Use of aerobic treadmill exercises on nerve regeneration after sciatic nerve injury in spontaneously hypertensive rats

Purpose: Various postoperative protocols have been proposed to improve outcomes and accelerate nerve regeneration. Recently, the use of physical exercise in a post-surgical neurorraphy procedure has shown good results when started early. We experimentally investigated the hypothesis that post-operative exercise speeds up results and improves clinical and morphologic parameters. Methods: Isogenic rats were randomly divided into four groups: 1 SHAM; 2 SHAM submitted to the exercise protocol (EP); 3 Grafting of the sciatic nerve; and 4 Grafting of the sciatic nerve associated with the EP. The EP was based on aerobic activities with a treadmill, with a progressive increase in time and intensity during 6 weeks. The results were evaluated by the sciatic functional index (SFI), morphometric and morphologic analysis of nerve distal to the lesion, and the number of spinal cord motor neurons, positive to the marker Fluoro-Gold (FG), captured retrogradely through neurorraphy. Results: Functional analysis (SFI) did not show a statistical difference between the group grafted with (­50.94) and without exercise (-65.79) after 90 days. The motoneurons count (Spinal cord histology) also showed no diference between these groups (834.5 × 833 respectively). Although functionally there is no difference between these groups, morphometric study showed a greater density (53.62) and larger fibers (7.762) in GRAFT group. When comparing both operated groups with both SHAM groups, all values were much lower. Conclusions: The experimental model that this aerobic treadmill exercises protocol did not modify nerve regeneration after sciatic nerve injury and repair with nerve graft.

Acute neuromuscular response during eccentric overload protocol by using a mechanical device to increase the load / Resposta neuromuscular aguda durante um protocolo de sobrecarga excêntrica usando um dispositivo mecânico para aumentar a carga

Abstract The aim of this study was to propose a mechanical device that could increase the mechanical load during the entire eccentric (ECC) action on a knee flexor machine and to compare the muscular activity when the device was used during a testing protocol. Fifteen physically active women were recruited, and they performed two protocols: control and eccentric overload. Control protocol was performed with concentric (CON) and ECC actions with similar load (60% of one repetition maximum) whilst eccentric overload protocol consisted of ECC actions with 40% more load than CON actions. Muscular activation was measured using surface electromyography of the biceps femoris (BF) and the gastrocnemius medialis (GM) muscles. ECC actions presented a higher muscular activation during eccentric overload protocol than control protocol for BF (p = 0.032), but not for the GM (p = 0.439). The mechanical device increased the mechanical load during the ECC muscle action and consequently increased the amplitude of the neural drive to the BF muscle; however, it did not increase the amplitude of the neural drive to the GM muscle.

Resumo O objetivo deste estudo foi propor um dispositivo mecânico que acoplado a uma cadeira flexora aumente a carga mecânica durante toda a ação excêntrica (ECC) e comparar a atividade muscular durante a utilização do dispositivo proposto. Quinze mulheres fisicamente ativas foram recrutadas e realizaram dois diferentes protocolos (controle e sobrecarga ECC). O protocolo controle foi realizado com ações concêntricas (CON) e ECC com carga iguais (60% de uma repetição máxima), enquanto o protocolo de sobrecarga ECC consistiu em ações ECC com 40% mais de carga do que as ações CON. A ativação muscular dos músculos biceps femoris (BF) e gastrocnemius medialis (GM) foi medida por meio de eletromiografia de superfície. Durante as ações ECC foi observada uma maior ativação do BF durante o protocolo de sobrecarga quando comparado ao protocolo controle (p = 0,032). No entanto, GM não apresentou diferenças na ativação entre os protocolos (p = 0,439). O dispositivo mecânico proposto foi capaz de aumentar a carga durante a ação ECC e, consequentemente, a atividade muscular do BF.

Far beyond the motor neuron: the role of glial cells in amyotrophic lateral sclerosis / Muito além do neurônio motor: o papel das células da glia na esclerose lateral amiotrófica

ABSTRACT Motor neuron disease is one of the major groups of neurodegenerative diseases, mainly represented by amyotrophic lateral sclerosis. Despite wide genetic and biochemical data regarding its pathophysiological mechanisms, motor neuron disease develops under a complex network of mechanisms not restricted to the unique functions of the alpha motor neurons but which actually involve diverse functions of glial cell interaction. This review aims to expose some of the leading roles of glial cells in the physiological mechanisms of neuron-glial cell interactions and the mechanisms related to motor neuron survival linked to glial cell functions.

