identified new mechanisms for preventing neuromas in both motor and sensory nerves with free muscle and dermal grafts, respectively. These procedures have been used to treat chronic neuropathic pain in nonamputees, as well, in order to reduce failure rates found with traditional neurectomy procedures. Herein, we focus our attention on Dermal Sensory-Regenerative Peripheral Nerve Interfaces (DS-RPNI, free dermal grafts) which can be used to physiologically "cap" sensory nerves following neurectomy and have been shown to significantly decrease neuropathic pain.

Post-traumatic radial nerve neuroma: A case report

Introduction

Radial nerve neuromas (RNNs) are mostly post-traumatic conditions that occur after a complete or partial section of a nerve. Here we report a case of post-traumatic RNN with good functional progression after intense physical rehabilitation.

Case presentation

A 49 years old patient with a post-complete section of the radial nerve underwent intensive physical rehabilitation with two sessions of ultrasound-guided injections of 10 % glucose saline around the neuroma. 12 months later, the patient improved his wrist and hand finger extension functions.

Conclusion

Several surgical and non-surgical therapies have been proposed for the treatment of neuromas. However, no consensus currently exists, and management is frequently adapted to each patient.

A small painful neuroma of the transverse cervical nerve treated with pulsed radiofrequency: A case report

BACKGROUND

Neck pain is a common complaint seen amongst patients from all ages. When common causes of neck pain have been ruled out, it is important to investigate further. A careful physical exam can help identify the painful structures. An ultrasound of the area can also be helpful to identify possible structures involved. Neuromas can be treated with oral medications as well as more invasive techniques, such as pulsed radiofrequency (PRF).

CASE DESCRIPTION

In this case report, we discuss a 67-year-old female who presented with left anterior neck pain after developing a cervical mass who was later diagnosed as non-Hodgkin lymphoma. A small neuroma of the left transverse cervical nerve was found on ultrasound and ultimately was treated with PRF with a complete resolution of her symptoms at two months follow-up.

CONCLUSION

PRF seems to be a useful tool for controlling neuropathic pain caused by a neuroma.

Prevalence of residual limb pain and symptomatic neuromas after lower extremity amputation: a systematic review and meta-analysis

ABSTRACT

Residual limb pain (RLP) is associated with (partial) extremity amputations and is defined as pain felt in the remaining part of the amputated limb. A common cause of RLP is neuroma formation after nerve transections. Neuromas can be very painful and severely debilitating pathologies, preventing prosthetic use, reducing quality of life, and requiring medication. Residual limb pain and symptomatic neuromas are often not properly recognized by physicians explaining the varying prevalence in the literature. This systematic review and meta-analysis aim to provide a comprehensive overview of published literature on the prevalence of RLP and symptomatic neuroma after lower extremity amputation. Studies reporting the prevalence of RLP and symptomatic neuroma pain in patients who have had a lower extremity amputation published between 2000 and 2020 were identified in PubMed and Embase. Random-effects meta-analyses of proportions were performed to quantify the prevalence of RLP and symptomatic neuroma. Subgroups were identified and analysed. For RLP, the pooled prevalence was 59% (95% CI: 51-67). For symptomatic neuromas, the pooled prevalence was 15% (95% CI: 7-28). Residual limb pain subgroup analysis showed statistically significant higher prevalence in patients aged >50 years, follow-up >2 years, and in studies using a self-administered questionnaire for data collection. The prevalence of RLP and symptomatic neuroma in patients who have had a lower extremity amputation is 59% and 15%, respectively. Knowledge of their high prevalence may result in better awareness among physicians, in turn providing timely and adequate management.

Residual limb pain: An evidence-based review

Acquired limb loss, whether from accident or amputation, occurs with an incidence of greater than 175,000 per year in the United States. Current prevalence is estimated at greater than 1.5 million and is expected to double within 30 years. While many patients with amputations may have no significant pain or sensory issues after healing from the initial loss, one-quarter to one-half of patients may have ongoing difficulties with residual limb pain, phantom limb pain, or phantom limb sensation. This review explores the potential etiologies of those symptoms, as well as a variety of treatment options that a practitioner may consider when approaching this condition.

Coaptation of Cutaneous Nerves for Intractable Stump Pain and Phantom Limb Pain after Upper Limb Amputation

Background

Various surgical treatments have been advocated for stump pain and phantom limb pain after limb amputation but the most effective is unknown. We report a case of intractable stump pain and phantom limb pain of the upper limb, which was successfully treated by end-to-end coaptation of the cutaneous nerves after multimodal treatment failures.

