Neuropatía motora multifocal: ¿cómo diagnosticar un caballo de Troya? / Multifocal motor neuropathy: how to diagnose a trojan horse?

Introducción: La neuropatía motora multifocal con bloqueos de la conducción (NMMBC) es una enfermedad crónica inmunomediada, con un compromiso exclusivo de los nervios motores. Es importante diferenciarla de otras enfermedades que cursan con afectación motora, debido a que ésta es una enfermedad tratable. Cuadro clínico: Paciente varón de 56 años, con compromiso motor progresivo en el miembro superior del lado derecho desde el año 2016. El examen neurofisiológico demostró la presencia de múltiples bloqueos de la conducción nerviosa. Los anticuerpos antigangliósidos fueron negativos. Se indicó tratamiento con inmunoglobulina endovenosa en varios ciclos, con mejoría progresiva del cuadro. Discusión: Se discute el plan diagnóstico clínico y electrofisiológico, los diagnósticos diferenciales, las hipótesis fisiopatológicas y el tratamiento de esta enfermedad de rara ocurrencia

Introduction: Multifocal motor neuropathy with conduction blocks (NMMBC) is a chronic immunemediated disease that exclusively involves the motor nerves. It is important to differentiate it from other diseases that present with motor involvement, because this is a treatable disease. Clinical picture: A 56-year-old male patient, with progressive motor involvement in the right upper limb since 2016. A neurophysiological examination revealed multiple nerve conduction blocks. Antiganglioside antibodies were negative. Treatment with intravenous immunoglobulin was indicated for several cycles with progressive improvement of the condition. Discussion: Clinical and electrophysiological diagnostic plans, differential diagnoses, pathophysiological hypotheses, and treatment of this rare disease are discussed

Determining the utility of minimum F-wave latency alterations in the electrodiagnosis of ulnar neuropathy at the elbow / Determinação da utilidade das alterações mínimas da latência da onda F no eletrodiagnóstico da neuropatia ulnar do cotovelo

ABSTRACT Background: Ulnar neuropathy at the elbow (UNE) is the second most common entrapment neuropathy. There is little information about the application of F-wave studies for evaluation of UNE. Objective: The aim of this study was to evaluate the diagnostic value of minimum F-wave (F-min) latency alterations by comparing this with nerve conduction analyses in UNE-suspected patients. Methods: Ninety-four UNE-suspected patients were admitted to this study. Sensory and motor nerve conduction and F-wave analyses on the median and ulnar nerves were performed on both upper extremities. Results: A total of 188 upper extremities of 94 patients were examined. Their mean age was 41.4±12.9 years, and 69 patients were female (73.4%). The mean ulnar-nerve across-elbow motor conduction velocity (MCV) in the affected arms was significantly slower than the velocity in healthy arms. The mean ulnar-nerve F-min latencies were significantly longer in the affected arms. Fifty-one patients were electrophysiologically diagnosed as presenting UNE (54.2%). Significantly slower mean ulnar-nerve across-elbow MCV, longer mean ulnar-nerve F-min latency and longer distal onset latency were detected in UNE-positive arms. Lastly, patients who were symptomatic but had normal nerve conduction were evaluated separately. Only the mean ulnar F-min latency was significantly longer in this group, compared with the healthy arms. Conclusion: Our study confirmed the utility of F-min latency measurements in the electrodiagnosis of UNE. F-wave latency differences can help in making an early diagnosis to provide better treatment options.

RESUMO Introdução: A neuropatia ulnar do cotovelo (NUC) é a segunda neuropatia por encarceramento mais comum. Existem poucas informações sobre a aplicação dos estudos da onda F para avaliação da NUC. Objetivo: O objetivo deste estudo foi avaliar o valor diagnóstico das alterações mínimas de latência da onda F (F-min), comparando-as com análises de condução nervosa em pacientes com suspeita de NUC. Métodos: Noventa e quatro pacientes com suspeita de NUC foram admitidos neste estudo. A condução nervosa sensitiva e motora e as análises da onda F nos nervos mediano e ulnar foram realizadas em ambas as extremidades superiores. Resultados: Um total de 188 membros superiores de 94 pacientes foi examinado. A média de idade foi 41,4±12,9 anos e 69 pacientes eram do sexo feminino (73,4%). A velocidade de condução motora média do nervo ulnar através do cotovelo (VCM) nos braços afetados foi significativamente mais lenta do que a velocidade em braços saudáveis. As latências médias F-min do nervo ulnar foram significativamente mais longas nos braços afetados. Cinquenta e um pacientes foram diagnosticados eletrofisiologicamente como apresentando NUC (54,2%). Pacientes com presença de NUC tiveram, de forma significativa, detecção de VCM mais lenta no nervo ulnar ao nível do cotovelo, presença de latência mais longa da onda F-mínima no nervo ulnar, bem como latência de início distal mais longa. Por fim, os pacientes sintomáticos, e com condução nervosa normal, foram avaliados separadamente. Apenas a latência da onda F mínima média do nervo ulnar foi significativamente maior neste grupo, em comparação com os braços saudáveis. Conclusão: Nosso estudo confirmou a utilidade das medidas de latência da onda F-mínima no eletrodiagnóstico da NUC. As diferenças de latência da onda F podem ajudar a fazer um diagnóstico precoce para fornecer melhores opções de tratamento.

