Immune brachial plexus neuropathy: suggestive evidence for an inflammatory-immune pathogenesis

Parsonage-Turner syndrome, affecting suprascapular nerve and especially to infraspinatus muscles after COVID-19 vaccination in a professional wrestler, a case report and literature review of causes and treatments

BACKGROUND

Acute peripheral neuropathy, also known as Parsonage-Turner syndrome or neuralgic amyotrophy, mostly affects the upper brachial plexus trunks, which include the shoulder girdle. It is typically accompanied by abrupt, intense pain, weakness, and sensory disruption. The etiology and causes of this disease are still unknown because of its low prevalence, however viral reactions-induced inflammation is one of its frequent causes.

CASE PRESENTATION

Here, we introduce a professional wrestler patient who was diagnosed with PTS after vaccination and was treated, and we review some articles in this field.

CONCLUSION

When it comes to shoulder-girdle complaints and pain, Parsonage-Turner syndrome can be a differential diagnosis. Corticosteroids during the acute period, followed by physical therapy, appear to be an efficient way to manage pain, inflammation, muscular atrophy, and the process of recovering to full nerve regeneration.

Parsonage-Turner Syndrome and Hereditary Brachial Plexus Neuropathy

Parsonage-Turner syndrome and hereditary brachial plexus neuropathy (HBPN) present with indistinguishable attacks of rapid-onset severe shoulder and arm pain, disabling weakness, and early muscle atrophy. Their combined incidence ranges from 3 to 100 in 100,000 persons per year. Dominant mutations of SEPT9 are the only known mutations responsible for HBPN. Parsonage and Turner termed the disorder "brachial neuralgic amyotrophy," highlighting neuropathic pain and muscle atrophy. Modern electrodiagnostic and imaging testing assists the diagnosis in distinction from mimicking disorders. Shoulder and upper limb nerves outside the brachial plexus are commonly affected including the phrenic nerve where diaphragm ultrasound improves diagnosis. Magnetic resonance imaging can show multifocal T2 nerve and muscle hyperintensities with nerve hourglass swellings and constrictions identifiable also by ultrasound. An inflammatory immune component is suggested by nerve biopsies and associated infectious, immunization, trauma, surgery, and childbirth triggers. High-dose pulsed steroids assist initial pain control; however, weakness and subsequent pain are not clearly responsive to steroids and instead benefit from time, physical therapy, and non-narcotic pain medications. Recurrent attacks in HBPN are common and prophylactic steroids or intravenous immunoglobulin may reduce surgical- or childbirth-induced attacks. Rehabilitation focusing on restoring functional scapular mechanics, energy conservation, contracture prevention, and pain management are critical. Lifetime residual pain and weakness are rare with most making dramatic functional recovery. Tendon transfers can be used when recovery does not occur after 18 months. Early neurolysis and nerve grafts are controversial. This review provides an update including new diagnostic tools, new associations, and new interventions crossing multiple medical disciplines.

Focal inflammatory neuropathies

This chapter focuses on neuropathies that present with focal involvement of nerve roots, plexus, and/or peripheral nerves associated with autoimmune and inflammatory mechanisms that present with focal involvement of nerve roots, plexus and/or peripheral nerves. The clinical presentation, diagnosis, and treatment of focal autoimmune demyelinating neuropathies, focal nonsystemic vasculitic disorders (diabetic and nondiabetic radiculoplexus neuropathies, postsurgical inflammatory neuropathy, and neuralgic amyotrophy), and focal neuropathies associated with sarcoidosis and bacterial and viral infections are reviewed.

[Diagnostics and treatment of hourglass-like nerve constrictions and torsions in neuralgic amyotrophy]

Neuralgic amyotrophy is a disease of the peripheral nervous system characterized by severe neuropathic pain followed by peripheral paralysis. A distinction is made between a hereditary and an idiopathic form, which is assumed to have an autoimmunological origin. Conservative medicinal treatment mainly consists of nonsteroidal anti-inflammatory drugs (NSAID), opioids and glucocorticoids; however, despite treatment, symptoms in the form of pain or paralysis persist in over 50% of cases. Inflammation can lead to strictures and torsions of peripheral nerves, which can be visualized by imaging using nerve sonography or magnetic resonance (MR) neurography and confirmed intraoperatively during surgical exploration. Based on the currently available data, patients with strictures and torsions of peripheral nerves can benefit from neurosurgical treatment.

Clinical, Neurophysiologic, and Pathologic Features in Patients With Early-Onset Postradiation Neuropathy

OBJECTIVES

The objective of this study was to study early-onset radiation-induced neuropathy reviewing neurologic course, steroid response, and available nerve biopsies.

METHODS

Patients coded with radiation-induced neuropathy within 6 months of radiation were reviewed from January 1,1999, to August 31, 2022. Patients had to have electrodiagnostically confirmed neuropathy localized within or distal to radiation fields. Neurologic course and nerve biopsies were reviewed.

RESULTS

Twenty-eight patients (16 male and 12 female patients, mean age 63.8 years) were identified. The average radiation dose was 4,659 cGy (range 1,000-7,208). Tumor infiltration was not observed on MRI and PET. Postradiation onsets averaged 2 months (range 0-5). Localizations included brachial (n = 4) plexopathies, lumbosacral (n = 12) plexopathies, radiculopathies (n = 10), and mononeuropathies (n = 2). Neuropathic pain (n = 25) and weakness (n = 25) were typical. The clinical courses were subacute monophasic (n = 14), chronic progressive (n = 8), or static (n = 1), and 5 were without follow-up. Nerve biopsies (n = 8) showed an inflammatory ischemic process with perivascular inflammatory infiltrates (n = 7) or microvasculitis (n = 2). Nine patients, 7 with monophasic courses, received steroid burst therapy with symptom improvement in 8. No patients recovered entirely back to baseline.

DISCUSSION

In contrast to chronic radiation-induced neuropathy, early-onset patients most commonly have painful monophasic courses with residual deficits, possibly steroid responsive. An ischemic inflammatory pathogenesis is suggested.