Case description

A 39-year-old man was referred to our department with a history of severe stump neuroma-related pain and phantom limb pain of his right upper limb. He had undergone multiple treatments over 26 years including medication, nerve blocks, and repeated surgeries. None had been successful for relief of pain. The clinical assessment showed a point of marked tenderness around the medial stump of the upper arm. Ultrasound-guided peripheral infiltration of local anaesthetic around the medial stump produced significant relief of his pain. Exploration around the medial limb stump revealed two stump neuromas of the medial cutaneous nerves of the forearm. Both stump neuromas were resected, and their stumps were coapted to each other. After 4 years, he was completely relieved of his pain and without any sensory deficit.

Conclusion

Successful nerve coaptations for painful stump neuromas of the upper limb are reported rarely. This case suggests this method can be helpful. The patient burden was minimal because it involved the resection and coaptation of the two neuromas. This method should be encouraged for cases of intractable stump-related pain in the upper limb.

How to cite this article

Kadota H, Ishida K. Coaptation of Cutaneous Nerves for Intractable Stump Pain and Phantom Limb Pain after Upper Limb Amputation. Strategies Trauma Limb Reconstr 2020;15(1):50-53.

Treatment of Neuroma-induced Chronic Pain and Management of Nerve Defects with Processed Nerve Allografts

Symptomatic neuromas can cause significant chronic pain and negatively impact quality of life. Symptoms often persist despite narcotics and nonoperative interventions, which are largely ineffective. With the opioid crisis, treatments for chronic pain that limit narcotics are needed. Traditional surgical options may result in neuroma recurrence. Autograft reconstruction often results in donor-site morbidity. Processed nerve allografts facilitate axonal growth, nerve regeneration, and eliminate donor-site morbidity.

Methods

A literature review was performed to identify studies in which chronic neuroma pain was treated with excision and processed nerve allograft reconstruction. PubMed was queried, and data from the studies were grouped into treatment effective and ineffective groups. Statistical analyses were performed on these groups, and further subgroup analysis was performed on overall change of preoperative and postoperative pain scores using a paired t test.

Results

Seven studies fulfilled inclusion criteria yielding 42 patients. Greater than 90% of patients had improvement of pain postoperatively. The preoperative and postoperative pain scores could be determined for 40 patients. The mean preoperative score was 7.9, and the mean postoperative score was 3.54. These results were statistically significant using a paired t test with a P value of <0.001.

Conclusions

Chronic pain resulting from symptomatic neuromas can be treated with neuroma excision and nerve stump reconstruction with processed nerve allograft. This obviates autograft-associated donor-site morbidity and provides a platform to potentially restore sensation to the involved nerve whenever a distal nerve end is available. Addressing the root cause is an important paradigm shift for treating symptomatic neuromas.

Current State of the Surgical Treatment of Terminal Neuromas

Painful terminal neuromas resulting from nerve injury following amputation are common. However, there is currently no universally accepted gold standard of treatment for this condition. A comprehensive literature review is presented on the treatment of terminal neuromas. Four categories of terminal neuroma surgical procedures are assessed: epineurial closure; nerve transposition with implantation; neurorrhaphy, and alternate target reinnervation. Significant patient and case studies are highlighted in each section, focusing on surgical technique and patient outcome metrics. Studies presented consisted of a PubMed search for "terminal neuromas," without year limitation. The current available research supports the use of implantation into muscle for the surgical treatment of terminal neuromas. However, this technique has several fundamental flaws that limit its utility, as it does not address the underlying physiology behind neuroma formation. Regenerative peripheral nerve interfaces and targeted muscle reinnervation are 2 techniques that seem to offer the most promise in preventing and treating terminal neuroma formation. Both techniques are also capable of generating control signals which can be used for both motor and sensory prosthetic control. Such technology has the potential to lead to the future restoration of lost limb function in amputees. Further clinical research employing larger patient groups with high-quality control groups and reproducible outcome measures is needed to determine the most effective and beneficial surgical treatment for terminal neuromas. Primary focus should be placed on investigating techniques that most closely approximate the theoretically ideal neuroma treatment, including targeted muscle reinnervation and regenerative peripheral nerve interfaces.

