Peripheral nerve stimulation (PNS): A valid and definitive therapeutical option for a case of anterior cutaneous nerve entrapment syndrome (ACNES).

Anterior cutaneous nerve entrapment syndrome (ACNES) is a cause of moderate to severe chronic pain, hyperesthesia/hypoesthesia, and altered perception of heat/cold in a specific region of the anterior abdominal wall, referable to the territory of innervation of one or more anterior branches of the intercostal nerves. None of the therapeutic options currently available has proved to be effective in the long term or decisive. In recent years, we have begun to treat purely sensory neuropathies, such as this, with the implantation of wireless peripheral nerve stimulators (PNS), achieving the safety of modular and personalized analgesia. We report the case of a 41-year-old man suffering from ACNES of the 8th intercostal nerve for two years. We first performed two consecutive ultrasound-guided diagnostic blocks of the anterior cutaneous branch of the 8th intercostal right nerve and then elected the patient for ultrasound-guided nerve decompression followed by neuromodulation and pulsed-radiofrequency (PRF). Taking into account full employment, young age, and the likelihood of having to repeat the treatment several times, we considered him for Peripheral Nerve Stimulation (PNS) implantation under ultrasound guidance, and we implanted the wireless lead at the anterior branch of the right 8th intercostal nerve, and programmed tonic stimulation 100 Hz PW 200 ms. The patient reported immediate pain relief and never took medication for this problem again, at two years follow-up. PNS has had an increasing role in the management of chronic neuropathic pain, especially in merely sensitive neuropathies like ACNES. We support future research on this theme.

Delayed vagal nerve compressive neuropathy following placement of vagal nerve stimulator: case report.

Vagal neuropathy causing vocal fold palsy is an uncommon complication of vagal nerve stimulator (VNS) placement. It may be associated with intraoperative nerve injury or with device stimulation. Here we present the first case of delayed, compressive vagal neuropathy associated with VNS coil placement which presented with progressive hoarseness and vocal cord paralysis. Coil removal and vagal neurolysis was performed to relieve the compression. Larger 3 mm VNS coils were placed for continuation of therapy. Coils with a larger inner diameter should be employed where possible to prevent this complication. The frequency of VNS-associated vagal nerve compression may warrant further investigation.

Middle cluneal nerve entrapment sites in the surgical field.

INTRODUCTION: Middle cluneal nerve (MCN) entrapment around the sacroiliac joint elicits low back pain (LBP). For surgical decompression to be successful, the course of the MCN must be known. We retrospectively studied the MCN course in 15 patients who had undergone MCN neurolysis. METHODS: Enrolled in this retrospective study were 15 patients (18 sides). We inspected their surgical records and videos to determine the course of the entrapped MCN. The area between the posterior superior- and the posterior inferior iliac spine was divided into areas A-D from the rostral side. The MCN transit points were identified at the midline and the lateral edge connecting the posterior superior- and posterior inferior iliac spine. Before and 6 months after surgery, the patients recorded the degree of LBP on the numerical rating scale and the Roland-Morris Disability Questionnaire. RESULTS: We decompressed 24 MCNs. The mean number was 1.3 nerves per patient (range 1-2). The MCN course was oblique in the cranio-caudal direction; the nerve tended to be observed in areas C and D. In six patients (40%), we detected two MCN branches, they were in the same area and adjacent. Postoperatively, LBP was improved significantly in all patients. CONCLUSION: Between the posterior superior- and the posterior inferior iliac spine, the MCN ran obliquely in the cranio-caudal direction; it was prominent in areas on the caudal side. In six (40%) patients, we decompressed two adjacent MCNs. Our findings are useful for MCN decompression surgery.

[Rare nerve compression neuropathies] / Seltene Nervenkompressionssyndrome.

