The overall distribution pattern of the hand's cutaneous nerves and its clinical implications in sensory reconstruction / Patrón de distribución general de los nervios cutáneos de la mano y sus implicancias clínicas en la reconstrucción sensorial

SUMMARY: The objective of this study was to reveal the overall distribution pattern of the hand's cutaneous nerves to provide a morphological basis for the selection and matching of the hand skin for sensory reconstruction during flap transplantation. The hands of 12 adult cadavers were used for the study. Palmar region and dorsum of the hand were divided into regions I-VI. The skin of the hand containing subcutaneous fat was removed close to the muscle surface. The modified Sihler's staining method was used to visualize the overall distribution pattern of the cutaneous nerves and the areas they innervate. The median nerve, superficial branch of the ulnar nerve, and the superficial branch of the radial nerve innervated 59.27 % (containing 4.65 % of the palmar cutaneous branch of the median nerve), 36.91 %, and 3.82 % of the palm area, respectively. The superficial branch of the radial nerve, the dorsal branch of the ulnar nerve, and the median nerve innervated 45.16 %, 47.25 %, and 7.59 % of the hand's dorsal skin area, respectively. Communication was found between the arborized branches of these cutaneous nerves. Region III of the palm and region VI of the dorsum of the hand had relatively more dense nerve distribution. Except for region V, the density of the total nerve branches in each palm region was higher than that of the dorsum of the hand. The total number of nerve branches in the distal phalanx and dorsum decreased from the thumb to the digitus minimus. Our results provide morphological guidance when designing a reasonable matching flap to improve the hand's sensory function reconstruction.

RESUMEN: El objetivo de este estudio fue revelar el patrón de distribución general de los nervios cutáneos de la mano y proporcionar una base morfológica para la selección y adaptación de la piel de la mano, para la reconstrucción sensorial durante el trasplante de colgajo. Para el estudio se utilizaron 12 manos de cadáveres adultos. Las regiones palmar y dorsal se dividieron en regiones I-VI. La piel de la mano que contiene grasa subcutánea se eliminó cerca de la superficie del músculo. Para visualizar el patrón de distribución general de los nervios cutáneos y las áreas que inervan se utilizó el método de tinción de Sihler modificado. El nervio mediano, la rama superficial del nervio ulnar y la rama superficial del nervio radial inervaban el 59,27 % (que contenía el 4,65 % de la rama cutánea palmar del nervio mediano), el 36,91 % y el 3,82 % del área de la palma, respectivamente. La rama super-ficial del nervio radial, la rama dorsal del nervio ulnar y el nervio mediano inervaban el 45,16 %, el 47,25 % y el 7,59 % del área dorsal de la mano, respectivamente. Se observó comunicación entre las ramas arborizadas de estos nervios cutáneos. La región III de la palma y la región VI del dorso de la mano tenían una distribución nerviosa relativamente más densa. A excepción de la región V, la densidad de las ramas nerviosas totales en cada región de la palma fue mayor que el dorso de la mano. El número total de ramas nerviosas en la falange distal y el dorso disminuyó desde el pulgar hasta el dedo mínimo. Nuestros resultados proporcionan una guía morfológica al diseñar un colgajo compatible razonable para mejorar la reconstrucción de la función sensorial de la mano.

Palmar cutaneous branch of median nerve: an anatomical study / Rama cutánea palmar del nervio mediano: un estudio anatómico

The purpose of this study was to determine the origin, frequency and anatomical variations of the palmar cutaneous branch of the median nerve (PCBMN) and its clinical implications in surgical procedures such as decompression of the carpal tunnel and volar approach to the wrist. Dissection of 30 forearms from 18 adult male specimens (9 bilateral, 7 right limbs and 5 left limbs) were performed using 2.5X magnification loupe in order to better understand the PCBMN. Origin, number, length, positioning, anatomical relations and variations were recorded and analyzed. The PCBMN was identified in all dissected forearms, being the most distal branch of the median nerve in all forearms. The average origin was 4.8 cm (ranging 3.8 to 6.5 cm) proximal to the wrist flexion crease. Anatomical variations of the PCBMN are not rare and could endanger the nerve during surgical approach for the volar wrist and proximal palm. We did not find the PCBMN positioned ulnar to the fourth metacarpal axis as well as radial to the flexor carpi radialis tendon.

El objetivo de este estudio fue determinar el origen, la frecuencia y las variaciones anatómicas de la rama cutánea palmar del nervio mediano (RCPNM) y sus implicaciones clínicas en procedimientos quirúrgicos como la descompresión del túnel carpiano y el abordaje palmar de la muñeca. Se realizó la disección de 30 antebrazos de 18 especímenes adultos de sexo masculino (9 bilaterales, 7 miembros derechos y 5 miembros izquierdos) utilizando una lupa de aumento de 2,5X para comprender mejor la RCPNM. Origen, número, longitud, posicionamiento, relaciones anatómicas y variaciones fueron registradas y analizadas. El RCPNM fue identificado en todos los antebrazos disecados, siendo la rama más distal del nervio mediano en todos los antebrazos. El origen promedio fue de 4,8 cm (rango de 3,8 a 6,5 cm) proximal al pliegue de flexión de la muñeca. Las variaciones anatómicas de la RCPNM no son raras y podrían poner en peligro el nervio durante el abordaje quirúrgico de la cara volar y palmar proximal de la muñeca. No encontramos el RCPNM posicionado a nivel ulnar del cuarto metacarpiano, así como radial al tendón del músculo flexor radial del carpo.

Pruritus in cholestasis / Prurido na colestase

Pruritus represents one of the main clinical complaints in medical practice, and leads to significant impairment of life quality and some discomfort. Although the knowledge of its main primary and secondary etiologies is well-established in Internal Medicine, especially in Hepatology, its pathophysiological basis and specific therapeutic-directed approaches are still very complex and need a proper systematization for comprehension. This review aims to present the main current themes regarding the main clinical, pathophysiological, therapeutical and management aspects of cholestasis-associated pruritus. METHODS: The authors performed a wide review of practical clinical guidelines, review articles and original articles from manuscripts published and indexed in PubMed. CONCLUSIONS: Pruritus in cholestasis represents a complex symptom in clinical practice and can be secondary to different pathophysiological mechanisms; its early recognition allows a proper therapeutic approach in most cases.

