Neuralgic amyotrophy: variable expression in 40 patients

[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.

[Neuralgic amyotrophy: a common cause of unilateral and bilateral diaphragmatic pareses]

There are several causes for unilateral or bilateral diaphragmatic paresis. The most common cause is an (intraoperative) injury to the phrenic nerve.However, in up to 20% of cases, no explanation can be found despite extensive workup. Neuralgic amyotrophy (NA, also known as Parsonage-Turner syndrome) is a common underdiagnosed multifocal autoimmune-inflammatory disease that predominantly affects proximal nerve segments of the upper extremities. Classic symptoms include acute onset of severe pain in the shoulder girdle with delayed onset of paresis of the shoulder and arm muscles. In at least 7% of cases, the phrenic nerve is also affected. Based on the annual incidence of NA of 1:1000, the entity as a cause of diaphragmatic dysfunction is probably not as uncommon as previously thought. However, clinical experience shows that this diagnosis is often not considered, and diaphragmatic paresis gets wrongly classified as idiopathic.This is particularly disastrous because in the early stage of NA, medical therapy with corticosteroids is mostly not considered and the possibility that surgical repair of the diaphragm may be performed prematurely, given that the condition may resolve spontaneously many months after symptom onset.The aim of the present article is to raise awareness of the entity of NA as a cause of diaphragmatic paresis and to establish a standardized approach to diagnosis and treatment.

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.

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.

A Parsonage-Turner Syndrome secondary to Parvovirus B19 infection

Parvovirus B19 (PVB19) is a small DNA virus that causes the fifth disease in children; however it can also affect adults. The infection can be asymptomatic in about a quarter of healthy subjects. Typical clinical manifestations are: short lived fever accompanied by asthenia, myalgias and pharyngodynia; symmetrical acute polyarthritis; megalo-erytema in child; maculopulotic rash and/or fleeting purpuric at the extremities in adult; adenopathies in the cervical area. Atypical manifestions can affect neurological system (both central and peripheral), hearth and kidney. We describe a 37-year-old man with neuralgic amyotrophy (Parsonage-Turner syndrome) caused by Parvovirus B19 infection.

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.

Cervical Radiculopathy Focus on Characteristics and Differential Diagnosis

Cervical radiculopathy is characterized by neurological dysfunction caused by compression and inflammation of the spinal nerves or nerve roots of the cervical spine. It mainly presents with neck and arm pain, sensory loss, motor dysfunction, and reflex changes according to the dermatomal distribution. The most common causes of cervical radiculopathy are cervical disc herniation and cervical spondylosis. It is important to find the exact symptomatic segment and distinguish between conditions that may mimic certain cervical radicular compression syndromes through meticulous physical examinations and precise reading of radiographs. Non-surgical treatments are recommended as an initial management. Surgery is applicable to patients with intractable or persistent pain despite sufficient conservative management or with severe or progressive neurological deficits. Cervical radiculopathy is treated surgically by anterior and/or posterior approaches. The appropriate choice of surgical treatment should be individualized, considering the patient’s main pathophysiology, specific clinical symptoms and radiographic findings thoroughly.

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.

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.

Neuralgic Amyotrophy in a 66-year-old Hiker: a Case Report

Introduction

Neuralgic amyotrophy (NA) or Parsonage Turner syndrome is a clinical syndrome characterized by sudden attack of neuropathic pain, motor weakness and sensory loss that could be more or less clinically present. Different interpretations regarding the differential diagnosis, symptoms, cause and treatment were given till now.

Aim

We report our experience with a 66-year-old male who had a sudden pain attack and palsy in shoulder region, without sensory loss, and associated calcific tendinitis of rotator cuff and degenerative changes in cervical spine.

Case report

Patient came to our hospital with strong pain in shoulder area and signs of frozen shoulder. Active abduction and anteflexion was only to 30 degrees. He experienced the intense pain with visual analogue scale (VAS) 10/10 a night before, during his sleep. No trauma. Neurontin (gabapentin) was given to the patient. After 4 days, he felt better with abduction and anteflexion to 90 degrees. After 2 weeks VAS was 3/10, abduction and anteflection to 100 degrees.

Conclusion

Neuralgic amyotrophy (NA) is a self-limiting inflammatory disorder usually with idiopathic etiology. The condition can be challenging to treat since many associated symptoms and diagnostic tests and procedures may mimic NA. In that case, accurate differential diagnosis is essential.