RESUMO A doença do neurônio motor constitui um dos principais grupos de doenças neurodegenerativas, representadas principalmente pela esclerose lateral amiotrófica. Apesar dos amplos dados genéticos e bioquímicos em relação aos seus mecanismos fisiopatológicos, a doença do neurônio motor se desenvolve sob uma complexa rede de mecanismos não restritos às funções particulares dos neurônios motores alfa, mas, na verdade, envolvendo diversas funções interativas das células da glia. Esta revisão tem como objetivo expor alguns dos principais papéis das células da glia nos mecanismos fisiológicos de interações neurônio-glia e os mecanismos relacionados à sobrevivência do neurônio motor ligados a funções das células da glia.

Tibial and fibular nerves evaluation using intraoperative electromyography in rats

ABSTRACT PURPOSE: To evaluate a new model of intraoperative electromyographic (EMG) assessment of the tibial and fibular nerves, and its respectives motor units in rats. METHODS: Eight Wistar rats underwent intraoperative EMG on both hind limbs at two different moments: week 0 and week 12. Supramaximal electrical stimulation applied on sciatic nerve, and compound muscle action potential recorded on the gastrocnemius muscle (GM) and the extensor digitorum longus muscle (EDLM) through electrodes at specifics points. Motor function assessment was performaced through Walking Track Test. RESULTS: Exposing the muscles and nerves for examination did not alter tibial (p=0.918) or fibular (p=0.877) function between the evaluation moments. Electromyography of the GM, innervated by the tibial nerve, revealed similar amplitude (p=0.069) and latency (p=0.256) at week 0 and at 12 weeks, creating a standard of normality. Meanwhile, electromyography of the EDLM, innervated by the fibular nerve, showed significant differences between the amplitudes (p=0.003) and latencies (p=0.021) at the two different moments of observation. CONCLUSION: Intraoperative electromyography determined and quantified gastrocnemius muscle motor unit integrity, innervated by tibial nerve. Although this study was not useful to, objectively, assess extensor digitorum longus muscle motor unit, innervated by fibular nerve.

Interaction between affordance and handedness recognition: a chronometric study

The visualization of tools and manipulable objects activates motor-related areas in the cortex, facilitating possible actions toward them. This pattern of activity may underlie the phenomenon of object affordance. Some cortical motor neurons are also covertly activated during the recognition of body parts such as hands. One hypothesis is that different subpopulations of motor neurons in the frontal cortex are activated in each motor program; for example, canonical neurons in the premotor cortex are responsible for the affordance of visual objects, while mirror neurons support motor imagery triggered during handedness recognition. However, the question remains whether these subpopulations work independently. This hypothesis can be tested with a manual reaction time (MRT) task with a priming paradigm to evaluate whether the view of a manipulable object interferes with the motor imagery of the subject's hand. The MRT provides a measure of the course of information processing in the brain and allows indirect evaluation of cognitive processes. Our results suggest that canonical and mirror neurons work together to create a motor plan involving hand movements to facilitate successful object manipulation.

Un primer análisis de la investigación en México sobre los determinantes sociales de la salud: 2005-2012 / A first analysis of research on social determinants of health in Mexico: 2005-2012

Objetivo. Examinar la investigación hecha en México sobre los determinantes sociales de la salud (DSS) durante el periodo 2005-2012 con base en la caracterización del sistema nacional de investigación en salud y la producción científica sobre este tema. Material y métodos. Análisis en dos etapas: revisión documental de fuentes oficiales sobre investigación en salud en México y búsqueda sistemática de literatura sobre DSS. Resultados. Los DSS fueron mencionados en el Programa de Acción Específico de Investigación en Salud 2007-2012, pero no figuran en las estrategias y objetivos; en su lugar, se enfatizan primordialmente aspectos de infraestructura y administrativos. En el periodo se publicaron 145 artículos sobre DSS, cuyas temáticas más abordadas fueron "condiciones de salud", "sistemas de salud" y "nutrición y obesidad". Conclusiones. A pesar de que existe investigación en México sobre DSS, la instrumentación de esos hallazgos en políticas de salud no se ha implementado. El Programa Sectorial de Salud 2013-2018 representa una ventana de oportunidad para posicionar resultados de investigación que promuevan políticas de equidad en salud.