Autoimmune Axonal Neuropathies

OBJECTIVE

This article reviews autoimmune axonal neuropathies, their characteristic clinical features, disease and antibody associations, appropriate ancillary testing, treatment, and prognosis.

LATEST DEVELOPMENTS

In 2021, the American College of Rheumatology and the Vasculitis Foundation released new summary guidelines for the treatment of antineutrophil cytoplasmic autoantibody-associated vasculitides. In addition, novel autoantibodies have been recently identified; they are often paraneoplastic and associated with axonal neuropathies.

ESSENTIAL POINTS

Recognition of autoimmune axonal neuropathies is important because of the potential for effective treatment to either reverse deficits or slow the progression of disease. It is necessary to properly assess for associations with other systemic disorders (eg, systemic vasculitis, connective tissue disease, neoplasm) so that adequate treatment for both neurologic and non-neurologic aspects of the disease can be initiated.

Multimodal Pain Management for Parsonage-Turner Syndrome in the Acute Rehabilitation Setting: A Case Report

Parsonage-Turner syndrome (PTS) is a rare neurological condition characterized by acute shoulder pain and novel neuromuscular weakness in the distribution of the brachial plexus. We present a case report highlighting the difficulties in the diagnosis and management of this condition. A multidisciplinary approach is often required to control this unique type of pain, consisting of neuropathic medications, non-steroidal anti-inflammatory drugs (NSAIDs) to control neuromuscular pain, and modalities provided by experienced physical therapists. Finally, a comprehensive, structured rehabilitation program focusing on the range of motion, neuromuscular re-education, and strengthening is imperative to regain function, reduce symptoms, and improve recovery.

[Peripheral neuropathies during systemic diseases: Part II (vasculitis)]

Primary systemic vasculitides, mainly of the small and medium-sized vessels, are frequently associated with peripheral neuropathies. When the disease is already known, the appearance of a neuropathy should suggest a specific injury, especially when associated with other systemic manifestations. Conversely, when neuropathy is inaugural, close collaboration between neurologists and internists is necessary to reach a diagnosis. A standardized electro-clinical investigation specifying the topography, the evolution and the mechanism of the nerve damage enables the positive diagnosis of the neuropathy. Several elements orient the etiological diagnosis and allow to eliminate the main differential diagnosis: non systemic vasculitic neuropathy. The existence of associated systemic manifestations (glomerular or vascular nephropathy, interstitial lung disease, intra-alveolar hemorrhage, ENT involvement…), biological markers (ANCA, cryoglobulinemia, rheumatoid factor), and invasive examinations allowing histological analysis (neuromuscular biopsy) are all useful tools for.

Parsonage-Turner Syndrome Following SARS-CoV-2 Infection: A Systematic Review

Parsonage-Turner syndrome (PTS) is an inflammatory disorder of the brachial plexus. Hypothesized underlying causes focus on immune-mediated processes, as more than half of patients present some antecedent event or possible predisposing condition, such as infection, vaccination, exercise, or surgery. Recently, PTS was reported following the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We aimed to investigate data on PTS triggered by SARS-CoV-2 infection to provide an extensive perspective on this pathology and to reveal what other, more specific, research questions can be further addressed. In addition, we aimed to highlight research gaps requiring further attention. We systematically reviewed two databases (LitCOVID and the World Health Organization database on COVID-19) to January 2023. We found 26 cases of PTS in patients with previous SARS-CoV-2 infection. The clinical and paraclinical spectrum was heterogeneous, ranging from classical PTS to pure sensory neuropathy, extended neuropathy, spinal accessory nerve involvement, and diaphragmatic palsy. Also, two familial cases were reported. Among them, 93.8% of patients had severe pain, 80.8% were reported to present a motor deficit, and 53.8% of patients presented muscle wasting. Paresthesia was noted in 46.2% of PTS individuals and a sensory loss was reported in 34.6% of patients. The present systematic review highlights the necessity of having a high index of suspicion of PTS in patients with previous SARS-CoV-2 infection, as the clinical manifestations can be variable. Also, there is a need for a standardized approach to investigation and reporting on PTS. Future studies should aim for a comprehensive assessment of patients. Factors including the baseline characteristics of the patients, evolution, and treatments should be consistently assessed across studies. In addition, a thorough differential diagnosis should be employed.

Neuralgic amyotrophy detected by magnetic resonance neurography: subclinical, bilateral, and multifocal brachial plexus involvement

INTRODUCTION

Neuralgic amyotrophy (NA) is a painful non-traumatic peripheral nervous system condition affecting the brachial plexus. Signal abnormalities in nerves and muscles have been detected in these patients using magnetic resonance neurography (MRN).

METHODS

Electronic medical records and MRN images obtained in a 3 T scanner, in 14 adult patients diagnosed with NA at our Neurological institution (Neuromuscular Disorders Section), between December 2015 and December 2019 were retrospectively reviewed. The study was first approved by our Institutional Ethics Committee.

RESULTS

Subclinical, multifocal, and bilateral nerve signal anomalies were recorded in the brachial plexus of these patients. We identified four different types of nerve constriction without entrapment, which we categorized as follows: incomplete focal (type I), complete focal or hourglass (type II), multifocal or string of pearls (type III) and segmental (type IV).

CONCLUSIONS

Given that MRN is an accurate diagnostic tool to detect nerve damage, we believe abnormal findings could improve early detection of NA patients.

A Rare Case of Neuralgic Amyotrophy Associated with Brucella Infection

Multiple micro-organisms associated with Neuralgic Amyotrophy (NA) have been reported and Brucella species should be an important and overlooked infectious cause or trigger.We report a rare case of neuralgic amyotrophy associated with Brucella infection and is believed to be the first such case report in China. A 42-year-old male with brucellosis was confirmed serologically, who presented recurrent fever and fatigue and suddenly developed severe pain in the right shoulder within one week, followed by the inability to lift and abduct the proximal end of the right upper limb. Based on typical clinical manifestions, MRI neuroimaging of the brachial plexus and neuro-electrophysiological studies to confirm a diagnosis of NA and presented spontaneous recovery during this period, immunomodulatory treatment with corticosteroid or intravenous immunoglobulin had not been attempted, leaving a serious movement disorder in the right upper limb. Even rare, NA and other neurobrucellosis forms should be considered as complications of Brucella infection.