Phrenic nerve palsy in patients with neuralgic amyotrophy: case series study

BACKGROUND

Neuralgic amyotrophy (NA) is a relatively uncommon syndrome causing brachial nerves dysfunction. However, it can also affect other nerves including phrenic nerve, which is often misdiagnosed.

CASE REPORT

To determine the incidence and characteristics of phrenic nerve palsy in patients with NA in our population, we analyzed the records of all patients with phrenic nerve palsy and/or NA at the University Hospital and the county hospital within the last 10 years. We found that totally, seven patients were confirmed to have NA and phrenic nerve palsy. All of them are male of average age 51.9 years old (51.9±7.4) and had shortness of breath following shoulder and/or neck pain. All of them had elevated diaphragm found in SNIFF test and/or on chest X-ray. Pulmonary function test done in 6 patients demonstrated restrictive lung disease. Six patients needed long-term bi-level positive airway pressure (BiPAP) treatment but mechanic ventilation was not needed.

CLINICAL REHABILITATION IMPACT

Our cohort represents one of the largest case series yet reported for phrenic nerve involvement in NA. Most of these patients have had significant pulmonary compromise in the early stage of onset of shoulder/neck pain requiring ongoing BiPAP and specialist monitoring. Recognition of this subset of patients may further require nerve conduction studies/electromyography and respiratory testing.

The electrodiagnostic natural history of parsonage-turner syndrome

INTRODUCTION

Recovery from Parsonage-Turner syndrome (PTS) is generally favorable, although recovery times have been shown to vary, in part because there are no universally accepted outcome measures. In this study, we describe the electrodiagnostic natural history of this condition based on objective electrodiagnostic testing, and propose that complete electrodiagnostic recovery can be seen as early as 1 year.

METHODS

Twenty-six subjects with 29 affected nerves confirmed as PTS were followed every 3 months for electrodiagnostic testing, or until full reinnervation was confirmed.

RESULTS

Twenty-three cases (79.3%) demonstrated electrodiagnostic evidence of initial recovery at a mean of 5.8 months. Nine cases (31%) showed complete electrodiagnostic recovery at a mean of 1 year. When excluding cases with <1 year of follow-up, 52.9% achieved complete electrodiagnostic recovery.

CONCLUSIONS

In contrast to previous reports, full electrodiagnostic recovery of PTS was demonstrated at a mean of 1 year in > 50% of patients with longer term follow-up. Muscle Nerve 56: 737-743, 2017.

Neuralgic amyotrophy triggered by hepatitis E virus: a particular phenotype

The neuralgic amyotrophy may be of difficult diagnosis, due to phenotypic variability, with different initial presentations (upper plexus multiple mononeuropathy, lumbosacral involvement, distal reached, phrenic involvement). To date, there is little guidance on these patients' therapeutic management, especially those for which neuralgic amyotrophy is triggered by hepatitis E virus (HEV-NA). The study aims to identify specific features that characterize patients bearing the neuralgic amyotrophy triggered by HEV. We first describe a new case report of HEV-neuralgic amyotrophy, with delayed diaphragmatic reach. Then, the literature was searched for reports of HEV-NA (n = 39), and neuralgic amyotrophy with phrenic paresis (n = 42) from 1999 to June 2016. Relevant data were retrieved, analyzed and compared with the parameters of idiopathic neuralgic amyotrophy (n = 199) of the largest cohort, described by Van Alfen and Van Engelen in 2006. Compared to the published cohort, HEV-NA patients were more likely to be men (M/F 34/5 vs. 136/63, p = 0.017), with more frequent bilateral symptoms (86.8% cases vs. 28.5%, p < 0.0001) as well as phrenic paresis (18.0 vs. 6.6%, p = 0.028). The clinical improvement is poor, with 15.6% of cases with remission only. A particular phenotype characteristic of the HEV-induced neuralgic amyotrophy has arisen. Our findings call for action in validating the above-mentioned features that illustrate the HEV-NA cases as an early diagnosis would prevent complications, especially the phrenic damage often associated with a worse functional outcome.

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.

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.