O prurido representa uma das principais queixas clínicas na prática médica e origina importante comprometimento da qualidade de vida, além de desconforto. Apesar de suas principais etiologias primárias e secundárias serem de conhecimento bem estabelecido na Clínica Médica, em especial na Hepatologia, suas bases fisiopatológicas e os princípios da terapêutica específica direcionada são bastante complexos e necessitam uma sistematização adequada para sua compreensão apropriada. Esta revisão objetiva abordar os principais temas atuais referentes às bases clínicas, fisiopatológicas, terapêuticas e de manejo do prurido relacionados à colestase. Os autores realizaram ampla revisão em diretrizes clínicas práticas, artigos de revisão e publicações originais de artigos publicados e indexados na base PubMed. O prurido na colestase representa um sintoma complexo na prática clínica e pode decorrer de diferentes mecanismos fisiopatológicos secundários. Seu reconhecimento precoce possibilita a abordagem terapêutica apropriada na maioria dos casos.

Bilateral triad of persistent median artery, a bifid median nerve and high origin of its palmar cutaneous branch: a case report and clinical implications / Tríada bilateral correspondiente a arteria mediana persistente, nervio mediano bífido y origen alto de la rama cutánea palmar: reporte de caso e implicancias clínicas

We report the association of a persistent median artery, a bifid median nerve with a rare very high origin palmar cutaneous branch, presenting bilaterally in the upper limb of a 75-year-old female cadaver. The persistent median nerve with a bifid median nerve has been reported in patients presenting with carpal tunnel syndrome. Reports of this neurovascular anomaly occurring in association with a high origin palmar cutaneous branch however, are few. This subset of patients is at risk of inadvertent nerve transection during forearm and wrist surgery. Pre-operative magnetic resonance imaging (MRI) and high resolution sonography (HRS) can be used to screen this triad. MRI can reveal if the patient's disability is associated with a persistent median nerve, a bifid median nerve. HRS can help identify a palmar cutaneous branch of the median nerve that arises in an unexpected high forearm location. Such knowledge will help surgeons in selecting the most appropriate surgical procedure, and help avoid inadvertent injury to cutaneous nerves arising in unexpected locations. In patients presenting with a bilateral carpal tunnel syndrome, hand surgeons should consider very high on the list of differential diagnosis a persistent median artery with a concomitant bifid median nerve, with a high suspicion of a possible bilateral occurrence of a bilaterally high arising palmar cutaneous branch of the median nerve.

En este estudio se presenta la disposición bilateral de una arteria mediana persistente, un nervio mediano bífido con ramo cutáneo palmar de origen alto, en los miembros superiores de un cadáver de sexo femenino de 75 años de edad. Clínicamente se asocia la presencia del nervio mediano bífido en pacientes con síndrome de túnel carpiano. Sin embargo, son escasos los informes de esta anomalía neurovascular en asociación con un ramo cutáneo palmar del nervio mediano de origen alto. Este subconjunto de pacientes podría sufrir de transección del nervio durante la cirugía de antebrazo y de la muñeca. Se recomienda utilizar la imagen preoperatoria de resonancia magnética (RM) y sonografía de alta resolución (SAR) para detectar esta tríada. La RM puede revelar si la discapacidad del paciente se asocia con un nervio mediano persistente, un nervio mediano bífido. SAR puede ayudar a identificar un ramo cutáneo palmar del nervio mediano que surge en una situación alta del antebrazo en forma inesperada. Tal conocimiento ayudará a los cirujanos en la selección del procedimiento quirúrgico más apropiado, y a evitar una lesión inadvertida de nervios cutáneos que surgen en lugares inesperados. En los pacientes que presentan un síndrome del túnel carpiano bilateral, los cirujanos de mano deben considerar como prioridad en la lista de diagnóstico diferencial una arteria mediana persistente con un nervio mediano bífido concomitante, con una alta sospecha de una posible aparición bilateral de un ramo cutáneo palmar bilateral alto que surja del nervio mediano.

Effectiveness of hip muscle strengthening in patellofemoral pain syndrome patients: a systematic review

Introduction: Patellofemoral pain syndrome (PFPS) is characterized by anterior knee pain, which may limit the performance of functional activities. The influence of hip joint motion on the development of this syndrome has already been documented in the literature. In this regard, studies have investigated the effectiveness of hip muscle strengthening in patients with PFPS. Objectives: The aims of this systematic review were (1) to summarize the literature related to the effects of hip muscle strengthening on pain intensity, muscle strength, and function in individuals with PFPS and (2) to evaluate the methodological quality of the selected studies. Method: A search for randomized controlled clinical trials was conducted using the following databases: Google Scholar, MEDLINE, PEDro, LILACS, and SciELO. The selected studies had to distinguish the effects of hip muscle strengthening in a group of patients with PFPS, as compared to non-intervention or other kinds of intervention, and had to investigate the following outcomes: pain, muscle strength, and function. The methodological quality of the selected studies was analyzed by means of the PEDro scale. Results: Seven studies were selected. These studies demonstrated that hip muscle strengthening was effective in reducing pain. However, the studies disagreed regarding the treatments' ability to improve muscle strength. Improvement in functional capabilities after hip muscle strengthening was found in five studies. Conclusion: Hip muscle strengthening is effective in reducing the intensity of pain and improving functional capabilities in patients with PFPS, despite the lack of evidence for its ability to increase muscle strength. .

Lesão de nervo cutâneo antebraquial lateral relacionada à venipuntura: o que saber? / Venipuncture-related lateral antebrachial cutaneous nerve injury: what to know? / Lesión del nervio cutáneo antebraquial lateral relacionada con la venopunción: ¿qué debemos saber?

Justificativa e objetivos: a venipuntura é um dos procedimentos mais comuns na prática anestésica cotidiana. Embora geralmente inócuas, lesões de nervos periféricos com sequelas graves foram descritas após venipuntura. Apresentamos um caso de lesão de nervo cutâneo antebraquial lateral relacionada à venipuntura, juntamente com as informações de diagnóstico e prognóstico essenciais para a prática cotidiana. Relato de caso: paciente do sexo masculino, 27 anos, submetido à venipuntura de fossa antecubital direita, com uma agulha de calibre 20, para avaliação metabólica de rotina. O paciente sofreu uma dor aguda, tipo choque elétrico, que percorreu a face lateral do antebraço desde a fossa antecubital proximal até o pulso lateral direito e a base do polegar direito. Após 24 horas, o paciente ainda sentia a dor semelhante a choque elétrico que foi classificada como 8/10 no braço distal lateral direito, no pulso lateral direito e na base do polegar, acompanhada de parestesia. Fizemos uma revisão da literatura e o paciente recebeu orientação sobre os resultados publicados a respeito desse tipo de lesão. Durante o acompanhamento, o paciente relatou que a disestesia diminuiu cerca de 3-4 semanas após a lesão inicial e que não restou déficit neurológico. Conclusões: lesões de nervos periféricos foram descritas pós-venipuntura, mas a literatura é limitada. Os nervos da fossa antecubital estão classicamente localizados em um plano logo abaixo - e muito próximos - das veias, o que os torna susceptíveis a lesões durante a flebotomia; além disso, sabe-se que existe uma extensa variação anatômica, o que sugere que mesmo uma venipuntura satisfatória não traumática pode danificar diretamente esses ...