Objective. To examine the research on social determinants of health (SDH) produced in Mexico during the period 2005-2012, based on the characterization of the national health research system and the scientific production on this topic. Materials and methods. Two-stage analyses: Review of Mexican documents and official sources on health research and systematic bibliographic review of the literature on SDH. Results. Although SDH were mentioned in the Specific Action Plan for Health Research 2007-2012, they are not implemented in strategies and goals, as the emphasis is put mostly in infrastructure and administrative aspects of research. In the period studied, 145 articles were published on SDH topics such as health conditions, health systems and nutrition and obesity. Conclusions. In spite of the availability of research on SDH in Mexico, the operationalization of such findings into health policies has not been possible. The current Sectorial Program on Health 2013-2018 represents a window of opportunity to position research findings that promote health equity policies.

Esclerosis lateral amiotrófica: ¿es el astrocito la célula primariamente dañada? / [Amyotrophic lateral sclerosis: is the astrocyte the cell primarily involved?].

So far, amyotrophic lateral sclerosis (ALS) is thought as due to a primary insult of the motor neurons. None of its pathogenic processes proved to be the cause of the illness, nor can be blamed environmental agents. Motor neurons die by apoptosis, leaving the possibility that their death might be due to an unfriendly environment, unable to sustain their health, rather than being directly targeted themselves. These reasons justify an examination of the astrocytes, because they have the most important role controlling the neurons’ environment. It is known that astrocytes are plastic, enslaving their functions to the requirements of the neurons to which they are related. Each population of astrocytes is unique, and if it were affected the consequences would reach the neurons that it normally sustains. In regard to the motor neurons, this situation would lead to a disturbed production and release of astrocytic neurotransmitters and transporters, impairing nutritional and trophic support as well. For explaining the spreading of muscle symptoms in ALS, correlated with the type of spreading observed at the cortical and spinal motor neurons pools, the present hypotheses suggests that the illness-causing process is spreading among astrocytes, through their gap junctions, depriving the motor neurons of their support. Also it is postulated that a normal astrocytic protein becomes misfolded and infectious, inducing the misfolding of its wild type, travelling from one protoplasmatic astrocyte to another and to the fibrous astrocytes encircling the pyramidal pathway which joints the upper and lower motoneurones.

Effect of walking and resting after three cryotherapy modalities on the recovery of sensory and motor nerve conduction velocity in healthy subjects / Efeito da marcha e do repouso após aplicação de três protocolos de crioterapia na recuperação da velocidade de condução sensorial e motora em sujeitos saudáveis

BACKGROUND: Different cryotherapy modalities have distinct effects on sensory and motor nerve conduction parameters. However, it is unclear how these parameters change during the post-cooling period and how the exercise carried out in this period would influence the recovery of nerve conduction velocity (NCV). OBJECTIVES: To compare the effects of three cryotherapy modalities on post-cooling NCV and to analyze the effect of walking on the recovery of sensory and motor NCV. METHODS: Thirty six healthy young subjects were randomly allocated into three groups: ice massage (n=12), ice pack (n=12) and cold water immersion (n=12). The modalities were applied to the right leg. The subjects of each modality group were again randomized to perform a post-cooling activity: a) 30min rest, b) walking 15 min followed by 15 min rest. The NCV of sural (sensory) and posterior tibial (motor) nerves was evaluated. Initial (pre-cooling) and final (30 min post-cooling) NCV were compared using a paired t-test. The effects of the modalities and the post-cooling activities on NCV were evaluated by an analysis of covariance. The significance level was α=0.05. RESULTS: There was a significant difference between immersion and ice massage on final sensory NCV (p=0.009). Ice pack and ice massage showed similar effects (p>0.05). Walking accelerated the recovery of sensory and motor NCV, regardless of the modality previously applied (p<0.0001). CONCLUSIONS: Cold water immersion was the most effective modality for maintaining reduced sensory nerve conduction after cooling. Walking after cooling, with any of the three modalities, enhances the recovery of sensory and motor NCV.