Efeito da mobilização neural no tratamento da dor em indivíduos com cervicobraquialgia: uma revisão sistemática / Effect of neural mobilization on the treatment of pain in individuals with cervicobrachialgia: a systematic review

: A cervicobraquialgia (CB) é caracterizada por uma dor com origem em diferentes níveis estruturais da coluna cervical baixa (C3- C7), com irradiação bilateral ou unilateral para o membro superior. Considerando as causas e consequências advindas da CB, novas modalidades de tratamento têm sido propostas na tentativa de promover intervenções efetivas. Entre os procedimentos fisioterapêuticos encontram-se as técnicas de terapia manual como liberação miofascial, quiropraxia, mobilização articular, estabilização segmentar e a mobilização neural (MN) que procura restabelecer a função do tecido neural, sua condução elétrica, elasticidade, movimento e fluxo axoplasmático. Sendo assim, o objetivo do estudo foi avaliar sistematicamente as evidências sobre o efeito da MN no tratamento da dor em indivíduos com CB. A busca bibliográfica foi realizada no período entre Novembro de 2018 a Junho de 2019, sem limite de ano de publicação, nas bases de dados: PEDro, PubMed, Biblioteca Virtual em Saúde (Lilacs, Scielo e Medline) e Cochrane Library. A análise foi restrita aos ensaios clínicos randomizados. Para a análise etodológica dos artigos aptos a inclusão, foi utilizada a escala PEDro. Foi encontrado um total de 38 artigos. Após remoção de duplicatas, 14 artigos foram elegidos por resumo, 8 artigos foram recuperados para leitura completa e analisados quanto a sua adequação, dos quais 3 foram excluídos por não cumprirem os critérios de elegibilidade, ao fim 5 artigos foram incluídos na revisão. Houve redução significativa da dor, em pacientes tratados com MN. Considerando os resultados obtidos nesta revisão, foi possível concluir que a MN demonstra ser eficaz na redução da dor presente na CB. Embora os estudos mostrem que os resultados da MN como tratamento da CB são significativamente inferiores ao efeito do Ibuprofeno, deve-se ter em consideração as consequências a longo prazo para a saúde sobre a utilização de anti- inflamatórios orais.(AU)

Cervicobrachialgia (CB) is characterized by pain originating from different structural levels of the lower cervical spine (C3-C7), w ith bilateral or unilateral irradiation to the upper limb. Considering the causes and consequences of CB, new treatment modalities have been proposed in an attempt to promote effective interventions. Among the physical therapy procedures are manual therapy techniques such as myofascial release, chiropractic, joint mobilization, segmental stabilization and neural mobilization (NM) that seeks to restore the function of neural tissue, its electrical conduction, elasticity, movement and ax oplasmic flow . Thus, the objective of the study w as to evaluate systematically evaluate the evidence on the effect of NM on pain management in individuals w ith CB. The bibliographic search w as performed from November 2018 to June 2019, w ithout limit of year of publication, in the databases: PEDro, PubMed, Virtual Health Library (Lilacs, Scielo and Medline) and Cochrane Library. The analysis w as restricted to randomized controlled trials. For the methodological analysis of the articles eligible for inc lusion, the PEDro scale w as used. A total of 38 articles w ere found. After removal of duplicates, 14 articles w ere elected by abstract, 8 articles w ere retrieved for full reading and analyzed for suitability, of w hich 3 w ere excluded for not meeting eligibility c riteria, at the end 5 articles w ere included in the review . There was a significant pain reduction in patients treated w ith NM. Considering the results obtained in this review , it w as concluded that NM demonstrates to be effective in reducing pain present in CB. Although studies show that the results of NM as a treatment for CB are significantly low er than the effect of ibuprofen, consideration should be given to the long-term health consequences about the utilization of oral anti-inflammatory drugs.(AU)

Electrophysiological evaluation of carpal tunnel syndrome female patients after vitamin D replacement / Avaliação eletrofisiológica de pacientes do sexo feminino com síndrome do túnel do carpo após reposição de vitamina D