Background and objectives: Venipuncture is one of the most common procedures performed in daily anesthetic practice. Though usually innocuous, peripheral nerve injuries with serious sequelae have been described following venipuncture. We present a case of venipuncture related lateral antebrachial cutaneous nerve injury, alongside the essential diagnostic and prognostic information for day to day practice. Case: 27-Year old male who underwent venipuncture of the right antecubital fossa with a 20-gauge needle, for routine metabolic assessment. The patient suffered a shooting, electric-type pain traveling on the lateral side of the forearm, from the antecubital fossa proximally, to the right lateral wrist and base of the right thumb. After 24 h, the patient still experienced shooting, electric-type pain that was rated as 8/10 at the right distal lateral arm, right lateral wrist and base of the thumb, accompanied by paresthesia. The literature was reviewed and the patient was counseled regarding published outcomes of these type of injuries. At follow-up, the patient stated that the dysesthesia subsided approximately 3-4 weeks after initial injury, and reported no remaining neurologic deficits. Conclusions: Peripheral nerve injuries have been described after venipuncture, but the literature is limited. Nerves in the antecubital fossa classically lie on a plane just beneath, and in close proximity to, the veins, making them susceptible to injury during phlebotomy; also it has been shown that there is a large range of anatomic variation, suggesting that even a nontraumatic, satisfactory venipuncture can directly damage these nerves. Anesthesiologists must be aware of this possible complication, diagnosis and prognostication to adequately counsel patients in the event that this complication occurs. .

Justificación y objetivos: la venopunción es uno de los procedimientos más comunes en la práctica anestésica cotidiana. Aunque en general es inocua, se han descrito lesiones de los nervios periféricos con secuelas graves después de la venopunción. Presentamos un caso de lesión de nervio cutáneo antebraquial lateral relacionada con la venopunción, conjuntamente con la información de diagnóstico y pronóstico que son esenciales para la práctica cotidiana. Caso: paciente del sexo masculino, de 27 años, sometido a venopunción de la fosa antecubital derecha con una aguja de calibre 20 para evaluación metabólica de rutina. El paciente sufrió un dolor agudo de tipo descarga eléctrica, recorriendo el lateral del antebrazo desde la fosa antecubital proximal hasta la muñeca derecha y la base del pulgar derecho. Después 24 h, el paciente todavía sentía un dolor parecido a una descarga eléctrica que fue clasificado como 8/10 en el brazo distal lateral derecho, en la muñeca derecha y en la base del pulgar, acompañado de parestesia. Hicimos una revisión de la literatura y el paciente recibió orientación sobre los resultados publicados respecto a ese tipo de lesión. Durante el seguimiento, el paciente relató que la disestesia disminuyó aproximadamente 3-4 semanas después de la lesión inicial y no informó déficit neurológico. Conclusiones: se han descrito lesiones de nervios periféricos tras venopunción, pero la literatura es limitada. Los nervios de la fosa antecubital están clásicamente localizados en un plano inmediatamente inferior (y muy cercanos) a las venas, lo que los hace susceptibles a lesiones durante la flebotomía. Además, se sabe que existe una extensa variación anatómica, sugiriendo que incluso una ...

Understanding itch: An update on mediators and mechanisms of pruritus.

Pruritus is the most common symptom secondary to skin diseases. Advances in the fi elds of neurobiology, immunology and physiology have made it possible for us to understand and unravel the deeper pathophysiological basis of pruritus. This review aims to update our current understanding of the mechanisms and mediators of pruritus. Special attention is paid to endogenous itch mediators particularly newly identifi ed ones like endovanilloids, opioids, neurotrophins, cannabinoids, proteases and cytokines. Various theories explaining the peripheral encoding of itch are reviewed. Multiple neural pathways including the central itch pathways as well as supraspinal processing of itch and brain areas involved in pruritus are highlighted. Apart from peripheral itch mediators, spinal neural receptors are also involved in control of itch and should form part of the development of a novel antipruritic strategy. Further studies are required to fi ll the lacunae in our current understanding of the pathophysiology of pruritus.

Hanseníase neural, aspectos diagnósticos da forma neural pura e mecanismos imunopatogênicos da lesão do nervo na doença. Participação de quimiocinas CCL2 e CXCL10 e metaloproteinases 2 e 9 / Neural leprosy, pure neural leprosy diagnosis and imunopatogenic mechanisms of nerve damage during the disease. Participation of chemokines CCL2 and CXCL10) and metalloproteinases 2 and 9

O diagnóstico da hanseníase neural pura baseia-se em dados clínicos e laboratoriais do paciente, incluindo a histopatologia de espécimes de biópsia de nervo e detecção de DNA de Mycobacterium leprae (M. leprae) pelo PCR. Como o exame histopatológico e a técnica PCR podem não ser suficientes para confirmar o diagnóstico, a imunomarcação de lipoarabinomanana (LAM) e/ou Glicolipídio fenólico 1 (PGL1) - componentes de parede celular de M. leprae foi utilizada na primeira etapa deste estudo, na tentativa de detectar qualquer presença vestigial do M. leprae em amostras de nervo sem bacilos. Além disso, sabe-se que a lesão do nervo na hanseníase pode diretamente ser induzida pelo M. leprae nos estágios iniciais da infecção, no entanto, os mecanismos imunomediados adicionam severidade ao comprometimento da função neural em períodos sintomáticos da doença. Este estudo investigou também a expressão imuno-histoquímica de marcadores envolvidos nos mecanismos de patogenicidade do dano ao nervo na hanseníase. Os imunomarcadores selecionados foram: quimiocinas CXCL10, CCL2, CD3, CD4, CD8, CD45RA, CD45RO, CD68, HLA-DR, e metaloproteinases 2 e 9. O estudo foi desenvolvido em espécimes de biópsias congeladas de nervo coletados de pacientes com HNP (n=23 / 6 BAAR+ e 17 BAAR - PCR +) e pacientes diagnosticados com outras neuropatias (n=5) utilizados como controle. Todas as amostras foram criosseccionadas e submetidas à imunoperoxidase. Os resultados iniciais demonstraram que as 6 amostras de nervos BAAR+ são LAM+/PGL1+. Já entre as 17 amostras de nervos BAAR-, 8 são LAM+ e/ou PGL1+. Nas 17 amostras de nervos BAAR-PCR+, apenas 7 tiveram resultados LAM+ e/ou PGL1+. A detecção de imunorreatividade para LAM e PGL1 nas amostras de nervo do grupo HNP contribuiu para a maior eficiência diagnóstica na ausência recursos a diagnósticos moleculares...