Shoulder Pain and Dysfunction After Vaccination: A Systematic Review

BACKGROUND

Persistent shoulder pain and dysfunction after vaccination are relatively rare but well-known complications after inoculations into the deltoid muscle. The term SIRVA (shoulder injury related to vaccine administration) is frequently used to encompass many of these occurrences; however, multiple distinct pathologies with similar presentations have been reported after vaccination. We performed a systematic review of the literature on vaccine-related shoulder injuries to help guide practitioners in appropriate workup and treatment based on specific diagnoses.

METHODS

PubMed was used to search for combinations of multiple keywords (including vaccine, immunization, SIRVA, injury, inflammation, bursitis, Parsonage-Turner syndrome, and neuritis), and all references of each potential article were reviewed. A total of 56 articles were included. Patient demographics, vaccine information, presentation, diagnostic studies, treatment, and outcomes were recorded.

RESULTS

Diagnoses were divided into 3 categories: (1) local inflammatory reaction (SIRVA), (2) brachial neuritis, and (3) direct nerve injury. The included articles reported on 57 cases of SIRVA, 18 of brachial neuritis, and 4 of direct nerve injury. The diagnoses reported for the SIRVA cases included frozen shoulder, pseudoseptic arthritis, subacromial bursitis, rotator cuff injury, and lytic lesions of the humeral head. Various treatments were used, and most patients had resolution of symptoms with conservative treatment including physical therapy, analgesics, and/or corticosteroid injections. Advanced imaging rarely provided information that affected treatment. The brachial neuritis and direct nerve injury cases were typically confirmed with electromyography/nerve conduction studies. Treatment of these 2 categories was nonoperative in all cases, typically with analgesics and/or corticosteroids, and most patients had symptomatic improvement after a few months, with most patients regaining strength. However, some (1 of 3 patients with brachial neuritis and >1 year of follow-up and 2 of 4 patients with direct injury) had residual weakness.

CONCLUSIONS

Medical professionals should be aware of the various pathologies that can lead to prolonged shoulder pain after vaccination. Fortunately, most of these conditions can be treated successfully with nonoperative modalities, although differentiating among the diagnoses can help guide treatment, as some likely benefit from systemic corticosteroids or localized corticosteroid injections. Outcomes for most patients have been good, with the majority recovering without residual pain or deficits.

LEVEL OF EVIDENCE

Prognostic Level IV.

Electrodiagnostic Assessment of Plexopathies

Disorders of the brachial and lumbosacral plexus are complex and may occur as a consequence of trauma, compression, inflammatory disorders, malignant infiltration, or delayed effects of radiation therapy. An understanding of plexus anatomy and surrounding structures will allow the electromyographer to facilitate an efficient and comprehensive assessment of the plexus. A careful and thorough electrodiagnostic assessment allows for localization within the plexus and may provide important information about underlying pathology and prognosis.

Neuralgic Amyotrophy: Its Importance in Orthopedics Practice

The present academic work aims to contribute to an early diagnosis of neuralgic amyotrophy (NA) because of its high prevalence in the population. This disease is a neuromuscular syndrome with unclear etiology; it affects mostly the brachial plexus, causing acute pain in the affected shoulder, paralysis, and disabilities. Considering the importance of an early treatment that can modify the prognosis of the patient, knowing the last updates about the syndrome as its clinical presentation is important. Data analysis was conducted through an online non-systematic review that indicated the epidemiology, pathophysiology, and differential diagnosis and prognosis of NA. Knowledge of the clinical features of NA is not common; however, it is important in orthopedic practice because it requires differentiation from spine pathologies.

Magnetic Resonance Neurography (MRN) of the Brachial Plexus: A Case of Parsonage Turner Syndrome and a Basic Review of Imaging of the Brachial Plexus

The Parsonage-Turner syndrome (PTS) or immune-mediated brachial plexopathy is a monophasic illness with well-described semiology and reasonable insights into pathogenesis. With the advent of spectacular advancements in magnetic resonance imaging (MRI) technology directed at shortening the T2 echo times and annihilating the "magic angle" and with short tau inversion recovery (STIR) sequences, we now have a new window into the evolution of inflammatory changes involving the nerve roots, brachial plexus and the peripheral nerves in inflammatory diseases of the nerves. Not only can these imaging modalities exclude other structural pathologies but they can also localise disease of the brachial plexus and outline the extent of disease and so allow the clinician to explore the natural history of immune-mediated brachial plexopathies. Indeed, these imaging sequences can antedate electromyographic findings and they can determine the effects of chronic denervation of muscle and fatty replacement. We present one such case of the PTS in order to demonstrate the power of these imaging modalities. In so doing, we outline some of the very basic correlations between the physics of MRI and pathology of the brachial plexus. An unexpected finding in this case report is the dramatic resolution of power loss following immunotherapy in our patient who had positive image findings on T2-weighted sequences and STIR imaging and who otherwise has had a static course. The implications of these findings are explored and adumbrated on.

Peripheral neuropathic pain

Neuropathic pain (NP) can have either central nervous system causes or ones from the peripheral nervous system. This article will focus on the epidemiology, classifications, pathology, non-invasive treatments and invasive treatments as a general review of NP involving the peripheral nervous system. NP has characteristic symptomatology such as burning and electrical sensations. It occurs in up to 10% of the general population. Its frequency can be attributed to its occurrence in neck and back pain, diabetes and patients receiving chemotherapy. There are a wide range of pharmacologic options to control this type of pain and when such measures fail, numerous interventional methods can be employed such as nerve blocks and implanted stimulators. NP has a cost to the patient and society in terms of emotional consequences, quality of life, lost wages and the cost of assistance from the medical system and thus deserves serious consideration for prevention, treatment and control.