Painful Traumatic Neuromas in Subcutaneous Fat: Visibility and Morphologic Features With Ultrasound

OBJECTIVES

Subcutaneous neuromas usually result from trauma and may lead to dissatisfaction in patients with a trigger point, loss of sensitivity in the relevant territory of innervation, and spontaneous neuropathic pain. Confirming clinically suspected cases of neuroma may prove difficult. The objective of this study was to evaluate the visibility and morphologic features of traumatic subcutaneous neuromas of the limbs with ultrasound (US).

METHODS

Between January 2012 and August 2016, 38 consecutive patients clinically suspected of having subcutaneous neuromas were investigated with US. The diagnosis was confirmed on the basis of a focal morphologic abnormality of the nerve associated with trigger pain. Each neuroma was classified into 1 of 3 subtypes based on its injury pattern. The subtypes were terminal neuroma, spindle neuroma, and scar encasement, either isolated or associated with these subtypes.

RESULTS

Forty-four lesions were found in the 38 patients, including 29 spindle neuromas (65.9%), 14 terminal neuromas (31.8%) and 1 scar encasement with no nerve caliber abnormality (2.3%). Fifteen neuromas (35% of all neuromas) were associated with scar encasement. In 13 cases that required surgery, the diagnosis of neuroma or scar encasement could be surgically proven and confirmed the validity of the US findings.

CONCLUSIONS

Ultrasound can be used to show and classify subcutaneous nerves of the upper and lower limbs with high accuracy. The US trigger sign provides an indication of neuroma involvement in pain. This modality can play a substantial role both in the preoperative planning of neuroma surgery and in therapeutic US-guided procedures.

Surgical Algorithm for Neuroma Management: A Changing Treatment Paradigm

Successful treatment of the painful neuroma is a particular challenge to the nerve surgeon. Historically, symptomatic neuromas have primarily been treated with excision and implantation techniques, which are inherently passive and do not address the terminal end of the nerve. Over the past decade, the surgical management of neuromas has undergone a paradigm shift synchronous with the development of contemporary techniques aiming to satisfy the nerve end. In this article, we describe the important features of surgical treatment, including the approach to diagnosis with consideration of neuroma type and the decision of partial versus complete neuroma excision. A comprehensive list of the available surgical techniques for management following neuroma excision is presented, the choice of which is often predicated upon the availability of the terminal nerve end for reconstruction. Techniques for neuroma reconstruction in the presence of an intact terminal nerve end include hollow tube reconstruction and auto- or allograft nerve reconstruction. Techniques for neuroma management in the absence of an intact or identifiable terminal nerve end include submuscular or interosseous implantation, centro-central neurorrhaphy, relocation nerve grafting, nerve cap placement, use of regenerative peripheral nerve interface, "end-to-side" neurorrhaphy, and targeted muscle reinnervation. These techniques can be further categorized into passive/ablative and active/reconstructive modalities. The nerve surgeon must be aware of available treatment options and should carefully choose the most appropriate intervention for each patient. Comparative studies are lacking and will be necessary in the future to determine the relative effectiveness of each technique.

Surgical Algorithm for Neuroma Management: A Changing Treatment Paradigm

Successful treatment of the painful neuroma is a particular challenge to the nerve surgeon. Historically, symptomatic neuromas have primarily been treated with excision and implantation techniques, which are inherently passive and do not address the terminal end of the nerve. Over the past decade, the surgical management of neuromas has undergone a paradigm shift synchronous with the development of contemporary techniques aiming to satisfy the nerve end. In this article, we describe the important features of surgical treatment, including the approach to diagnosis with consideration of neuroma type and the decision of partial versus complete neuroma excision. A comprehensive list of the available surgical techniques for management following neuroma excision is presented, the choice of which is often predicated upon the availability of the terminal nerve end for reconstruction. Techniques for neuroma reconstruction in the presence of an intact terminal nerve end include hollow tube reconstruction and auto- or allograft nerve reconstruction. Techniques for neuroma management in the absence of an intact or identifiable terminal nerve end include submuscular or interosseous implantation, centro-central neurorrhaphy, relocation nerve grafting, nerve cap placement, use of regenerative peripheral nerve interface, “end-to-side” neurorrhaphy, and targeted muscle reinnervation. These techniques can be further categorized into passive/ablative and active/reconstructive modalities. The nerve surgeon must be aware of available treatment options and should carefully choose the most appropriate intervention for each patient. Comparative studies are lacking and will be necessary in the future to determine the relative effectiveness of each technique.