The diagnosis of pure neural leprosy (PNL) is based on clinical and laboratory data, including the histopathology of nerve biopsy specimens and detection of M. leprae DNA by polymerase chain reaction (PCR). Given that histopathological examination and PCR methods may not be sufficient to confirm diagnosis, immunolabeling of lipoarabinomanan (LAM) and/or phenolic glycolipid 1 (PGL1) M. leprae wall components were utilized in the first step of this investigation in an attempt to detect any vestigial presence of M. leprae in AFB- nerve samples. Furthermore, it´s well known that nerve damage in leprosy can be directly induced by Mycobacterium leprae in the early stages of infection; however, immunomediated mechanisms add gravity to the impairment of neural function in symptomatic periods of the disease. Therefore, this study also investigated the immunohistochemical expression of immunomarkers involved in the pathogenic mechanisms of leprosy nerve damage. These markers selected were CXCL10, CCL2 chemokines and CD3, CD4, CD8, CD45RA, CD45RO, CD68, HLA-DR, metalloproteinases 2 and 9 in nerve biopsy specimens collected from leprosy (23) and nonleprosy patients (5) suffering peripheral neuropathy. Twenty-three PNL nerve samples (6 AFB+ and 17 AFB-PCR+) were cryosectioned and submitted to LAM and PGL1 immunohistochemical staining by immunoperoxidase; 5 nonleprosy nerve samples were used as controls. The 6 AFB-positive samples showed LAM/PGL1 immunoreactivity. Among the 17 AFB- samples, only 8 revealed LAM and/or PGL1 immunoreactivity. In 17 AFB-PCR+ patients, just 7 had LAM and/or PGL1-positive nerve results. In the PNL cases, the detection of immunolabeled LAM and PGL1 in the nerve samples would have contributed to enhanced diagnostic efficiency in the absence of molecular diagnostic facilities...

Actividad espontánea de nociceptores cutáneos en pacientes con neuropatía de fibras delgadas / Spontaneous activity of cutaneous nociceptors in patients with painful polyneuropathy. Report of three patients

Background: Painful polyneuropathy may result from selective impairment of small diameter nerve fibers, while tactile and motor functions are preserved. In these patients clinical and electrophysiological assessment is usually unrevealing. We report three patients with a pure painful polyneuropathy. One of them had neurogenic pruritus additionally. Quantitative sensory analysis disclosed a slight warm hypoesthesia (3/3) and paradoxical hot sensation (2/3) in the feet. Intraneural recordings from the peroneal nerve demonstrated abnormal spontaneous activity in 8 of 17 nociceptive afferents. One of them displayed double firing reflecting impulse multiplication. These results support the notion that patients with pain or pruritus with a distal distribution similar to a polyneuropathy, could have small diameter afferent fiber damage, despite normal function of large diameter fibers.

Comunicación masiva del ramo superficial del nervio radial con el nervio cutáneo antebraquial lateral, un análisis morfométrico: 1+1 < 2 / Massive communication between the superficial branch of radial nerve and the lateral cutaneous nerve of the forearm, a morphometric study: 1+1 < 2

La distribución de los ramos nerviosos sensitivos en el borde lateral y en el dorso de la mano han sido descritos con mayor exactitud en las últimas décadas, debido al avance de nuevas técnicas de diagnóstico, las cuales han permitido detectar que alrededor del 40 por ciento de la población examinada presenta algún grado de variación anatómica en el territorio de distribución de los nervios involucrados. Conocer el número de fibras que componen un ramo nervioso cutáneo de la región de la mano, ha adquirido mayor relevancia con el desarrollo de técnicas de microcirugía y de ultrasonografía, procedimientos que han demostrado la utilidad de este conocimiento en el diagnóstico y tratamiento de las lesiones nerviosas. Así, la arquitectura fascicular, el área adiposa y el área vascular de un ramo nervioso determinado constituyen datos que se ha demostrado se modifican con la edad y, en consecuencia, van condicionar la conducta terapéutica y el pronóstico de las lesiones nerviosas. En este caso presentamos una variación anatómica bilateral extremadamente rara, que involucra al ramo superficial del nervio radial y al nervio cutáneo lateral antebraquial; situación que aparece descrita en la literatura especializada sólo una vez y que modifica notablemente la inervación sensitiva del borde radial de la mano...

The distribution of sensory nerve branches in the lateral and the back of the hand have been described more accurately in recent decades due to advances in new diagnostic techniques, which have identified that about 40 percent of the population examined have some degree of anatomical variation in the distribution area of the sensitive nerves involved. The knowledge of the number of fibers forming a sensitive nerve of the hand has become more important with the development of microsurgical techniques and ultrasonography; procedures that have demonstrated the usefulness of this information in the diagnosis and treatment of nerve injuries. Thus, the fascicular architecture, adipose tissue area and the vascular area of a nerve branch, data that has been demonstrated that change with age, will determine the therapeutic and prognosis of nerve injuries. In this case we present an extremely rare and bilateral anatomical variation, involving the superficial branch of radial nerve and the lateral antebrachial cutaneous nerve, a situation that is described in the literature only once and which notably alter the sensory innervations of the radial edge of the hand...

Immunoelectron microscopy study of superficial skin nerves in drug-induced acute urticaria / Estudo de microscopia imunoeletrônica dos nervos superficiais da pele na urticária aguda induzida por medicamentos

BACKGROUND: Few studies have evaluated the ultrastructure of the superficial skin nerves in urticaria. OBJECTIVE: The objective of this study was to describe findings in superficial skin nerves in cases of drug-induced acute urticaria. METHODS: Seven patients with drug-induced acute urticaria were included in the study. Skin biopsies were obtained from the urticarial lesion and from the apparently normal skin. The 14 fragments collected were processed for immunogold electron microscopy using single stains for antitryptase and anti-FXIIIa antibodies, as well as double immunogold labeling for both. RESULTS: Some sections showed mast cells in the process of degranulation. Following double immunogold staining, 10 nm (FXIIIa) and 15 nm (Tryptase) gold particles were found together throughout the granules in mast cells, indicating that tryptase and FXIIIa are located inside each one of the granules of these cells. Interestingly, we found strong evidence of the presence of tryptase and factor XIIIa in the superficial skin nerves of these patients, both in cases of urticarial lesions (wheals) and in the apparently normal skin. CONCLUSIONS: Tryptase and FXIIIa are present in the superficial nerves of the skin in drug-induced acute urticaria. This is the first report of tryptase and FXIIIa expression in the superficial skin nerves of patients with urticaria. Tryptase may be participating in neural activation in these patients, while FXIIIa may be present in the nerves to guarantee the functional integrity of structures.