Outcomes of Microneurolysis of Hourglass Constrictions in Chronic Neuralgic Amyotrophy

PURPOSE

Wide variability in the recovery of patients affected by neuralgic amyotrophy (NA) is recognized, with up to 30% experiencing residual motor deficits. Using magnetic resonance imaging and ultrasound (US), we identified hourglass constrictions (HGCs) in all affected nerves of patients with chronic motor paralysis from NA. We hypothesized that chronic NA patients undergoing microsurgical epineurolysis and perineurolysis of constrictions would experience greater recovery compared with patients managed nonsurgically.

METHODS

We treated 24 patients with chronic motor palsy from NA and HGCs identified on magnetic resonance imaging and US either with microsurgical epineurolysis and perineurolysis of HGCs (11 of 24) or nonsurgically (13 of 24). Muscle strength (both groups) and electrodiagnostic testing (EDX) (operative group) was performed before and after surgery. Preoperative EDX confirmed muscle denervation in the distribution of affected nerve(s). All patients met criteria for microneurolysis: 12 months without improvement since onset or failure of clinical and EDX improvement after 6 months documented by 3 successive examinations, each at least 6 weeks apart.

RESULTS

Mean time from onset to surgery was 12.5 ± 4.0 months. Average time to most recent post-onset follow-up occurred at 27.3 months (range, 18-42 months; 15 nerves). Average time to latest follow-up among nonsurgical patients was 33.6 months (range, 18-108 months; 16 nerves). Constrictions involved individual fascicular groups (FCs) of the median nerve and the suprascapular, axillary and radial nerves proper (HGCs). Nine of 11 operative patients experienced clinical recovery compared with 3 of 13 nonsurgical patients. EMG revealed significant motor unit recovery from axonal regeneration in the operative group.

CONCLUSIONS

Microsurgical epineurolysis and perineurolysis of FCs and HGCs was associated with significantly improved clinical and nerve regeneration at an average follow-up of 14.8 months compared with nonsurgical management. We recommend microneurolysis of HGCs and FCs as a treatment option for patients with chronic NA who have failed to improve with nonsurgical treatment.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Isolated Musculocutaneous Neuropathy Secondary to an Immune-Mediated Brachial Plexopathy: A Case Report of a Rare Phenotype With a Side Note on Patterns of Weakness and an Update on Nerve Pathology

We describe a 50-year-old man who developed a low-frequency pattern of weakness, musculocutaneous neuropathy, with weakness of the biceps, coracobrachialis and brachialis in an immune-mediated brachial plexopathy. The aim of this article is to highlight both the low- and high-frequency patterns of weakness of the immune-mediated brachial plexopathies, and we focus on the patterns of recognition. We then segue into the pathology of the immune-mediated plexopathies and highlight the recent spectacular magnetic resonance imaging studies that demonstrate hourglass constrictions of peripheral nerves outside of the brachial plexus in afflicted patients. This opens up a window for the exciting possibility of neurolysis of constricted nerves in patients who have not responded adequately to immunotherapy.

Brachial and lumbosacral plexopathies: A review

Diseases of the brachial and lumbosacral plexus are uncommon and complex. The diagnosis of plexopathies is often challenging for the clinician, both in terms of localizing a patient's symptoms to the plexus as well as determining the etiology. The non-specific clinical features and similar presentations to other root, nerve, and non-neurologic disorders emphasize the importance of a high clinical index of suspicion for a plexopathy and comprehensive clinical evaluation. Various diagnostic tests, including electrodiagnostic (EDX) studies, neuroimaging (including ultrasound, MRI, or PET), serologic studies, and genetic testing, may be used to confirm a plexopathy and assist in identifying the underlying etiology. EDX testing plays an important role in confirming a plexopathy defining the localization, pathophysiology, chronicity, severity, and prognosis. Given the complexity of the plexus anatomy, multiple common and uncommon NCS and an extensive needle examination is often required, and a comprehensive, individualized approach to each patient is necessary. Treatment of plexopathies often focuses on symptomatic management although, depending on the etiology, specific targeted treatments may improve outcome. This article reviews the clinical features, EDX approaches, and evaluation and treatment of brachial and lumbosacral plexopathies.

Neuralgic amyotrophy: a paradigm shift in diagnosis and treatment

Neuralgic amyotrophy (NA), also known as Parsonage-Turner syndrome, is characterised by sudden pain attacks, followed by patchy muscle paresis in the upper extremity. Recent reports have shown that incidence is much higher than previously assumed and that the majority of patients never achieve full recovery. Traditionally, the diagnosis was mainly based on clinical observations and treatment options were confined to application of corticosteroids and symptomatic management, without proven positive effects on long-term outcomes. These views, however, have been challenged in the last years. Improved imaging methods in MRI and high-resolution ultrasound have led to the identification of structural peripheral nerve pathologies in NA, most notably hourglass-like constrictions. These pathognomonic findings have paved the way for more accurate diagnosis through high-resolution imaging. Furthermore, surgery has shown to improve clinical outcomes in such cases, indicating the viability of peripheral nerve surgery as a valuable treatment option in NA. In this review, we present an update on the current knowledge on this disease, including pathophysiology and clinical presentation, moving on to diagnostic and treatment paradigms with a focus on recent radiological findings and surgical reports. Finally, we present a surgical treatment algorithm to support clinical decision making, with the aim to encourage translation into day-to-day practice.

Update on classification, epidemiology, clinical phenotype and imaging of the nonsystemic vasculitic neuropathies

PURPOSE OF REVIEW

Single-organ vasculitis of the peripheral nervous system (PNS) is often designated nonsystemic vasculitic neuropathy (NSVN). Several variants or subtypes have been distinguished, including migratory sensory neuropathy, postsurgical inflammatory neuropathy, diabetic radiculoplexus neuropathies, skin-nerve vasculitides, and, arguably, neuralgic amyotrophy. NSVN often presents as nondiabetic lumbosacral radiculoplexus neuropathy (LRPN). This review updates classification, clinical features, epidemiology, and imaging of these disorders.

