Consideraciones anátomo-clínicas sobre el nervio radial en el codo / Anatomical and clinical considerations about the radial nerve in the elbow

El recorrido del nervio radial a través del codo constituye, para este elemento nervioso, un camino con riesgo de lesiones intrínsecas o extrínsecas. Cambios de la morfología de las estructuras osteomusculares que constituyen el desfiladero del nervio radial, tanto patológicos como traumáticos, pueden determinar el atrapamiento y compresión del mismo, determinando el daño del nervio y/o la inflamación localizada a nivel de las estructuras circundantes. Mediante la disección de 30 preparados, formolizados al 10 por ciento, y el análisis subsecuente de la disposición de las estructuras musculares e inserción de las mismas, se determinaron los posibles puntos de riesgo anatómico que pudiesen alterar al nervio radial o a sus ramos en la canal bicipital lateral o en su ingreso y distribución en el parte proximal del antebrazo (relación con el músculo supinador y los músculos extensores radial largo y corto). Definimos 4 zonas de posible atrapamiento y compresión del nervio radial y sus ramos: 1. Septo intermuscular lateral. 2. Músculo extensor radial corto. 3. Músculo supinator, a nivel de la Arcada de Frohse. 4. Músculo supinator, a la salida de la masa muscular, en el dorso del antebrazo. La compresión del nervio radial a nivel del codo es una de las neuropatías del miembro superior, más frecuentes. El objetivo de este trabajo fue analizar las implicancias anatómicas del recorrido del nervio radial en su pasaje desde el brazo al antebrazo, especialmente las relaciones con las estructuras osteomusculares, cuyas alteraciones pueden ser las responsables de patologías compresivas del nervio radial que puedan llevar a dolor, parestesias, con o sin pérdida sensorial y/o impotencia funcional.

The radial nerve route through elbow constitutes, for this nervous element, a way with risk of intrinsic or extrinsic injuries. Morphologic changes of the structures that constitute the denle of the radial nerve, pathological as much traumatic, can determine it atrapment and compression, determining the damage of the nerve and/or the inflammation located at level of the surrounding structures. 30 forearm-elbow, preserved with formol to 10 percent, were dissected, and the subsequent analysis of the disposition of the muscular structures and insertion of the same ones, will determine the possible points of anatomical risk that they will affect the radial nerve or its branches in the brachial track or in the proximal forearm (relation with the supinator muscle and extensor carpi radialis longus and brevis muscles).We defined 4 zones of atrapment and compression of the radial nerve and its branches: 1. External intermuscular setum; 2. Extensor carpi radialis brevis muscle; 3. Supinator muscle , atlevelof theFrohse's Arch;4. Supinator muscle, when coming out of the muscular mass, in the back of the forearm. The compression of the radial nerve at level of the elbow is one of the frequent neuropathies of the superior member. It is for that reason that the objective of this work consists of analyzing the anatomical aspects of the route of the radial nerve in its passage from the arm to the forearm, specially relations with morphological structures, whose alterations determines pathologies of the radial nerve which can take to pain, parestesies, with lost sensorial and functional impotence.

Neuropatías por Atrapamiento / Entrapment neuropathies

Nerve entrapment and compression produce a pathology known as mononeuropathy, which consists in the isolated affectation of a peripheral nerve due to mechanical forces that act on themselves for a prolonged period. Neuropathies by entrapment affect diverse nerves along its path. The most frequent points of entrapment are – in the upper limbs – the path along the carpal tunnel for the median nerve, and the cubital channel at the level of the elbow for the cubital nerve. Diagnosis of these pathologies is based fundamentally on clinical and electrodiagnostic studies. Each one of the phases of the nerve entrapment lesion has its classification in the neurophysiological study, starting with a focal slowing of conduction (due to focal demyelinization), followed by a blocked nerve conduction and temporal dispersion through the compression site and, in later stages, the electromyography shows signs of denervation of the distal muscles (axonal damage).

[Evaluation of neurotoxic effects of lead acetate on rat radial nerve]

Lead toxicity is a common popular problem. Many researches were performed about this toxicity both in-vivo and in-vitro since 100 years ago.Those studies showed that lead have toxic effects such as behavioral disorders, decrease of IQ and decrease of learning and memory. Also lead has neurotoxic effects such as decrease of neuronal density in visual cortex of monkey, cell death in hippocampus and decrease of acetylcolin in rat's hippocampus. In this study we examin neurotoxic effects of lead on rat's radial nerve because radial nerve is a mix nerve. 24 adult male rats were divided in six groups. Groups I and II received lead acetate 4% and 2%, groups III and IV received distilled water and normal water for one month. After this time, we killed rats and exposed radial nerve from behind of arm. Then studied them with light and electron microscopy. In experimental groups we saw decrease of myelin sheath diameter and decrease of nuclear density in schwann cell. Also we saw many granules in mitochondrial matrix, active macrophage, edema and disarrangement of myelin sheath layers. We suggest that lead neurophaty is due to schwann cell injury and this lesion lead to decrease of myelin sheath

Reaçäo hansênica tipo I na hanseníase borderline tuberculóide durante a poliquimioterapia: época de aparecimento e nervos acometidos / Type I reaction in borderline tuberculoid leprosy under multidrug therapy: time of onset and nerves affected

FUNDAMENTOS - A reaçäo tipo I é pouco estudada na literatura. OBJETIVOS - Descrever a época de aparecimento da reaçäo tipo 1 e os nervos acometidos, nos pacientes portadores de hanseníase borderline tuberculóide (BT), durante a poliquimioterapia(PQT). PACIENTES E MÉTODOS - Estudo longitudinal realizado no Ambulatório de Dermatologia da Faculdade de Medicina da UFMG. Setenta e um pacientes com hanseníase BT foram incluídos no estudo de agosto de 1989 a agosto de 1993. RESULTADOS - 89,3 por cento dos pacientes hansenianos BT com reaçäo tipo 1 apresentaram esse surto atá a sexta dose de tratamento. O nervo ulnar foi o mais acometido nas reaçöes tipo 1 (37,0 por cento). CONCLUSÃO - A reaçäo tipo 1 nos pacientes hansenianos BT ocorre mais frequentemente até a sexta dose de PQT. O nervo ulnar foi o mais acometido

Exame palpatório de nervos periféricos (espessados na hansenáse) e suas vias anatômicas / Palpations of peripheral nerves (thickened in leprosy) and their anatomical pathways

Este trabalho demonstra, por meio de dissecçäo, o trajeto superficial dos nervos comprometidos na hanseníase. Nessa doença, as lesöes ocorrem com mais frequência em determinados nervos que, nesses casos, se tornam mais espessos do que o normal. Esses nervos específicos säo superficiais em alguma parte de seus trajetos anatômicos e, aí, mais facilmente palpáveis

Treatment of radial neuropathy associated with fracture humerus

Twelve humeral shaft fractures with associated radial nerve injuries in twelve patients, with adequate follow-up were seen over a period of three years. Initial treatment was closed reduction and plaster fixation in eleven patients. Two of the twelve patients were treated by delayed exploration at ten and twelve weeks. All patients had complete recovery of radial nerve functions. We recommend careful observation for return of radial nerve functions, and exploration at twelve weeks after injury if there is still no clinical or electromyographic evidence of recovery at that time