FUNDAMENTOS: Poucos autores têm estudado a ultraestrutura dos nervos superficiais na urticária. OBJETIVO: Descrever os achados nos nervos cutâneos superficiais em casos de urticária aguda induzida por medicamentos. MÉTODOS: Sete pacientes com urticária aguda induzida por medicamentos foram incluídos no estudo. Foram obtidas biopsias da pele da lesão urticariforme e da pele aparentemente normal. Os 14 fragmentos coletados foram processados usando imunomarcação com ouro para anticorpos anti-triptase e anti-FXIIIa separadamente, além da dupla imunomarcação com ambos anticorpos. A seguir as amostras foram submetidas à análise por microscopia imunoeletrônica. RESULTADOS: Alguns cortes demonstraram mastócitos em processo de degranulação. Após a imunomarcação dupla, partículas de ouro de 10 nm (FXIIIa) e partículas de ouro de 15 nm (Triptase) apresentavam-se juntas em grânulos de mastócitos indicando que a triptase e o FXIIIa se localizam dentro de cada um dos grânulos dessas células. Curiosamente, foi encontrada uma forte evidência da presença da triptase e do fator XIIIa nos nervos superficiais dos pacientes avaliados, tanto em lesões urticadas, como na pele aparentemente normal. CONCLUSÕES: A triptase e o FXIIIa estão presentes nos nervos superficiais da pele na urticária aguda medicamentosa. Este é o primeiro relato da expressão de triptase e de FXIIIa nos nervos superficiais na urticária. A triptase poderia estar participando da ativação neural nos pacientes estudados. O FXIIIa poderia estar presente nos nervos, com a finalidade de manter a integridade funcional dessas estruturas.

Leprosy patients: neurotrophic factors and axonal markers in skin lesions / Pacientes com hanseníase: fatores neurotróficos e marcadores axonais em lesões de pele

Neurotrophins are growth factors with crucial roles in neural pathophysiology. These mediators functionally modulate nociceptive fibers, and changes in neurotrophins expression have been correlated with early loss of nociception in leprosy. This study investigated the expression of NGF, BDNF, and NT3 in dermal nerves of leprosy patients. Characterization of Remak bundles was achieved by p75NTR, and axonal markers NF-L and PGP 9.5 immunostaining. Clinical parameters of neural impairment have been evaluated by Semmes-Wenstein monofilaments. Our findings demonstrated decrease of NGF in borderline leprosy, when compared to control specimens. Similar results were observed in PGP 9.5 expression (borderline: p<0.001 and lepromatous: p<0.05) and NF-L (lepromatous: p<0.05), suggesting advanced Remak bundles degeneration in multibacillary leprosy. It has also been observed positive correlation between p75NTR and PGP 9.5, indicating association between Schwann cells and axons in Remak bundles. Present data indicate that neurotrophins imbalance may participate in the establishment of peripheral nerve damage.

Neurotrofinas são fatores de crescimento com papel fundamental na fisiopatologia neural. Esses mediadores modulam funcionalmente fibras nociceptivas. Mudanças em sua expressão têm sido relacionadas à perda precoce da nocicepção na hanseníase. Este estudo investigou a expressão de NGF, BDNF e NT3 em nervos dérmicos de pacientes hansenianos. A caracterização de fibras nervosas não mielinizadas foi feita por p75NTR e marcadores axonais NF-L e PGP 9.5. Os parâmetros clínicos de dano neural foram avaliados por monofilamentos Semmes-Wenstein. Nossos achados demonstram diminuição de NGF nos pacientes dimorfos em comparação aos controles. Resultados similares foram observados para PGP 9.5 (dimorfos: p<0,001; virchowianos: p<0,05) e NF-L (virchowianos: p<0.05), sugerindo degeneração avançada das terminações nervosas na hanseníase multibacilar. Foi observada correlação positiva entre p75NTR e PGP 9.5, indicando associação entre células de Schwann e axônios em fibras nervosas não mielinizadas. Os resultados indicam que o desequilíbrio na expressão das neurotrofinas pode participar do dano neural periférico.

Thermal record of the test tubes method used for small fibers assessment / Registro térmico do método dos tubos de ensaio aplicado na avaliação de fibras finas

In Brazil, the test that uses test tubes filled with cold water (25ºC) and tubes filled with water heated to a temperature of 45ºC is recommended by the Ministry of Health as a way of evaluate thermal sensitivity on the injured skin of leprosy patients. The purpose of this work was to quantify the thermal stimulation applied to the skin, as well as the temperature variation of the heated water and of the tube's outer surface during stimulation sessions. The experiment had the participation of 14 healthy volunteers (31.2±11.4 years-old), ten of which were male (33.1±13.5 years-old) and four were female (26.5±4.7 years-old). Three consecutive stimulation sessions were carried out, each of them with four stimuli. The maximum skin temperature at the end of the stimuli was measured at 35.8±0.6ºC. Such temperature values may be useful in the assessment of the loss of small fibers, which are responsible for the sensation of warmth.

No Brasil, o teste que utiliza tubos de ensaio preenchidos com água aquecida (45ºC) e resfriada (25ºC) é preconizado pelo Ministério da Saúde como forma de avaliar a sensibilidade térmica nas lesões de pele de pacientes com hanseníase. O objetivo deste trabalho foi quantificar o estímulo térmico na pele e a variação das temperaturas da água aquecida e da superfície externa do tubo, durante as sessões de estimulação. O experimento contou com 14 voluntários saudáveis (31,2±11,4 anos), sendo dez do gênero masculino (33,1±13,5 anos) e quatro do gênero feminino (26,5±4,7 anos). Realizaram-se três sessões seguidas de estimulação com quatro estímulos em cada sessão. A temperatura registrada na pele, ao final dos estímulos, apresentou diferenças entre as sessões, atingindo o máximo de 35,8±0,6ºC. Estes valores de temperatura podem ser úteis na avaliação da perda de fibras finas responsáveis pela sensação de aquecimento.

