Multidisciplinary strategies to treat painful mononeuropathies in the upper extremity: from lab to bedside.

Neuropathic pain in the upper extremity is a serious problem, commonly involving relatively young patients. The pain causes loss of function and productivity, changes a patient's lifestyle and can progress into a chronic pain syndrome with secondary psychosocial co-morbidities. Treating patients with a painful mononeuropathy remains challenging, with a monodisciplinary approach often having limited treatment efficacy. This narrative review discusses how to deal with this challenge in the treatment of patients with peripheral nerve injury pain, addressing the four important pillars: (1) diagnosing a painful mononeuropathy; (2) clinical pain phenotyping; (3) personalized pain treatment; and (4) using a multidisciplinary team approach.

Sacral dural arteriovenous fistula mimicking multiple mononeuropathy.

A sacral dural arteriovenous fistula (dAVF) is extremely rare, and the pathophysiological and clinical features have not been established. A 70-year-old man developed gradually progressive right-dominant bilateral sensory disorder of the lower limbs. His clinical course and electrophysiological findings were similar to those of multiple mononeuropathy. However, angiography showed a sacral dAVF at the right intervertebral foramen between the fifth lumbar and first sacral vertebrae. Endovascular embolization of the dAVF improved his clinical symptoms and electrophysiological findings. A sacral dAVF can mimic multiple mononeuropathy in terms of its clinical features and electrophysiological findings. A sacral dAVF is a treatable disease and should be considered as a differential diagnosis of lower extremity disorders.

Health economic evaluation of different treatment strategies for peripheral entrapment mononeuropathies: a systematic review.

Introduction: In this era of cost-conscious health systems, it is of utmost importance to identify and establish the most cost-effective treatment option. However, in the case of peripheral entrapment mononeuropathies there is alack of data regarding economically effective treatment strategies. Therefore, the objective was to conduct an economic evaluation including both costs and benefits of various treatment strategies applied to peripheral entrapment mononeuropathies to estimate the relative cost-effective treatment regimens.Areas covered: Over the 19 years, seven excellent-high quality economic evaluations of three types of peripheral entrapment mononeuropathies were identified in four countries. Our findings showed that surgery was the most cost-effective therapy followed by same cost efficacy of infiltrative therapy and conservative therapy for peripheral entrapment mononeuropathies. However, the fact that surgery was the most common comparator (n = 6) in our selected studies cannot be neglected.Expert opinion: Due to huge methodological variability, the finding of surgery as the cost-effective treatment strategy remains tentative and the decision about the most suitable clinical and cost-effective therapy should be individualized from case to case. Moreover, the economic evaluation of all possible treatment strategies for peripheral entrapment mononeuropathies over alonger period of analysis is required in future studies.

Treatment of spontaneous anterior interosseous nerve palsy.

OBJECTIVE: The purpose of this study was to clarify the clinical outcomes of spontaneous anterior interosseous nerve palsy (AINP) treated nonsurgically or surgically. METHODS: The authors retrospectively evaluated the clinical course of 27 patients affected with AINP, treated nonsurgically or surgically. Thirteen patients underwent surgical treatment (interfascicular neurolysis), and 14 patients underwent conservative nonsurgical treatment. The mean patient age at the onset of symptoms was 49 years (range 17-77 years). The mean follow-up duration from onset to the latest follow-up examination was 23 months (range 12-38 months). RRESULTS: In 12 of 14 patients receiving conservative treatment, signs of recovery from the palsy were obtained within 6 months. These patients showed a recovery of manual muscle test (MMT) grade ≥ 3. In contrast, 2 patients who took more than 12 months from symptom onset to initial recovery showed poor recovery (MMT grade ≤ 2). Surgical treatment was performed in 13 patients because of no sign of recovery from palsy. The mean period from symptom onset to the operation was 8.4 months (range 6-14 months). Ten of 13 patients who underwent surgical treatment within 8 months after symptom onset showed good recovery, with MMT grade ≥ 4. However, 3 patients who underwent surgical treatment more than 12 months after onset showed recovery with MMT grade ≤ 3. CONCLUSIONS: Conservative treatment for AINP may be continued when patients show signs of recovery within 6 months after symptom onset. In contrast, surgical treatment may be performed within 8 months from the onset of symptoms when the patients show no recovery signs for 6 months. ABBREVIATIONS: AIN = anterior interosseous nerve; AINP = anterior interosseous nerve palsy; FDP1 = flexor digitorum profundus of the index finger; FPL = flexor pollicis longus; MMT = manual muscle test; NSG = nonsurgical treatment group; SG = surgical treatment group.