RECENT FINDINGS

A recent study showed the annual incidence of LRPN in Olmstead County, Minnesota to be 4.16/100 000:2.79/100 000 diabetic and 1.27/100 000 nondiabetic. This study was the first to determine the incidence or prevalence of any vasculitic neuropathy. In NSVN, ultrasonography shows multifocal enlargement of proximal and distal nerves. In neuralgic amyotrophy, MRI and ultrasound reveal multifocal enlargements and focal constrictions in nerves derived from the brachial plexus. Histopathology of these chronic lesions shows inflammation and rare vasculitis. Diffusion tensor imaging of tibial nerves in NSVN revealed decreased fractional anisotropy in one study.

SUMMARY

Single-organ PNS vasculitides are the most common inflammatory neuropathies. Neuralgic amyotrophy might result from PNS vasculitis, but further study is necessary. The usefulness of focal nerve enlargements or constrictions in understanding pathological mechanisms, directing biopsies, and monitoring disease activity in NSVN should be further investigated.

Spectrum of diabetic neuropathies

The diabetic state results in neuropathy. The main causative mechanism is hyperglycemia, although microvascular involvement, hypertriglyceridemia, as well as genetic and immune mechanisms may be contributory. There is a growing spectrum of types of diabetic neuropathies that differ based on the type of fibers involved (e.g. myelinated, unmyelinated, autonomic, somatic), distribution of nerves involved, and mechanisms of neuropathy. The most common type is distal sensory neuropathy (DSN), which affects the distal ends of large myelinated fibers, more often sensory than motor, and is often asymptomatic. The next-most common is distal small fiber neuropathy (DSFN), which largely affects the unmyelinated fibers and carries the phenotype of burning feet syndrome. Diabetic autonomic neuropathy (DAN) occurs when widespread involvement of autonomic unmyelinated fibers occurs, and patients can be incapacitated with orthostatic hypotension as well as neurogenic bladder and bowel involvement. Radiculoplexus diabetic neuropathy causes proximal weakness and pain, usually in the lower extremity, and has a combination of immune, inflammatory, and vascular mechanisms. The nerve roots and plexus are involved. These patients present with proximal weakness of a subacute onset, often with severe pain and some autonomic failure. Finally, rapid and sustained reduction of blood glucose can result in treatment-induced diabetic neuropathy (TIND), which largely affects the sensory and autonomic fibers. This occurs if HbA1c is rapidly reduced within 3 months, and the likelihood is proportional to the original A1c and the size of the reduction.

Neuralgic Amyotrophy Presenting with Multifocal Myonecrosis and Rhabdomyolysis

Neuralgic amyotrophy (NA), also known as Parsonage-Turner syndrome, is an idiopathic disorder characterized by rapid-onset unilateral upper extremity pain, paralysis, and sensory disturbance in the distribution of the brachial plexus. The etiology is unknown, and there is a multitude of alternative clinical presentations as well as secondary triggers, which make the diagnosis challenging. To date, there has been no report of NA presenting with frank myonecrosis. In this report, we document the first case of NA presenting with multifocal myonecrosis of the shoulder girdle muscles and rhabdomyolysis. This case posed a unique challenge in the diagnostic workup and management as many causes of myonecrosis present similarly to NA, and NA is a diagnosis of exclusion. Our patient underwent exhaustive testing and several trials of therapy before diagnosis could be made. Such evaluations are expensive and carry risks for patients. As such, it is important that physicians recognize this unique presentation of NA.

Clinico-diagnostic features of neuralgic amyotrophy in childhood

Neuralgic amyotrophy (NA), even known as Personage-Turner's syndrome (PTS), is a neurologic condition, affecting the lower motor neurons of brachial plexus and/or individual nerves or nerve branches, characterized by pain, muscle weakness/atrophy, and sensory symptoms. NA has an acute/subacute onset, after an infection or vaccination; it is more common in male and is rare in the pediatric population. The etiology remains uncertain, being considered heterogeneous and multifactorial. A severe acute neurologic pain around the shoulder girdle is the classic presenting symptom at onset. As the pain subsides, weakness and paresis develop. NA is usually unilateral, but sometimes, a subclinical contralateral limb involvement could be present and bilateral affection has been described. The diagnosis is clinical, through a comprehensive history and neurological examination. However, electrophysiological testing and imaging are critical, because there is no diagnostic test for PTS and it remains a diagnosis of exclusion. Upper brachial plexus peripheral involvement with weakness of periscapular and perihumeral muscles is the classic presentation, associated with electrophysiological evidence of denervation in the affected muscles. Imaging, laboratory, and genetic testing can be useful for the differential diagnosis. NA is in most cases a self-limiting condition, and it is characterized by good recovery. Treatment of NA usually involves a combination of corticosteroids, analgesics, immobilization, and physical therapy, even if limited data are available in children. Physiotherapy is required to maintain muscle strength.

Parsonage Turner syndrome caused by Staphylococcus aureus spondylodiscitis

Parsonage Turner syndrome (otherwise known as PTS, neuralgic amyotrophy or acute brachial neuritis) is a rare, but clinically significant cause of atraumatic shoulder girdle pain and weakness. Diagnosis is primarily clinical and can be challenging due to its heterogeneous presentation. A case of PTS following systemic infection from Staphylococcus aureus spondylodiscitis is presented. Timely consideration of the diagnosis prevented unnecessary investigation and allowed effective rehabilitation. This is the first case of PTS preceded by S. aureus infection. PTS should be considered in those presenting with acute, atraumatic shoulder dysfunction after systemic infection.

Post-operative emergence of acute brachial neuritis following posterior cervical laminectomy with fusion: A case report and review of the literature

Introduction

Idiopathic brachial plexus neuritis or neuralgic amyotrophy is a rare neurological condition whose true etiology currently remains unknown. Epidemiologically, the incidence of this condition is exceptionally rare with only 1.6 cases for every 100,000 people (Turner and Parsonage, 1987). Symptoms present an initial acute and sudden pain to the shoulder girdle and upper arm which is followed by a sense of profound weakness and numbness to the upper arm (Parsonage and Turner, 1948). Localized neuropathy within the arm-pit region may also be presented. The pain often exacerbates upon movement of the shoulder. Due to the anatomic location affected and the nature of the clinical symptoms presented, accurate diagnosis of brachial plexus neuritis poses a challenging diagnostic task for physicians due to remarkably similar symptoms expressed by differential diagnoses.

