Focal slowing of nerve conduction velocity in leprosy patients unveiled through multisegmented nerve analysis.

BACKGROUND AND AIMS: Leprosy is a chronic infectious disease caused by Mycobacterium leprae (M. leprae), an intracellular bacillus that systematically invades the peripheral nerves. Diagnosing leprosy neuropathy is still a defying skill, and late diagnosis and treatment are still a reality. Based on the biological characteristics of M. leprae, particularly its preference for invading the Schwann cells localized at the coldest areas of human body, we hypothesized that these areas have focal demyelination that may escape detection through standard nerve conduction studies (NCSs) protocols. METHODS: Twenty-five patients with confirmed multibacillary leprosy and 14 controls were accessed. A multisegmented NCS protocol (MP) was performed, targeting short segments through the coldest areas, to identify focal areas of slowed conduction velocity. The effectiveness of this multisegmented protocol was compared to the standard protocol (SP) to detect abnormalities. RESULTS: All leprosy patients presented an abnormal study with the MP, contrasting to 19 with the SP. The most frequent NCS pattern was an asymmetric neuropathy with focal slowing of conduction velocity, found in 23 out of 25 leprosy patients. Significant differences favoring the proposed method were observed when comparing the MP with the SP. Notably, the MP increased the sensitivity to detect abnormalities by 122%, 133%, and 257% for the median, peroneal, and tibial nerves, respectively. MP also increases sensitivity to detect focal abnormalities in the ulnar nerve. INTERPRETATION: The MP protocol significantly increases the sensitivity of NCSs to detect neurophysiological abnormalities in leprosy neuropathy.

Peripheral neuropathy in patients with gout, beyond focal nerve compression: a cross-sectional study.

Neuropathies secondary to tophus compression in gout patients are well known; however, limited data exist on other types of peripheral neuropathies (PN). Our aim was to describe PN frequency, characteristics, distribution, patterns, and associated factors in gout patients through clinical evaluation, a PN questionnaire, and nerve conduction studies (NCS). This cross-sectional descriptive study included consecutive gout patients (ACR/EULAR 2015 criteria) from our clinic. All underwent evaluation by Rheumatology and Rehabilitation departments, with IRB approval. Based on NCS, patients were categorized as PN + (presence) or PN- (absence). PN + patients were further classified as local peripheral neuropathy (LPN) or generalized somatic peripheral neuropathy (GPN). We enrolled 162 patients, 98% male (72% tophaceous gout). Mean age (SD): 49.4 (12) years; mean BMI: 27.9 (6.0) kg/m2. Comorbidities included dyslipidemia (53%), hypertension (28%), and obesity (23.5%). Abnormal NCS: 65% (n = 106); 52% LPN, 48% GPN. PN + patients were older, had lower education, and severe tophaceous gout. GPN patients were older, had lower education, and higher DN4 scores compared to LPN or PN- groups (p = 0.05); other risk factors were not significant. Over half of gout patients experienced neuropathy, with 48% having multiplex mononeuropathy or polyneuropathy. This was associated with joint damage and functional impairment. Mechanisms and risk factors remain unclear. Early recognition and management are crucial for optimizing clinical outcomes and quality of life in these patients. Key Points Peripheral neuropathies in gout patients had been scarcely reported and studied. This paper report that: • PN in gout is more frequent and more diverse than previously reported. • Mononeuropathies are frequent, median but also ulnar, peroneal and tibial nerves could be injured. • Unexpected, generalized neuropathies (polyneuropathy and multiplex mononeuropathy) are frequent and associated to severe gout. • The direct role of hyperuricemia /or gout in peripheral nerves require further studies.

The sural-sparing pattern in clinical variants and electrophysiological subtypes of Guillain-Barré syndrome / Padrão de preservação do sural nas variantes clínicas e subtipos eletrofisiológicos da síndrome de Guillain-Barré