Abstract Objective: The effects of vitamin D on the central and peripheral nervous system continue to be investigated today. In the present study, we aimed to evaluate pain and electrophysiologic response in patients with carpal tunnel syndrome (CTS) who have undergone replacement therapy due to vitamin D deficiency. Methods: Fifty female patients diagnosed with mild and moderate CTS and accompanied by vitamin D deficiency were included in this study. Nerve conduction study (NCS) was performed before and after vitamin D replacement, and the patient's pain was evaluated with Visual Analogue Scale (VAS). Results: When NCS were compared before and after treatment, there was a statistically significant improvement in the median distal sensory onset latency (DSOL) and sensory conduction velocity (CV) and motor distal latencies (DML) values (p=0.001; p<0.001; p=0.001, respectively). At the same time, there was a decrease in the VAS values in patients (p<0.001). When the two groups were compared there was an improvement in DSOL and sensory CV in both groups, but in DML only in moderate CTS group. Conclusion: In this study, it was shown that mild and moderate CTS patients had an improvement in pain and electrophysiological parameters after vitamin D replacement. Replacing vitamin D in early stages of CTS may be beneficial.

Resumo Objetivo: Os efeitos da vitamina D no sistema nervoso central e periférico continuam sendo investigados atualmente. Neste estudo, objetivamos avaliar a dor e a resposta eletrofisiológica em pacientes com síndrome do túnel do carpo (STC) submetidos a terapia de reposição devido à deficiência de vitamina D. Métodos: Cinquenta pacientes do sexo feminino diagnosticadas com STC leve e moderada e acompanhadas de deficiência de vitamina D foram incluídas neste estudo. O estudo da condução nervosa (ECN) foi realizado antes e após a reposição da vitamina D, e a dor do paciente foi avaliada com a Escala Visual Analógica (EVA). Resultados: Quando a ECN foi comparada antes e após o tratamento, houve uma melhora estatisticamente significativa na latência mediana do início sensorial distal (DSOL) e nos valores de velocidade de condução sensorial (VC) e latência distal motora (LDM) (p=0,001; p<0,001; p=0,001, respectivamente). Ao mesmo tempo, houve uma diminuição dos valores da EVA nos pacientes (p<0,001). Quando os dois grupos foram comparados, houve uma melhora no DSOL e no VC sensorial em ambos, mas no LDM apenas no grupo STC moderado. Conclusão: Neste estudo, foi demonstrado que pacientes com STC leve e moderada apresentaram melhora da dor e parâmetros eletrofisiológicos após a reposição de vitamina D. A substituição da vitamina D nos estágios iniciais da STC pode ser benéfica.

Sensibilidad y especificidad de tres métodos complementarios para el diagnóstico de síndrome de túnel carpiano / Sensitivity and specificity of three complementary methods in the diagnosis of carpal tunnel syndrome

Resumen: Introducción: Actualmente, no existe un estándar de referencia aceptado universalmente para el diagnóstico del síndrome de túnel carpiano, por lo que se le considera una patología de «clase latente¼, es decir, que carece de alguna prueba diagnóstica que dé certeza absoluta de la presencia de la enfermedad. Métodos: Estudio prospectivo, observacional y analítico en el cual se evaluaron los tres métodos diagnósticos utilizados para el síndrome de túnel carpiano (examen clínico, ecografía y electromiografía). En él, se establecieron valores de normalidad para cada método diagnóstico. Resultados: Se evaluó un total de 50 personas (14 hombres y 36 mujeres). El examen clínico presentó correlación positiva y significativa con el diámetro del nervio mediano afectado (ecografía) (R = 0.694 y p = 0.032). Los valores del área bajo la curva (AUC, por sus siglas en inglés) para la velocidad de conducción del nervio mediano (VCNM), velocidad de conducción de nervio cubital (VCNC) y latencia distal motora (LDM) por electromiografía fueron de 0.60, 0.519 y < 0.50, respectivamente, lo cual determinó que el valor diagnóstico de las características por electromiografía es malo. Conclusión: Nuestro trabajo establece al examen clínico como una herramienta de buena calidad, siendo el método más sensible para el diagnóstico de síndrome de túnel carpiano. Si existiera la necesidad de realizar una confirmación diagnóstica, la ecografía mostró ser un estudio altamente satisfactorio, el cual genera menos estrés, dolor e invasión al paciente, disminuyendo, a su vez, el gasto de salud y agilizando el proceso.