UNCOMMON NERVE COMPRESSION SYNDROMES: In regard to the complex anatomical relationship of peripheral nerves and muscles, tendons, fasciae as well as their long course within those anatomical structures and additional close contact to bony structures, they are prone to suffer from local compression syndromes. Hence creating a vast majority of entrapment syndromes - well described in literature for almost every single nerve. The purpose of this article is to give an overview of symptoms, signs, diagnostic studies and treatment options, addressing especially the less known syndromes. Compression syndromes of the upper arm and shoulder region include the suprascapular nerve syndrome the compression of the axillary nerve within the spatium quadrilaterale and the compression of the long thoracic nerve at the chest wall. The upper extremity offers a variety of infrequent entrapment syndromes, as the pronator teres syndrome and anterior interosseus syndrome, both resulting from pressure to the median nerve in the forearm. Compression neuropathy in the course of the radial nerve in the distal upper extremity is also known as supinator syndrome. Guyon's canal syndrome is the ulnar side equivalent to the well-known carpal tunnel syndrome. In the case of a Cheiralgia paresthetica, a compression of a sensory branch of the superficial radial nerve can be seen. In the lower extremities, a variety of nerves especially in the groin and thigh area can be compressed as they pass through the narrow spaces between the abdominal muscles or underneath the inguinal ligament. Compression of the lateral femoral cutaneous nerve is the most common syndrome. Compression syndromes of the femoral and obturator nerves are most often iatrogenic. Pain around the knee, especially the lateral part and following orthopedic procedures of the knee, can arise from a compression or a lesion of a small infrapatellar branch of the saphenous nerve. Another probably underdiagnosed syndrome is piriformis syndrome, resulting from an entrapment of the sciatic nerve as it passes through certain muscular structures. In the distal lower extremity, the peroneal and tibial nerves can be compressed at multple sites, clinically known as peroneal nerve paralysis resulting from nerve compression around the fibular head, the anterior and posterior tarsal tunnel syndrome, and Morton's metatarsalgia.

[Rare Compression Syndrome of the Median Nerve due to a Supracondylar Humeral Process and a Ligament of Struthers]. / Seltenes Kompressionssyndrom des N. medianus durch den Processus supracondylaris und das Struthers-Ligament.

INTRODUCTION: A supracondylar process is a bony spur on the distal anteromedial surface of the humerus, and it is considered an anatomical variant with a prevalence of 0.4-2.7% according to anatomical studies. In almost all cases, it is associated with a fibrous, sometimes ossified ligament, which extends from the supracondylar process to the medial epicondyle. This ligament is known in the literature as the ligament of Struthers, named after the Scottish anatomist who first described it in detail in 1854. In rare cases, the supracondylar process can be a clinically relevant finding as a cause of nerve compression syndrome. The median and ulnar nerve can be trapped by the ring-shaped structure formed by the ligament of Struthers and the supracondylar process. CASE REPORT: A 59-year-old patient with symptoms of a cubital tunnel syndrome and additional ipsilateral sensory deficits in his thumb was referred to our clinic. Electroneurography showed no signs of an additional carpal tunnel syndrome. Preoperative x-ray and CT scans of the upper arm revealed a supracondylar process, which led us to suspect an associated entrapment of the median nerve. An MRI scan of the upper arm showed a ligament of Struthers and signs of a related median nerve compression as we initially assumed. We performed a surgical decompression of the median nerve in the distal upper arm and of the ulnar nerve in the cubital tunnel. Intraoperatively, there was evidence of compression of the median nerve due to the supracondylar process and the ligament of Struthers. The latter was cleaved and then resected along with the supracondylar process. Three months after surgery, the patient had no motor or sensory deficits. SUMMARY: The ring-shaped structure formed by the supracondylar process and ligament of Struthers represents a rare cause of compression syndrome of the median and ulnar nerve. Its incidence remains unknown so far. This anatomical variant should be considered a differential diagnosis in case of possibly related nerve entrapment symptoms after ruling out other, more frequent nerve compression causes. Moreover, the supracondylar process should be completely resected including the periosteum during surgery to minimise the risk of recurrence.

Electrodiagnostic testing in dogs with disorders of the spinal cord or cauda equina.