Abstract Background Guillain-Barré syndrome (GBS) is the most common cause of acute flaccid paralysis worldwide and can be classified into electrophysiological subtypes and clinical variants. Objective This study aimed to compare the frequency of the sural-sparing pattern (SSP) in subtypes and variants of GBS. Methods This retrospective cohort study analyzed clinical and electrophysiological data of 171 patients with GBS hospitalized in public and private hospitals of Natal, Rio Grande do Norte, Brazil, between 1994 and 2018; all cases were followed up by the same neurologist in a reference neurology center. Patients were classified according to electrophysiological subtypes and clinical variants, and the SSP frequency was compared in both categories. The exact Fisher test and Bonferroni correction were used for statistical analysis. Results The SSP was present in 53% (57 of 107) of the patients with acute inflammatory demyelinating polyradiculoneuropathy (AIDP), 8% (4 of 48) of the patients with axonal subtypes, and 31% (5 of 16) of the equivocal cases. The SSP frequency in the AIDP was significantly higher than in the axonal subtypes (p < 0.0001); the value was kept high after serial electrophysiological examinations. Only the paraparetic subtype did not present SSP. Conclusion The SSP may be present in AIDP and axonal subtypes, including acute motor axonal neuropathy, but it is significantly more present in AIDP. Moreover, the clinical variants reflect a specific pathological process and are correlated to its typical electrophysiological subtype, affecting the SSP frequency.

Resumo Antecedentes A síndrome de Guillain-Barré (GBS) é a causa mais comum de paralisia flácida aguda em todo o mundo e pode ser classificada em subtipos eletrofisiológicos e variantes clínicas. Objetivo Este estudo teve como objetivo comparar a frequência do padrão de preservação do sural (SSP) em subtipos e variantes de GBS. Métodos É um estudo de coorte retrospectivo que analisou dados clínicos e eletrofisiológicos de 171 pacientes com GBS internados em hospitais públicos e privados de Natal, Rio Grande do Norte, Brasil, entre 1994 e 2018. Todos os casos foram acompanhados pelo mesmo neurologista em centro de referência em neurologia. Os pacientes foram classificados de acordo com os subtipos eletrofisiológicos e variantes clínicas e a frequência do SSP foi comparada em ambas as categorias. O teste exato de Fisher e a correção de Bonferroni foram utilizados para análise estatística. Resultados O SSP esteve presente em 53% (57 de 107) dos pacientes com polirradiculoneuropatia desmielinizante inflamatória aguda (PDIA), em 8% (4 de 48) dos pacientes com subtipos axonais e em 31% (5 de 16) dos casos não definidos. A frequência do SSP no AIDP foi significativamente maior do que nos subtipos axonais (p < 0,0001); o valor manteve-se elevado após exames eletrofisiológicos seriados. Apenas o subtipo paraparético não apresentou SSP. Conclusão O SSP pode estar presente na PDIA e nos subtipos axonais, incluindo a neuropatia axonal motora aguda, mas está significativamente mais presente na PDIA. Além disso, as variantes clínicas refletem um processo patológico específico e estão correlacionadas ao seu subtipo eletrofisiológico típico, afetando a frequência do SSP.

Cytokines profile in pure neural leprosy.

Introduction: Pure Neural Leprosy (PNL) is a form of this long time known disease that affects only the peripheral nervous system. Since it is a rare form of the disease, its pathophisiology is still poorly understood. Objective: Describe the cytokines profile in patients with PNL. Methods: 30 Patients diagnosed with PNL in the Souza Araujo Outpatient Clinic and with cytokines evaluated were selected. They were evaluated by neurologists and diagnosed after a nerve biopsy. Serum levels of IL-1 ß, IL-6, IL-10, IL-17, TNF, CCL-2/MCP-1, IFN-ϒ, CXCL-10/IP-10 and TGF-ß were evaluates at the moment of the diagnosis. Results: Neural thickening was a common clinical finding in this groups of patients. Small and medium sensitive fibers signs and symptoms were present in 92% of the patients and motor involvement in 53%. 43% of patients presented neuropathic pain and no one had neuritis TGF-beta, IL-17, CCl-2 and IP-10. CCL-2 levels were associated with demyelinating patters and IP-10 and IL-1o were associated with axonal patterns at NCS. Discussion: PNL patients' cytokine profile appears to be different of other clinical forms of leprosy, with the presence of cytokines described in both tuberculoid and lepromatous leprosy. High levels of CCl-2 may be related to the presence of silent neuritis as well as the presence of IL-10. PNL is unique a form of leprosy, therefore, understanding its immunological profiles essential to better understand the disease itself.