Complex Scapular Winging following Total Shoulder Arthroplasty in a Patient with Ehlers-Danlos Syndrome

This is a unique case of a female patient with features of classical and hypermobile types of Ehlers-Danlos syndrome (EDS) who developed complex scapular winging from spinal accessory and long thoracic neuropathies. These neurological problems became manifest after an uncomplicated total shoulder arthroplasty (TSA). The patient had a complex postoperative course with extensive work-up in addition to revision shoulder surgery and manipulations to treat shoulder stiffness. It was eventually suspected that the periscapular nerve impairments occurred during physical therapy sessions after her TSA. This interpretation was further supported by genetic evidence that, in addition to EDS, the patient had an unrecognized genetic propensity for nerve palsies from stretch or pressure (“hereditary neuropathy with liability to pressure palsies” (HNPP)). By two years after the TSA the neuropathies had only partially improved, leaving the patient with persistent scapular winging and shoulder weakness. With this case we alert surgeons and physical therapists that patients with EDS can have not only a complicated course after TSA, but rare concurrent conditions that can further increase the propensity of neurological injuries that result in compromised shoulder function.

Spinal Cord Stimulation for Refractory Neuropathic Pain of Neuralgic Amyotrophy

The aim of this paper was to report the effect of temporary and chronic spinal cord stimulation for refractory neuropathic pain in neuralgic amyotrophy (NA). A 35-year-old female presented with two-months history of a severe, relentless neuropathic pain of the left shoulder, forearm, palm, and fingers. The neuropathic pain was refractory to various medical treatments, including nonsteroidal anti-inflammatory drugs, opiates, epidural and stellate ganglion blocks, and typically unrelenting. The diagnosis of NA was made with the characteristic clinical history and magnetic resonance imaging. The patient underwent a temporary spinal cord stimulation to achieve an adequate pain relief because her pain was notoriously difficult to control and lasted longer than the average duration (about 4 weeks on average) of a painful phase of NA. Permanent stimulation was given with paddle lead. The neuropathic pain in her NA persisted and she continued using the spinal cord stimulation with 12 months after development of NA. The temporary spinal cord stimulation was effective in a patient with an extraordinary prolonged, acute painful phase of NA attack, and the subsequent chronic stimulation was also useful in achieving an adequate analgesia during the chronic phase of NA.

Hourglass-Like Constrictions of Peripheral Nerve in the Upper Extremity

BACKGROUND:

The development of an hourglass-like constriction in the nerve is rare, and its origin is unknown. Its clinical manifestations are not well documented, and the treatment protocol has not been established.

OBJECTIVE:

To identify the cause, presentation, and possible treatment for patients with nerve palsies secondary to an hourglass-like constriction in the affected nerves.

METHODS:

Patients presenting with peripheral nerve palsy caused by an hourglass-like constriction of nerves were retrospectively investigated in 2 hand centers. The patients' presentation and neurological findings were reviewed, and the immunohistochemistry of excised specimens was studied.

RESULTS:

Forty-two patients who presented with 47 nerve palsies were examined. Forty-one patients experienced a sudden onset of pain in the upper limb, followed by flaccid paralysis in the affected muscles. Ten patients had multiple nerve involvement. Surgical exploration found 1 or more hourglass-like constrictions in the nerve. The treatments included internal neurolysis, neurorrhaphy, and nerve grafting. Thirty-one of 42 patients (36 nerves) were followed up for a mean of 48 months (range, 8–157 months). Fifteen of 16 nerves treated by neurolysis, 10 of 13 nerves treated by neurorrhaphy, and 4 of 7 nerves treated by nerve grafting had good recovery. CD8-positive T-lymphocyte infiltration was observed in all the excised specimens.

CONCLUSION:

The clinical presentation of patients with hourglass-like constrictions in their nerves is similar to that of patients with neuralgic amyotrophy. Histochemical analysis suggests that the pathogenesis may be immunological in origin. The role of surgery in this condition is uncertain.

Acute brachial plexus neuropathy with involvement of cranial nerves IX, X, XI and XII

INTRODUCTION

Acute brachial plexus neuropathy is characterized by acute onset of shoulder girdle and arm pain, followed by weakness of the shoulder and arm muscles. It affects primarily nerves of the upper trunk of the brachial plexus and the long thoracic nerve. Cranial nerve involvement is an infrequent association and implies a diagnostic challenge. We report a unique case of acute brachial plexus neuropathy with involvement of the cranial nerves IX, X, XI and XII.

CASE REPORT

Fifty six year-old woman who developed acute dysphonia, dysphagia and left shoulder pain, followed, six days later, by left arm weakness. Needle examination showed only fibrillation potentials and positive sharp waves in the left deltoid muscle. MRI of the brachial plexus shows enlargement of the trunks, cords and terminal branches, with mild gadolinium enhancement.