Long-term treatment of chronic orofacial, pudendal, and central neuropathic limb pain with repetitive transcranial magnetic stimulation of the motor cortex.

OBJECTIVE: To assess the long-term analgesic effects of high-frequency repetitive transcranial magnetic stimulation (rTMS) of the motor cortex in patients with chronic pain syndrome. METHODS: The study included 57 patients (orofacial pain, n = 26, pudendal neuralgia, n = 18, and neuropathic limb pain, n = 13) with an "induction phase" of 12 daily rTMS sessions for 3 weeks, followed by a "maintenance phase" of bi-monthly sessions for the next five months. RESULTS: All pain measures significantly decreased from baseline to the end of the induction phase. Analgesic response, defined as pain intensity decrease ≥ 30% compared to baseline, was observed in 39 patients (68%), who could be differentiated from non-responders from the 7th rTMS session. At the end of the maintenance phase (D180), 27 patients (47%) were still responders. Anxio-depressive symptoms and quality of life also improved. The analgesic response at the end of the induction phase was associated with lower pain score at baseline, and the response at the end of the maintenance phase was associated with lower anxio-depressive score at baseline. CONCLUSION: The analgesic efficacy of motor cortex rTMS can be maintained in the long term in various chronic pain conditions. Patients with high pain level and severe anxio-depressive symptoms may have a less favorable profile to respond to the procedure. SIGNIFICANCE: The overall impact of rTMS treatment on daily life requires a multidimensional evaluation that goes beyond the analgesic effect that can be achieved.

Utility and practice of electrodiagnostic testing in the pediatric population: An AANEM consensus statement.

Nerve conduction studies and needle electromyography, collectively known as electrodiagnostic (EDX) studies, have been available for pediatric patients for decades, but the accessibility of this diagnostic modality and the approach to testing vary significantly depending on the physician and institution. The maturation of molecular diagnostic approaches and other diagnostic technologies such as neuromuscular ultrasound indicate that an analysis of current needs and practices for EDX studies in the pediatric population is warranted. The American Association of Neuromuscular & Electrodiagnostic Medicine convened a consensus panel to perform literature searches, share collective experiences, and develop a consensus statement. The panel found that electrodiagnostic studies continue to have high utility for the diagnosis of numerous childhood neuromuscular disorders, and that standardized approaches along with the use of high-quality reference values are important to maximize the diagnostic yield of these tests in infants, children, and adolescents.

Prospective case series on the use of peripheral nerve stimulation for focal mononeuropathy treatment.

Aim: This case series looks at outcomes in 39 patients implanted using the Bioness Stimrouter system on various isolated mononeuropathies. Patients & methods: A case series of 39 patients with a total of 42 implants were enrolled starting August 2017 at various pain management centers. Results: Of 39 patients studied, 78% of the participants noticed an improvement in their pain. There was a 71% reduction in pain scores with the average preprocedure score of 8 improving to 2 post-implant. Participants noted on average a 72% improvement in activity with the greatest observed in the brachial plexus (80%) and suprascapular nerve (80%) and smallest in the intercostal nerve (40%). Approximately 89% of those implanted with a peripheral nerve stimulator experienced a greater than 50% reduction in opioid consumption. Conclusion: Peripheral nerve stimulators are a new, minimally invasive neuromodulation modality that shows promising early results in our 39-patient case series.