Current Ultrasound Application in the Foot and Ankle

This article is a comprehensive review of the current utilizations of ultrasound in the treatment of orthopedic conditions of the foot and ankle. It reviews the diagnostic and interventional applications to commonly encountered lower-extremity ailments, including plantar fasciosis, tendinosis, and peripheral nerve disorders. It also outlines minimally invasive ultrasound-guided procedures and emerging therapies as alternatives to current treatments. These emerging therapies can be used to assist surgeons and provide options for patients needing intervention. Techniques such as hydrodissection, injection, aspiration, tenotomy, and fasciotomy are discussed, giving readers insight into different treatment modalities and options to help manage their patients.

Pulsed radiofrequency of brachial plexus under ultrasound guidance for refractory stump pain: a case report

The post-amputation (pain) syndrome, including stump pain, phantom limb sensation, and phantom limb pain is common but difficult to treat. Refractory stump pain in the syndrome is an extremely challenging and troublesome clinical condition. Patients respond poorly to drugs, nerve blocks, and other effective treatments like spinal cord stimulation and surgery. Pulsed radiofrequency (PRF) technique has been shown to be effective in reducing neuropathic pain. This report describes a patient with persistent and refractory upper limb stump pain being successfully relieved with PRF of brachial plexus under ultrasound guidance after a 6-month follow-up period, suggesting that PRF may be considered as an alternative treatment for refractory stump-neuroma pain.

Prevention of Painful Neuroma and Phantom Limb Pain After Transfemoral Amputations Through Concomitant Nerve Coaptation and Collagen Nerve Wrapping

BACKGROUND

Postamputation pain is a debilitating condition that affects almost 60% of transfemoral amputees. Recent appreciation for the contribution of peripheral nerve derangement to the development of postamputation pain has resulted in focus on the role of nerve reconstruction in preventing pain after amputation.

OBJECTIVE

To propose a method involving tibial and common peroneal nerve coaptation at the time of amputation, as a means to prevent residual limb pain and phantom sequelae resulting from neuroma formation.

METHODS

Between May 2014 and May 2015, 17 patients underwent transfemoral amputation and nerve management through either (1) common peroneal nerve-to- tibial nerve coaptation and collagen nerve wrapping or (2) traction neurectomy alone. Visual analog scores (VAS) for pain, analgesic requirements, neuroma formation, phantom pain/sensations, and ambulatory status were compared between cohorts.

RESULTS

Six patients underwent nerve coaptation/collagen nerve wrapping, whereas 11 underwent traction neurectomy. At 2 months, VAS scores were similar between cohorts (3 vs 3.82; P = .88); however, neuroma (0% vs 36.3%; P = .24) and phantom pain (0% and 54.5%; P = .03) were significantly lower after coaptation. After 6 months, VAS scores (0.75 vs 5.6; P = .02) as well as neuroma (0% vs 54.5%; P = .03) and phantom pain (0% vs 63.6%; P = .01) remained lower among patients who underwent coaptation. At follow-up, 67% of coaptation patients were ambulating with a prosthesis vs 9% of neurectomy patients (P = .01).

CONCLUSION

Preemptive coaptation and collagen nerve wrapping is associated with lower VAS pain scores, phantom symptoms, and neuroma formation, with higher ambulation rates after 6 months when compared with traction neurectomy alone.

ABBREVIATIONS

CPN, common peroneal nervePAP, Postamputation painPLP, phantom limb painPS, phantom sensationsRLP, residual limb painTN, tibial nerve.

Ultrasound-guided alcohol neurolysis and radiofrequency ablation of painful stump neuroma: effective treatments for post-amputation pain

BACKGROUND

Post-amputation pain (PAP) is highly prevalent after limb amputation, and stump neuromas play a key role in the generation of the pain. Presently, PAP refractory to medical management is frequently treated with minimally invasive procedures guided by ultrasound, such as alcohol neurolysis and radiofrequency ablation (RFA).

OBJECTIVE

To record the immediate and long-term efficacy of alcohol neurolysis and RFA. We first used alcohol neurolysis and then, when necessary, we performed RFA on PAP patients.

STUDY DESIGN

Prospective case series.

SETTING

Pain management center.

METHODS

Thirteen subjects were treated with ultrasound-guided procedures.

