Alteración de las fibras finas A-delta por entrampamiento del nervio mediano en la muñeca utilizando el período silente cutáneo / The impairment of A-delta fibers in median nerve compression at the wrist, using the cutaneous silent period

El síndrome del túnel carpiano (STC) es una neuropatía por entrampamiento a nivel de la muñeca que cursa con dolor, parestesias y disestesias dolorosas. El diagnóstico electrofisiológico se basa en el estudio de la neuroconducción de las fibras gruesas. Nuestra hipótesis consiste en la existencia del compromiso de las fibras nerviosas finas y que este compromiso se correlaciona con el grado de gravedad. Se evaluaron retrospectivamente 69 manos correspondientes a 47 pacientes, varones y mujeres (edad media 53.8, rango 22-87 años) y como grupo contro, 21 manos correspondientes a los lados asintomáticos de estos casos. Se realizaron estudios de neuroconducción motora, sensitiva y ondas F para clasificar a las manos según el grado de gravedad. Se realizó el período silente cutáneo (PSC) en todas las manos. Se evaluaron latencias medias y duraciones medias del PSC. Las latencias medias se hallaron significativamente prolongadas en las manos con neuropatía (84.3 ± 16.3 mseg) con respecto a las manos sin neuropatía (74.8 ± 11.6 mseg), p < 0.05. Las latencias medias se hallaron más prolongadas en las manos con neuropatía de mayor gravedad (p < 0.05). En los 3 pacientes con neuropatía grado más grave no se halló el PSC. Se demostró el compromiso de las fibras finas A-delta en los pacientes con STC, con mayor compromiso a mayor severidad. El PSC puede usarse como complemento de los estudios de neuroconducción motora y sensitiva.

Carpal tunnel síndrome (CTS) is an entrapment neuropathy of the median nerve at the wrist, that leads to pain, paresthesia and painful dysesthesia. The electrophysiological diagnosis is based upon nerve conduction studies which evaluate thick nerve fibers. Our hypothesis is that there is an additional dysfunction of small fibers in CTS, which correlates with the degree of severity of the neuropathy. A retrospective study of 69 hands that belonged to 47 patients of both sexes (mean age 53.8, years, range 22-87) was performed, and, as a control group, 21 hands which corresponded to the asymptomatic side of those patients were evaluated. Motor and sensory conduction studies, as well as F-waves were performed to classify the neuropathy according to the degree of severity. Cutaneous silent period (CSP) was elicited in all hands. Mean onset latencies and durations of CSP were evaluated. Mean onset latencies were significantly prolonged in neuropathic hands (84.3 ± 16.3 msec) compared to asymptomatic hands (74.8 ± 11.6 msec) (p < 0.05). Mean latencies of the CSP were even prolonged (p < 0.05) in hands affected by a more severe neuropathy. In the 3 hands with most severe neuropathy, a CSP could not be elicited. In CTS an impairment of A-delta fibers was recorded through the CSP. The more severe the neuropathy is, the more impairment of A-delta fibers can be found. CSP may be assessed as a complement of motor and sensory nerve conduction studies in this neuropathy.

Cognitive performance of primary open-angle glaucoma and normal-tension glaucoma patients / Desempenho cognitivo em pacientes com glaucoma primário de ângulo aberto e glaucoma de pressão normal

ABSTRACT Purpose: To assess cognitive performance differences among primary open-angle glaucoma (POAG) patients, normal-tension glaucoma (NTG) patients, and healthy control (C) subjects. Methods: A total of 60 participants (20 POAG, 20 NTG, and 20 C subjects) were included in this study. A detailed ophthalmologic examination was performed on all participants. A spectral domain-optical coherence tomography (SD-OCT) system was used to measure the ganglion cell-inner plexiform layer (GC-IPL) and retinal nerve fiber layer (RNFL) thicknesses. To assess the cognitive performance of all participants, detailed neurological examinations, including the mini-mental state examination (MMSE), were performed by the same neurologist. Results: There were no significant differences among the groups in terms of age (p =0.348) or gender (p =0.935). The mean RNFL thicknesses were significantly different among the groups (85.2 ± 14.7, 76.8 ± 10.3, and 91.4 ± 7.7 µm in the POAG, NTG, and C subjects, respectively; p <0.001). The mean GC-IPL thicknesses were 77.5 ± 9.7 µm in the POAG group, 73.4 ± 7.8 µm in the NTG group, and 78.8 ± 3.8 µm in the C group. Differences among the groups were not statistically significant (p =0.085). MMSE scores were 26.1 ± 1.4, 25.7 ± 2.3, and 28.8 ± 0.9 in the POAG, NTG, and C groups, respectively. There were significant differences among the three groups (p <0.001). Specifically, there were significant differences between the NTG and C groups (p <0.001), and between the POAG and C groups (p =0.001). There was no significant difference between the POAG and NTG groups (p =0.595). Conclusions: There appear to be similar risk factors in glaucoma and neurodegenerative disorders that cause deterioration in cognitive performance. Comparing the low MMSE scores of the POAG and NTG patients with the scores of healthy C participants supports our hypothesis. Consequently, it is recommended that a neurologist should also examine glaucoma patients.