Electrodiagnostic (EDX) testing is uncommonly utilized in dogs other than for investigation of disorders of the neuromuscular system. In dogs with diseases affecting the spinal cord or cauda equina, EDX testing can provide functional data complementary to imaging information that together can guide therapeutic and management approaches. Additionally, in some clinical scenarios, EDX testing prior to advanced imaging is integral to identifying if there is spinal cord or cauda equina involvement and can aid in determining the appropriate diagnostic path. This review will outline EDX testing methods that have been reported in dogs relating to the diagnosis, monitoring or prognosis of various conditions affecting the spinal cord and cauda equina. The various tests will be briefly outlined regarding how they are performed and what information is provided. The main focus will be on clinical applications including highlighting situations where EDX testing is useful for differentiating between neurologic and non-neurologic presentations. Additional ways these EDX techniques could be incorporated in the management of diseases of the spinal cord and cauda equina in dogs will be presented.

Identification and decompression of superior cluneal nerve implicated in low back pain.

INTRODUCTION: Low back pain (LBP) can be attributable to entrapment of the superior cluneal nerve (SCN) around the iliac crest. Surgical decompression is a useful treatment; however, finding all entrapped SCNs involved in patients with LBP can be difficult. We performed a retrospective study to help identify entrapped SCNs in the narrow surgical field. METHODS: We enrolled 20 LBP patient (22 sides) with SCN entrapment. They were 9 males and 11 females; their mean age was 72.5 years. We developed a 3-step procedure for successful SCN decompression surgery. In step 1, the thoracolumbar fascia is exposed and the SCN penetrating the fascia is released. In step 2, the fascia is opened and the SCN is released. In step 3, the fascia above the iliac crest is opened and the SCN is released. RESULTS: We successfully released 66 nerves; the average was 3.0 ± 0.8 (1-4) per patient. Step 1 detected 18 nerves (27.3%), step 2 identified 35 (53.0%), and in step 3, 13 (19.7%) were recognized. By tracing the thin nerves branching off the SCN, we found 7 nerves (10.6%). We performed 22 operations; step 1 identified 16 SCNs (72.7%), step 2 identified 21 (95.5%), and step 3 found 12 nerves (54.5%). CONCLUSIONS: The SCN is most readily identified upon opening of the thoracolumbar fascia. To identify as many SCN branches as possible, our 3-step method may be useful.

How Do We Treat Children with Anterior Cutaneous Nerve Entrapment Syndrome and Is the Biopsychosocial Model Also Being Applied? A Scoping Review.

Background: Evidence-based guidelines for managing anterior cutaneous nerve entrapment syndrome (ACNES) in children are absent. The primary aim of this review was to scrutinize the evidence supporting currently used treatment interventions. In accordance with the World Health Organization (WHO) guidelines for managing chronic pain in children, these patients and their families and caregivers should be treated within the context of the biopsychosocial model; pain should not be treated purely as a biomedical problem. Therefore, our second aim was to evaluate whether these interventions are applied within the context of the biopsychosocial model, utilizing an inter- or multidisciplinary approach. Materials and Methods: A scoping review of the literature was conducted to explore treatment strategies for ACNES in children. To ensure a comprehensive overview of published literature on this topic, the search was not restricted based on study type. Two reviewers independently assessed titles and abstracts. After excluding records unrelated to children, full texts were screened for inclusion. Any discrepancies in judgement were resolved through discussion with a third reviewer. Results: Out of 35 relevant titles, 22 were included in this review. Only 4 articles provided information on long-term outcomes. The overall quality of the review was deemed low. The majority of reports did not address treatment or education within the psychological and social domains. A structural qualitative analysis was not feasible due to the substantial heterogeneity of the data. Conclusion: The evidence supporting current treatment strategies in children with ACNES is of low quality. More research is needed to establish an evidence-based treatment algorithm for patients with this challenging pain problem. In line with the WHO recommendation, greater emphasis should be placed on a biopsychosocial approach. The ultimate goal should be the development of a generic treatment algorithm outlining an approach to ACNES applicable to all professionals involved.

Unintended dural tears during unilateral biportal endoscopic lumbar surgery: incidence and risk factors.