CONTEXTUALIZAÇÃO: Diferentes protocolos de crioterapia têm ação distinta nos parâmetros de condução neural sensorial e motora. No entanto, não se sabe como é o comportamento desses parâmetros no período pós-resfriamento e como o exercício físico realizado nesse período atuaria na recuperação da velocidade de condução nervosa (VCN). OBJETIVOS: Comparar o efeito de três protocolos de crioterapia na VCN pós-resfriamento e analisar o efeito da marcha pós-resfriamento na recuperação da VCN sensorial e motora. MÉTODOS: Trinta e seis sujeitos jovens e saudáveis foram alocados aleatoriamente em três grupos: criomassagem (n=12), pacote de gelo (n=12); imersão em água gelada (n=12). As modalidades foram aplicadas na perna direita. Os sujeitos de cada grupo foram novamente aleatorizados para realizar uma atividade pós-resfriamento: a) 30 min de repouso; b) 15 min de marcha seguidos de 15 min de repouso. Avaliou-se a VCN nos nervos sural (sensorial) e tibial posterior (motor). Comparações entre VCN inicial e final (30 min pós-resfriamento) foram realizadas com teste t de Student pareado. Os efeitos das modalidades e das atividades pós-resfriamento na VCN foram avaliados mediante análise de covariância. O nível de significância foi α=0,05. RESULTADOS: Houve efeito diferente entre imersão e criomassagem na VCN sensorial final (p=0,009). Pacote de gelo e criomassagem apresentaram efeitos similares (p>0,05). A marcha acelerou a recuperação da VCN sensorial e motora, independente da modalidade previamente aplicada (p<0,0001). CONCLUSÕES: Imersão em água gelada foi o procedimento mais eficaz para manter diminuída a condução nervosa sensorial após o resfriamento. A marcha pós-crioterapia, com qualquer um dos três protocolos, acelera a recuperação da VCN sensorial e motora.

The immunomodulator glatiramer acetate influences spinal motoneuron plasticity during the course of multiple sclerosis in an animal model

The immunomodulador glatiramer acetate (GA) has been shown to significantly reduce the severity of symptoms during the course of multiple sclerosis and in its animal model - experimental autoimmune encephalomyelitis (EAE). Since GA may influence the response of non-neuronal cells in the spinal cord, it is possible that, to some extent, this drug affects the synaptic changes induced during the exacerbation of EAE. In the present study, we investigated whether GA has a positive influence on the loss of inputs to the motoneurons during the course of EAE in rats. Lewis rats were subjected to EAE associated with GA or placebo treatment. The animals were sacrificed after 15 days of treatment and the spinal cords processed for immunohistochemical analysis and transmission electron microscopy. A correlation between the synaptic changes and glial activation was obtained by performing labeling of synaptophysin and glial fibrillary acidic protein using immunohistochemical analysis. Ultrastructural analysis of the terminals apposed to alpha motoneurons was also performed by electron transmission microscopy. Interestingly, although the GA treatment preserved synaptophysin labeling, it did not significantly reduce the glial reaction, indicating that inflammatory activity was still present. Also, ultrastructural analysis showed that GA treatment significantly prevented retraction of both F and S type terminals compared to placebo. The present results indicate that the immunomodulator GA has an influence on the stability of nerve terminals in the spinal cord, which in turn may contribute to its neuroprotective effects during the course of multiple sclerosis.

Growth factor-expressing human neural progenitor cell grafts protect motor neurons but do not ameliorate motor performance and survival in ALS mice

Neural progenitor cells (NPs) have shown several promising benefits for the treatment of neurological disorders. To evaluate the therapeutic potential of human neural progenitor cells (hNPs) in amyotrophic lateral sclerosis (ALS), we transplanted hNPs or growth factor (GF)-expressing hNPs into the central nervous system (CNS) of mutant Cu/Zn superoxide dismutase (SOD(1G93A)) transgenic mice. The hNPs were engineered to express brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1), VEGF, neurotrophin-3 (NT-3), or glial cell-derived neurotrophic factor (GDNF), respectively, by adenoviral vector and GDNF by lentiviral vector before transplantation. Donor-derived cells engrafted and migrated into the spinal cord or brain of ALS mice and differentiated into neurons, oligodendrocytes, or glutamate transporter-1 (GLT1)-expressing astrocytes while some cells retained immature markers. Transplantation of GDNF- or IGF-1-expressing hNPs attenuated the loss of motor neurons and induced trophic changes in motor neurons of the spinal cord. However, improvement in motor performance and extension of lifespan were not observed in all hNP transplantation groups compared to vehicle-injected controls. Moreover, the lifespan of GDNF-expressing hNP recipient mice by lentiviral vector was shortened compared to controls, which was largely due to the decreased survival times of female animals. These results imply that although implanted hNPs differentiate into GLT1-expressing astrocytes and secrete GFs, which maintain dying motor neurons, inadequate trophic support could be harmful and there is sexual dimorphism in response to GDNF delivery in ALS mice. Therefore, additional therapeutic approaches may be required for full functional recovery.