F-waves persistence in peripheral sensory syndromes / Persistência das ondas-F nas síndromes sensitivas periféricas

Abstract Background The distinction between sensory neuronopathies (SN), which is by definition purely sensory, and sensory polyneuropathies (SP) and sensory multineuropathies (SM) is important for etiologic investigation and prognosis estimation. However, this task is often challenging in clinical practice. We hypothesize that F-wave assessment might be helpful, since it is able to detect subtle signs of motor involvement, which are found in SP and SM, but not in SN. Objective The aim of the present study was to determine whether F-waves are useful to distinguish SN from SP and SM. Methods We selected 21 patients with SP (12 diabetes mellitus, 4 transthyretin familial amyloid polyneuropathy, 4 others), 22 with SM (22 leprosy), and 26 with SN (13 immune-mediated, 10 idiopathic, 3 others) according to clinical-electrophysiological-etiological criteria. For every subject, we collected data on height and performed 20 supramaximal distal stimuli in median, ulnar, peroneal, and tibial nerves, bilaterally, to record F-waves. Latencies (minimum and mean) and persistences were compared across groups using the Kruskal-Wallis and Bonferroni tests. P-values < 0.05 were considered significant. Results All groups were age, gender, and height-matched. Overall, there were no significant between-group differences regarding F-wave latencies. In contrast, F-wave persistence was able to stratify the groups. Peroneal F-wave persistence was higher, bilaterally, in the SN group compared to SM and SP (p < 0.05). In addition, F-waves persistence of the ulnar and tibial nerves was also helpful to separate SN from SP (p < 0.05). Conclusion F-wave persistence of the peroneal nerves might be an additional and useful diagnostic tool to differentiate peripheral sensory syndromes.

Resumo Antecedentes A distinção entre neuronopatias sensitivas (SN) e polineuropatias sensitivas (SP) e multineuropatias sensitivas (SM) é importante para a investigação etiológica e para o prognóstico. Contudo, esta tarefa é desafiadora na prática clínica. Hipotetizou-se que a avaliação das ondas-F pode ser útil, por ser capaz de detectar envolvimento motor nas SP e SM, mas não nas SN. Objetivo Determinar se as ondas-F podem ajudar a distinguir entre SN, SP e SM. Métodos Selecionou-se 21 pacientes com SP (12 diabetes mellitus, 4 ATTR-FAP e 4 com outras neuropatias), 22 com SM (22 hanseníases) e 26 com SN (13 imunomediadas, 10 idiopáticas e 3 com outras neuronopatias), de acordo com critérios clínicos, etiológicos e eletrofisiológicos. Para cada indivíduo, foi aferida a altura e foram aplicados 20 estímulos distais supramáximos nos nervos mediano, ulnar, fibular e tibial, bilateralmente, para registrar as ondas-F. Uma comparação foi feita, por grupo, das latências (mínimas e médias) e persistências pelos testes Kruskal-Wallis e Bonferroni. Valores de p < 0.05 foram considerados estatisticamente significativos. Resultados Todos os grupos foram pareados por idade, sexo e altura. Não houve diferença estatística significativa entre os grupos quanto às latências das ondas-F. A persistência da onda-F foi capaz de estratificar os grupos, sendo as dos nervos fibulares bilateralmente maiores no grupo SN que nos grupos SM e SP (p < 0.05). Adicionalmente, a persistência das ondas-F dos nervos ulnares e tibiais também foi útil para distinguir SN de SP (p < 0.05). Conclusão A persistência das ondas-F dos nervos fibulares pode ser uma ferramenta adicional e útil para diferenciar síndromes sensitivas periféricas.

How Knowledgeable Are Spine Surgeons Regarding EMG-NCS for Cervical Spine Conditions? An International Aospine Survey.

STUDY DESIGN: Cross-sectional, international survey. OBJECTIVES: To evaluate the knowledge of spine surgeons regarding the use of electromyography (EMG) and nerve conduction studies (NCS) for degenerative cervical spine conditions (DCC). METHODS: All members of AO Spine International were emailed an anonymous survey to evaluate their clinical knowledge about the use of EMG and nerve conduction studies for DCC. Descriptive statistics were used to analyze the results, as well as to compare the answers among different groups of surgeons and assess demographic characteristics. RESULTS: A total of 402 participants answered the survey, 91.79% were men from the 5 continents. There were 221 orthopedic surgeons (55.39%) and 171 neurosurgeons (42.86%), more than a half of them with a complete spinal fellowship (56.44%). The most common reasons that surgeons obtain the test is to differentiate a radiculopathy from a peripheral nerve compression (88.06%). As a group, the responding surgeons' knowledge regarding EMG-NCS was poor. Only 53.46% of surgeons correctly answered that EMG-NCS is unable to differentiate a C5 from a C6 radiculopathy. Only 23.47% of the surgeons knew that EMG-NCS are not able to diagnose a pre vs a post-fixed brachial plexus. Only 25% of the surgeons correctly answered a question regarding the test's ability to diagnose other neurological diseases. CONCLUSIONS: We found that our respondents' knowledge regarding EMG-NCS for DCC was poor. Identifying the weak points of knowledge about EMG-NCS may help to educate surgeons on the indications for the test and the proper way to interpret the results.