BACKGROUND: An unintended dural tear (DT) is the most common intraoperative complication of lumbar spine surgery. The unilateral biportal endoscopic technique (UBE) has become increasingly popular for treating various degenerative diseases of the lumbar spine; however, the DT incidence and risk factors specific to UBE remain undetermined. Therefore, this study aimed to evaluate the incidence and risk factors of DTs in UBE. METHOD: Data from all patients who underwent UBE for degenerative lumbar spinal diseases from November 2018 to December 2021 at our institution were used to assess the effects of demographics, diagnosis, and type of surgery on unintended DT risk. RESULTS: Overall, 24/608 patients (3.95%) experienced DTs and were treated with primary suture repair or bed rest. Although several patients experienced mild symptoms of cerebrospinal fluid (CSF) leaks, no serious postoperative sequelae such as nerve root entrapment, meningitis, or intracranial hemorrhage occurred. Additionally, no significant correlations were identified between DT and sex (P = 0.882), body mass index (BMI) (P = 0.758), smoking status (P = 0.506), diabetes (P = 0.672), hypertension (P = 0.187), or surgeon experience (P = 0.442). However, older patients were more likely to experience DT than younger patients (P = 0.034), and patients with lumbar spinal stenosis (LSS) were more likely to experience DT than patients with lumbar disc herniation (LDH) (P = 0.035). Additionally, DT was more common in revision versus primary surgery (P < 0.0001) and in unilateral laminotomy with bilateral decompression (ULBD) versus unilateral decompression (P = 0.031). Univariate logistic regression analysis revealed that age, LSS, ULBD, and revision surgery were significant risk factors for DT. CONCLUSIONS: In this UBE cohort, we found that the incidence of DT was 3.95%. Additionally, older age, LSS, ULBD, and revision surgery significantly increased the risk of DT in UBE surgery.

Lateral Femoral Cutaneous Nerve Cryoneurolysis for Meralgia Paresthetica: A Case Report.

Meralgia paresthetica (MP) is a disorder of lateral femoral cutaneous nerve mononeuropathy caused by entrapment or compression of the nerve. It is characterized by numbing, tingling, and burning pain in the lateral aspect of the thigh. The current treatments for MP include conventional medical management, peripheral nerve blocks, and surgical interventions. Some patients who suffer from MP can experience intractable pain and medical management of MP is often inadequate to provide satisfactory pain control. Although regional anesthesia provides excellent pain relief, the analgesic effects of peripheral nerve block are short-lived. Emerging evidence suggests that cryoneurolysis has a low-risk safety profile and can provide prolonged pain relief of superficial nerves when administered appropriately. We present a successful case of a patient with intractable neuropathic pain resulting from MP treated with cryoneurolysis therapy. The patient demonstrated immediate pain relief by 100% after the procedure followed by 80% and 60% pain reduction at 1-month and 3-months follow-up, respectively. Cryoneurolysis may be an alternative modality for patients who fail at conventional medical treatments of neuropathic pain.

Visceral symptoms in patients with anterior cutaneous nerve entrapment syndrome (ACNES): expression of viscerosomatic reflexes?

PURPOSE: Anterior cutaneous nerve entrapment (ACNES) is characterized by neuropathic pain in a predictable, circumscript abdominal area. The diagnostic delay is long, with half of ACNES-affected individuals reporting nausea, bloating, or loss of appetite mimicking visceral disease. The aim of this study was to describe these phenomena and to determine whether treatment could successfully reverse the visceral symptoms. METHODS: This prospective observational study was conducted between July 2017 and December 2020 at SolviMáx, Center of Excellence for Chronic Abdominal Wall and Groin Pain, Máxima Medical Center, Eindhoven. Adult patients who fulfilled published criteria for ACNES and reported at least one visceral symptom at intake were eligible for the study. A self-developed Visceral Complaints ACNES Score (VICAS) questionnaire that scores several visceral symptoms (minimum 1 point, maximum 9 points) was completed before and after therapy. The success of treatment was defined as at least 50% reduction in pain. RESULTS: Data from 100 selected patients (86 females) aged 39 ± 5 years were available for analysis. Frequently reported symptoms were abdominal bloating (78%), nausea (66%) and altered defecation (50%). Successful treatment significantly reduced the number of visceral symptoms, with a VICAS before of 3 (range 1-8) and after of 1 (range 0-6) (p < 0.001). A low baseline VICAS was associated with successful treatment outcome (OR 0.738, 95% CI 0.546-0.999). CONCLUSION: Patients with ACNES may report a variety of visceral symptoms. Successful treatment substantially reduces these visceral symptoms in selected patients.

