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Resumen Introducción. La cirugía de síndrome del túnel del carpo (STC) es efectiva, aunque algunos reportes muestran satisfacción de solo el 75% luego de los procedimientos. La escala funcional histórico-objetiva (HiOb) es la que mejor se correlaciona con el estado neurofisiológico del nervio mediano. Objetivo. Determinar los resultados clínicos, funcionales y electrofisiológicos luego de una liberación quirúrgica en pacientes con STC. Materiales y métodos. Estudio analítico y descriptivo de pacientes con STC operados entre 2013 y 2014. Todos los individuos tenían pruebas clínicas y electrofisiológicas pre y post quirúrgicas. Resultados. Se estudiaron 36 pacientes con edad promedio de 49 años; los signos clínicos prequirúrgicos más frecuentes fueron Phalen y elevación de manos (91%). El seguimiento mínimo fue 6 meses. Hubo mejoría del dolor; de los signos de Tinel, de Phalen y de elevación de manos; en la escala HiOb, y en el Cuestionario de Boston, tanto en la función como en los síntomas. Los resultados electrofisiológicos mostraron mejoría en latencia distal motora del nervio mediano, latencia distal sensitiva del nervio mediano y delta sensitivo. Conclusiones. La liberación quirúrgica del STC es un procedimiento eficaz en la mejoría del dolor, los síntomas, las escalas funcionales y los hallazgos electrofisiológicos. El signo de Tinel prequirúrgico se asocia a peores resultados en el cuestionario de Boston. Abstract Introduction: Carpal tunnel release surgery is effective, although some reports show a satisfaction level of only 75% after surgery. The functional historical-objective scale (HiOb) is the one that best correlates with the neurophysiological state of the median nerve. Objective: To determine clinical, functional and electrophysiological outcomes following surgical release in patients with carpal tunnel syndrome. Materials and methods: Analytical and descriptive study of patients with carpal tunnel syndrome who underwent surgery between 2013 and 2014. All individuals underwent pre- and postoperative clinical and electrophysiological testing. Results: 36 patients with an average age of 49 years were studied; the most frequent preoperative clinical signs were Phalen's test and hand elevation (91%). The minimum follow-up time was 6 months. There was improvement in pain; in the signs of Tinel's, Phalen's and hand elevation; in the HiOb scale, and in the Boston Questionnaire, both in terms of function and symptoms. Electrophysiological results showed improvement in distal motor latency of the median nerve, distal sensory latency of the median nerve, and delta sensory latency. Conclusions: Carpal tunnel release surgery is an effective procedure to improve pain, symptoms, functional scales and electrophysiological findings. Tinel's preoperative sign is associated with worse outcomes in the Boston questionnaire.

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.

RESUMEN Objetivo Determinar la confiabilidad entre dos observadores y el cambio mínimo detectable de los estudios de neuroconducción para diagnosticar el síndrome de túnel carpiano. Métodos Se estudiaron 69 pacientes remitidos para estudio electrofisiológico por sospecha de síndrome de túnel carpiano. A los pacientes, se les realizaron dos exámenes, dos días diferentes, por dos evaluadores. Se evaluaron las latencias sensitivas y motoras de los nervios mediano y cubital; todos fueron clasificados como negativos, incipientes, leves, moderados, severos o extremos. Se calculó la variación relativa entre ensayos, el coeficiente de correlación intraclase, el índice de kappa, el límite de acuerdo y el cambio mínimo detectable. Resultados La variación relativa entre ensayos de la latencia motora del nervio mediano fue de -6,8 % a 15,9 % con coeficiente de correlación intraclase de 0,98 para la diferencia con la latencia del nervio cubital. El cambio mínimo detectable fue de 0,4ms. La variación relativa entre ensayos de la latencia sensitiva del nervio mediano fue -5,0 % a 11 % con coeficiente de correlación intraclase de 0,95 para la diferencia con el nervio cubital. El cambio mínimo detectable fue de 0,2ms. La clasificación ele trofisiológica coincidió en 93 % de los casos, índice de kappa de 0,89. Conclusiones Las latencias sensitivas y motoras del nervio mediano así como la diferencia de estas con el nervio cubital son medidas confiables. El cambio mínimo detectable obtenido en nuestro estudio le sirve al clínico para establecer si los cambios de las latencias en estudios consecutivos o después del tratamiento son significativos. ABSTRACT Objective To determine the reliability of neuroconduction studies by comparing two observers and detecting minimum changes when diagnosing carpal tunnel syndrome. Methods Sixty-nine patients referred for electrophysiological study due to suspected carpal tunnel syndrome were studied. The patients underwent two examinations, performed by two evaluators, on two different days. Sensory and motor latencies of the median and ulnar nerves were evaluated; all were classified as negative, incipient, mild, moderate, severe or extreme. Relative interval variation, intraclass correlation coefficient, kappa index, limit of agreement and minimum detectable change were estimated. Results The relative variation of motor nerve latency of the median nerve was -6.8% to 15.9%, with intraclass correlation coefficient of 0.98 for the difference of median-ulnar nerve latency. The minimum detected change was 0.4ms, while the relative interval variation of sensory latency of the median nerve was -5.0% to 11%, with intraclass correlation coefficient of 0.95 for difference with the ulnar nerve. The minimum detectable change was 0.2ms. Electrophysiological classification agreed in 93% of the cases, with a kappa index of 0.89. Conclusions Sensory and motor latencies of the median nerve, as well as the difference between them and the ulnar nerve, are reliable measures. The minimum detectable change obtained in our study helps clinicians to establish whether changes in latencies in consecutive or post-treatment studies are significant.