DISCUSSION

This case illustrates the unique presentation of neuralgic amyotrophy with involvement of nerves outside the brachial plexus, and the importance of MRI for diagnosis, in the absence of electrophysiologic involvement.

Brachial plexopathy

Brachial plexus injury can occur as a result of trauma, inflammation or malignancies, and associated complications. The current topic is concerned with various forms of brachial plexopathy, its clinical features, pathophysiology, imaging findings, and management. Idiopathic brachial neuritis (IBN), often preceded with antecedent events such as infection, commonly present with abruptonset painful asymmetric upper limb weakness with associated wasting around the shoulder girdle and arm muscles. Idiopathic hypertrophic brachial neuritis, a rare condition, is usually painless to begin with, unlike IBN. Hereditary neuralgic amyotrophy is an autosomal-dominant disorder characterized by repeated episodes of paralysis and sensory disturbances in an affected limb, which is preceded by severe pain. While the frequency of the episodes tends to decrease with age, affected individuals suffer from residual deficits. Neurogenic thoracic outlet syndrome affects the lower trunk of the brachial plexus. It is diagnosed on the basis of electrophysiology and is amenable to surgical intervention. Cancer-related brachial plexopathy may occur secondary to metastatic infiltration or radiation therapy. Traumatic brachial plexus injury is commonly encountered in neurology, orthopedic, and plastic surgery set-ups. Trauma may be a direct blow or traction or stretch injury. The prognosis depends on the extent and site of injury as well as the surgical expertise.

Recurrent Vocal Fold Paralysis and Parsonage-Turner Syndrome

Background. Parsonage-Turner syndrome, or neuralgic amyotrophy (NA), is an acute brachial plexus neuritis that typically presents with unilateral shoulder pain and amyotrophy but also can affect other peripheral nerves, including the recurrent laryngeal nerve. Idiopathic vocal fold paralysis (VFP) represents approximately 12% of the VFP cases and recurrence is extremely rare.Methods and Results. We report a man with isolated recurrent unilateral right VFP and a diagnosis of NA years before.Conclusions. We emphasize that shoulder pain and amyotrophy should be inquired in any patient suffering from inexplicable dysphonia, and Parsonage-Turner syndrome should be considered in the differential diagnosis of idiopathic VFP.

[Radial nerve palsy as a presenting feature of neuralgic amyotrophy]

A 28-year-old man noticed weakness in his left arm when he woke up. He was diagnosed as left radial nerve palsy and managed conservatively at a local hospital. A few days later, severe pain of the brachium appeared. Although severe pain improved in a year, dysesthesia and muscle atrophy remained. On admission, muscle weakness and atrophy were found in muscles innervated predominantly by the left radial nerve. In addition, needle-electromyography and computed tomography revealed the involvement of muscles innervated by the left suprascapular, long thoracic and axillary nerves, and we diagnosed the patient as neuralgic amyotrophy. Neuralgic amyotrophy should be kept in mind in diagnosing acute onset, painful radial palsy.

Neuralgic amyotrophy (Parsonage-Turner syndrome)

Neuralgic amyotrophy (Parsonage-Turner syndrome or brachial plexus neuritis) is an uncommon syndrome whose cause is unknown. The suprascapular and axillary nerves and corresponding muscles are affected most frequently. The disorder exhibits a broad range of clinical manifestations, and patients frequently present to physicians of different subspecialties. Accurate diagnosis can be challenging and requires a thorough history and physical examination. Nerve conduction velocity and imaging studies assist in the evaluation. Treatment consists of symptomatic management. Symptoms can persist for more than than a year, but most patients note resolution of symptoms over time.

Intravenous immunoglobulin (IVIg) with methylprednisolone pulse therapy for motor impairment of neuralgic amyotrophy: clinical observations in 10 cases

BACKGROUND

Neuralgic amyotrophy (NA) is a distinct peripheral nervous system disorder characterized by attacks of acute neuropathic pain and rapid multifocal weakness and atrophy unilaterally in the upper limb. The current hypothesis is that the episodes are caused by an immune-mediated response to the brachial plexus, however, therapeutic strategies for NA have not been well established.

METHODS AND RESULTS

We retrospectively reviewed 15 case series of NA; 10 of the 15 patients received intravenous immunoglobulin (IVIg) with methylprednisolone pulse therapy (MPPT) and 9 of these 0 patients showed clinical improvement of motor impairment.