RESULTS

All patients were treated with neurolysis using alcohol solutions guided by ultrasound. Seven (54%) of 13 subjects achieved pain relief after 1-3 alcohol injection treatments. The remaining 6 subjects obtained pain relief after receiving 2 administrations of ultrasound-guided RFA. After a 6-month follow-up evaluation period, pain quantities were also assessed. Both stump pain (including intermittent sharp pain and continuous burning pain) and phantom pain were relieved. The frequency of intermittent sharp pain was decreased, and no complications were noted during the observation.

CONCLUSION

The use of ultrasound guidance for alcohol injection and RFA of painful stump neuromas is a simple, radiation-free, safe, and effective procedure that provides sustained pain relief in PAP patients. In this case series, RFA was found to be an effective alternative to alcohol injection.

Reduction in mechanical allodynia in complex regional pain syndrome patients with ultrasound-guided pulsed radiofrequency treatment of the superficial peroneal nerve

The superficial peroneal nerve is vulnerable to damage from ankle sprain injuries and fractures as well as surgery to this region. And it is also one of the most commonly involved nerves in complex regional pain syndrome type II in the foot and ankle region. We report two cases of ultrasound-guided pulsed radiofrequency treatment of superficial peroneal nerve for reduction of allodynia in CRPS patients.

Traumatic neuroma of the superficial peroneal nerve in a patient: a case report and review of the literature

BACKGROUND

Traumatic neuromas are rare benign tumors, which are common in trauma or post-operation and accompanied with obvious symptoms of pain. This study will show the superficial peroneal nerve neuroma occurring after resection of hemangioma.

CASE PRESENTATION

A 44-year-old male had an operation of the right leg cavernous hemangioma resection in 1995. Half a year after the operation, pain around the wound appeared and gradually aggravated. The patient had the lesion exploration resection in 2013, and the pathological result showed traumatic neuroma. Within half a year of the second operation, severe pain showed up again, so neuroma resection proceeded in May 2015. The postoperative pathological and immunohistochemical results showed traumatic neuroma. According to the postoperative follow-up, there were no symptoms of pain appearing again.

LITERATURE REVIEW

The pain is obvious, and B ultrasonography is the most efficient way to find neuromas. Both conservative and operative therapy have their advantages and disadvantages.

CONCLUSIONS

There remain many unanswered questions in relation to the treatment of traumatic neuromas, and further research is required, although we have already had adequate understanding of traumatic neuromas.

Dorsal Root Ganglion (DRG) Stimulation in the Treatment of Phantom Limb Pain (PLP)

OBJECTIVES

Phantom limb pain (PLP) is a neuropathic condition in which pain is perceived as arising from an amputated limb. PLP is distinct from, although associated with, pain in the residual limb and nonpainful phantom sensations of the missing limb. Its treatment is extremely challenging; pharmaceutical options, while commonly employed, may be insufficient or intolerable. Neuromodulatory interventions such as spinal cord stimulation have generated mixed results and may be limited by poor somatotopic specificity. It was theorized that dorsal root ganglion (DRG) neuromodulation may be more effective.

MATERIALS AND METHODS

Patients trialed a DRG neurostimulation system for their PLP and were subsequently implanted if results were positive. Retrospective chart review was completed, including pain ratings on a 100-mm visual analogue scale (VAS) and patient-reported outcomes.

RESULTS

Across eight patients, the average baseline pain rating was 85.5 mm. At follow-up (mean of 14.4 months), pain was rated at 43.5 mm. Subjective ratings of quality of life and functional capacity improved. Some patients reduced or eliminated pain medications. Patients reported precise concordance of the paresthesia with painful regions, including in their phantom limbs; in one case, stimulation eliminated PLP as well as nonpainful phantom sensations. Three patients experienced a diminution of pain relief, despite good initial outcomes.

CONCLUSIONS

DRG neuromodulation may be an effective tool in treating this pain etiology. Clinical outcomes in this report support recent converging evidence suggesting that the DRG may be the site of PLP generation and/or maintenance. Further research is warranted to elucidate mechanisms and optimal treatment pathways.

Ultrasound-guided pulsed radio frequency treatment in Morton's neuroma

BACKGROUND

Morton's neuroma is a perineural fibrosis of an intermetatarsal plantar nerve. Burning, numbness, paresthesia, and tingling down the interspaces of involved toes may also be experienced. Taking into account all of this information, we designed a prospective open-label study to evaluate the efficacy of pulsed radio frequency on Morton's neuroma.