División Alta del Nervio Fibular Superficial: Origen Precoz de los Nervios Cutáneos Dorsales del Pie / High Division of Superficial Fibular Nerve: Early Origin of the Dorsal Cutaneous Nerves of the Foot

Los nervios cutáneos dorsales del pie se originan a partir del nervio fibular superficial (NFS), después que éste pasa desde el compartimiento lateral de la pierna a través de la fascia profunda, para luego distribuirse superficialmente en el dorso del pie. A veces, el nervio fibular superficial se divide precozmente, por lo que estos nervios se originan profundamente y con una disposición diferente. Con el propósito de dar a conocer en estos casos, los niveles de origen de los nervios cutáneos dorsales del pie y el punto de penetración en la fascia profunda de la pierna, se estudiaron 16 muestras de individuos, chilenos, adultos, fijadas en formaldehido al 10 por ciento. En 2 de ellas, su origen se observó a un nivel alto, cerca de la parte proximal de la fíbula. En el primer caso, el nervio cutáneo dorsal intermedio se originó directamente de la división posterior del NFS; la división anterior del NFS se subdividió en dos ramos, los que después de un corto trayecto se unieron y formaron el nervio cutáneo dorsal medial. En el segundo caso, los nervios cutáneos dorsales intermedio y medial se originaron directamente del NFS, que después de un corto trayecto se dividió en estos dos nervios. El origen de los nervios cutáneos dorsales del pie se registró en relación al epicóndilo lateral del fémur y el paso de éstos a través de la fascia profunda de la pierna hacia su distribución cutánea fue relacionado al maléolo lateral. Aunque el origen de los nervios cutáneos dorsales del pie ocurra a un nivel próximo a la cabeza de la fíbula, perforan la fascia mencionada, en su tercio distal. Un conocimiento detallado del NFS y de sus ramos y variaciones anatómicas puede reducir lesiones iatrogénicas en éstos durante los procedimientos quirúrgicos realizados en el compartimiento lateral de la pierna.

The dorsal cutaneous nerves of the foot originate from the superficial fibular nerve (SFN), then pass from the lateral compartment of the leg piercing the deep fascia, thus distributed superficially in the dorsum of the foot. Sometimes SFN splits early, so these nerves originate deeply and with a different arrangement. The objective of this research was to study in these cases, the origin of the dorsal cutaneous nerves of the foot and pierce point level in the deep fascia of the leg. We studied 16 formolized samples of Chilean adult individuals. In two of them its origin was observed at a high level, near the proximal epiphysis of the fibula. In the first case the intermediate dorsal cutaneous nerve arose directly from the posterior division of SFN, of short course; the anterior division of SFN was subdivided into two branches, which after a short course, both branches joined to form the medial dorsal cutaneous nerve. In the second case the medial and intermediate dorsal cutaneous nerves originated directly from the SFN, which after a short course, it divided in these two nerves. The origin level was recorded in relation to the lateral epicondyle of the femur and the passage of these nerves through the deep fascia of the leg for its skin distribution was located in relation to the lateral malleolus. Although the origin of the dorsal cutaneous nerves of the foot occur very close to the proximal epiphysis of the fibula, passing through the mentioned fascia in its distal third. A detailed knowledge of the branches of the SFN and variations can reduce injuries in these nerves during surgical procedures in the lateral compartment of the leg.

Morfometría de los nervios sensitivos del dorso del pie en el hombre / Morphometry of the sensitive nerves of the dorsum of the foot in man

La inervación cutánea del dorso del pie, está dada por los nervios fibular superficial (NFS), ramo del nervio fibular común; sus ramos, cutáneo dorsal medial (NCDM) y cutáneo dorsal intermedio (NCDI), así como también por el cutáneo dorsal lateral (NCDL), ramo del nervio sural y el ramo cutáneo del nervio fibular profundo (RCNFP). Estos, pueden ser lesionados en su proximidad con estructuras óseas en su ubicación más superficial, en intervenciones quirúrgicas, por compresión, tracción o fricción crónica. Realizamos un estudio morfométrico y estereológico en 5 muestras de NFS, NCDM, NCDI, NCDL y RCNFP en cadáveres de individuos adultos, masculinos. Se obtuvieron secciones transversales de cada uno de los nervios después de su origen, a nivel del tercio distal de la pierna y del dorso del pie. Realizamos cortes de 4 um de grosor, teñidos con H.E. El promedio de fascículos fue: NFS 12 (D.E. 2,39); NCDM 8 (D.E. 4,82); NCDI 5 (D.E. 1,67); NCDL 7 (D.E. 3,27) y RCNFP 4 (D.E. 1,30). El promedio de fibras para el NFS, NCDM, NCDI, NCDL y RCNFP fue: 14.080, 7.636, 4.602, 3.732 y 2.941, respectivamente. El área promedio del NFS, NCDM, NCDI, NCDL y RCNFP fue: 1,54 mm2 (D. E. 0,22), 0,82 mm2 (D. E. 0,31), 0,54 mm2 (D. E. 0,23), 0,42 mm2 (D.E. 0,19) y 0,32 mm2 (D.E. 0,13) respectivamente. Con este estudio, se espera contribuir al conocimiento morfológico respecto a los factores que podrían influir en el grado de recuperación de lesiones nerviosas, importantes en la clínica y en las técnicas de microcirugía.

The cutaneous innervation on the dorsum of the foot, is given by the superficial fibular nerves (SFN) a branch of the common fibular nerve: its branches, and cutaneous medial dorsal (MDCn) and cutaneous intermediate dorsal (IDCn). Also, the cutaneous lateral dorsal (LDCn) branch of the sural nerve and cutaneous branch of the deep fibular nerve (DFCBn). These can be injured in their proximity with osseous structures in their most superficial location, in surgical procedures, by compression, traction or chronic friction. We carried out a morphometric and stereological study in 5 samples of SFN, MDCn, IDCn, LDCn and DFCBn in cadavers of adult male individuals. Transverse sections of each of the nerves were obtained following its origin, at the level of the distal third of the leg and dorsum of the foot. We realized slices of 4 um thick, stained with H.E. The average of the fascicles was: SFN 12 (D. E. 2.39); MDCn 8 (D. E. 4.82); IDCn 5 (D. E. 1.67); LDCn 7 (D. E. 3.27) and DFCBn 4 (D. E. 1.30). The average of fibers for SFN, MDCn, IDCn, LDCn, and DFCBn was: 14.080, 7.636, 4.602, 3.732 y 2.941 respectively. Average area of SFN, MDCn, IDCn, LDCn, and DFCBn was 1.54 mm2 (D. E. 0.22), 0.82 mm2 (D. E. 0.31), 0.54 mm2 (D. E. 0.23), 0.42 mm2 (D. E. 0.19) y 0.32 mm2 (D. E. 0.13) respectively. With this study we hope to contribute to morphological information in reference to factors that could influence in the degree of recovery of nerve lesions, important in clinic as well as microsurgery techniques.