Characterization of the Sensory Nerve Action Potential of the Sural Nerve in Patients Over 60 Years of Age without Peripheral Neuropathy.

Demonstration of the possibility to obtain the sensory nerve action potential (SNAP) of sural nerve in patients over 60 years old, without peripheral neuropathy. Prospective study on 101 patients older than 60 years of age. Stimulation was applied 12 cm proximal to the recording point. Two hundred and two SNAPs of the sural nerve were collected with an average peak latency of 3.2 ms, onset latency of 2.6 ms, peak-to-peak amplitude of 15.2 µV and velocity of 45.7 m/s. It was possible to obtain the sural nerve SNAP in all tested patients older than 60, without peripheral neuropathy. The values obtained in this study prove to be useful as a reference in the evaluation of patients older than 60 years of age.

Very low peroneal nerve compound muscle action potential amplitude predicts poor outcome in patients with Guillain-Barré syndrome: a prospective cohort.

INTRODUCTION: Twenty percent of patients with Guillain-Barré syndrome (GBS) have poor outcomes despite proper management. The aim of the study was to characterize electrophysiological factors related to poor outcome in patients with GBS. METHODS: We conducted an observational study from a prospective cohort of 91 patients with GBS in a tertiary healthcare center in Mexico, from 2017 to 2019. Demographics and nerve conduction studies were performed on admission, and a 3-month follow-up for GBS disability score was ensued, allocating patients in good (GBS disability score ≤ 2) and poor outcome (GBS disability score ≥ 3) groups. A logistic regression analysis for independent walk at 3 months was performed. Kaplan-Meier estimator curves for independent walk in very low (< 20% LLN) and low-normal ( ≥20% LLN) peroneal nerve CMAPs are presented. RESULTS: From the 91 GBS patients included, 37 (40.6%) did not regain independent walk at 3 months. Axonal variants were more common in the poor outcome group (31.4% vs 59.4%, p = 0.01) as well as AIDP variants with motor conduction block (6.6% vs 42.4%, p = 0.018). Univariable analysis was statistically significant for very low median, ulnar, tibial, and peroneal CMAP amplitudes in poor outcome patients; however, multivariable analysis was only significant for very low peroneal nerve CMAP amplitude (OR 3.6 [1.1-11.5, p = 0.024]). Conversely, a greater proportion of GBS patients with low-normal CMAPs recovered independent walk at 90 days (75% vs 30%, p < 0.001). CONCLUSION: Severe axonal injury of the peroneal nerve, axonal, and AIDP with motor conduction block variants predicts worse functional outcome regarding independent walk at 3 months.

Comparison between nerve conduction study and high-resolution ultrasonography with color doppler in type 1 and type 2 leprosy reactions.

OBJECTIVE: To analyze the role of high-resolution ultrasonography with color Doppler (HRUS with CD) to diagnose inflammatory activity (IA) in nerves of leprosy patients under type 1 (RT1) and 2 (RT2) reactions compared to Nerve Conduction Studies (NCS). METHODS: Leprosy patients with signs or symptoms suggestive of neuritis (RT1 and RT2) without corticosteroids use were selected. They were evaluated by NCS and subsequently by HRUS with CD. Subacute segmental demyelination and the presence of blood flow, respectively, were considered signs of IA. The two methods were compared for their ability to diagnose patients with leprosy reactions. RESULTS: A total of 257 nerves from 35 patients were evaluated. NCS and HRUS with CD diagnosed IA in 68% and 74% of patients, respectively. When both methods were used concomitantly, the diagnosis rate was 91.4%. HRUS with CD was particular helpful when there was minimal neurophysiological compromise in NCS or when motor potentials were not detected. CONCLUSION: HRUS with CD was able to detect leprosy reactions, especially when combined with NCS. It was especially useful in two opposite situations: nerves with only minor changes and those without motor response in NCS. SIGNIFICANCE: Our data shows the usefulness of HRUS and CD, similar to NCS, as a tool to diagnose leprosy reactions.