Abstract: Introduction: Currently there is no universally accepted standard of reference for the diagnosis of carpal tunnel syndrome so it is considered a «latent class¼ pathology, that is, it lacks any diagnostic tests that absolutely certain the presence of disease. Methods: Prospective, observational and analytical study evaluating the three diagnostic methods used for carpal tunnel syndrome (clinical examination, ultrasound and electromyography). Normality values were set for each diagnostic method. Results: 50 people (14 men and 36 women) were evaluated. The clinical examination showed a positive and significant correlation with the diameter of the affected median nerve (ecography) (R = 0.694, p = 0.032). The values of the under the curve area (UCA) for median nerve conduction speed (MNCS), cubital nerve conduction speed (CNCS), and distal latency (DL) by electromyography were 0.60, 0.519 and less than 0.50 respectively. This states that the diagnostic value of electromyography characteristics is bad. Conclusion: Our work establishes clinical examination as a good quality tool being the most sensitive method for diagnosing carpal tunnel syndrome. If there was a need for diagnostic confirmation, the ultrasound proved to be a highly satisfactory study generating less stress, pain and invasion to the patient, decreasing health expenditure and speeding up the process.

Association of motor nerve conduction block with different subtypes of childhood Guillain-Barré syndrome / 中国当代儿科杂志

OBJECTIVE@#To study the association of motor nerve conduction block (CB) with different subtypes of childhood Guillain-Barré syndrome (GBS).@*METHODS@#A retrospective analysis was performed on the clinical and nerve electrophysiological data of 50 children with GBS. According to the results of nerve electrophysiology, the children were divided into an acute inflammatory demyelinating polyneuropathy (AIDP) group with 29 children and an acute motor axonal neuropathy (AMAN) group with 21 children. According to the presence or absence of motor nerve CB, the children with AMAN or AIDP were further divided into subgroups: group AMAN with or without motor nerve CB (n=10 and 11 respectively) and group AIDP with or without motor nerve CB group (n=19 and 10 respectively). The subgroups were compared in terms of age of onset, sex, Hughes Functional Grading Scale (HFGS) at nadir for the most severe involvement of motor function, and short-term prognosis based on HFGS score at 1 month after disease onset.@*RESULTS@#Motor nerve CB was reversible in children with AMAN. AMAN children with motor nerve CB had a significantly lower HFGS score than those without motor nerve CB at 1 month after onset (P<0.05). AIDP children with motor nerve CB had a significantly higher HFGS score than those with motor nerve CB at 1 month after onset (P<0.05).@*CONCLUSIONS@#AMAN with reversible motor nerve CB suggests mild nerve fiber lesion and has better recovery than AMAN and AIDP without motor nerve CB in short term.

Different distributions of nerve demyelination in chronic acquired multifocal polyneuropathies / 中华医学杂志(英文版)

BACKGROUND@#Multifocal motor neuropathy (MMN), Lewis-Sumner syndrome (LSS), and many chronic inflammatory demyelinating polyradiculoneuropathies (CIDPs) are representative of acquired multifocal polyneuropathy and are characterized by conduction block (CB). This retrospective study aimed to investigate the demyelinating distribution and the selective vulnerability of MMN, LSS, and CIDP with CB (CIDP-CB) in nerves.@*METHODS@#Fifteen LSS subjects (107 nerves), 24 MMN subjects (176 nerves), and 17 CIDP-CB subjects (110 nerves) were included. Their clinical information was recorded, blood and cerebrospinal fluid tests were conducted, and nerve conductions of the median, ulnar, radial, peroneal, and tibial nerves were evaluated. CB, temporal dispersion, distal motor latency (DML), and F-wave latency were recorded, and nerve conduction velocity, terminal latency index, and modified F-wave ratio were calculated.@*RESULTS@#CB was more likely to occur around the elbow in CIDP-CB than in MMN (78.6% vs. 6.8%, P < 0.01) but less likely to occur between the wrist and the elbow than in LSS (10.7% vs. 39.3%, P < 0.05). Tibial nerve CB was most frequently observed in MMN (47.4%, P < 0.05). CIDP-CB was characterized by a prolonged DML in all nerves, and slow motor nerve velocity of the upper limb was significant when CB nerves were excluded (P < 0.05).@*CONCLUSIONS@#We report the different distributions of segmental and diffuse demyelination of the ulnar and tibial nerves in LSS, MMN, and CIDP-CB. These distinct distributions could help in differentiating among these conditions.