[Ultrasound of nerves of the lower extremities]. / Nervensonographie der unteren Extremitäten.

The ability to visualize the nerves of the lower extremities differs from that of the upper extremities in sonography because the soft tissue cover is significantly larger in some cases. Landmarks are also defined for the lower extremities, which enable precise visualization of the nerves. Nerves and muscles are to be understood as a functional unit. In addition to the clarification of nerve compression syndromes, polyneuropathies and nerve tumors, sonography is also used to visualize muscle atrophy.

A clinicopathological study of low back pain due to middle cluneal nerve entrapment: case series.

PURPOSE: The middle cluneal nerve (MCN) is a pure sensory nerve around the middle buttock. Its entrapment between the iliac crest and the long posterior sacroiliac ligament elicits low back pain (LBP) that can be treated by MCN neurolysis or neurectomy. Because few studies examined the pathology of MCN entrapment (MCN-E) we subjected 7 neurectomized specimens from 6 LBP patients to pathologic study. METHODS: We present 6 consecutive patients (7 sides) with intractable LBP who underwent successful MCN neurectomy. Their symptom duration ranged from 6 to 96 months (average 47.3 months); the follow-up period ranged from 6 to 17 months (average 11.7 months). The surgical outcomes were evaluated using the numerical rating scale (NRS) for LBP and the Roland-Morris Disability Questionnaire (RDQ) score. The resected MCNs underwent neuropathological analysis. RESULTS: Postoperatively, all 6 patients reported immediate LBP amelioration; their NRS and RDQ scores were improved significantly. Pathological study of the 7 resected nerves showed that the myelinated fiber density was decreased in 6 nerves; we observed marked enlargement (n = 5), perineurial thickening and disruption (n = 6), intrafascicular fibrous changes (n = 5), myelinated fibers separated by fibrous cells under the perineurium (n = 4), and Renaut bodies (n = 3). The 7th nerve appeared normal with respect to the density and size of the myelinated fibers, however, the perineurium was slightly thickened. CONCLUSION: We present pathological evidence at the MCN compression site of 7 nerves from 6 patients whose LBP was alleviated by MCN neurectomy, indicating that MCN entrapment can elicit LBP.

Pulsed radiofrequency or surgery for anterior cutaneous nerve entrapment syndrome: Long-term results of a randomized controlled trial.

PURPOSE: Patients with anterior cutaneous nerve entrapment syndrome (ACNES) often require a step-up treatment strategy including abdominal wall injections, pulsed radiofrequency (PRF) or a neurectomy. Long-term success rates of PRF and surgery are largely unknown. The aim of the current study was to report on the long-term efficacy of PRF and neurectomy in ACNES patients who earlier participated in the randomized controlled PULSE trial. METHODS: Patients who completed the PULSE trial were contacted about pain status and additional treatments in the following years. Treatment success was based on numerical rating scale (NRS) following IMMPACT recommendations and Patient Global Impression of Change (PGIC) scores. RESULTS: A total of 44 of the original 60 patients were eligible for analysis (73.3%). Median follow-up was 71.5 months. One patient (4.3%) was still free of pain after a single PRF session, and five additional patients (21.7%) were free of pain by repetitive PRF treatments. By contrast, 13 patients (61.9%) in the neurectomy group were still free of pain without additional treatments. All pain recurrences and therefore primary re-interventions occurred in the first 2 years after the initial treatment. CONCLUSION: Approximately one in five ACNES patients undergoing PRF treatment reports long-term success obviating the need of surgical intervention. Surgery for ACNES is long-term effective in approximately two of three operated patients. Recurrent ACNES beyond 2 years after either intervention is rare.

