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.

[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.

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.

Variations of the obturator nerve and implications in obturator nerve entrapment treatment: an anatomical study.

INTRODUCTION: Obturator nerve entrapment or idiopathic obturator neuralgia is an unfamiliar pathology for many physicians which can lead to diagnostic errancy. This study aims to identify the potential compression areas of the obturator nerve to improve therapeutic management. MATERIAL AND METHODS: 18 anatomical dissections of lower limbs from 9 anatomical cadavers were performed. Endopelvic and exopelvic surgical approaches were utilized to study the anatomical variations of the nerve and to identify areas of entrapment. RESULTS: On 7 limbs, the posterior branch of the obturator nerve passed through the external obturator muscle. A fascia between the adductor brevis and longus muscles was present in 9 of the 18 limbs. The anterior branch of the obturator nerve was highly adherent to the fascia in 6 cases. In 3 limbs, the medial femoral circumflex artery was in close connection with the posterior branch of the nerve. CONCLUSION: Idiopathic obturator neuropathy remains a difficult diagnosis. Our cadaveric study did not allow us to formally identify one or more potential anatomical entrapment zones. However, it allowed the identification of zones at risk. A clinical study with staged analgesic blocks would be necessary to identify an anatomical area of compression and would allow targeted surgical neurolysis.

Suprascapular nerve entrapment caused by a large hematoma of the scapula: a case report.

BACKGROUND: Suprascapular nerve entrapment is a rare disorder that is frequently misdiagnosed as another disease. The suprascapular nerve is commonly entrapped at the following two sites: the suprascapular and spinoglenoid notches. Nerve entrapment at the spinoglenoid notch causes infraspinatus muscle weakness and atrophy. Patients present with posterior shoulder pain and weakness. Magnetic resonance imaging is used to confirm the diagnosis of a spinoglenoid cyst and nerve compression. Open or arthroscopic aspiration or decompression is indicated for patients with cysts in whom conservative treatment has failed and those with cysts associated with suprascapular nerve compression. CASE PRESENTATION: Herein, we describe the case of a 49-year-old man with suprascapular nerve entrapment caused by a large cyst, namely, a hematoma, in the superior scapular and spinoglenoid notches. Open surgical decompression of the suprascapular nerve was performed owing to an intact rotator cuff and glenoid labrum. CONCLUSION: Posterior shoulder pain promptly resolved without complications.

Radial Tunnel Syndrome: Review and Best Evidence.

Radial tunnel syndrome (RTS) is caused by compression of the posterior interosseous nerve and consists of a constellation of symptoms that have previously been characterized as aspects of other disease processes, as opposed to a distinct diagnosis. First described in the mid-20th century as "radial pronator syndrome," knowledge regarding the anatomy and presentation of RTS has advanced markedly over the past several decades. However, there remains notable controversy and ongoing research regarding diagnostic imaging, nonsurgical treatment options, and indications for surgical intervention. In this review, we will discuss the anatomic considerations of RTS, relevant physical examination findings, potential diagnostic modalities, and outcomes of several treatment options.

Unusual causes for meralgia paresthetica: systematic review of the literature and single center experience.

Meralgia paresthetica is often idiopathic, but sometimes symptoms may be caused by traumatic injury to the lateral femoral cutaneous nerve (LFCN) or compression of this nerve by a mass lesion. In this article the literature is reviewed on unusual causes for meralgia paresthetica, including different types of traumatic injury and compression of the LFCN by mass lesions. In addition, the experience from our center with the surgical treatment of unusual causes of meralgia paresthetica is presented. A PubMed search was performed on unusual causes for meralgia paresthetica. Specific attention was paid to factors that may have predisposed to LFCN injury and clues that may have pointed at a mass lesion. Moreover, our own database on all surgically treated cases of meralgia paresthetica between April 2014 and September 2022 was reviewed to identify unusual causes for meralgia paresthetica. A total of 66 articles was identified that reported results on unusual causes for meralgia paresthetica: 37 on traumatic injuries of the LFCN and 29 on compression of the LFCN by mass lesions. Most frequent cause of traumatic injury in the literature was iatrogenic, including different procedures around the anterior superior iliac spine, intra-abdominal procedures and positioning for surgery. In our own surgical database of 187 cases, there were 14 cases of traumatic LFCN injury and 4 cases in which symptoms were related to a mass lesion. It is important to consider traumatic causes or compression by a mass lesion in patients that present with meralgia paresthetica.