Dexmedetomidine attenuates P2X4 and NLRP3 expression in the spine of rats with diabetic neuropathic pain

Abstract Purpose: To evaluate the effects of Dexmedetomidine (Dex) on spinal pathology and inflammatory factor in a rat model of Diabetic neuropathic pain (DNP). Methods: The rats were divided into 3 groups (eight in each group): normal group (N group), diabetic neuropathic pain model group (DNP group), and DNP model with dexmedetomidine (Dex group). The rat model of diabetes was established with intraperitoneal streptozotocin (STZ) injections. Nerve cell ultrastructure was evaluated with transmission electron microscopy (TEM). The mechanical withdrawal threshold (MWT) and motor nerve conduction velocity (MNCV) tests documented that DNP rat model was characterized by a decreased pain threshold and nerve conduction velocity. Results: Dex restored the phenotype of neurocytes, reduced the extent of demyelination and improved MWT and MNCV of DNP-treated rats (P=0.01, P=0.038, respectively). The expression of three pain-and inflammation-associated factors (P2X4, NLRP3, and IL-IP) was significantly upregulated at the protein level in DNP rats, and this change was reversed by Dex administration (P=0.0022, P=0.0092, P=0.0028, respectively). Conclusion: The P2X4/NLRP3 signaling pathway is implicated in the development and presence of DNP in vivo, and Dex protects from this disorder.

Riché-Cannieu Anastomosis: Structure, Function, and Clinical Significance / Anastomose de Riché-Cannieu: estrutura, função e significância clínica

Abstract Objective To define the anatomy pattern and the incidence of Riché-Cannieu anastomosis, that is, median and ulnar communication in the palmar aspect of the hand. Materials Methods A total of 80 anatomical dissections were performed on 60 hands of 30 cadavers from 1979 to 1982, and on 20 hands from 2012 to 2015. All of these procedures were performed at the Department of Anatomy of our institution. The incidence of Riché-Cannieu anastomosis and the innervation of the thenar muscles were studied. Results Riché-Cannieu anastomosis was identified in every dissected hand (100%). The extramuscular Riché-Cannieu anastomosis was recorded in 57 hands, and the intramuscular, in 19 hands. The association of extra- and intramuscular Riché-Cannieu anastomoses occurred in four hands. The ulnar component always originated from the deep branch. The anastomotic branch arising from the median nerve originated from the motor thenar branch (recurrent branch) of the median nerve in most of the observations. The median-ulnar double innervation only to the deep head of the flexor pollicis brevis was identified in 29 of 80 hands. The double innervation only of the superficial head of the flexor pollicis brevis was found in 13 hands. In 12 hands, the deep head of the flexor pollicis brevis was absent. The double innervation of the superficial and deep heads of the flexor pollicis brevis occurred in 14 hands. The oblique head of the adductor pollicis received double innervation in 12 hands. The deep head of the flexor pollicis brevis and the oblique head of adductor pollicis were doubly-innervated in nine hands. The transverse head of the adductor pollicis received double innervation in two hands. Double innervation of the deep head of the flexor pollicis brevis and the transverse head of the adductor pollicis were found in one hand. Conclusion According to the present study, Riché-Cannieu anastomosis should be considered a normal anatomical neural connection, not an anatomical variation. Knowledge of this anastomosis is essential because the presence of such neural communication may result in confusing clinical, surgical, and electromyographic findings in cases of median or ulnar damage or entrapment.

Resumo Objetivo Definir a anatomia e a incidência da anastomose de Riché-Cannieu, ou seja, a comunicação entre os nervos medianos e ulnar na palma da mão. Materiais e Métodos Foram dissecadas 60 mãos de 30 cadáveres frescos de adultos, entre 1979 a 1982, e 20 mãos entre 2011 e 2015, num total de 80 mãos, no Departamento de Anatomia da nossa instituição. A incidência da anastomose de Riché-Cannieu e a inervação dos músculos da região do tênar foram estudadas. Resultados A anastomose de Riché-Cannieu foi identificada em todas as mãos dissecadas (100%). A anastomose de Riché-Cannieu extramuscular foi registrada em 57 mãos, e a intramuscular, em 19, e a associação das anastomoses extra e intramuscular, em 4 mãos. O componente ulnar da anastomose de Riché-Cannieu foi sempre do seu ramo profundo. O ramo anastomótico oriundo do nervo originava-se do ramo recorrente do nervo mediano na maioria das observações. A dupla inervação mediano-ulnar apenas da cabeça profunda do músculo flexor curto do polegar foi identificada em 29 de 80 mãos. Observou-se dupla inervação apenas da cabeça superficial do músculo flexor curto do polegar em 13 mãos. Foi observada dupla inervação das cabeças superficial e profunda do flexor curto do polegar em 14 mãos. A cabeça oblíqua do adutor do polegar recebeu inervação dupla em 12 mãos. A cabeça profunda do músculo flexor curto do polegar e a cabeça oblíqua do adutor do polegar foram inervadas duplamente em nove mãos. A cabeça transversa do adutor do polegar recebeu inervação dupla em duas mãos. A inervação dupla da cabeça profunda do flexor curto do polegar e da cabeça transversa do adutor do polegar foi observada em uma mão. Conclusão De acordo com o presente estudo, a anastomose de Riché-Cannieu deve ser considerada uma conexão nervosa normal, e não uma variação anatômica. O conhecimento dessa anastomose é essencial, pois a presença dessa comunicação neural pode resultar em achados clínicos, cirúrgicos e eletromiográficos confusos em casos de lesões ou síndromes compressivas dos nervos mediano ou ulnar.