Presentation of case

Here, we report the case of a 55-year-old woman who underwent surgery entailing cervical laminectomy with instrumented fusion. She presented with postoperative symptoms of severe pain in the left arm with significant weakness within 24 h after surgery. A diagnosis of brachial plexus neuritis was made based on the symptoms presented and upon review of imaging scans.

Discussion

After a six-month follow-up visit, the patient recovered from the brachial neuritis but has residual numbness in the hand. The presentation of this case serves to transmit three fundamental purposes. First, this case serves to establish an intriguing possible association of the post-surgical period of cervical laminectomy with acute brachial neuritis and signifies the importance post-operative linkage with brachial neuritis in general. Second, this case also highlights the importance of close clinical monitoring of patients with unique symptoms within the postoperative follow-up period to ensure successful improvement and accurate diagnosis.

Conclusion

As an underdiagnosed and relatively obscure condition, this case serves as an imperative reference for physicians to illuminate differential diagnosis of similar symptomatic conditions and also to promote knowledge of brachial plexus neuritis which can lead to an early and precise diagnosis.

Spontaneous peripheral nerve palsy with hourglass-like fascicular constriction in the upper extremity

OBJECTIVE

Spontaneous paralysis from hourglass-like fascicular constriction of peripheral nerves is rare, its clinical manifestations are not well documented, and its pathogenesis remains unknown. The unclear origin of this disorder and difficulty in diagnosis result in its uncertain management. The authors sought to gain a more thorough understanding of this condition through describing the anatomy, clinical features, etiology, and treatment of hourglass-like constriction.

METHODS

The authors retrospectively reviewed 20 patients (22 nerves) with hourglass-like constriction. The patients' clinical information was reviewed. Preoperative sonographic assessment and electrophysiological examination of involved nerves were performed. Surgical treatments included interfascicular neurolysis and neurorrhaphy. Samples of tissue subjected to resected constriction were sent for pathological analysis. The patients had regular face-to-face follow-up visits.

RESULTS

Acute pain was always the first symptom and was followed by paralysis. Paralysis progression was rapid and serious. Surgical exploration indicated an hourglass-like constricted segment completely unrelated to the compressive structures. Electrophysiological analysis showed severe denervation, and histopathological examination showed inflammatory cell infiltration, demyelination, and reduction of nerve fibers.

CONCLUSIONS

Hourglass-like fascicular constrictive neuropathy has an integrative effect from multiple different mechanisms. Surgical intervention is beneficial for selected patients who do not recover in a timely fashion and have hourglass-like lesions confirmed by preoperative ultrasound imaging. The authors recommend that early surgical intervention of the nerve be offered to patients who do not show any signs of recovery 3 months after onset. Both interfascicular neurolysis and neurorrhaphy are effective treatment methods. Mild to moderate constriction can usually be treated successfully by interfascicular neurolysis alone, whereas more advanced lesions with loss of fascicle continuity (severe constriction) may be best treated with resection and direct neurorrhaphy.

Recurrent Brachial Neuritis Attacks in Presentation of B-Cell Lymphoma

We describe a 51-year-old woman who over 5 years had 9 painful monophasic attacks affecting the brachial plexus before a fascicular plexus biopsy diagnosed large B-cell lymphoma. The initial attacks were responsive to steroids with clinical resolution. At last attack, magnetic resonance imaging showed multifocal T2 hyperintensities and nodular gadolinium enhancement in the right brachial plexus not seen previously. Also seen were similar changes in the thoracic spinal cord, basal ganglia, cerebellum, and brainstem. Positron emission tomography revealed marked hypermetabolic activity of the plexus facilitating targeted fascicular brachial plexus biopsy, making the pathological diagnosis. Neurolymphomatosis affecting the peripheral nervous system typically presents with insidious painful progressive infiltration of nerves, roots, or plexi. Recurrent idiopathic brachial neuritis attacks (ie, Parsonage-Turner syndrome) in contrast most commonly are seen in persons with a family history and a discoverable genetic cause by SEPT9 mutations, which tested negative in this patient. This case illustrates how neurolymphomatosis, which represents a malignant transformation of B cells within peripheral nerves, can sometimes present with paraneoplastic immune-responsive neuritis mimicking Parsonage-Turner syndrome. Recurrence, an immune-refractory course or insidious progressive involvement of the nervous system, should raise suspicion of neurolymphomatosis.

Herpes zoster increased risk of neuralgic amyotrophy: a retrospective, population-based matched cohort study

Although neuralgic amyotrophy (NA) has occasionally been reported to be associated with reactivated herpes zoster, their associated risk remains unknown. The aim of this study was to assess the risk of developing NA following preceding herpes zoster. The authors used the National Health Insurance Research Database of Taiwan to select 41,548 patients with newly diagnosed herpes zoster during the period 2000 to 2010 and randomly extracted 166,192 matched control subjects. All participants in the study and control groups were followed for 3 months after the diagnosis to identify those who developed NA. Cox proportional hazards regression analyses were performed to evaluate the subsequent risk of NA. Twenty-one subjects from the group with herpes zoster (0.05%) developed NA over the 3-month period and 46 from the group without herpes zoster (0.03%). The patients with herpes zoster had a higher risk of developing NA (adjusted hazard ratio = 1.408, 95% confidence interval = 1.013-2.319, P = 0.030). In the patients with herpes zoster, female sex, age ≥ 65, hepatitis E virus (HEV), and having had a recent infectious event including pneumonia and influenza were risk factors for developing NA (adjusted HR 2.746, 1.998, 2.735, 2.016, and 1.718, respectively, all P < 0.05). Patients with herpes zoster attack have a higher risk of developing NA over a 3-month period after diagnosis, especially those who are female, age ≥ 65, HEV, or have experienced a recent infectious event or pneumonia and influenza.