[Postoperative compressive neuropathies after orthopedic surgeries]. / Neuropathies périphériques dues au positionnement opératoire en chirurgie orthopédique.

Peripheral neuropathies after orthopedic surgery are a rare complication (0.14 % on average) but with a significant impact on quality of life that requires close monitoring and physiotherapy sessions. Surgical positioning is a preventable cause responsible for about 20-30 % of the observed neuropathies. Orthopedic surgery is one of the most affected areas because of the positions maintained for long periods of time that are particularly at risk of compression or nerve stretching. The objective of this article is to list, through a narrative review of the literature, the most frequently affected nerves, the clinical presentation as well as the risk factors, and to draw general practitioner's attention to this issue.

Les neuropathies périphériques après une intervention chirurgicale orthopédique sont une complication rare (0,14 % en moyenne) mais avec un impact important sur la qualité de vie, et nécessitent un suivi rapproché et des séances de physiothérapie. Parmi les causes évitables, le positionnement opératoire est responsable d'environ 20 à 30 % des neuropathies observées. La chirurgie orthopédique représente l'un des secteurs les plus touchés en raison des positions à risque de compression ou d'étirement nerveux maintenues pendant de longues durées. L'objectif de cet article est de présenter, par une revue narrative de la littérature, les nerfs les plus fréquemment touchés, le tableau clinique ainsi que les facteurs de risques associés, afin de sensibiliser le médecin de premier recours à cette problématique.

Ossification of Superior Transverse Scapular Ligament - Incidence, Embryology and Association with Suprascapular Neuropathy.

Introduction: Suprascapular notch is present at superior border of scapula just medial to coracoid process. This is covered by superior transverse scapular ligament (STSL). Suprascapular nerve passes below this ligament while suprascapular vessels pass above it. STSL ossification is a rare finding with variable incidences in different population groups. Materials and Methods: We observed 60 dry bony scapulae, 30 prosected formalin fixed upper limbs with scapula and 10 embalmed cadavers for the presence of ossified STSL. Results: There were complete ossification of STSL in two dried bony specimens of sacpula. Conclusion: Ossified STSL may be the causative factor for suprascapular neuropathy. The mainstay of management in cases of neuropathy or compression of suprascapular nerve is release of suprascapular ligament by either open or arthroscopic surgical approach. So, it is extremely important to know this type of variation to minimize any damage to related structure and plan the management accordingly.

[RADIAL TUNNEL SYNDROME].

INTRODUCTION: The radial tunnel syndrome (RTS) is an entrapment of the radial nerve in the forearm. It is characterized by pain focused on the trapping area in the proximal forearm as well as pain radiated down the forearm. The syndrome is more common in men and in our estimation, there is a circumstantial connection to the continuous use of the computer keyboard. Radial tunnel syndrome is a consequence of nerve entrapment in the tunnel, which is formed from a covering consisting of the supinator muscle and the distal margins of this muscle. There is a clear association between radial tunnel syndrome and the occurrence of tennis elbow. The sensitivity in nearby locations along with the lack of familiarity of some of the clinicians with RTS lead to misdiagnosis and therefore, even to mistreatment in some cases. The physical examination is the most important means of making the correct diagnosis. The treatment of radial tunnel syndrome is divided into the conservative one in which emphasis is placed on physiotherapy and mobilizations of the nerve and the surgical one during which decompression of the radial canal is performed and in fact release of pressure at the exact anatomical location.

Radial Tunnel Syndrome: Case Report and Comprehensive Critical Review of a Compression Neuropathy Surrounded by Controversy.

Radial tunnel syndrome (RTS) is an uncommon controversial entity thought to cause chronic lateral proximal forearm pain due to compression of the deep branch of the radial nerve, without paralysis or sensory changes. Diagnostic confusion for pain conditions in this region results from inconsistent definitions, terminology, tests, and descriptions in the literature of RTS and "tennis elbow," or lateral epicondylitis. A case of bilateral RTS with signs discordant with traditionally used clinical diagnostic tests was successfully relieved with surgical decompression and led us to perform a comprehensive critical review of the condition. We delineate the controversy surrounding its diagnosis and aim to facilitate appropriate management and identify other areas for further study in this controversial condition. Clinical validity and evidence of anatomical rationale for the traditionally used Maudsley's provocative test is unclear in diagnosis of RTS or in chronic lateral elbow pain, if at all. Neither imaging nor electrophysiological studies contribute to a clinical diagnosis which is supported by short-term improvement after an injection with long-acting local anesthetic and corticosteroid. Accurate diagnosis and treatment of RTS can significantly improve quality of life, but validity and evidence for traditional clinical tests and definitions must be clarified.

