Guía para la realizacion de bloqueos de nervio periferico

Los avances tecnológicos y el desarrollo de las diferentes técnicas de anestesia regional; bloqueos de nervio periférico, han permitido el crecimiento de esta área expandiendo su uso a otros escenarios. El presente documento es una guía para su adecuada realización y busca incrementar la seguridad en una técnica que cada día tiene más adeptos. Es necesario conocer los principios fisiológicos de la neuroconducción y el funcionamiento del estimulador de nervio periférico, al igual que la anatomía de troncos y nervios periféricos, hecho que conducirá a un mejor aprendizaje de las técnicas de abordaje. El presente documento espera disminuir la presentación de complicaciones en esta técnica anestésica.Materiales y métodos: Búsqueda de literatura en las bases de datos referenciales de PubMed, Cochrane, Scielo, LILACS y se Amplio según la bibliografía encontrada en los artículos revisados por los autores; la búsqueda fue hecha en términos MeSH incluidos en las palabras claves. El Propósito de esta revisión es dar pautas generales fáciles de entender en la realización de bloqueos de nervio periférico, permitiendo su realización adecuada y segura.

Validación diagnóstica del test neural 1 para el síndrome de túnel del carpo

El objetivo de este estudio fue realizar una prueba de validez diagnostica del test neural 1 para el diagnóstico del Síndrome de Túnel del Carpo (STC) utilizando como prueba de referencia o de oro el test de conducción nerviosa. En este estudio participaron 115 sujetos, 230 manos con sospecha clínica de STC quienes fueron evaluados con el test de conducción nerviosa y el test neural 1. Se encontró una sensibilidad del 93.0% (IC 95%:88,21-96,79) y una especificidad del 6,67% (IC 95%:0,0-33,59), razón de verosimilitud positiva fue de 1,00 y razón de verosimilitud negativa de 1,05. Valor predictivo positivo de 86,9% y un valor predictivo negativo de 12,5%. Se concluye que el test neural 1 es una prueba clínica de alta sensibilidad y baja especificidad de gran utilidad para el monitoreo e identificación del STC. Es un procedimiento para el diagnóstico clínico de bajo costo que puede incluirse en los exámenes de rutina de los trabajadores como complemento a las pruebas clínicas sugeridas por las Gatiso para dar mayor precisión a la identificación temprana del STC. Se sugiere combinarla con otros test de mayor especificidad para ser aplicada en trabajadores en condiciones de riesgo o que presenten síntomas en miembros superiores y realizar otros estudios en donde participen sujetos sin diagnóstico clínico del STC.

Achados audiológicos e eletrofisiológicos de indivíduos com a síndrome G/BBB

A síndrome G/BBB é uma condição rara, caracterizada por hipertelorismo, fissura de lábio e palato e hipospádia. Não foram encontrados trabalhos sobre a audição em indivíduos com esta síndrome. OBJETIVO: Investigar a função auditiva em pacientes com síndrome G/BBB quanto à ocorrência ou não de perda auditiva e a condução nervosa auditiva periférica e central. MATERIAL E MÉTODO: Catorze pacientes de 7 a 34 anos, do gênero masculino, com a síndrome G/BBB, foram avaliados por meio de otoscopia, audiometria, timpanometria e potenciais evocados auditivos de tronco encefálico (PEATE). Forma de Estudo: Estudo de série clínico prospectivo. RESULTADOS: Limiares audiométricos normais em 12 (66,7%) pacientes da amostra e alterados em dois (33,3%), sendo um com perda condutiva e um neurossensorial. Quanto ao PEATE, foram encontrados: latências absolutas da onda I normais em todos os pacientes, aumento das latências absolutas da onda III e V em dois e seis pacientes respectivamente; latências interpicos I-III, III-V e I-V aumentadas em quatro, três e oito pacientes, respectivamente. CONCLUSÃO: Perdas auditivas periféricas podem ocorrer na síndrome G/BBB. Há evidências de comprometimento das vias auditivas centrais em nível do tronco encefálico. Estudos com exames de imagem são necessários para maior clareza dos achados clínicos.

Electromyographical, ultrasonographical and morphological modifications in semitendinous muscle after transposition as ventral perineal muscle flap

The aim of this study was to evaluate modifications occurring in semitendinous muscle after transposition as a ventral perineal muscle flap using electromyography, ultrasonography, and morphological studies. Ten male crossbreed dogs of 3-4 year old were used. The left semitendinous muscle was cut close to the popliteus lymph node, rotated and sutured at the perineal region. The contralateral muscle was considered as control. Motor nerve conduction studies of both sciatic-tibial nerves, and electromyographic and ultrasonographic examinations of both semitendinous muscles were performed before surgery and 15, 30, 60, and 90 days postoperatively. Semitendinous muscle samples were collected for morphological analysis 90 days after surgery. No alterations were observed in clinical gait examinations, or in goniometrical and electroneuromyographical studies in pelvic limbs after surgery. Electromyography demonstrated that the transposed muscle was able to contract, but atrophy was detected by ultrasonography and morphological analysis.