Distribución de los nervios cutáneo dorsal medial y cutáneo dorsal intermedio en el hombre / Distribution of the medial dorsal cutaneous and intermediate dorsal cutaneous nerves in man

Gran parte de la inervación sensitiva del dorso del pie está dada por los ramos cutáneos del nervio fibular superficial, los nervios cutáneo dorsal medial (NCDM) y cutáneo dorsal intermedio (NCDI). El objetivo de esta investigación fue estudiar las divisiones de los NCDM y NCDI a nivel del tercio distal de la pierna y el dorso del pie, para contribuir con conocimientos específicos al abordaje quirúrgico de la región. Disecamos 19 piernas y pies en cadáveres de individuos adultos, masculinos, correspondientes al Departamento de Morfología de la Universidad de La Frontera de Temuco. Se dividió el dorso del pie, en tercios anterior, medio, posterior y luego, las divisiones observadas se padronizaron. La división de los NCDM y NCDI, en ramos medial y lateral, se observó en el tercio distal de la pierna, en un 47,4 por ciento y 52,6 por ciento respectivamente. La división del ramo medial de los NCDM y NCDI en ramos terminales, se observó en el tercio posterior del dorso del pie (42,2 por ciento) y en el tercio distal de la pierna (21,1 por ciento), respectivamente. La división del ramo lateral de los NCDM y NCDI en ramos terminales, se observó en el tercio posterior del dorso del pie (21,1 por ciento) y en el tercio anterior del dorso del pie (15,8 por ciento) respectivamente. La división de los ramos terminales del ramo medial de los NCDM y NCDI en nervios digitales dorsales, se observó en el tercio medio del dorso del pie en un 21,1 por ciento y 15,6 por ciento respectivamente. La división de los ramos terminales del ramo lateral de los NCDM y NCDI en nervios digitales dorsales, se observó en el tercio anterior del dorso del pie en un 15,8 por ciento, para ambos. Estos datos, pueden servir de referencia durante los procedimientos quirúrgicos realizados en la región, evitando lesiones iatrogénicas del área.

The sensory innervation of the dorsum of the foot is given by the cutaneous branches of the superficial fibular nerve, the medial dorsal cutaneous (MDCn) and intermediate dorsal cutaneous (IDCn) nerves. The aim of this research was to study the divisions of the MDCn and IDCn at the distal third of the leg and dorsum of the foot, to contribute expertise for the surgical approach in the región. Nineteen legs and feet of adult male cadavers, of the Department of Morphology, Universidad de La Frontera in Temuco, were dissected. We divided the dorsum of the foot in anterior, middle and posterior third, then the divisions were observed and patterned. The division of the MDCn and IDCn in medial and lateral branches was observed in the distal third of the leg, 47.4 percent and 52.6 percent respectively. The division of the medial branch of the MDCn and IDCn in terminal branches, was observed in the posterior third of the dorsum of the foot (42.2 percent) and in the distal third of the leg (21.1 percent), respectively. The division of the lateral branch of the MDCn and IDCn in terminal branches, was observed in the posterior third of the dorsum of the foot (21.1 percent) and in the anterior third of the dorsum of the foot (15.8 percent) respectively. The division of the terminal branches of the medial branch of the MDCn and IDCn in dorsal digital nerves was observed in the middle third of the dorsum of the foot at 21.1 percent and 15.6 percent respectively. The division of the terminal branches of the lateral branch of the MDCn and IDCn in dorsal digital nerves was observed in the anterior third of the dorsum of the foot at 15.8 percent for both. These data may serve as a reference during surgical procedures performed in the region, avoiding iatrogenic injuries of the area.

Preventing Lateral Skin Numbness after Medial Unicompartmental Knee Arthroplasty

BACKGROUND: The authors report the results of preserving the infrapatellar branch of the saphenous nerve during unicompartmental knee arthroplasty to prevent lateral skin numbness. METHODS: All 100 cases had medial compartmental osteoarthritis and a minimally invasive technique had been used. The mean follow-up duration was two years and eight months (range, 24 to 42 months). RESULTS: The classification according to the location of this nerve was observed as either Mochida Type I with 76 cases (76%), Type II with 16 cases (16%), and unclassified type with 8 cases (8%). In Type I, the nerve was saved in 62 cases (82%), but could not be preserved in Type II because of the surgical procedure. These results showed that the mean distance from the joint line to the nerve of Type I was 9.13 mm (range, 4 to 15 mm) and the nerve passed inferiorly. CONCLUSIONS: This study showed the location of this nerve can be predicted ahead of the procedure, which will help preserve it during the surgery.

Efeitos dos receptores adrenérgicos no reparo tecidual cutâneo / Effects of adrenergic receptors in cutaneous tissue repair

Os receptores adrenérgicos regulam diversas funções do sistema tegumentar; entretanto, o papel destes receptores no processo de reparo tecidual cutâneo ainda não é completamente compreendido. O objetivo deste trabalho foi investigar o papel dos receptores alfa- e beta-adrenérgicos no reparo tecidual cutâneo em ratos. Inicialmente observamos que o bloqueio dos receptores beta1- e beta2-adrenérgicos (através da administração de propranolol) reduz a contração, a re-epitelização e a deposição de colágeno em lesões excisionais cutâneas, mas aumenta o infiltrado inflamatório, a proliferação celular, a densidade miofibroblástica e de vasos sanguíneos. Em seguida avaliamos se ambos receptores beta1- e beta2-adrenérgicos participam das alterações causadas pela administração de propranolol no reparo de lesões excisionais cutâneas e se os receptores alfa1- e alfa2-adrenérgicos participam do reparo destas lesões. O bloqueio de ambos receptores beta1- e beta1-adrenérgicos retarda a resposta inflamatória, o desenvolvimento do tecido de granulação e o remodelamento do tecido. Entretanto, o bloqueio do receptor beta1-adrenérgico não altera a re-epitelização. Além disso, o bloqueio dos receptores alfa1- e alfa2-adrenérgicos não compromete o reparo de lesões excisionais cutâneas. Posteriormente investigamos se o retardo induzido pela administração de propranolol no reparo tecidual cutâneo ocorre através da ativação dos receptores alfa-adrenérgicos. O bloqueio simultâneo dos receptores beta1-, beta2-, alfa1- e alfa2-adrenérgicos prejudica o fechamento, a re-epitelização, a mobilização de mastócitos e a proliferação celular de lesões excisionais cutâneas sem um efeito sinérgico ou a ativação dos receptores a-adrenérgicos. Além disso, estudamos os efeitos dos receptores alfa- e beta-adrenérgicos na formação do tecido de granulação em implantes de esponjas de poliuretano. O bloqueio dos receptores beta1- e beta2-adrenérgicos, mas não o bloqueio dos receptores alfa1 e alfa2...