Correlation Nerve Conduction Studies with Findings of the Ultrasound of the Median Nerve in Patients with Carpal Tunnel Syndrome.

BACKGROUND: Ultrasonography is a diagnostic resource that serves as a complement in the evaluation of patients with carpal tunnel syndrome. The correlation of ultrasonography findings with nerve conduction studies can serve to classify new phenotypes and to evaluate therapeutic responses. OBJECTIVES: To determine the diagnostic sensitivity of ultrasound, the correlation between the diameter of the nerve (CSA) against the motor and sensitive latencies, and the capacity to differentiate the mild, moderate and severe degrees of the electrophysiological classification of carpal tunnel syndrome. METHODS: A cross-sectional study with prospective data collection was carried out. An ultrasonography system with a 15 MHz transducer was used. Nerve conduction studies of the median nerve were performed with conventional techniques. Data from the most symptomatic hand were used. Determination of the correlations of nerve diameter with motor and sensitive latencies of the median nerve was performed in four age groups: <40(n=11), 40-54 (n=47), 55-70 (n=42) y >70(n=27). RESULTS: A total of 127 patients were evaluated (average age = 58.2 years: minimum = 26; maximum = 85; SD = 13.4); 109 (85.8%) were female patients. According to the electrophysiological classification, 40 (31.5%) were mild ; 60 (47.2%) were moderate ; and 27 (21.3%) were severe . Significant differences in the area of the median nerve were found between the electrophysiological types (mild, moderate and severe; p = 0.000). The diagnostic sensitivity of ultrasonography differed for each age group. In general, the diagnostic sensitivity was high in patients with severe cases and low for mild cases. The capacity for ultrasonography to classify the degrees of electrophysiological severity was different for each age group. For patients above 70 years and in the age group of 40 to 54 years, the CSA did not differentiate the electrophysiologically moderate cases from the severe ones. CONCLUSION: There is a well-defined and significant correlation between nerve conduction studies and median nerve diameter in patients with Carpal Tunnel Syndrome. However, it shows that the exclusive use of the ultrasonographic measurement of the cross-sectional area through the inlet of the carpal tunnel would not be enough to confirm or rule out an entrapment of the median nerve through the carpal tunnel, nor to predict in every case their electrophysiological severity.

Comparison between nerve conduction study anf high-resolution ultrasonography with color doppler in type 1 and type 2 leprosy

Objective: To analyze the role of high-resolution ultrasonography with color Doppler (HRUS with CD) to diagnose inflammatory activity (IA) in nerves of leprosy patients under type 1 (RT1) and 2 (RT2) reactions compared to Nerve Conduction Studies (NCS). Methods: Leprosy patients with signs or symptoms suggestive of neuritis (RT1 and RT2) without corticosteroids use were selected. They were evaluated by NCS and subsequently by HRUS with CD. Subacute segmental demyelination and the presence of blood flow, respectively, were considered signs of IA. The two methods were compared for their ability to diagnose patients with leprosy reactions. Results: A total of 257 nerves from 35 patients were evaluated. NCS and HRUS with CD diagnosed IA in 68% and 74% of patients, respectively. When both methods were used concomitantly, the diagnosis rate was 91.4%. HRUS with CD was particular helpful when there was minimal neurophysiological compromise in NCS or when motor potentials were not detected. Conclusion: HRUS with CD was able to detect leprosy reactions, especially when combined with NCS. It was especially useful in two opposite situations: nerves with only minor changes and those without motor response in NCS. Significance: Our data shows the usefulness of HRUS and CD, similar to NCS, as a tool to diagnose leprosy reactions.

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)

Effectiveness of ultrasonography and nerve conduction studies in the diagnosing of carpal tunnel syndrome: clinical trial on accuracy.