Ação neuro-muscular do veneno crotálico: dados preliminares

Estudamos 6 pacientes, 2 cães e um coelho com intoxicação crotálica. Avaliamos a condução nervosa periférica sensitiva e motora, a transmissão neuromuscular e eletromiografias. As biópsias de músculo foram processadas por histoquímica. Os 6 pacientes apresentaram mononeuropatia sensitiva no nervo periférico adjacente ao local da inoculação do veneno e encontramos evidências histoquímicas de miopatia mitocondrial. Os defeitos da transmissão neuromuscular foram mínimos. A maioria dos autores admite que veneno crotálico determina síndrome miastênica. Nossos achados indicam que ptose palpebral, facies miastênico e fraqueza muscular observados após acidente crotálico, correspondem provavelmente a miopatia mitocondrial, muitas vezes transitória e reversível.

Lumbar muscles recruitment during resistance exercise for upper limbs

The aim of this study was to evaluate the EMG activity of lumbar multifidus (MU), longissimus thoracis (LT) and iliocostalis (IC) muscles during an upper limb resistance exercise (biceps curl). Ten healthy males performed maximal voluntary isometric contraction (MVC) of the trunk extensors, after this, the biceps curl exercise was executed at 25%, 30%, 35% and 40% one repetition maximum during 1 min, with 10 min rest between them. EMG root mean square (RMS) and median frequency (MFreq) were calculated for each lifting and lowering of the bar during the exercise bouts, to calculate slopes and intercepts. The results showed increases in the RMS and decreases in the MFreq slopes. RMS slopes were no different between muscles, indicating similar fatigue process along the exercise irrespective of the load level. MU and LT presented higher RMS irrespective of the load level, which can be related to the specific function during the standing position. on the other hand, IC and MU presented higher MFreq intercepts compared to LT, demonstrating possible differences in the muscle fiber conduction velocity of these muscles. These findings suggest that trunk muscles are differently activate during upper limb exercises, and the fatigue process affects the lumbar muscles similarly. (C) 2008 Elsevier Ltd. All rights reserved.

Silent period in carpal tunnel syndrome

The silent period is a misunderstood electrophysiological phenomenon leading to several different hypotheses explaining its electrogenesis. It has been studied by different authors and different methodologies giving a wide variability of results, therefore an exact pattern of its normal values does not exist. This work was undertaken to define the normal morphology and duration of the silent period obtained by supramaximal stimulus of the median nerve, during maximum isometric effort of the abductor pollicis brevis muscle against resistance, using 20 adult volunteers without neurological alterations. The normal median duration was 104.6 milliseconds. The same methodology was applied to 20 hands from 20 patients with carpal tunnel syndrome. The silent period showed many types of morphological alterations, but the major alteration observed was a tendency to temporal elongation. No correlation between the severity of the carpal tunnel syndrome and the silent period alterations were observed.

Effects of ethanol on human visual evoked potentials

Studies of the effect of ethanol on human visual evoked potentials are rare and usually involve chronic alcoholic patients. The effect of acute ethanol ingestion has seldom been investigated. We have studied the effect of acute alcoholic poisoning on pattern-reversal visual evoked potentials (PR-VEP) and flash light visual evoked potentials (F-VEP) in 20 normal volunteers. We observed different effects with ethanol: statistically significant prolonged latencies of F-VEP after ingestion, and no significant differences in the latencies of the PR-VEP components. We hypothesize a selective ethanol effect on the afferent transmission of rods, mainly dependent on GABA and glutamatergic neurotransmission, influencing F-VEP latencies, and no effect on cone afferent transmission, as alcohol doesn't influence PR-VEP latencies.

The silent period in patients with chronic renal failure undergoing hemodialysis

Silent period was evaluated in 20 adult male patients with chronic renal failure undergoing hemodialysis. Readings were obtained by supramaximal stimulus to the median nerve, during maximum isometric effort of the abductor pollicis brevis muscle against resistance. Two types of abnormalities were observed, motor neuron hypoexcitability with elongated silent period, and motor neuron hyperexcitability with reduction or absence of silent period. Some abnormalities are probably linked with dialysis duration, but show no correlation to presence or absence of peripheral neuropathy. The silent period alterations described in this study could possibly correlate with some other clinical feature frequently seen in patients with chronic renal failure such as hypereflexia of the deep tendon reflexes.