Potencial de ação duplo e alterações ecográficas do nervo mediano em doentes com síndrome do túnel cárpico / Double peak action potential and ultrasonography nerve evaluation in patients with carpal tunnel syndrome

Introdução: A síndrome do túnel cárpico (STC) é sustentada pela presença de lentificação do potencial de ação do nervo mediano no estudo ortodrómico de condução nervosa sensitiva em comparação com o nervo radial (EC-MR). Uma técnica modificada de registo simultâneo de ambos os nervos (EC-MRsimul) pode ser utilizada, detetando a lentificação do nervo mediano através da presença de potencial de ação sensitivo duplo (PAS-D). O objetivo deste estudo é correlacionar o PAS-D com os achados de EC-MR e com o edema perineural em doentes com diagnóstico de STC. Métodos: Indivíduos saudáveis e doentes com STC há menos de 12 meses foram submetidos a avaliação eletrofisiológica, incluindo o EC-MR e o EC-MRsimul. Foi também realizada ultrassonografia para registo da área seccional do nervo mediano (AS-NM) no punho e antebraço e, respetivo índice punho-antebraço (I-PA). Resultados: Foram recrutados 38 doentes com idade média de 54,8 ± 15,3 anos com STC e 18 indivíduos saudáveis. A diferença de latência distal entre o nervo mediano e radial foi superior nos doentes (0,80 ± 0,30ms vs. 0,15 ± 0,20ms; p=0,015). O EC­MRsimul demonstrou a presença de PAS-D nos indivíduos sintomáticos. A AS­NM no punho foi também superior nos doentes (8,9 ± 0,9mm2 vs. 6,6 ± 0,7mm2; p<0.003), tendo sido identificado um quisto sinovial e um neurinoma. O edema perineural traduzido pela AS-SM correlacionou-se positivamente com a diferença de latência interpico no EC-MR e com a presença de PAS-D. Conclusão: O PAS-D está associado à presença de lentificação da condução e ao edema perineural do nervo mediano no contexto de STC ou devido a lesões ocupantes de espaço. (AU)

Introduction: Carpal tunnel syndrome (CTS) is characterized by median nerve action potential slowing, which can be shown in comparative orthodromic sensory nerve conduction studies between median and radial nerve (NCS-MR). A modified technique with simultaneous recording of both nerves (NCS-MRsimul) can also be used to detect median nerve slowing through the presence of double peak action potential (DPp). The study aims to correlate the presence of DPp with NCS-MR findings and with perineural edema in patients diagnosed with STC. Methods: Healthy individuals and patients with CTS for less than 12 months underwent NCS-MR and MRsimul. An ultrasonography evaluation was also performed to record the medial nerve sectional area (SA-MN) on the wrist and forearm, and the wrist-to-forearm ratio (WFR) was calculated. Results: We recruited 38 patients with CTS whose mean age was 54.8 ± 15.3 years and 18 healthy individuals. Distal latency difference between the median and radial nerves was higher in patients with CTS (0.80 ± 0.30 ms vs. 0.15 ± 0.20 ms, p = 0.015). NCS-MRsimul showed DPp in symptomatic individuals. SA-MN in the wrist was also higher in patients with CTS (8.9 ± 0.9 mm2 vs. 6.6 ± 0.7 mm2 , p <0.003). Ultrasonography evaluation identified a synovial cyst and a neurinoma. Perineural edema traduced by higher SA-MN and WFR correlated positively with interpeak latency difference in NCS-MR and with the presence of DPp. Conclusions: DPp was associated with median nerve sensory action potential slowing and with perineural edema due to either CTS or to space-occupying lesions. (AU)

The Correlation of the Grading of Chemotherapy-Induced Peripheral Neurotoxicity (CIPN) Using the Total Neuropathy Score-Reduced and Various Electrophysiological Parameters in Breast Cancer Patients