CONCLUSION

Our clinical observations do not contradict the possibility that IVIg with MPPT may be one of the potential therapeutics for NA, however the efficacy remains to be established. Further confirmatory trials are needed in patients with various clinical severities and phases of NA. Further basic research and confirmatory trials should be performed to survey the efficacy of such immunomodulation therapy for NA.

MRI findings and steroid therapy for neuralgic amyotrophy in children

Neuralgic amyotrophy is not uncommon in adults but is relatively rare in children. We recently encountered 2 cases of neuralgic amyotrophy in children. Patient 1 was a 7-year-old girl who developed a right leg paralysis after an epileptic seizure. Lumbar plexus T(2)-weighted magnetic resonance imaging (MRI) revealed a hyperintense and thickened portion extending from the root to the knee region of the right sciatic nerve, and T(1)-weighted conventional spin echo with gadolinium administration revealed enhancement. Patient 2 was a 4-year-old boy who experienced a sudden onset of severe right arm pain and paralysis. T(2)-weighted MRI with a short tau inversion recovery revealed a slightly thickened and high intensity region at the right C(6)-C(8) level. After high-dose methylprednisolone pulse therapy was performed in each case, patient 1 experienced complete recovery, whereas patient 2 experienced only amelioration of pain. A diagnosis of neuralgic amyotrophy in children was facilitated by an MRI study (T(2) weighed with short tau inversion recovery and T(1) weighted with gadolinium enhancement), and early steroid therapy might have improved the condition of these children.

Typical brachial neuritis (Parsonage-Turner syndrome) with hourglass-like constrictions in the affected nerves

PURPOSE

To report on 5 patients who had acute brachial neuritis (Parsonage-Turner syndrome) with hourglass-like constriction in the affected nerves.

METHODS

We retrospectively reviewed 5 patients who were treated in our department from December 2003 to December 2008. Acute, intense pain around the shoulder girdle and upper arm was the first symptom and was followed by muscle weakness and atrophy. Clinical and EMG examinations showed involvement of 2 or more nerves in the affected extremity. Those severely affected nerves that had no response to conservative treatment were explored, and an hourglass-like constriction was identified. Neurolysis was performed at the sites of constrictions in 2 radial nerves and 1 median nerve. The constricted portion was resected, and direct coaptation was performed in 1 radial nerve and 1 musculocutaneous nerve. The constricted portion was resected, and nerve graft was performed in 2 radial nerves and 1 median nerve.

RESULTS

All patients were followed up for 24 to 84 months after surgery. Of 3 nerves treated with external neurolysis, all attained full recovery. Of 2 nerves treated with resection and neurorrhaphy, 1 attained full recovery, and the other had an incomplete recovery. Of 3 nerves treated with resection and nerve graft, 1 (4-cm nerve graft) attained full recovery, and 2 (4-cm and 13-cm nerve graft, respectively) had incomplete recovery.

CONCLUSIONS

The site of nerve lesion of brachial neuritis was not necessarily within the brachial plexus. Our finding of hourglass-like constrictions in individual peripheral nerves suggest that multifocal involvement of terminal branch lesions may underlie the complex patterns of paralysis often encountered clinically.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Clinical and pathophysiological concepts of neuralgic amyotrophy

Neuralgic amyotrophy--also known as Parsonage-Turner syndrome or brachial plexus neuritis--is a distinct and painful peripheral neuropathy that causes episodes of multifocal paresis and sensory loss in a brachial plexus distribution with concomitant involvement of other PNS structures (such as the lumbosacral plexus or phrenic nerve) in a large number of patients. The phenotype can be limited or extensive and the amount of disability experienced also varies between patients, but many are left with residual disabilities that affect their ability to work and their everyday life. Both idiopathic and hereditary forms exist. The latter form is genetically heterogeneous, but in 55% of affected families, neuralgic amyotrophy is associated with a point mutation or duplication in the SEPT9 gene on chromosome 17q25. The disease is thought to result from an underlying genetic predisposition, a susceptibility to mechanical injury of the brachial plexus (possibly representing disturbance of the epineurial blood-nerve barrier), and an immune or autoimmune trigger for the attacks. The precise pathophysiological mechanisms are still unclear; treatment is empirical, and preventive measures are not yet available. This Review provides an overview of the current clinical and pathophysiological concepts and research topics in neuralgic amyotrophy.