The natural history of carpal tunnel syndrome: A study of 20 hands evaluated 4 to 9 years after initial diagnosis

Carpal tunnel syndrome (CTS) is the most frequent entrapment neuropathy. In the last decade several papers have been published on epidemiology, clinical aspects, diagnosis, and treatment, but little is known about its natural history. The objective of this work was to study the natural history of CTS syndrome. From 358 patients with clinical and conduction study diagnosis of CTS, 12 cases were identified that had refused surgical treatment, had not used anti-inflammatory medications, and had not undergone orthopaedic procedures, such as immobilization or anaesthetic infiltration. These 12 patients have 20 compromised hands which have been followed up for between 4 and 9 years. In all cases sensory and motor conduction studies were performed on the median nerve, at the beginning and end of follow-up period. Electrical improvement was marked in 5 hands and slight in 3; there was no significant change in 10, and deterioration in 2. As 8 hands (7 patients) showed improved clinical symptoms and conduction studies over several years, this brings the universally accepted procedure of surgical treatment into doubt.

Estudo comparativo experimental da injeção perineural do álcool benzílico 0,75% e do álcool etílico absoluto nos nervos palmares de eqüinos

The clinical and histopathological effects of two alcoholic neurolytics were studied in horses. Normal horses were shod with a designed shoe adaptted with 5 screws to produce solar pain. After gait and lameness score analysis, the palmar nerve of 5 horses was injected with 5 ml of 0,75% benzyl alcohol (Group A) and 5 horses were injected with 5 ml of absolute ethyl alcohol (Group B). The animals were submitted to regular lameness evaluation and solar sensibility tests during next six months. The solar sensitivity returned 5 months latter in the group injected with benzyl alcohol 0,75%, while in the group injected with absolute ethyl alcohol, the sole was still desensitized 6 months latter. The histopathological findings showed that the nerve injected with benzyl alcohol 0,75%, resulted in axonotmesis, characterized by axonal nerve degeneration, with possibilities for the nerve conduction recovery. The perineural injection of ethyl alcohol absolute, resulted in neurotmesis with difficult nerve regeneration. It was concluded that chemical neurolysis with alcohol is an option for temporary or permanent nerve blocks in horses.

A importância das informações aferentes podais para o controle postural

Introduction. The postural control involves a complex mechanism for connecting the afferent and efferent pathways and their integration into the central nervous system (CNS). Three systems are responsible to obtain outside information: visual, vestibular and sensory. Recent studies have shown that among such systems, the CNS shows a greater predilection for sensory information to postural control. Objective. Given this, the review proposes to discuss the feet sensory information importance and its reflection in postural control mechanisms. Method. For this reason, a literature search was carried out by PubMed and Bireme libraries, and papers of the last five years were selected. Specific books were also used. Discussion. Studies were separated into topics on sensory information integration to neuro-motor answer, postural feed-forward adjustments recruitment mechanisms; neuro-muscular coordination and synergy responses and the musculoskeletal tissues role. Conclusion. Despite has been found a large number of studies, the real mechanism that the CNS uses to filter, integrate and process the sensory information and select the appropriate motor response, be it for the movement or posture for the stabilization remains obscure.

Mechanisms in the bed nucleus of the stria terminalis involved in control of autonomic and neuroendocrine functions: A review

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Commissural nucleus of the solitary tract regulates the antihypertensive effects elicited by moxonidine

The rostral ventrolateral medulla (RVLM) contains the presympathetic neurons involved in cardiovascular regulation that has been implicated as one of the most important central sites for the antihypertensive action of moxonidine (an α2-adrenergic and imidazoline agonist). Here, we sought to evaluate the cardiovascular effects produced by moxonidine injected into another important brainstem site, the commissural nucleus of the solitary tract (commNTS). Mean arterial pressure (MAP), heart rate (HR), splanchnic sympathetic nerve activity (sSNA) and activity of putative sympathoexcitatory vasomotor neurons of the RVLM were recorded in conscious or urethane-anesthetized, and artificial ventilated male Wistar rats. In conscious or anesthetized rats, moxonidine (2.5 and 5. nmol/50. nl) injected into the commNTS reduced MAP, HR and sSNA. The injection of moxonidine into the commNTS also elicited a reduction of 28% in the activity of sympathoexcitatory vasomotor neurons of the RVLM. To further assess the notion that moxonidine could act in another brainstem area to elicit the antihypertensive effects, a group with electrolytic lesions of the commNTS or sham and with stainless steel guide-cannulas implanted into the 4th V were used. In the sham group, moxonidine (20. nmol/1. μl) injected into 4th V decreased MAP and HR. The hypotension but not the bradycardia produced by moxonidine into the 4th V was reduced in acute (1. day) commNTS-lesioned rats. These data suggest that moxonidine can certainly act in other brainstem regions, such as commNTS to produce its beneficial therapeutic effects, such as hypotension and reduction in sympathetic nerve activity. © 2013 IBRO.

Dessensibilização dos nervos palmares em eqüinos: estudo comparativo experimental do álcool benzílico 0,75% e álcool etílico absoluto (95,5% PA)

Pós-graduação em Medicina Veterinária - FMVZ