METHODS

Twenty patients with Morton's neuroma were experiencing symptomatic neuroma pain in the foot not relieved by routine conservative treatment. All of the patients had been evaluated by a specialized orthopedist and were offered pulsed radio frequency as a last option before having surgery. Initially, pain level (numerical rating scale), successful pain control (a ≥50% pain decrease was accepted as successful pain control), comfort when walking (yes or no), and satisfaction level (satisfied or not satisfied) were evaluated.

RESULTS

We found a decrease in the pain level in 18 of 20 patients, successful pain control in 12, and wearing shoes and walking without pain in 16. Overall, satisfaction was rated as excellent or good by 12 patients with Morton's neuroma in this series.

CONCLUSIONS

This evidence indicates that ultrasound-guided pulsed radio frequency is a promising treatment modality in the management of Morton's neuroma pain.

Does targeted nerve implantation reduce neuroma pain in amputees?

BACKGROUND

Symptomatic neuroma occurs in 13% to 32% of amputees, causing pain and limiting or preventing the use of prosthetic devices. Targeted nerve implantation (TNI) is a procedure that seeks to prevent or treat neuroma-related pain in amputees by implanting the proximal amputated nerve stump onto a surgically denervated portion of a nearby muscle at a secondary motor point so that regenerating axons might arborize into the intramuscular motor nerve branches rather than form a neuroma. However, the efficacy of this approach has not been demonstrated.

QUESTIONS/PURPOSES

We asked: Does TNI (1) prevent primary neuroma-related pain in the setting of acute traumatic amputation and (2) reduce established neuroma pain in upper- and lower-extremity amputees?

METHODS

We retrospectively reviewed two groups of patients treated by one surgeon: (1) 12 patients who underwent primary TNI for neuroma prevention at the time of acute amputation and (2) 23 patients with established neuromas who underwent neuroma excision with secondary TNI. The primary outcome was the presence or absence of palpation-induced neuroma pain at last followup, based on a review of medical records. The patients presented here represent 71% of those who underwent primary TNI (12 of 17) and 79% of those who underwent neuroma excision with secondary TNI (23 of 29 patients) during the period in question; the others were lost to followup. Minimum followup was 8 months (mean, 22 months; range, 8-60 months) for the primary TNI group and 4 months (mean, 22 months; range, 4-72 months) for the secondary TNI group.

RESULTS

At last followup, 11 of 12 patients (92%) after primary TNI and 20 of 23 patients (87%) after secondary TNI were free of palpation-induced neuroma pain.

CONCLUSIONS

TNI performed either primarily at the time of acute amputation or secondarily for the treatment of established symptomatic neuroma is associated with a low frequency of neuroma-related pain. By providing a distal target for regenerating axons, TNI may offer an effective strategy for the prevention and treatment of neuroma pain in amputees.

Pulsed radiofrequency ablation under ultrasound guidance for huge neuroma

Amputation neuroma can cause very serious, intractable pain. Many treatment modalities are suggested for painful neuroma. Pharmacologic treatment shows a limited effect on eliminating the pain, and surgical treatment has a high recurrence rate. We applied pulsed radiofrequency treatment at the neuroma stalk under ultrasonography guidance. The long-term outcome was very successful, prompting us to report this case.

The physiologic effects of pain on the endocrine system

Severe pain has profound physiologic effects on the endocrine system. Serum hormone abnormalities may result and these serve as biomarkers for the presence of severe pain and the need to replace hormones to achieve pain control. Initially severe pain causes a hyperarousal of the hypothalamic-pituitary-adrenal system which results in elevated serum hormone levels such as adrenocorticotropin, cortisol, and pregnenolone. If the severe pain does not abate, however, the system cannot maintain its normal hormone production and serum levels of some hormones may drop below normal range. Some hormones are so critical to pain control that a deficiency may enhance pain and retard healing.

Painful neuromas

OBJECTIVES

To perform a topical review of the published literature on painful neuromas.

METHODS

A MEDLINE search was performed using the MESH terms "neuroma", "pain", "diagnosis", and "treatment" for all dates.

RESULTS

Acoustic neuromas and intraabdominal neuromas were excluded from a total of 7616 articles. The reference lists from these articles were further reviewed to obtain other relevant articles.