Neuroradiologic and neurophysiologic findings of neuralgic amyotrophy

OBJECTIVE

Neuralgic amyotrophy (NA) is a distinct clinical syndrome that is characterized by the acute onset of shoulder and arm pain, weakness, and sensory loss. The purpose of this study was to assess the clinical characteristics of NA and to determine appropriate diagnostic modalities.

METHODS

We reviewed the medical and radiologic records of 10 patients diagnosed with NA retrospectively. Neurophysiologic studies were performed in all patients and magnetic resonance neurography was performed in the last three patients.

RESULTS

A total of 10 patients were enrolled in our study. All patients had clinical findings compatible with NA. The most common clinical presentation was severe shoulder pain and weakness in seven patients (70%). Neurophysiologic study results were abnormal in all patients. Brachial plexus magnetic resonance neurography showed that the affected brachial plexus showed a thickened and hyper-intense trunk. All patients were managed conservatively with analgesics and physical therapy. The pain and paralysis of all patients improved clinically within 6 months of the initiation of treatment.

CONCLUSION

NA is a rare disease but the symptoms of NA can mimic those of other diseases. Neurophysiologic studies and magnetic resonance neurography are extremely useful tools for the diagnosis of NA.

Idiopathic neuralgic amyotrophy in children. Case report, 4 year follow up and review of the literature

BACKGROUND

Idiopathic neuralgic amyotrophy (INA) is a neurological disorder with a suspected autoimmune cause, and is characterized by a sudden onset of pain and subsequent atrophies of the arm and shoulder muscles. It has rarely been documented in children, but it has been suggested that the prognostic outcome is worse in children compared with adults.

AIM AND METHODS

We present a case and 4 year follow up of severe INA in a 12-year-old boy along with a thorough review of reported cases in children, to provide an overview of the paediatric phenotype and prognosis.

RESULTS

The patient presented with severe pain and a subsequent paresis around the right shoulder girdle. Blood tests, MRI and X-ray of the shoulder were all normal. Electromyography revealed patchy denervation of individual nerves of the brachial plexus. At 5 months he started recovering, but full recovery was only achieved after 3-4 years. We then reviewed the literature and identified 58 paediatric cases of INA. In total, 63% made a full recovery, 25% made a partial, and 13% made no recovery. Overall, recovery was quick with a mean recovery time of 11.1 months. Specific preceding events such as osteomyelitis, viral- and upper airway infections were frequently associated with INA, but with an age dependent pattern.

CONCLUSION

INA is a rare neurological disorder, especially in children. When compared with adults, pain and bilateral affection seems less common, and recovery is quick. Although limited by its retrospective nature, this review suggests that the paediatric phenotype is different and milder from that of adults. It also indicates a better prognosis in children than previously anticipated.

[Case of neuralgic amyotrophy with anti GT1a antibody]

A 48-year-old-man had intense pain in the neck and muscle weakness in the left upper limb after he presented low grade fever and appetite loss for a week. Several days later, he developed intense pain and severe muscle weakness in bilateral upper limbs. Laboratory examination showed elevated liver enzyme levels. His muscle weakness was severe in the right upper limb and was moderate in the left upper limb. Deep tendon reflexes were decreased in the bilateral upper limbs. CSF showed albuminocytologic dissiciation. A diagnosis of neuralgic amyotrophy was made. His liver dysfunction improved gradually. IgM and IgG anti-GT1a antibodies were positive. Future studies are required to elucidate whether anti-GT1a antibody is associated with the primary pathophysiology of neuralgic amyotrophy.

IDIOPATHIC BRACHIAL NEURITIS

Parsonage-Turner syndrome (PTS) is a rare syndrome of unknown cause, affecting mainly the lower motor neurons of the brachial plexus. The brachial plexus is a group of nerves that conduct signals from the spine to the shoulder, arm, and hand. PTS is usually characterized by the sudden onset of severe 1-sided shoulder pain, followed by paralysis of the shoulder and lack of muscle control in the arm, wrist, or hand several days later. PTS can vary greatly in presentation and nerve involvement. Also known as brachial plexus neuritis or neuralgic amyotrophy, PTS is a common condition characterized by inflammation of a network of nerves that control and supply, or innervate, the muscles of the chest, shoulders, and arms. Individuals with the condition first experience severe pain across the shoulder and upper arm. Within a few hours or days, weakness, wasting (atrophy), and paralysis may affect the muscles of the shoulder. Although individuals with the condition may experience paralysis of the affected areas for months or, in some cases, years, recovery is usually eventually complete.