BACKGROUND: The aim of this study was to evaluate the effectiveness of two diagnostic tests routinely used for diagnosing carpal tunnel syndrome (CTS)-ultrasonography (US) and nerve conduction studies (NCS)-by comparing their accuracy based on surgical results, with the remission of paresthesia as the reference standard. METHODS: We enrolled 115 patients, all of the female gender with a high probability of a clinical diagnosis of CTS. All patients underwent US and NCS for a diagnosis and subsequent surgical treatment. As a primary outcome, the accuracy of the US and NCS diagnoses was measured by comparing their diagnoses compared with those determined by the surgical outcomes. Their accuracy was secondarily evaluated based on before and after scores of the Boston Carpal Tunnel Questionnaire (BCTQ). RESULTS: Overall, 104 patients (90.4%) were diagnosed with CTS by the surgical reference standard, 97 (84.3%) by NCS, and 90 (78.3%) by US. The concordance of NCS and surgical treatment (p < 0.001; kappa = 0.648) was superior to that of US and surgical treatment (p < 0.001; kappa = 0.423). The sensitivity and specificity of US and NCS were similar (p = 1.000 and p = 0.152, respectively: McNemar's test). The BCTQ scores were lower after surgery in patients diagnosed by both US and NCS (p < 0.001and p < 0.001, respectively: analysis of variance). CONCLUSIONS: US and NCS effectively diagnosed CTS with good sensitivity but were not effective enough to rule out a suspicion of CTS. TRIAL REGISTRATION: This study was registered at September, 10 th, 2015, and the registration number was NCT02553811 .

Correlating Median Nerve Cross-sectional Area With Nerve Conduction Studies.

PURPOSE: To determine whether there is a correlation between the cross-sectional area (CSA) of the median nerve, as measured using ultrasound, and the distal motor and/or sensory latencies as measured on nerve conduction studies. METHODS: Patients with clinical signs and symptoms of carpal tunnel syndrome were prospectively enrolled in this study. Subjects underwent ultrasound measurement of the CSA of the median nerve at the carpal tunnel inlet by a fellowship-trained hand surgeon, followed by nerve conduction studies (NCS) by a certified electrodiagnostic technician who was blinded to the results of the ultrasound examination. Pearson correlations were performed to compare CSA and NCS. RESULTS: Pearson correlation was r = 0.57 between CSA and distal motor latency and r = 0.47 between CSA and distal sensory latency. Correlation was r = 0.81 between distal motor latency and distal sensory latency. CONCLUSIONS: There is a correlation between CSA of the median nerve and NCS. Further research is necessary to determine which test correlates better with patient symptoms and function. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

Carpal tunnel syndrome in the elderly: nerve conduction parameters / Síndrome do túnel do carpo em idosos: parâmetros de condução nervosa

Objective: To establish nerve conduction parameters for carpal tunnel syndrome (CTS) electrodiagnosis in the elderly. Method: Thirty healthy subjects (65-86 years), 9 male and 21 female, were studied. Routine median and ulnar sensory and motor nerve conduction studies, median mixed palmar latency, comparative latency techniques median to ulnar (sensory, mixed and motor lumbrical-interossei), median to radial (sensory), and combined sensory index (CSI) were performed in both hands. Results: The upper limits of normality (97.5 percent) were: median sensory distal latency 3.80 ms (14 cm); median motor distal latency 4.30 ms (8 cm); median palmar latency 2.45 ms (8 cm); lumbrical-interossei latency difference 0.60 ms (8 cm); comparative median to radial 0.95 ms (10 cm); comparative median to ulnar 0.95 ms (14 cm); comparative palmar median to ulnar 0.50 ms (8 cm); and CSI 2.20 ms. Sensory and mixed latencies were measured at peak. Conclusion: Our results establish new nerve conduction parameters for mild CTS electrodiagnosis in the elderly and will be helpful to reduce the number of false positive cases in this age.

Objetivo: Estabelecer parâmetros de condução nervosa para o eletrodiagnóstico da síndrome do túnel do carpo (STC) em idosos. Método: Foram estudadas 30 pessoas idosas (65-86 anos) saudáveis. Foi realizado estudo de condução nervosa sensitiva e motora rotineira dos nervos mediano e ulnar, latência palmar mista do mediano, técnicas de comparação de latências mediano-ulnar (sensitivo, misto e motor lumbrical-interósseo) e mediano-radial (sensitivo) e índice sensitivo combinado (ISC) em ambas as mãos. Resultados: Os limites superiores de normalidade, 97,5 por cento foram: latência distal sensitiva do mediano 3,80 ms (14 cm); latência distal motora do mediano 4,30 ms (8 cm), latência palmar do mediano 2,45 ms (8 cm), diferença de latência lumbrical-interósseo 0,60 ms (8 cm), comparação mediano-radial 0,95 ms (10 cm), comparação mediano-ulnar 0,95 ms (14 cm), comparação mediano-ulnar palmar 0,50 ms (8 cm) e ISC 2,20 ms. As latências sensitivas e mistas foram medidas no pico. Conclusão: Nossos resultados estabelecem novos valores de condução nervosa para o eletrodiagnóstico da STC leve em idosos.