DISCUSSION

Neuromas develop as part of a normal reparative process following peripheral nerve injury. Painful neuromas can induce intense pain resulting in immense suffering and disability. MRI aids the diagnosis, but, ultrasound imaging allows cost effective accurate diagnosis and localization of neuromas by demonstrating their direct contiguity with the nerve of origin. Management options for painful neuromas include pharmacotherapy, prosthetic adjustments, steroid injection, chemical neurolysis, cryoablation, and radiofrequency ablation. Ultrasound imaging guidance has improved the success in localizing and targeting the neuromas. This review discusses the patho-physiology and accumulated evidence for various therapies and the current percutaneous interventional management options for painful neuromas.

A case of subcutaneous neuroma presenting with intractable pain and allodynia over the anteromedial aspect of the knee

INTRODUCTION

With the exception of interdigital neuromas, cutaneous neuromas are relatively rare and often present a diagnostic challenge.

CASE REPORT

We describe a case of a 30-year-old man with a 9-month history of intractable pain and touch allodynia on the medial side of his proximal left leg. Although the exact focus of the pain and allodynia was initially difficult to detect, a subsequent thorough physical examination revealed touch allodynia in a 1×1-cm area overlying the proximal tibia, immediately below the left patella. Ultrasonography of this site with a 7.5-MHz linear probe showed a 2×4-mm round hypoechoic mass with smooth margins that was suspected to be a neuroma arising from the infrapatellar branch of the saphenous nerve. An excisional biopsy was then performed, the pathology of which revealed perineurial thickening, inflammatory cells in the perineurium, and neovascularization, consistent with neuroma. All symptoms disappeared immediately after an excisional biopsy.

CONCLUSIONS

The diagnosis of cutaneous neuroma should be considered in all patients who have intractable pain and allodynia at unusual locations and in atypical patterns. In addition, ultrasonography can prove very useful in the detection of small cutaneous neuromas if the site of symptoms can be precisely localized.

Treatment of meralgia paresthetica with ultrasound-guided pulsed radiofrequency ablation of the lateral femoral cutaneous nerve

A 23-year-old female with an 18-month history of left anterolateral thigh paresthesias and burning pain consistent with meralgia paresthetica was referred to our clinic after failing trials of physical therapy, nonsteroidal anti-inflammatories, gabapentin, and amitriptyline. We performed 3 lateral femoral cutaneous nerve blocks with corticosteroid over a 4-month period; however, each block provided only temporary relief. As this pain was limiting the patient's ability to perform her functions as an active duty service member, we elected to perform a pulsed radiofrequency treatment of the lateral femoral cutaneous nerve with ultrasound guidance and nerve stimulation. After locating the lateral femoral cutaneous nerve with ultrasound and reproducing the patient's dysthesia with stimulation, pulsed radiofrequency treatment was performed at 42°C for 120 seconds. The needle was then rotated 180° and an additional cycle of pulsed radiofrequency treatment was performed followed by injection of 0.25% ropivacaine with 4 mg of dexamethasone. At 1.5 and 3 month follow-up visits, the patient reported excellent pain relief with activity and improved ability to perform her duties as an active duty service member. ▪

21. Phantom pain

Phantom pain is pain caused by elimination or interruption of sensory nerve impulses by destroying or injuring the sensory nerve fibers after amputation or deafferentation. The reported incidence of phantom limb pain after trauma, injury or peripheral vascular diseases is 60% to 80%. Over half the patients with phantom pain have stump pain as well. Phantom pain can also occur in other parts of the body; it has been described after mastectomies and enucleation of the eye. Most patients with phantom pain have intermittent pain, with intervals that range from 1 day to several weeks. Even intervals of over a year have been reported. The pain often presents itself in the form of attacks that vary in duration from a few seconds to minutes or hours. In most cases, the pain is experienced distally in the missing limb, in places with the most extensive innervation density and cortical representation. Although there are still many questions as to the underlying mechanisms, peripheral as well as central neuronal mechanisms seem to be involved. Conservative therapy consists of drug treatment with amitriptyline, tramadol, carbamazepine, ketamine, or morphine. Based on the available evidence some effect may be expected from drug treatment. When conservative treatment fails, pulsed radiofrequency treatment of the stump neuroma or of the spinal ganglion (DRG) or spinal cord stimulation could be considered (evidence score 0). These treatments should only be applied in a study design.