Pronator syndrome and anterior interosseous nerve palsy due to neurolymphomatosis: a case report.

Pronator syndrome is a median nerve entrapment neuropathy that can be difficult to diagnose due to its variable presentation and objective findings. Neurolymphomatosis is an uncommon disease in which malignant lymphocytes infiltrate central or peripheral nerve endoneurium and is often missed for prolonged periods prior to diagnosis. We present a rare case of pronator syndrome and anterior interosseous nerve palsy due to neurolymphomatosis that was occult on initial MRI in spite of the presence of a median nerve mass discovered intra-operatively during neurolysis. This case demonstrates the value of ultrasound for the examination of peripheral nerve pathology and illustrates its utility as an adjunct to MRI, in part due to the ability to screen a large region.

Causes, symptoms, and treatments of nerve entrapments around the elbow: Current concepts.

The elbow is a joint extremely susceptible to stiffness, even after a trivial trauma. As for other joints, several factors can generate stiffness such as immobilisation, joint incongruity, heterotopic ossification, adhesions, or pain. Prolonged joint immobilisation, pursued to assure bony and ligamentous healing, represents the most acknowledged risk factor for joint stiffness. The elbow is a common site of nerve entrapment syndromes. The reasons are multifactorial, but peculiar elbow anatomy and biomechanics play a role. Passing from the arm into the forearm, the ulnar, median, and radial nerves run at the elbow in close rapport with the joint, fibrous arches and through narrow fibro-osseous tunnel. The elbow joint, in fact, has a large range of flexion which exposes nerves lying posterior to the axis of rotation to traction and those anterior to compression.

Electrical Stimulation Use in Upper Extremity Peripheral Nerve Injuries.

Peripheral nerve injuries can be debilitating and often have a variable course of recovery. Electrical stimulation (ES) has been used as an intervention to attempt to overcome the limits of peripheral nerve surgery and improve patient outcomes after peripheral nerve injury. Little has been written in the orthopaedic literature regarding the use of this technology. The purpose of this review was to provide a focused analysis of past and current literature surrounding the utilization of ES in the treatment of various upper extremity peripheral nerve pathologies including compression neuropathies and nerve transection. We aimed to provide clarity on the clinical benefits, appropriate timing for its employment, risks and limitations, and the need for future studies of ES.

Median nerve entrapment during closed reduction of antebrachium fracture in a child.

This is a case report of a four-year-old boy who suffered a forearm fracture managed with closed reduction and casting for six weeks. Postoperatively, the patient showed symptoms of median nerve affection which was misinterpreted as neuropraxia. Ultrasonography of the forearm revealed that the median nerve was trapped in the radius fracture site. The patient underwent a second operation with neurolysis and nerve grafting. This case report highlights the use of ultrasonography in the diagnostics of nerve entrapment neuropathy.

Uterine Fibroid-Induced Compressive Neuropathy of Lumbar Plexus and Obturator Nerve.

Introduction: Uterine fibroids are the most common gynecologic tumors in reproductive-aged women with a prevalence of up to 80%. Symptoms can range from heavy vaginal bleeding and bulk symptoms to, less frequently, deep vein thrombosis and bowel obstruction. Case Description: A 32-year-old female patient presented with acute-onset of right groin and knee pain, and difficulty ambulating. A large posterior uterine fibroid was found to be compressing branches of the lumbar plexus, including the obturator nerve. The patient underwent gynecologic evaluation and an urgent laparoscopic myomectomy. Postoperatively, she had significant improvement in neurologic symptoms. She continued physical therapy for residual mild paresthesia and pain with prolonged ambulation. Discussion: Large pelvic masses such as uterine fibroids should be considered on the differential diagnosis for acute-onset non-gynecologic symptoms such as compressive neuropathy, which require urgent evaluation and possible surgical management.