Meralgia paresthetica mimic after Moderna COVID­19 vaccine.

This report describes the case of a 56-year-old male who developed unilateral right anterior thigh numbness which began 16 hours after receiving his second Moderna COVID-19 vaccine in the left deltoid. The numbness persisted and after one week a circular, raised, painless area with a red border appeared in the center of the anterior thigh which resolved after 2 weeks spontaneously. There was no clinical history or risk factors consistent with meralgia paresthetica. At his 6 month follow up the patient reported that his symptoms spontaneously resolved. While many other non-specific neurologic side effects of COVID-19 vaccines have been documented, this is the first case of meralgia paresthetica documented after a vaccine without any other risk factors for the syndrome. COVID vaccines should be considered as a potential cause of very localized peripheral neuropathy.

[Entrapment syndromes of the intercostal nerve and its branches]. / Síndromes por atrapamiento del nervio intercostal y sus ramas.

Musculoskeletal chest pain poses a broad differential diagnosis, among which intercostal nerve involvement stands out. Its entrapment or that of any of its branches can resemble visceral pain and therefore can easily go unnoticed. With a good examination and the use of dynamic ultrasound, the diagnostic approach can be simpler. We present a 40-year-old man evaluated in a rehabilitation department for right lower rib pain, triggered by certain movements and associated with a pectus excavatum type thoracic deformity. Using dynamic ultrasound maneuvers, he was diagnosed with neuralgia of the 7th right intercostal nerve secondary to dynamic entrapment in the context of a thoracic deformity with costal hypermobility. We describe the clinical presentation, ultrasound imaging, treatment, and evolution after treatment. In this case, we describe entrapment syndromes of the intercostal nerve and its branches, their clinical and ultrasound diagnosis, and their therapeutic approach.

Osseous suprascapular canal: rare variant that would hinder suprascapular nerve block and posterior surgical approach.

PURPOSE: To report atypical anatomical variation of an osseous suprascapular canal, and to elaborate on its clinical significance as a potential anatomical factor that could obscure a direct posterior surgical approach and suprascapular nerve block. METHODS: Osteological observational study of the scapula with emphasis on the suprascapular space. The pool of investigated sample size was collectively 768 specimens composed of 529 adult dry scapulae (240 paired, 289 un-paired), 54 children dry scapulae, 135 wet scapulae observed during cadaveric dissections, 47 retrospective 3D CT reconstructions, and 3 retrospective full sequence shoulder MRI. The two reported cases came from the 240 (120 skeleton) observed paired scapulae. Furthermore, the osseous suprascapular canal was examined by X-rays and its internal path was exposed by CT sections. A narrative review was conducted to investigate any relevant reports on the subject matter. RESULTS: Two left dry bone scapulae with unilateral osseous suprascapular canal were found. The incidence of this atypical morphology of an osseous canal is probably five cases reported in three studies including this cases study. CONCLUSIONS: The reported cases aid in explaining additional possible anatomical factors that could lead to below threshold anesthetic effect in posterior suprascapular nerve block procedures. Therefore, it is more practical to visualize the suprascapular canal by some imaging method before attempting to blindly access the suprascapular nerve in nerve block or posterior surgical approach due to the rare potential existence of an ossified barrier hindering the procedure. LEVEL OF EVIDENCE: V Basic Science Research.

[Meralgia paraesthetica as complication of patient positioning : A not fully controllable risk]. / Meralgia paraesthetica als Lagerungsschaden : Kein voll beherrschbares Risiko.

Meralgia paraesthetica (MP) is the consequence of an entrapment or stretch injury of the lateral femoral cutaneous nerve at the crossing region with the inguinal ligament where the nerve exits the pelvis. It results in temporary or permanent sensory loss, paraesthesia and pain in the anterolateral region of the thigh. Idiopathic forms are known for example as seat belt syndrome or jeans syndrome. An MP can also occur as a complication of surgical or intensive care patient positioning. In focus are the lithotomy position, prone position and beach chair position.We analyzed 21 complaints about MP occurring for the first time postoperatively, which had been submitted to the expert committee for medical treatment errors at the North Rhine Medical Association over the past 10 years. Among these, six cases could be identified as positioning damage after a lithotomy position. In three cases MP occurred after supine positioning but the etiology could not be clarified with certainty. In 12 cases MP was recognized as a direct surgical complication.The pathophysiology, incidence and course as well as legal implications of position-related MP are discussed. Pressure damage to the nerve at its intersection with the inguinal ligament is assumed to be the main pathomechanism. Although all the cases presented here occurred after lithotomy positioning, the complication also appears to occur with other types of positioning according to the literature data, the most common being prone positioning. This also explains the increasingly published case reports of MP after prone positioning in COVID-19 patients for respiratory treatment. Safe avoidance of the positioning-related complication does not appear to be possible due to the anatomical variability of the course of the nerve and the unclear pathomechanisms.

