Meralgia parestésica / Meralgia paresthetica

Fundamento: la meralgia parestésica es una mononeuropatía por atrapamiento que genera dolor, parestesias y pérdida de la sensibilidad en el territorio del nervio cutáneo lateral del muslo. Objetivo: profundizar y actualizar los aspectos más importantes de la meralgia parestésica. Métodos: se realizó una revisión de la literatura en idioma español e inglés disponible en PubMed Central, Hinari y SciELO. Para ello se utilizaron los siguientes descriptores: meralgia paresthetica, mononeuropathy, lateral cutaneous nerve of the thigh. A partir de la información obtenida se realizó una revisión bibliográfica de un total de 107 artículos publicados, incluídas 34 citas seleccionadas para realizar la revisión, de ellas 24 de los últimos cinco años.Desarrollo: se insistió en aquellos tópicos controversiales dentro del tema como son: reseña anatómica, factores etiológicos, presentación clínica, estudios complementarios y tratamiento. Conclusiones:la meralgia parestésica es un reto médico, debido a que puede simular enfermedades comunes como los desordenes lumbares. Es una enfermedad autolimitada cuyo diagnóstico se realiza con un alto índice de sospecha basado en el conocimiento adecuado de la anatomía, la fisiopatología, los factores etiológicos y los elementos clínicos. El tratamiento, aunque con falta de consenso, ofrece resultados favorables en la mayoría de los pacientes(AU)

Background: meralgia paresthetica is an entrapment mononeuropathy which cause pain, paresthesias and sensory loss within the distribution of the lateral cutaneous nerve of the thigh. Objective: to update and to deepen in the most important aspects of meralgia paresthetica.Methods: a revision of the literature was made in English and Spanish, available in PubMed Central, Hinari and SciELO. The following descriptors were used: meralgia paresthetica, mononeuropathy, lateral cutaneous nerve of the thigh. Base on the obtained data, a bibliographic revision was made of 107 published articles, including 34 cites selected for the research, 24 of them of the last five years.Development: it was focus in those controversial topics like: anatomic characteristics, etiological factors, clinical presentation, complementary studies and treatment. Conclusions: meralgia paresthetica is a medical challenge; due to it can simulate common illness like lumbar disorders. It is a self limited disease which is diagnosed basing on a high suspicious index with an adequate knowledge of the anatomy, physiopathology, etiological factors and clinical elements. The treatment, although with lack of consensus, offers favorable results in most of the patients(AU)

Electrodiagnostic evaluation of compressive nerve injuries of the upper extremities.

Electrodiagnostic testing includes electromyography and nerve conduction studies that are physiologic tests used in the diagnosis of peripheral nerve injuries. It is a supplement rather than a replacement for a physical examination. This article reviews the terminology as well as the findings seen and used in electrodiagnostic studies. Common compression nerve injuries including the median, ulnar, radial, axillary, and suprascapular nerves and their electrical findings are reviewed.

Diabetic neuropathies. Classification, clinical features, and pathophysiological basis.

Diabetes mellitus is associated with a wide spectrum of neuropathy syndromes, ranging from a mild asymptomatic distal sensory neuropathy to a severe disabling radiculoplexus neuropathy. As the pathophysiology of these separate conditions is better understood, classification of the various phenotypes becomes important because of treatment implications. Here we provide a short summary of the history of the classification of diabetic neuropathies and try to describe the most common forms classified according to their presumed pathophysiology. We have tried to include epidemiological data where available, as well as histopathology of nerve in several diabetic neuropathies.

The clinical picture of neuropathic pain.

Neuropathic pains refer to a heterogeneous group of pain conditions characterised by lesion or dysfunction of the normal sensory pathways. Clinical characteristics include: delayed onset of pain after nervous system lesion, pain in area of sensory loss, spontaneous and different evoked types of pains. It has so far only been possible to classify these pains on basis of underlying cause or on anatomical location. The mechanisms underlying neuropathic pain are not yet clear, but neuronal hyperexcitability in those neurons that have lost their normal patterned input seems to be a common denominator for many, if not all types, of neuropathic pains. Along these lines, a mechanism-based classification has recently been proposed, which is an attractive approach because it provides a frame for a rationally based therapy of neuropathic pains. The clinical manifestations of neuronal hyperexcitability due to nervous system lesions is described.

Neuropathic pain: a possible role for the melanocortin system?

In humans, damage to the nervous system can lead to a pain state referred to as neuropathic pain. Here, we give a short overview of the clinical picture and classification of neuropathic pain and highlight some of the currently known pathophysiological mechanisms involved, with special emphasis on neuropeptide plasticity. In this context, we discuss a specific group of neuropeptides, the melanocortins. These peptides have been demonstrated to play a role in nociception and to functionally interact with the opiate system. Recently, we demonstrated that spinal melanocortin receptors are upregulated in a rat model of neuropathic pain and that blockade of the melanocortin MC(4) receptor has anti-allodynic effects in this condition, suggesting that the melanocortin system plays a role in neuropathic pain. A natural agonist of melanocortin receptors is alpha-melanocyte-stimulating hormone (alpha-MSH), derived from the precursor molecule pro-opiomelanocortin (POMC). Cleavage of this precursor also yields beta-endorphin, which is co-released with alpha-MSH in nociception-associated areas of the spinal cord. We hypothesise that melanocortin receptor blockade attenuates a tonic influence of alpha-MSH on nociception, thus allowing the analgesic effects of beta-endorphin to develop, resulting in the alleviation of allodynia. In this way, treatment with melanocortin receptor antagonists might enhance opioid efficacy in neuropathic pain, which would be of great benefit in clinical practice.

Mononeuropathy multiplex (AAEE case report #11).

Mononeuropathy multiplex is a syndrome of diverse causes, the most common of which is nerve ischemia due to microangiopathy associated with diabetes or the collagen-vascular diseases. The acquired inflammatory demyelinating neuropathies invariably are multifocal, although the clinical manifestations of these and other multifocal neuropathies may appear symmetrical. The identification of multifocal neuropathies is important because of the frequent therapeutic implications. A case of mononeuropathy multiplex associated with polyarteritis nodosa is described.