Carpal tunnel syndrome: long-term nerve conduction studies in 261 hands / Síndrome do tunel do carpo: estudo evolutivo de parâmetros de condução nervoso em 261 mãos

OBJECTIVE: To compare a long-term carpal tunnel syndrome (CTS) on nerve conduction studies (NCS) in hands treated non-surgically. METHOD: We retrospectively selected 261 symptomatic CTS hands (166 patients), all of them confirmed by NCS. In all cases, at least 2 NCS were performed in an interval greater than 12 months. Cases with associated polyneuropathy were excluded. NCS parameters for CTS electrodiagnosis included a sensory conduction velocity (SCV) <46.6 m/s (wrist to index finger, 14 cm) and distal motor latency (DML) >4.25 ms (wrist to APB, 8 cm). RESULTS: 92.8 percent were women; mean age was 49 years (20-76); the mean interval between NCS was 47 months (12-150). In the first exam, the median sensory nerve action potential (SNAP) and the compound action muscular potential were absent in 9.8 percent and 1.9 percent, respectively. In the second/last exam, SCV worsened in 54.2 percent, remained unchanged in 11.6 percent and improved in 34.2 percent. SNAP amplitude worsened in 57.7 percent, remained unchanged in 13.1 percent and improved in 29.2 percent. DML worsened in 52.9 percent, remained unchanged in 7.6 percent and improved in 39.5 percent. Overall, NCS parameters worsened in 54.9 percent, improved in 34.3 percent and remained unchanged in 10.8 percent. CONCLUSION: Long-term changing in NCS of CTS hands apparently were not related to clinical symptomatology and could lead to some difficulty in clinical correlation and prognosis. Aging, male gender and absent SNAP were more related to NCS worsening, regardless the mean interval time between the NCS.

OBJETIVO: Comparar evolutivamente parâmetros de condução nervosa (CN) na síndrome do túnel do carpo (STC) em mãos não submetidas à cirurgia. MÉTODO: Foram selecionadas retrospectivamente 261 mãos (166 pacientes) com STC sintomática confirmadas por CN e que posteriormente realizaram exame controle com intervalo >12 meses; foram excluídos casos com polineuropatia. Os parâmetros eletrodiagnósticos anormais foram: velocidade de condução sensitiva (VCS) <46,6 m/s, segmento pulso-II dedo, e latência distal motora (LDM) >4,25 ms, segmento pulso-APB (8 cm). RESULTADOS: 92,8 por cento eram mulheres; a média de idade foi 49 anos (20-76); o tempo médio entre os exames foi 47 meses (12-150); 9,8 por cento e 1,9 por cento não apresentaram potenciais de ação do nervo sensitivo (PANS) e potenciais de ação muscular compostos, no primeiro exame. No segundo exame a VCS piorou em 54,2 por cento, ficou igual em 11,6 por cento e melhorou em 34,2 por cento; a amplitude do PANS piorou em 57,7 por cento, ficou igual em 13,1 por cento e melhorou em 29,2 por cento; a LDM piorou em 52,9 por cento, ficou igual em 7,6 por cento e melhorou em 39,5 por cento. Incluindo todos os parâmetros eletrofisiológicos, houve piora em 54,9 por cento, melhora em 34,3 por cento e permaneceram sem alterações 10,8 por cento. CONCLUSÃO: As anormalidades da CN na STC podem oscilar ao longo do tempo e aparentemente independem da sintomatologia clínica, dificultando a correlação e prognóstico; idade mais avançada, sexo masculino e PANS ausentes no primeiro exame foram as variáveis que tiveram menor percentual de melhora evolutiva, independentemente do intervalo entre os exames.