Meralgia parestésica / Meralgia paresthetica

Fundamento: la meralgia parestésica es una mononeuropatía por atrapamiento que genera dolor, parestesias y pérdida de la sensibilidad en el territorio del nervio cutáneo lateral del muslo. Objetivo: profundizar y actualizar los aspectos más importantes de la meralgia parestésica. Métodos: se realizó una revisión de la literatura en idioma español e inglés disponible en PubMed Central, Hinari y SciELO. Para ello se utilizaron los siguientes descriptores: meralgia paresthetica, mononeuropathy, lateral cutaneous nerve of the thigh. A partir de la información obtenida se realizó una revisión bibliográfica de un total de 107 artículos publicados, incluídas 34 citas seleccionadas para realizar la revisión, de ellas 24 de los últimos cinco años.Desarrollo: se insistió en aquellos tópicos controversiales dentro del tema como son: reseña anatómica, factores etiológicos, presentación clínica, estudios complementarios y tratamiento. Conclusiones:la meralgia parestésica es un reto médico, debido a que puede simular enfermedades comunes como los desordenes lumbares. Es una enfermedad autolimitada cuyo diagnóstico se realiza con un alto índice de sospecha basado en el conocimiento adecuado de la anatomía, la fisiopatología, los factores etiológicos y los elementos clínicos. El tratamiento, aunque con falta de consenso, ofrece resultados favorables en la mayoría de los pacientes(AU)

Background: meralgia paresthetica is an entrapment mononeuropathy which cause pain, paresthesias and sensory loss within the distribution of the lateral cutaneous nerve of the thigh. Objective: to update and to deepen in the most important aspects of meralgia paresthetica.Methods: a revision of the literature was made in English and Spanish, available in PubMed Central, Hinari and SciELO. The following descriptors were used: meralgia paresthetica, mononeuropathy, lateral cutaneous nerve of the thigh. Base on the obtained data, a bibliographic revision was made of 107 published articles, including 34 cites selected for the research, 24 of them of the last five years.Development: it was focus in those controversial topics like: anatomic characteristics, etiological factors, clinical presentation, complementary studies and treatment. Conclusions: meralgia paresthetica is a medical challenge; due to it can simulate common illness like lumbar disorders. It is a self limited disease which is diagnosed basing on a high suspicious index with an adequate knowledge of the anatomy, physiopathology, etiological factors and clinical elements. The treatment, although with lack of consensus, offers favorable results in most of the patients(AU)

Plasma exchanges for the treatment of severe systemic necrotizing vasculitides in clinical daily practice: Data from the French Vasculitis Study Group.

The use of plasma exchanges (PLEX) in systemic necrotizing vasculitides (SNV) still need to be codified. To describe indications, efficacy and safety of PLEX for the treatment of SNV, we conducted a multicenter retrospective study on patients with ANCA-associated vasculitis (AAV) or non-viral polyarteritis nodosa (PAN) treated with PLEX. One hundred and fifty-two patients were included: GPA (n = 87), MPA (n = 56), EGPA (n = 4) and PAN (n = 5). PLEX were used for rapidly progressive glomerulonephritis (RPGN) in 126 cases (86%), alveolar hemorrhage in 64 cases (42%), and severe mononeuritis multiplex in 23 cases (15%). In patients with RPGN, there was a significant improvement in renal function compared to baseline value (P < 0.0001), the plateau being reached at month 3 after PLEX initiation, and estimated glomerular filtration rate improved especially as the number of PLEX increased. In patients with alveolar hemorrhage, mechanical ventilation was discontinued in all patients after a median time of 15 days. Patients treated for mononeuritis multiplex showed improvement of severe motor weakness. After a median follow of 22 months, 18 deaths (12%) were recorded, mainly in patients with RPGN and within the first 6 months. Incidence of end-stage renal disease and/or death was similar between groups of different baseline renal function, but was increased in MPO-ANCA compared to PR3-ANCA. Adverse events attributable to PLEX were recorded in 63%. No death occurred during PLEX. This large series describes indications, efficacy and safety of PLEX in daily practice. Randomized controlled studies are ongoing to define optimal indications, PLEX regimen and concomitant medications.

Compartment syndrome with mononeuropathies after anterior cruciate ligament reconstruction.