BACKGROUND: The accurate grading of chemotherapy-induced peripheral neuropathy (CIPN) represents an unsolved issue. This study evaluated usefulness of the reduced version of Total Neuropathy Score TNS (TNSr) and the correlation of this scale with various electrophysiological parameters. METHODS: Neuropathic symptoms and quality of life were assessed using the neuropathy symptom scale and the Functional Assessment of Cancer Therapy/Gynecologic Oncology Group Neurotoxicity (FACT/GOG-NTX) scale. A detailed neurologic examination, nerve conduction study (NCS), and the current perception threshold (CPT) were also performed. The TNSr score was calculated by a single examiner. We divided the patients with small fiber neuropathy and large fiber neuropathy and compared each variable between groups. Also, we analyzed correlations of the TNSr score with various parameters (NCS data, CPT score, and neuropathy symptom scales). RESULTS: Of 30 recruited patients, 16 (53%) had large fiber neuropathy, and the other 14 (47%) had small fiber neuropathy. Patients with large fiber neuropathy had a lower sural sensory nerve action potential (SNAP) (p=0.000), lower peroneal compound muscle action potential (CMAP) (p=0.002), higher National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE, NTC) sensory grade (p=0.029) and higher TNSr score (p=0.000). There were no differences in any domain of the FACT/G, neuropathy symptom scale, or FACT/GOG-NTX between the two groups. The TNSr score was most significantly correlated with the sural SNAP (p=0.000), NTC-sensory grade (p=0.000), neuropathy symptom scale (p=0.001), FACT/GOG-NTX score (p=0.009), and pin score (p=0.002). CONCLUSIONS: The TNSr score is correlated with sensory peripheral neurotoxicity and also present the symptom severity in CIPN.

Neuromyositis: A Rare Extramuscular Manifestation of Dermatomyositis

Dermatomyositis (DM) and polymyositis (PM) are representative idiopathic inflammatory myopathies characterized by symmetric and progressive proximal muscle weakness. Especially, DM is identified by characteristic skin lesions and has many extramuscular manifestations including various cardiac abnormalities, interstitial lung disease, and malignancy. However, involvement of peripheral nervous system in DM/PM is very rare and less known. The term “Neuromyositis” was introduced by Senator in 1893 to describe the concomitant involvement of the peripheral nervous system in DM/PM. Since then, a very few cases of neuromyositis have been reported mainly in the United States and Europe. Therefore, the pathogenetic mechanism and disease progression are unclear. In recent years, a few more cases were reported in Asia, specifically, China and Japan; however, none in Korea. Here, we describe a case of DM-associated neuromyositis in a 42-year-old man in Korea and review previous publications through literature research.

Current Concept of Guillain-Barré Syndrome / 대한신경근육질환학회지

Guillain-Barré syndrome (GBS) is nowadays consider as an umbrella term that has heterogenous presentation depend on their subtypes. GBS is clinical diagnosis and its diagnosis can be supported by laboratory findings from cerebral spinal fluid study, nerve conduction study, anti-ganglioside antibodies, spinal magnetic resonance imaging and nerve ultrasound. Understanding atypical subtypes and GBS mimicking diseases are crucial for correct diagnosis. Both proper medical care for respiratory and autonomic dysfunction and immunotherapy are essential to improve outcome of GBS. Here, we summarized the current concept on diagnosis, immunopathophysiology and treatment of GBS.

Interpretation of Electrodiagnostic Tests in Chronic Inflammatory Demyelinating Polyneuropathy: Classification Using Nerve Conduction Study / 대한신경근육질환학회지

Electrodiagnostic tests (EDX) is essential for the diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP). EDX could provide information about demyelinating pathology in the peripheral nerves. According to phenotypes, CIDP could be classified several phenotypes, which has different clinical manifestations, EDX could present a different distribution pattern of demyelinating lesions. In addition, EDX could be useful markers for predicting treatment response of prognosis of CIDP.

Accessory Belly of the Piriformis Muscle as a Cause of Piriformis Syndrome: a Case Report with Magnetic Resonance Imaging and Magnetic Resonance Neurography Imaging Findings

Piriformis syndrome caused by an accessory belly of the piriformis muscle is very rare. Only a few cases have been reported. Here, we report a case of piriformis syndrome resulting from an extremely rare type of accessory belly of the piriformis muscle originated at the proximal third portion of the main piriformis muscle and attached separately to the greater trochanter inferior to the insertion of the main piriformis muscle. A definitive diagnosis of piriformis syndrome was made based on magnetic resonance imaging and magnetic resonance neurography findings that were consistent with results of nerve conduction study and needle electromyography.

Could Ultrasound-Guided Stimulation of Sural Nerve Affect Nerve Conduction Study?