Hereditary neuralgic amyotrophy in childhood caused by duplication within the SEPT9 gene: A family study

Hereditary neuralgic amyotrophy (HNA) is an autosomal dominant disorder associated with episodic, recurrent, and painful neuropathies affecting the nerves of the brachial plexus. In this study, we report on a family of Lebanese descent with HNA onset in early childhood. The affected family members presented with platelet dysfunction. Platelet aggregation was reduced after stimulation with the agonists ADP and epinephrine in all affected family members. Flow cytometric analyses revealed impaired platelet δ‐secretion. The index patient and one brother suffered from kidney cysts. Molecular genetic analysis revealed a heterozygous duplication of exon 2 within the septin 9 (SEPT9) gene in all the affected family members. Such a young child with HNA (aged 2 years) caused by SEPT9 duplication has not been described so far.

The Mayo Clinic Experience With the Neurological Complications of the CTLA-4 Inhibitor Ipilimumab

Neurological complications are an increasingly recognized complication of the use of the immune checkpoint inhibitors in the treatment of solid tumors. Ipilimumab is a monoclonal antibody against cytotoxic T-lymphocyte antigen-4, an immune checkpoint inhibitor that suppresses T-cell effector function. The clinical spectrum of ipilimumab-associated neurological complications and optimum treatment approach is not established. We describe our institution's experience with ipilimumab and illustrate 2 cases of presumed autoimmune neurological phenomenon resulting from its use.

Symptomatic Neurological Epidural Metastasis with Interleukin-2 Therapy in Metastatic Renal Cell Carcinoma

Interleukin-2 has known efficacy in the treatment of metastatic renal cell carcinoma but it also has adverse effects mediated by an inflammatory mechanism and capillary leak syndrome. The authors report the case of a patient with a metastatic renal cell carcinoma who had an asymptomatic intra-epidural metastasis in the thoracic spine, which became symptomatic during IL-2 administration without any recurrence after specific treatment by surgery and radiotherapy.

Chronic Brachial Plexus Neuritis That Developed into Typical Neuralgic Amyotrophy and Positively Responded to Immunotherapy

Based on the hypothesis that autoimmunity plays a role in the pathogenesis of neuralgic amyotrophy (NA), immunotherapy is sometimes administered. Early intervention is recommended for a good prognosis. We herein report the case of a 55-year-old man who presented with neuralgia, weakness, and muscle atrophy in his right shoulder girdle and upper arm, which progressed for ten months following a marine sports accident. The patient was diagnosed with NA. His neurological deficits gradually improved after several courses of immunotherapy, suggesting that in addition to being effective for treating early-stage disease, immunotherapy may be effective for treating chronic cases.

Contralateral lumbosacral plexopathy following lumbar microdiscectomy

We describe the unique case of a 51-year-old lady who developed a contralateral lumbosacral plexopathy two days after a lumbar microdiscectomy. This is the first report to date of this complication occurring following this procedure. We review the literature regarding lumbosacral plexopathy and discuss the evidence base behind investigating and managing this condition and the potential pathophysiological mechanisms which underlie its development. We draw comparisons with the more widely recognised post-operative brachial neuritis, characterised by delayed onset brachial plexopathy developing after cervical decompression, and propose an immune-mediated inflammatory mechanism linking the two conditions.

Brachial Plexus Neuritis Associated With Anti-Programmed Cell Death-1 Antibodies: Report of 2 Cases

Recently, guidelines have been outlined for management of immune-related adverse events occurring with immune checkpoint inhibitors in cancer, irrespective of affected organ systems. Increasingly, these complications have been recognized as including diverse neuromuscular presentations, such as demyelinating and axonal length-dependent peripheral neuropathies, vasculitic neuropathy, myasthenia gravis, and myopathy. We present 2 cases of brachial plexopathy developing on anti-programmed cell death-1 checkpoint inhibitor therapies (pembrolizumab, nivolumab). Both cases had stereotypic lower-trunk brachial plexus-predominant onsets, and other clinical features distinguishing them from Parsonage-Turner syndrome (ie, idiopathic plexitis). Each case responded to withholding of anti-programmed cell death-1 therapy, along with initiation of high-dose methylprednisiolone therapy. However, both patients worsened when being weaned from corticosteroids. Discussed are the complexities in the decision to add a second-line immunosuppressant drug, such as infliximab, when dealing with neuritis attacks, for which improvement may be prolonged, given the inherent slow recovery seen with axonal injury. Integrated care with oncology and neurology is emphasized as best practice for affected patients.

Atypical presentation of Parsonage-Turner syndrome confounded by surgical rotator cuff injury

Parsonage-Turner syndrome (PTS) is a rare neuropathy that commonly presents as unexpected severe shoulder and arm pain that eventually subsides while weakness or paralysis ensues. During exceptions to this classic presentation, confirming PTS can be challenging. Alternative causes of upper extremity pain may confound the diagnostic algorithm. Moreover, objective findings from necessary diagnostic tests depend on when those tests are performed. We present an atypical onset of PTS, whereby the initial presentation of severe neuropathic pain was preceded by mild shoulder pain that should decrease one's clinical suspicion for PTS. This milder pain coincided with the presence of a rotator cuff injury, whereby surgical intervention preceded impending paralysis and hindered postoperative rehabilitation. Physicians should be aware of the possibility of atypical presentations of PTS in hopes of avoiding either untimely surgery or delays in diagnosis.