Compartment syndrome rarely follows anterior cruciate ligament reconstruction. However, when it does, it may result in mononeuropathies that are amenable to neurolysis. The authors of this study present an 18-yr-old woman who sustained a right anterior cruciate ligament tear and underwent uneventful anterior cruciate ligament reconstruction using femoral and popliteal nerve blocks. Postoperatively, she developed compartment syndrome requiring emergent fasciotomies. At 11 wks after fasciotomy, results of electrophysiologic tests showed evidence of severe fibular and tibial neuropathies. Magnetic resonance images showed extensive tricompartmental myonecrosis. Fibular and tibial neurolysis as well as decompression were performed, followed by intensive outpatient rehabilitation. At the 6-mo follow-up, she reported resolution of pain as well as significant improvement in sensation, strength, and function. Early recognition and intervention are crucial to prevent serious neurologic damage. Excessive tourniquet pressure and anesthetic nerve blocks may have been responsible.

Peripheral mononeuropathy associated with valproic acid poisoning in an adult patient.

OBJECTIVE: To present the case of axillary nerve neuropathy associated with valproic acid (VPA) poisoning. CASE REPORT: A 26-year-old man was hospitalized because of a suicide attempt with VPA overdose. Toxicology analysis revealed high serum VPA level (2,896 µmol/L; therapeutic range: 350 - 690 µmol/L). Three days after admission, the patient complained of weakness in his right arm. Neurological examination revealed weakness of flexion and abduction of the right arm and loss of sensation in the skin over the lateral upper right arm. A nerve conduction velocity test was normal in the ulnar, radial, median, musculocutaneous, and suprascapular nerves. Compound muscle action potential showed reduced amplitude and prolonged latencies in the right axillary nerve taken from Erb's point and absent taken from distal stimulation point. Right axillary nerve paresis was diagnosed and the patient underwent a physical therapy program, which resulted in gradual recovery. DISCUSSION: In the presented case, other possible causes of neuropathy were excluded by medical history, laboratory and radiological tests, and clinical course of the disease.The temporal relationship between the VPA poisoning and the occurrence of neuropathy supports the hypothesis of a VPA-caused axillary neuropathy. According to the Naranjo's Adverse Drug Reaction (ADR) Probability Scale, VPA-induced neuropathy was rated "probable". CONCLUSION: VPA-induced neuropathy may be a serious ADR, but it is potentially preventable and reversible. Thus, clinicians should be aware of this rare ADR.

Less common upper limb mononeuropathies.

This article will focus on the less commonly injured nerves of the upper extremity. These nerves may be involved when trauma results in fractures, dislocations, or swelling with resultant nerve compression. Tumors and ganglions can also compress nerves, causing pain and, over time, demyelination or axon degeneration with weakness. Other mechanisms for upper limb nerve injury include participation in high-level sports, that is, those that generate torque about the arm and shoulder, abnormal stresses about the joints and muscles, or muscle hypertrophy, which may result in nerve injury. The goals of this review are to discuss the clinical presentation and possible causes of upper extremity nerve entrapments and to formulate an electrodiagnostic plan for evaluation. Descriptions of the appropriate nerve conduction studies or needle electromyographic protocols are included for specific nerves. The purpose of the electrodiagnostic examination is to evaluate the degree of nerve injury, axon loss over time, and later, evidence for reinnervation to assist with prognostication. The latter has implications for management of the neuropathy, including the type of exercises and therapy that may be indicated to help maintain the stability and motion of the involved joint(s) and promote strengthening over time as the nerve regenerates.

[Avoidance, diagnostics and therapy of nerve lesions after total hip arthroplasty]. / Vermeidung, Diagnostik und Therapie von Nervenläsionen nach Hüftendoprothesenimplantation.

Nerve palsy following total hip arthroplasty is a rare complication. Developmental dysplasia of the hip, previous fracture treatment and medical comorbidities are characteristic risk factors. By accurate preparation of the patient and a careful operative technique nerve palsy can be avoided in most cases. Nerve palsy following poor patient positioning during the perioperative period should be avoided by close cooperation with anesthesiologists.In cases of postoperative nerve palsy correct diagnostics should be carried out immediately. Further treatment options should be considered to minimize the damage. For patients with definite nerve palsy, devices such as a foot drop splint are often necessary and should be carried out as soon as possible.

Mononeuropathy multiplex associated with acute parvovirus B19 infection: characteristics, treatment and outcome.