Magnetic Resonance Imaging Findings in Patients with Tarsal Tunnel Syndrome.

Tarsal tunnel syndrome (TTS) is a common entrapment syndrome whose diagnosis can be difficult. We compared preoperative magnetic resonance imaging (MRI) and operative findings in 23 consecutive TTS patients (28 sides) whose mean age was 74.5 years. The 1.5T MRI sequence was 3D T2* fat suppression. We compared the MRI findings with surgical records and intraoperative videos to evaluate them. MRI- and surgical findings revealed that a ganglion was involved on one side (3.6%), and the other 27 sides were diagnosed with idiopathic TTS. MRI visualized the nerve compression point on 23 sides (82.1%) but failed to reveal details required for surgical planning. During surgery of the other five sides (17.9%), three involved varices, and on one side each, there was connective tissue entrapment or nerve compression due to small vascular branch strangulation. MRI studies were useful for nerve compression due to a mass lesion or idiopathic factors. Although MRI revealed the compression site, it failed to identify the specific involvement of varices and small vessel branches and the presence of connective tissue entrapment.

Meralgia Paresthetica.

PURPOSE OF REVIEW: This review article summaries the epidemiology, etiology, clinical presentations, and latest treatment modalities of meralgia paresthetica, including the latest data about peripheral and spinal cord stimulation therapy. Meralgia paresthetica (MP) causes burning, stinging, or numbness in the anterolateral part of the thigh, usually due to compression of the lateral femoral cutaneous nerve (LFCN). RECENT FINDINGS: There are emerging data regarding the benefit of interventional pain procedures, including steroid injection and radiofrequency ablation, and other interventions including spinal cord and peripheral nerve stimulation reserved for refractory cases. The strength of evidence for treatment choices in meralgia paraesthetica is weak. Some observational studies are comparing local injection of corticosteroid versus surgical interventions. However, more extensive studies are needed regarding the long-term benefit of peripheral and spinal cord stimulation therapy.

Compressive femoral neuropathy caused by anticoagulant therapy induced retroperitoneal hematoma: A case report.

RATIONALE: Spontaneous retroperitoneal hematomas due to anticoagulant therapy rarely occur. Retroperitoneal hematomas can cause severe pain in the groin, quadriceps femoris muscle weakness, hemodynamic instability, and abdominal distension. They rarely cause compressive neuropathy of the femoral nerve transversing the iliacus muscle. Differential diagnosis is not easy because they have similar clinical features to retroperitoneal hematomas. PATIENT CONCERNS: A 72-year-old female patient whose right arm was stuck in a bookshelf for 5 days developed right cephalic vein thrombosis. After 5 days of intravenous heparin therapy for venous thrombosis, she presented with sudden right groin pain, right leg paresis, hemodynamic instability, and abdominal distension. DIAGNOSIS: Emergency abdominal and pelvic CT showed a large number of hematomas in the bilateral retroperitoneal space with active bleeding of the right lumbar artery. An electrodiagnostic study was performed 2 weeks later to check for neuromuscular damage in the right lower extremity, and right compressive femoral neuropathy was confirmed. INTERVENTIONS: Heparin therapy was discontinued; emergency embolization of the lumbar artery was performed. After 2 weeks, the patient started receiving physical, occupational, and transcutaneous electrical stimulation therapies. OUTCOMES: She became hemodynamically stable after arterial embolization; a significant decrease in hematoma and patency of the femoral nerve was confirmed on follow-up pelvic MRI. After 2 months of comprehensive rehabilitation, the muscle strength of the right leg significantly improved, and the pain disappeared. LESSONS: Although rare, spontaneous retroperitoneal hematomas may occur in patients receiving anticoagulant medications. They may even occur in patients receiving emergency anticoagulant therapy. Compressive femoral neuropathy due to retroperitoneal hematomas should be considered if muscle weakness and groin pain are observed. Early diagnosis and appropriate treatment plan of compressive femoral neuropathy due to retroperitoneal hematoma are helpful for a good prognosis.