Neuralgic amyotrophy. An update

A century after the first description of neuralgic amyotrophy (NA), its pathophysiology remains unknown. An inflammatory (auto)immune pathophysiology is presumed, with mechanical or infectious precipitating conditions, which triggers attacks. Clinically, NA is an acute and painful unique or multiple mononeuropathy that causes palsy, amyotrophy and sensory loss in an asymmetric and patchy distribution. It involves the upper brachial plexus rather than the other parts but also may involve the cervical plexus, lumbosacral plexus and cranial nerves. The impairment can be restricted to one fascicule of one nerve, plexus or root; limited to a few ones; or extensive, involving both upper limbs. Its evolution is usually monophasic and auto-limited and never leads to generalized polyneuropathy. Electrodiagnostically, NA is characterized by severe axonal damage. The recovery is usually good after 6 months to 3 years in 80% of cases. Persistent disability is present in 20% of idiopathic NA cases and is more frequent in hereditary NA, with frequent recurrences, more frequent bilateral impairment, and more atypical distribution (cervical plexus, lumbosacral plexus or cranial nerves) than with idiopathic NA. Hereditary NA is mainly linked to a mutation in the gene of the Septin-9 protein. When the patient is seen early after disease onset, treatment with corticosteroids for 2 weeks seems to shorten the pain duration and the delayed recovery. With diagnosis during the palsy period, treatment is based on pharmacologic and non-pharmacologic therapies according to the complaints of the patient.

Parsonage-Turner Syndrome: Clinical and Epidemiological Features From a Hand Surgeon's Perspective

BACKGROUND

Parsonage-Turner Syndrome (PTS) is a rare but serious condition characterized by spontaneous paresis of the upper extremity, typically lasting several months with variable recovery. With little literature on the behavior of PTS from a hand surgeon's perspective, accurate diagnosis and subsequent counseling of patients with PTS can be challenging.

METHODS

This study is a retrospective evaluation of the clinical features of all PTS patients seen over a 9-year period. Data was collected for gender, side affected, handedness, inciting event, clinical presentation, nerve involvement, time taken for recovery, and extent of recovery.

RESULTS

Thirty-eight adult cases of PTS were identified, representing an incidence of 0.34 per 1000. Fifty-five percent were female, with predomination of right handedness and dominant upper extremity involvement (60% and 58%, respectively). There was an inciting incident identified in 42% of cases, and 37% of these involved surgery. Twenty-nine percent of cases presented without experiencing typical neuropathic pain. There was a predomination of anterior interosseous nerve (AIN) or posterior interosseous nerve (PIN) involvement (42% overall). Only 44% of patients achieved a complete recovery, taking a mean duration of 10 months.

CONCLUSIONS

This study highlights both the rarity and atypical spectrum of clinical presentation of PTS, especially considering the more common involvement found for AIN and PIN. This highlights the likelihood that patients presenting with PTS to a hand surgical practice may differ from those typically described in the literature. The poor rate of recovery is in line with other recent reports and contrasts with the more positive outcomes found in earlier studies.

Neuralgic amyotrophy: An update on diagnosis, pathophysiology, and treatment

In this review we provide a current overview of the clinical features, pathophysiology, epidemiology, and diagnostic and therapeutic strategies in neuralgic amyotrophy (NA). The disorder has several phenotypic variations, with a classic form in 70% of the patients. It is not rare, with an incidence of 1 per 1,000 individuals, but it is still often missed. Recurrences are common, yet the proposed multifactorial etiology, which includes genetic, biomechanical, and immunologic factors, limits our capacity to predict or prevent them. NA is a clinical diagnosis, and ancillary studies serve to exclude infectious or malignant causes or to assess a differential diagnosis. If patients are seen early and are still in pain, a short trial of high-dose oral corticosteroids is advised, and adequate analgesia may require opioids and non-steroidal anti-inflammatory drugs. Persistent complaints are common, and a multidisciplinary rehabilitation approach focusing on scapular coordination, energy distribution strategies, and self-management is indicated.

Ultrasonographic identification of nerve pathology in neuralgic amyotrophy: Enlargement, constriction, fascicular entwinement, and torsion

INTRODUCTION

The aim of this study was to characterize the ultrasonographic findings on nerves in neuralgic amyotrophy.

METHODS

Fourteen patients with neuralgic amyotrophy were examined using high-resolution ultrasound.

RESULTS

Four types of abnormalities were found: (1) focal or diffuse nerve/fascicle enlargement (57%); (2) incomplete nerve constriction (36%); (3) complete nerve constriction with torsion (50%; hourglass-like appearance); and (4) fascicular entwinement (28%). Torsions were confirmed intraoperatively and were seen on the radial nerve in 85% of patients. A significant correlation was found between no spontaneous recovery of nerve function and constriction/torsion/fascicular entwinement (P = 0.007).

CONCLUSION

Ultrasonographic nerve pathology in neuralgic amyotrophy varies in order of severity from nerve enlargement to constriction to nerve torsion, with treatment ranging from conservative to surgical. We postulate that the constriction caused by inflammation is the precursor of torsion and that development of nerve torsion is facilitated by the rotational movements of limbs.

Parsonage-Turner syndrome

Objective

To describe the clinical, electrophysiological and imaging findings from Parsonage–Turner syndrome and evaluate the results from conservative treatment.

Methods

Eight cases were studied between February 2010 and February 2012, with a minimum follow-up of one year (mean of 14 months). All the patients answered a clinical questionnaire and underwent functional evaluation using the Constant and Murley score. After clinical suspicion was raised, an electromyography examination was performed to confirm the diagnosis.

Results

Eight patients (mean age of 29 years) were evaluated. The right side was affected in 70% of the cases, and the dominant side in 80% of the cases. All the patients reported that their shoulder pain had started suddenly, lasting from one to five days in six cases and up to 15 days in two cases. In three cases, severe atrophy of the deltoid muscle was observed. Hypotrophy of the supraspinatus and infraspinatus muscles was observed in three cases. A winged scapula was observed in the two remaining cases. Electromyography demonstrated involvement of the long thoracic nerve in these last two cases and confirmed the involvement of the axillary and suprascapular nerves in the remaining six cases. The mean score on the Constant and Murley scale was 96 at the end of the conservative treatment with non-steroidal anti-inflammatory drugs and physiotherapy. Six of the eight patients presented good recovery of muscle strength.

Conclusions

In the majority of the cases, the functional recovery was good, although muscle strength was not completely restored in some of them.