To describe the characteristics of peripheral neuropathy related to acute parvovirus B19 (B19V) infection. We reviewed clinical, electrophysiological and histological data of three patients with peripheral neuropathy and positive B19V detection (IgG, IgM and PCR) compatible with acute infection. The neuropathy fulfilled criteria for mononeuropathy multiplex (MM). It could be preceded by or concurrent with a limited purpuric eruption, but systemic manifestations were absent. The first neurological symptoms were always sensory and localized in a hand. Neuropathy was initially limited to a restricted sensory part of a nerve trunk territory. The course was subacute with successive and asymmetric injury of the limb and cranial nerves. Electromyographic study confirmed the diagnosis of MM with multifocal asymmetric sensory and motor axonal loss in two patients, whereas the neuropathy was purely sensory and limited to two nerves in the other patient. Nerve biopsies showed no evidence of necrotizing vasculitis but, in one patient, revealed a lymphocytic perivascular infiltrate evocative of hypersensitivity vasculitis secondary to an infectious agent. Intravenous immunoglobulin (IVIg) was systematically administered. Long-term outcome was good but with incomplete sensory recovery and, for one patient, persistence of a functional disability. B19 V infection should be considered in the etiological assessment of MM, especially in the event of a progressive sensory disorder in the hands and a concomitant history of rash. IVIg may be an effective treatment for this inflammatory disorder.

Sensory neuronopathy with Ro antibodies: response to combination immunosuppression.

The objective of this study was to describe a case of sensory neuronopathy syndrome (SNS) with Ro antibodies who had nearly complete functional recovery with combination immunosuppression. Plasma exchange, azathioprine, and hydroxychloroquine were used in combination. The gait ataxia, kinesthetic sensation, and sensory response amplitudes showed considerable recovery with excellent functional outcomes. Prompt combined therapy with azathioprine and hydroxychloroquine is a promising therapy for patients with sensory neuronopathy syndrome and Ro antibodies.

Clinical characterization and successful treatment of 6 patients with Churg-Strauss syndrome-associated neuropathy.

OBJECTIVE: To confirm the reported findings and clarify unknown clinical features of Churg-Strauss syndrome (CSS)-associated neuropathy and design appropriate treatment. PATIENTS AND METHODS: We assessed the clinical features of 6 patients with CSS-associated neuropathy. RESULTS: Mononeuritis multiplex was present in 4 cases and polyneuropathy in the remaining cases. Both groups progressed to sensori-motor polyneuropathy in an acute or subacute course. All cases showed bronchial asthma and eosinophilia. Two cases with serum antineutrophil cytoplasmic antibodies to myeloperoxidase (MPO-ANCA) had an acute clinical course and severe symptoms. Nerve conduction studies (NCS) of these 2 cases revealed conduction blocks at the initial stage, although NCS finally indicated sensori-motor axonopathy at the involved extremities. For treatment, high-dose corticosteroid therapy for 4 cases, and cyclophosphamide combined with corticosteroids for 1 case, were effective. For the remaining case, intravenous immunoglobulin (IVIg) at the chronic phase resulted in a slow improvement of neuropathy in the symptomatic aspect. There was no relapse of neuropathy with low-dose corticosteroid treatment for 14-24 months after the initial treatment, except 1 case. There was also no relapse in the other case that was treated with moderate-dose steroids. CONCLUSION: Our study showed that CSS-associated neuropathy is a treatable disorder and that the first choice therapy is high-dose corticosteroid. In cases where corticosteroids are ineffective or for severe cases, immunosuppressive therapy (cyclophosphamide) with steroids should be considered, and IVIg might be a treatment option.

[Inflammatory neuropathies and multineuritis]. / Neuropathies inflammatoires et mononévrites.

Inflammatory neuropathies include those neuropathies in which the diagnosis, outcome and type of treatment are badly known, the reason of this review. They are expressed as diffuse (such as CIDP and ganglionopathies), multifocal (vasculitic neuropathy) or focal (MMN; plexopathies; immune reconstitution inflammatory syndrome). These forms of neuropathies are important to be known because the beneficial therapeutic possibilities of immunosuppression.