Sensory nerve conduction velocity is greater in left handed persons.

Dependence of nerve conduction velocity on factors like age, sex and temperature is well known. Effect of handedness on nerve conduction velocity has not been studied adequately. In this study correlation between handedness and motor as well as sensory conduction velocity of right as well as left median nerve was studied in 84 medical students in the age group between 17-21 years out of which 72 were right handed and 12 were left handed. In addition auditory and visual reaction times were also studied. Sensory conduction velocity in both right and left median nerve was significantly higher in left handers as compared with right handers whereas, the motor conduction velocity in right handers and left handers was not different. The auditory and visual reaction times were also not different in these groups. Because of greater sensory conduction velocity in left handers there is a requirement of different set of normal reference values for left handers in clinical diagnosis.

The Correlation between F-wave Motor Unit Number Estimation (F-MUNE) and Functional Recovery in Stroke Patients

The aim of this study was to follow up the changes in the number of motor units according to the Brunnstrom stage through a motor unit number estimation of the Fwave (F-MUNE) after a stroke, and to identify the functional significance of F-MUNE. Twenty-five patients (15 men, 10 women) with a first unilateral stroke were recruited. The maximal M-potential was evoked by the supramaximal stimulation of the median nerve at the wrist, and the maximal stimulation intensity was determined on both hemiplegic and unaffected hands. The reproducible all-or-none F-wave was evoked in 30% of the maximal stimulation intensity and was constantly stimulated at that level. The prototypes of the F-wave were chosen, and the values of F-MUNE were calculated by dividing the amplitude of the maximal M-potential by the mean amplitude of the F-prototype. The changes in F-MUNE were compared according to the progression of the Brunnstrom stage and correlated with those of the functional scales. The mean motor unit numbers decreased significantly in the hemiplegic side compared with the unaffected side. According to the progression of the Brunnstrom stage, the values of F-MUNE were reduced significantly by increasing the amplitude and recruitment of the F-prototype, and the functional scores also improved. These results show that the F-MUNE equation did not show a functional recoveryrelated increase in stroke patients.

Estudo da condução nervosa motora na doença de McArdle: relato de caso / Motor nerve conduction study in McArdle disease: case report

McArdle disease (glycogenosis type V) is a metabolic myopathy with symptoms of exercise intolerance caused by deficiency of the enzyme myophosphorylase. In these patients, the motor nerve conduction studies after a short period of maximal voluntary muscle contraction or repetitive stimulation reveals characteristic findings of the disease. A 37-year-old man presented symptoms of exercise intolerance, muscular fatigue and cramps in the beginning of the physical activity with [quot ]second wind[quot ] phenomenon. The motor nerve conduction studies after a voluntary contraction of 30 and 90 seconds presented decrease in the amplitude of the compound muscle action potential in median, ulnar and deep peroneal nerves; and decrement after 200 stimulation at the 40 Hz in deep peroneal nerve. The electromyography presented myopathic pattern and during the ischemic exercise electric silence was not proven. The characteristic of electrophysiological studies are discussed with emphasis at the importance of the motor nerve conduction studies in the patients with suspicion of metabolic myopathy.

A doença de McArdle (glicogenose tipo V) é miopatia metabólica com sintomas de intolerância ao exercício, causados pela deficiência da enzima miofosforilase. Nesses pacientes, o estudo da condução nervosa motora após período de esforço muscular máximo ou ao estímulo repetitivo pode revelar achados característicos da doença. Descrevemos o caso de um homem de 37 anos com sintomas de intolerância aos exercícios, fadiga muscular e cãibras no início da atividade física com a presença do fenômeno de "second wind". O estudo da condução nervosa motora apresentava redução na amplitude do potencial de ação muscular composto após esforço de 30 e 90 segundos em nervos mediano, ulnar e fibular profundo e decremento após 200 estímulos a 40 Hz em nervo fibular profundo. A eletromiografia de agulha apresentava padrão miopático e durante o exercício isquêmico não se evidenciou silêncio elétrico. Discutimos as características eletrofisiológicas enfatizando a importância do estudo da condução nervosa motora e teste de estimulação repetitiva nos pacientes com suspeita de miopatia metabólica.