OBJECTIVE: To determine anatomical variation of the sural nerve (SN) by ultrasonography (US) and compare sensory nerve action potential (SNAP) of the SN obtained by a control method to that obtained with adjusted method using US. METHODS: Eighty legs of 40 healthy volunteers were enrolled. The location and formation of SN were investigated through US. Two methods of nerve conduction study (NCS) were then performed. In the control method, the cathode was placed 14 cm proximal to the lateral malleolus and the greatest SNAP amplitude was obtained by moving the cathode medially or laterally from just lateral to the calf-mid line. In adjusted NCS, the exact SN union site was stimulated in type 1. In other SN types, the stimulation was done directly over the nerve and the distance from the lateral malleolus was set to be 14 cm. RESULTS: It was found that 73.8% of the SNs were type 1, 22.5% were direct continuation of MSCN (type 2), and 3.8% were MSCN and LSCN without communicating (type 4). However, type 3 was not found. The union point in type 1 SN was 12.6±2.5 cm proximal to the lateral malleolus and 1.4±0.7 cm lateral to the calf-midline. After stimulation adjustment, SNAP amplitude in type 1 SN was significantly increased (20.7±5.5 μV vs. 27.1±6.7 μV). CONCLUSION: Anatomical variation of SN and its location were verified by US. US provides additional information for conducting sural NCS and helps obtain more accurate results.

Palmar Digital Neuropathy With Anatomical Variation of Median Nerve: Usefulness of Orthodromic Technique: A Case Report

Anatomic variation of palmar digital nerve pathways were reported in several cases. Selective exploration of palmar digital nerves with a nerve conduction study has been challenging, because of technical issues. We report a patient who received bilateral carpal tunnel release operation, complaining of a tingling sensation, and hypoesthesia on the middle and ring fingers. An electrodiagnostic study revealed a sensory neuropathy of palmar digital nerve of the left median nerve, supplying the ulnar side of the middle finger, and radial side of the ring finger. She underwent re-operation of open left carpal tunnel release, and a branching site of common digital nerves of the median nerve was identified not at the palm, but at a far proximal site around the distal wrist crease. Usefulness of an orthodromic sensory conduction study was clarified to eliminate volume conducted response or co-activation of nearby nerves in the patient with selective involvement of palmar digital nerve.

Painless cervical motor radiculopathy relieved by cervical epidural steroid injection: A case report

A 15-year-old male patient presented with a slow progression of painless right shoulder weakness over the previous six weeks. The magnetic resonance imaging revealed right C4–5 foraminal stenosis caused by right foraminal disc protrusion. The needle electromyography and nerve conduction studies revealed acute C5 and/or C6 radiculopathy. Instead of the initial surgical management modalities, we performed a cervical epidural steroid injection at the C4–5 level. From the day after the patient received the cervical epidural steroid injection, his right shoulder motor weakness improved progressively. Two weeks after the procedure, his right shoulder motor function had fully recovered.

miR-381 Attenuates Peripheral Neuropathic Phenotype Caused by Overexpression of PMP22

Charcot-Marie Tooth disease type 1A (CMT1A), the major type of CMT, is caused by duplication of peripheral myelin protein 22 (PMP22) gene whose overexpression causes structural and functional abnormalities in myelination. We investigated whether miRNA-mediated regulation of PMP22 expression could reduce the expression level of PMP22, thereby alleviating the demyelinating neuropathic phenotype of CMT1A. We found that several miRNAs were down-regulated in C22 mouse, a CMT1A mouse model. Among them, miR-381 could target 3′ untranslated region (3′UTR) of PMP22 in vitro based on Western botting and quantitative Real Time-PCR (qRT-PCR) results. In vivo efficacy of miR-381 was assessed by administration of LV-miR-381, an miR-381 expressing lentiviral vector, into the sciatic nerve of C22 mice by a single injection at postnatal day 6 (p6). Administration of LV-miR-381 reduced expression level of PMP22 along with elevated level of miR-381 in the sciatic nerve. Rotarod performance analysis revealed that locomotor coordination of LV-miR-381 administered C22 mice was significantly enhanced from 8 weeks post administration. Electrophysiologically, increased motor nerve conduction velocity was observed in treated mice. Histologically, toluidine blue staining and electron microscopy revealed that structural abnormalities of myelination were improved in sciatic nerves of LV-miR-381 treated mice. Therefore, delivery of miR-381 ameliorated the phenotype of peripheral neuropathy in CMT1A mouse model by down-regulating PMP22 expression. These data suggest that miRNA can be used as a potent therapeutic strategy to control diseases with copy number variations such as CMT1A.

Does the type of electrode affect the electromyoneurographic parameters in rats?

Abstract Purpose: To evaluate if the type of electrode (needle vs. surface) affects the electromyoneurography parameters in rats. Methods: Twenty male rats were anesthetized, then compound muscle action potential were recorded using a Neuropack S1 MEB- 9400©. All animals were submitted to two electroneuromyography analysis: first with surface electrode and then by needle electrode. We evaluated the latency, amplitude, duration and area of the negative peak of the gastrocnemius and cranial tibial muscles. Results: There were no significant differences between the groups in the mean of duration, latency, amplitude or area of the negative peak in gastrocnemius and cranial tibial muscles. Conclusion: The type of electrode does not affect the electroneuromyography parameters.