Cooling modifies mixed median and ulnar palmar studies in carpal tunnel syndrome / Influência do resfriamento nos parâmetros de condução nervosa mista do mediano e ulnar na síndrome do túnel do carpo

Temperature is an important and common variable that modifies nerve conduction study parameters in practice. Here we compare the effect of cooling on the mixed palmar median to ulnar negative peak-latency difference (PMU) in electrodiagnosis of carpal tunnel syndrome (CTS). Controls were 22 subjects (19 women, mean age 42.1 years, 44 hands). Patients were diagnosed with mild symptomatic CTS (25 women, mean age 46.6 years, 34 hands). PMU was obtained at the usual temperature, >32°C, and after wrist/hand cooling to <27°C in ice water. After cooling, there was a significantly greater increase in PMU and mixed ulnar palmar latency in patients versus controls. We concluded that cooling significantly modifies the PMU. We propose that the latencies of compressed nerve overreact to cooling and that this response could be a useful tool for incipient CTS electrodiagnosis. There was a significant latency overreaction of the ulnar nerve to cooling in CTS patients. We hypothesize that subclinical ulnar nerve compression is associated with CTS.

Temperatura é uma variável comum e importante que modifica os parâmetros de condução nervosa na prática eletrodiagnóstica. Neste trabalho nós estudamos o efeito do esfriamento na diferença de latências palmares entre o nervo mediano e ulnar (PMU), segmento palma-pulso, utilizada rotineiramente para o eletrodiagnóstico da síndrome do túnel do carpo (STC). Foram estudados 22 controles (19 mulheres, média de idade 42,1 anos, 44 mãos) e 25 pacientes (25 mulheres, média de idade 46,6 anos, 34 mãos) com diagnóstico de STC leve. PMU foi obtida em temperatura usual (>32°C), e após resfriamento de mão/pulso em água com gelo (<27°C). Após o resfriamento houve aumento significativo na PMU e na latência mista palmar do nervo ulnar nos pacientes quando comparados aos controles. Nós concluímos que o resfriamento modifica significativamente a PMU e propomos que as latências obtidas em nervos submetidos à compressão reagem de maneira mais acentuada ao frio e isso poderia ser uma arma útil para o eletrodiagnóstico da STC incipiente. Da mesma forma, houve reação mais acentuada ao frio no estudo da latência mista palmar do nervo ulnar nos pacientes mas não nos controles, que poderia levantar a hipótese de compressão subclínica do nervo ulnar.

Síndrome antifosfolípide: uma causa de neuropatia periférica? / Antiphospholipid syndrome: a cause of peripheral neuropathy?

Síndrome antifosfolípide ou síndrome do anticorpo antifosfolípide (SAF) é uma desordem auto-imune sistêmica, que se apresenta com trombose arterial ou venosa de repetição e complicações obstétricas, na presença de anticorpos antifosfolípides (aFL), seja anticardiolipina (aCL), anti-[beta]2glicoproteína I (anti-[beta]2GpI) ou anticoagulante lúpico (aL), todos envolvidos na sua patogênese. As manifestações clínicas incluem alterações cutâneas, cardíacas, pulmonares, renais e hematológicas, além de envolvimento do sistema nervoso. Várias manifestações neurológicas têm sido atribuídas à SAF. AVC (acidente vascular cerebral) é a complicação mais freqüente e de maior impacto clínico. Relato e série de casos, em diferentes publicações, têm descrito a associação entre neuropatia periférica, particularmente a síndrome de Guillain-Barré (SGB), e SAF. Faltam estudos com enfoque na neurocondução. O impacto que essas outras manifestações terão em futuras revisões para classificação dependerá de investigação clínico-epidemiológica, com desenho apropriado, para responder a essas questões.

Antiphospholipid syndrome (APS) or antiphospholipid antibodies syndrome is an autoimmune systemic disorder, associated with recurrent arterial and venous thrombosis and obstetric complications, in the presence of antiphospholipid antibodies. Either anti-cardiolipin, anti-[beta]2glicoprotein I (anti-[beta]2GpI) antibodies or the presence of the lupus anticoagulant phenomenon can be related to its pathogenesis. The clinical manifestations include skin disease, cardiac, pulmonary, renal and hematologic features, and neurologic involvement. A large number of neurologic manifestations has been described in association with APS. The most common and serious complication is stroke. Case reports and case series have pointed out the relationship between peripheral neuropathy syndromes, particularly Guillain-Barré, and APS. Studies on nerve conduction in APS are lacking. Their impact in the next classification of APS will depend on the development of appropriated clinical-epidemiologic studies.