Spinal motoneuron excitability in iron deficiency anaemia.

Decreased tissue oxygenation resulting from iron deficiency anaemia produces generalized weakness and fatigue. The precise physiological mechanism underlying this weakness is unknown and studies in this regard have been scarce. One possible underlying mechanism has been suggested to be reduction of spinal motoneuron excitability. F waves are low amplitude motor responses to nerve stimulation, produced by antidromic activation of the peripheral motor fibers, resulting in recurrent discharge of motoneurons. F waves have been established as an efficient tool to assess spinal motoneuron excitability. 15 patients of iron deficiency anaemia using inclusion criteria of hemoglobin level < 9 g/dL and serum ferritin < 15 microg/L were studied. 8 controls with hemoglobin levels > 12 g/ dL were also included. Bilateral median and common peroneal F wave studies were performed. F wave mean latency, chronodispersion, persistence and mean amplitude were studied. They were within the normal range and no significant differences between the patients and the controls were found. We conclude that spinal motoneuron excitability is not reduced in iron deficiency anaemia. A decreased tissue oxygenation leading to a change in the brain neurotransmitters may have a role to play.

Inervación del músculo semitendinoso, biometría de sus ramos y localización de sus puntos motores / Inervation of the semitendinous muscle, biometry of the branches and location of its motor points

La inervación motora de la musculatura esquelética es conocida, sin embargo, los padrones de distribución de esos ramos y los puntos motores son descritos de forma general. Con el propósito de aportar antecedentes anatómicos y biométricos sobre la inervación de la musculatura de los miembros, estudiamos las características de los ramos que inervan al músculo semitendinoso, considerando su origen respecto a la tuberosidad isquiática (TI), su longitud, la división de los ramos principales, como también la localización de los puntos motores respecto de la TI. La investigación se realizó en 28 miembros inferiores de 14 cadáveres formolizados, de individuos brasileños, adultos, de ambos sexos, de edades entre 25 y 65 años, pertenecientes a la disciplina de Anatomía Humana de la Universidade Federal de Santa Catarina, Brasil. Inicialmente registramos la distancia entre la parte inferior de la TI y una línea transversal que se extendió entre las partes más sobresalientes de los cóndilos femorales (LBE). En cada una de las muestras se realizó cuidadosa disección, observando los ramos musculares y registrando las mediciones respectivas. En la totalidad de los casos, los ramos dirigidos al músculo en cuestión procedieron de la porción tibial del nervio isquiático. El número más frecuente de ramos encontrados fue de 2, presentándose 9 casos en el lado derecho y 11 en el izquierdo; con 3 ramos observamos 2 casos en el lado derecho y 1 en el izquierdo; con un ramo hubo 3 casos en el lado derecho y 2 en el izquierdo. La distancia promedio para el origen de R1 fue de 30,5 + 10,4 mm y para R2 fue de 112,5 + 44,3 mm en el lado derecho, y, de 22,8 + 12,7 mm para R1 y de 106,2 + 38,2 mm para R2 en el izquierdo. La longitud promedio de R1 en el lado derecho fue de 9,2 + 5,3 mm y de R2 fue de 53,5 + 31,6 mm; en el lado izquierdo R1 tuvo una longitud de 12,2 + 6,6 mm y R2 de 49,3 + 25,6 mm. La mayoría de los ramos musculares principales se subdividieron antes de ingresar en el vientre muscular en 2,3,4 y hasta 5 ramos secundarios. Se presentan también las distancias entre la TI y los puntos motores, como también la correlación entre la distancia TI-LBE y el origen de los ramos así como con los puntos motores. Los datos aportados podrán ser usados como referencia en los procedimientos clínico-quirúrgicos y de electroestimulación.