Introduction: Central areolar choroidal dystrophy (CACD) is a rare, inherited disease that can lead to profound visual disturbance. It is characterized by atrophic changes, particularly in the macula. Specific genotypic mutations are responsible for the autosomal dominant form of this disease. However, there is a distinct retinal dystrophy that combines central areolar choroidal dystrophy with autosomal dominantly inherited drusen. It has been proposed that patients with a specific mutation in the peripherin/RDS gene may manifest a combined presentation. Case report: Here we describe a case of a patient who reported with significantly decreased best-corrected visual acuity of fifteen years of duration in the right eye more than the left. Dilated fundus examination found macular changes that were consistent with central areolar choroidal dystrophy. In addition, there was evidence of surrounding congenital drusen throughout the arcades of both eyes. Electrodiagnostics, optical coherence tomography, and fundus fluorescein angiography were used to confirm the diagnosis of CACD. Conclusion: Central areolar choroidal dystrophy normally presents without drusen. However, in patients manifesting a specific mutation, central areolar choridal dystrophy may present in conjunction with drusen. It appears that the Arg142Trp mutation is one of the factors predisposing to drusen formation.

El síndrome de Guillain Barré es una poliradiculoneuropatía aguda con varias formas de presentación y actualmente la principal causa de parálisis aguda arrefléctica en el mundo, su diagnóstico es clínico y los exámenes de apoyo como el electrodiagnóstico son utilizados para realizar el diagnóstico diferencial, clasificar entre las distintas variantes (desmielinizantes o axonales) y definir pronóstico. El propósito de este trabajo es realizar una revisión narrativa de la literatura disponible, haciendo énfasis en el estudio electrofisiológico, hallazgos precoces y describir los errores más frecuentes, como también destacar la importancia de realizar la clasificación del cuadro para orientar las acciones de rehabilitación hacia la recuperación funcional.

Objetivo: Establecer valores normales de referencia de latencias distales motoras y sensitivas de los nervios mediano y ulnar para el diagnóstico electrofisiológico de síndrome de túnel del carpo (STC) teniendo en cuenta las características demográficas de nuestro medio. Métodos Se realizaron estudios de neuroconducción sensitiva y motora de los nervios mediano y ulnar en 184 individuos asintomáticos (rango de edad 18 a 75 años). Con los resultados se construyeron tablas de referencia con promedios, desviaciones estándar y percentiles y se compararon con edad, género, talla y peso. Resultados:Para el nervio mediano se encontró una latencia motora distal y sensitiva al pico promedio de 3.4 ms (DE=0.4) y 3.1 ms (DE=0.3), respectivamente (prueba convencional). La diferencia de la latencia motora mediano-ulnar fue de 0.8 ms (DE=0.3); la diferencia de la latencia sensitiva mediano-ulnar al pico fue de 0.08 ms (DE=0.2) (prueba convencional). La latencia motora y sensitiva del nervio mediano mostró una correlación positiva con la edad y la talla. Conclusiones: Aunque los resultados de este estudio tienen un alcance limitado y preliminar por el tipo y tamaño de muestra utilizado, éstos muestran algunas diferencias con los datos obtenidos en investigaciones de otros países y sirven como una primera guía para el diagnóstico de STC en un laboratorio de electrofisiología en nuestro medio.

A method by which ocular artefacts (OAs) in the electroencephalogram (EEG) may be removed automatically online by electro-oculogram (EOG) subtraction is demonstrated. This is achieved by a combination of recursively calculating the required cross-correlations, a fast matrix inversion method, and the use of a modern microprocessor with a high clock rate. Although recursive calculations are involved, the method itself is essentially non-recursive, which means that distortion of any evoked potentials is minimised. The method may be applied simultaneously to any number of EEG channels.