Adrenoceptors regulate several functions of the skin; however, the role of adrenoceptors on cutaneous wound healing is not completely understood yet. The aim of this study was to investigate the role of the alfa- and beta-adrenoceptors on cutaneous wound healing in rats. Firstly, we observe that the blockage of beta1- and beta2-adrenoceptors (through propranolol administration) reduces wound contraction, re-epithelialization, and collagen deposition, but increases inflammatory infiltrate, cellular proliferation, density of myofibroblasts and blood vessels. Subsequently, we evaluate if both beta1- and beta2-adrenoceptors play a role in the propranolol-induced alterations on cutaneous wound healing and if alfa1- and alfa2-adrenoceptors participate in cutaneous wound healing. The blockade of both beta1- e beta2-adrenoceptors delays inflammatory response, granulation tissue formation and tissue remodeling. However, the blockade of beta1-adrenoceptors does not alter re-epithelialization. Moreover, the blockage of the alfa1- and alfa2-adrenoceptors does not compromise tissue repair of the cutaneous excisional lesions. Furthermore, we evaluate if propranolol-induced alterations on cutaneous wound healing occur through alfa1- and alfa2-adrenoceptors activation. The simultaneous blockade of beta1-, beta2-, alfa1- and alfa2-adrenoceptors impairs wound contraction, re-epithelialization, mast cells mobilization, and cellular proliferation of the cutaneous excisional lesions without a synergic effect or alfa-adrenoceptors activation. In addition, we study the effects of alfa- and beta-adrenoceptors blockade on granulation tissue formation in polyurethane sponges implants. The blockade of beta1- and beta2-adrenoceptors, but not alfa1- and alfa2-adrenoceptors, delays inflammatory cells migration, myofibroblastic differentiation, angiogenesis, and collagen fibers organization. Moreover, we also evaluate the effects of administration of a low dose of propranolol ...

Limiar de sensibilidade cutânea dos pés em pacientes diabéticos através do pressure specified sensory device: uma avaliação da neuropatia / Cutaneous sensibility threshold in the feet of diabetic patients with pressure specified sensory device: an assessment of the neuropathy

OBJETIVO: A neuropatia diabética leva à diminuição ou perda da sensibilidade protetora do pé, tornando o diabético mais vulnerável ao trauma mecânico, consequentemente, levando-o à formação de feridas e eventualmente, perda segmentar nos membros inferiores. A profilaxia das complicações neuropáticas deve ser iniciada pela identificação do grau de neuropatia e, portanto, do comprometimento neurológico. O Pressure Specified Sensory DeviceTM foi desenvolvido para quantificar o limiar de pressão aplicada sobre a pele, necessário para que o paciente sinta o estímulo de um ponto estático, um ponto em movimento, dois pontos estáticos e dois pontos em movimento. É um meio direto para se avaliar os sistemas de fibras de adaptação lenta e rápida e seus respectivos receptores periféricos. MÉTODOS: Trinta e três pacientes diabéticos do tipo II, sem história prévia de feridas e/ou amputações nos pés foram avaliados neste estudo de corte transversal. A sensibilidade nos territórios cutâneos dos nervos plantar medial, calcâneo e o ramo profundo do nervo fibular foi avaliada usando os testes de um ponto estático (1PE), um ponto dinâmico (1PD), dois pontos estáticos (2PE) e dois dinâmicos (2PD). RESULTADOS: Nos três territórios nervosos examinados encontramos valores alterados para as modalidades estática e dinâmica em relação ao padrão de normalidade. As diferenças foram estatisticamente significantes com p < 0,05. CONCLUSÃO: A quantificação numérica do limiar de pressão cutânea nos permite tanto a avaliação do conjunto fibra/receptor, quanto à determinação do déficit funcional da fibra nervosa imposto pela neuropatia diabética.

OBJECTIVES: Neuropathy is a severe progressive loss of protective sensation in the feet, increasing patient vulnerability to mechanical trauma and consequently more prone to development of chronic wounds, major distortion of the foot bone architecture and to eventual limb amputation. Prophylaxis should be enforced to avoid foot ulceration and for this purpose, evaluation of the degree of loss of sensation on the skin is essential. The PSSD (Pressure Specified Sensory DeviceTM) was developed to quantify the threshold of pressure applied to the skin that the patient might recognize as positive. Pressure of one or two points is tested both statically and with movement, thus assessing the function of fast and slow response nerve fibers. METHODS: 33 diabetic patients, type II, with no previous history of wounds on the lower extremity were studied. The tests used were, one point static, one point moving and two points, static and moving on the cutaneous territory of the fibular nerve and posterior tibial nerve (two territories - medial plantar and calcaneous nerves). RESULTS: Altered values were observed for the static and dynamic tests over the three nerve territories studied. Differences were statically significant (p < 0.05). This numeric quantification of the threshold of pressure supports the evaluation of the status of the fiber/receptor structures as well as the functional deficit subsequent to diabetic neuropathy.

Respiratory and non respiratory oscillations of the skin blood flow: a window to the function of the sympathetic fibers to the skin blood vessels

OBJECTIVE OF THE STUDY: The skin blood flow (SBF) has been known to oscillate in frequency and amplitude. The nature and type of these oscillations have remained obscure. We studied the oscillations of the SBF in frequency and amplitude with non invasive techniques during normal breathing at rest and compared it to the oscillations during rhythmic paced breathing at 6 cycles per minute. SUBJECTS AND METHODS: Thirty healthy subjects were studied under normothermic conditions. The following variables were recorded: 1) EKG signal; 2) SBF signal given by an infrared photoplethysmograph; 3) respiratory movements (RM). A correlation of the frequency of the respiration, the SBF and the EKG was made. The variability of the amplitudes of the SBF, RR intervals and pulse intervals was analyzed in the time domain and with spectral analysis using Fourier analysis. RESULTS: We found no clear respiratory modulation of the amplitude of the SBF during natural breathing at rest. With default breathing there was a low frequency oscillations (LF 0.04 to 0.15 Hz) modulation of the amplitude of the SBF that was non respiratory in nature. During rhythmic breathing at 0.1 Hz there was a strong modulation at LF of the SBF with a typical waxing and waning appearance, decreasing in amplitude during the tachycardia period and increasing in amplitude during the bradycardia period. CONCLUSIONS: Under normothermic conditions there is a consistent variability of the frequency and amplitude of the SBF with normal and rhythmic breathing. While breathing at rest the modulation of SBF amplitude was clearly seen at LF and non respiratory related. With rhythmic breathing there is a strong modulation of amplitude and frequency at the respiratory frequency.