Magnetic stimulation accelerating rehabilitation of peripheral nerve injury / 华中科技大学学报（医学）（英德文版）

The effect of magnetic stimulation (MS) on sciatic nerve injury was observed. After sciatic nerve was crushed in 40 Sprague Dawley (SD) rats, one randomly selected group (group D) was subjected, from the 4th day post-operatively to 3 min of continuous 70% of maximum output of MS daily for 8 weeks. The other group (group E) served as a control group. The nerve regeneration and motor function recovery were evaluated by walking track analysis (sciatic function index, SFI; toe spreading reflex, TSR), electrophysiological, histological and acetylcholineesterase histochemistry. The SFI in the group D was greater than in the group E with the difference being statistically significant (P 6.5 microns) in the group D was greater than in the control group with the difference being statistically significant (P 0.05). It can be concluded that MS can enhance functional recovery and has a considerable effect in the treatment of the peripheral nerve injury.

Motor dysfunction on the nonhemiplegic side in patients with intracerebral haemorrhage.

This study was undertaken to evaluate the motor dysfunction on the nonhemiplegic side in patients with acute intracerebral haemorrhage (ICH) and correlate these with radiological and motor evoked potentials findings. 28 patients (23 males, 5 females), with CT proven ICH within 10 days of ictus were subjected to clinical evaluation and central motor conduction studies (CMCT) of upper limbs. The patient's age ranged between 28 and 84 years. Motor signs on the nonhemiplegic side were present in 17 patients in the form of increased tone (10), hyperreflexia (13) and extensor plantar response (10). Sixteen of these patients had severe weakness on the hemiplegic side. Most of the patients had putaminal haemorrhage (13) and thalamic and lobar haemorrhage was seen in 2 patients each. The motor dysfunction on the nonhemiplegic side correlated with midline shift but not with the size of haematoma. CMCT findings correlated with motor signs on the nonhemiplegic side in 6 patients. In the patients without any signs on the nonhemiplegic side, CMCT was normal. Out of 17 patients with motor dysfunction on the nonhemiplegic side 9 revealed improvement in CMCT at 1 month followup. The patients with CMCT abnormalities on the nonhemiplegic side either died (2) or had poor outcome (9). Motor dysfunction on the nonhemiplegic side may be due to tentorial herniation and suggests a poor outcome.

Carpal tunnel syndrome - electrodiagnostic aspects of fifty seven symptomatic hands.

Electrodiagnostic data of fifty seven symptomatic extremities with carpal tunnel syndrome (CTS) are described. Practice recommendations made by American Academy of Neurology, American Association of Electrodiagnostic Medicine and American Academy of Physical Medicine and Rehabilitation regarding electrodiagnostic studies were considered while confirming CTS diagnosis by electrodiagnostic studies. Median sensory nerve conduction studies were the commonest abnormalities noted. The median orthodromic sensory latencies were prolonged in 86% and sensory nerve action potential amplitude abnormalities were seen in 82%. Prolongation of the conduction in the short segment across the wrist in the median nerve was seen in 96.5% and the difference in the conduction between median and ulnar nerve across the wrist was significant in all the 57 extremities. The median motor latencies were prolonged in 67% of hands. Higher incidence of electrodiagnostic abnormalities observed in this study might be due to inclusion of patients with severe disease.

Factor de crecimiento neuronal y sus posibles implicaciones terapéuticas en la actualidad / Nerve growth factor and its possible therapeutical implications today

Desde 1934 se realizaron estudios analizando los efectos que sobre las células sensitivas y neuronas motoras espinales que inervaban las extremidades de animales, producía la extirpación de primordios nerviosos. Las observaciones obtenidas de estos estudios (después de algunos años) permitieron el descubrimiento de un factor promotor del crecimiento neuronal, al cual se designó como factor de crecimiento neuronal (NGF). El NFG es la sustancia mejor caracterizada dentro de una familia de moléculas que se requieren para la supervivencia y el desarrollo de neuronas durante etapas embrionarias del crecimiento y durante la vida adulta. Se ha observado que, bajo ciertas circunstancias, la infusión exógena de BGF puede promover la supervivencia neuronal y la regeneración axonal, por lo cual, en la actualidad, se ha intentado la utilización de este factor para mejorar algunas condiciones patológicas en las cuales el principal componente es el daño neuronal, pudiendo producirse este último por diferentes mecanismos. Dado lo anterior, se ha postulado que la administración de BGF recombinante humano pudiera ser, en el futuro, de utilidad para el tratamiento de enfermedades del sistema nervioso central y periférico, ya que en algunos de los estudios realizados se ha demostrado que este factor puede tener efectos benéficos