RESUMO Objetivos: Avaliar as diferenças de desempenho cognitivo entre pacientes com glaucoma primário de ângulo aberto (POAG), glaucoma de pressão normal (NTG) e controle de indivíduos saudáveis (C). Métodos: Um total de 60 pessoas (20 POAG, 20 NTG e 20 indivíduos saudáveis) foram incluídos neste estudo. Um exame oftalmológico detalhado foi realizado em todos os participantes. Um sistema de tomografia de coerência óptica de domínio espectral (SD-OCT) foi utilizado para medir as espessuras da camada de células ganglionares plexiforme interna (GC-IPL) e da camada de fibras nervosas da retina (RNFL). Para avaliar o desempenho cognitivo de todos os participantes, foi realizado pelo mesmo neurologista um exame neurológico detalhado, incluindo mini-exame do estado mental (MMSE). Resultados: Não houve diferenças significativas entre os grupos em termos de idade (p=0,348) e sexo (p=0,935). Espessuras médias da RNFL foram significativamente diferentes, sendo 85,2 ± 14,7, 76,8 ± 10,3 e 91,4 ± 7,7 µm nos grupos POAG, NTG e controles, respectivamente (p<0,001). As espessuras médias da GC-IPL observadas foram 77.5 ± 9.7 μm no grupo POAG, 73,4 ± 7,8 µm no grupo NTG e 78,8 ± 3,8 µm nos controlos. As diferenças entre os grupos não foram estatisticamente significantes (p=0,085). Graduações do MMSE foram 26,1 ± 1,4, 25,7 ± 2,3 e 28,8 ± 0,9 nos grupos POAG, NTG e controles, respectivamente. Houve diferenças significativas entre os três grupos (p<0,001). Houve diferença significativa entre NTG e saudáveis (p<0,001). Houve diferença significativa entre POAG e saudáveis (p=0,001). Não houve diferença significativa entre o POAG e NTG (p=0,595). Conclusões: Parecem haver fatores de risco semelhantes no glaucoma e nos distúrbios neurodegenerativos que causam deterioração no desempenho cognitivo. Comparando a baixa graduação do MMSE de pacientes com POAG e NTG com controles saudáveis referenda nossa hipótese. Consequentemente recomenda-se que um neurologista também examine os pacientes de glaucoma.

Small fiber dysfunction in patients with Wilson's disease / Disfunção de fibras finas em pacientes com doença de Wilson

Objective: Patients with Wilson’s disease (WD) may develop a wide variety of neuropsychiatric symptoms, but there are few reports of autonomic dysfunction. Here, we described evidence of small fiber and/or autonomic dysfunction in 4 patients with WD and levodopa-responsive parkinsonism. Method: We reviewed the charts of 4 patients with WD who underwent evaluation for the presence of neuromuscular dysfunction and water-induced skin wrinkling test (SWT). Results: Two men and 2 women (33±3.5 years) with WD were evaluated. They all had parkinsonism at some point during their disease course. Parkinsonism on patient 4 almost completely subsided with treatment of WD. Two patients had significant sensory and 2 significant autonomic complaints, including syncopal spells. NCS/EMG was normal in all but SWT was abnormal in half of them (mean 4-digit wrinkling of 0.25 and 1). Discussion: A subset of patients with WD exhibit evidence of abnormal skin wrinkling test (small fiber neuropathy). .

Objetivo: Pacientes com doença de Wilson (DW) podem desenvolver uma ampla variedade de sintomas neuropsiquiátricos, mas existem poucos relatos de disfunção autonômica. Aqui, nós descrevemos evidência de disfunção de fibras finas/autonômica em 4 pacientes com DW e parkinsonismo responsivo à levodopa. Método: Nós revisamos os prontuários de 4 pacientes com DW que foram submetidos a avaliação neuromuscular e ao teste de quantificação do enrugamento cutâneo (TEC). Resultados: Dois homens e 2 mulheres (33±3,5 anos) com DW foram avaliados. Todos apresentaram parkinsonismo durante o curso de sua doença. Parkinsonismo no paciente 4 quase completamente desapareceu com tratamento da DW. Dois pacientes apresentaram queixas sensitivas e 2 apresentaram queixas autonômicas significativas incluindo episódios de síncope. Eletroneuromiografia foi normal em todos e TEC foi anormal em metade deles (score do TEC nos 4 dedos de 0,25 e 1). Discussão: Um subgrupo de pacientes com DW apresenta evidência de TEC anormal (neuropatia de fibras finas). .

Effect of electrical stimulation of the cranial tibial muscle after end-to-side neurorrhaphy of the peroneal nerve in rats

PURPOSE: To investigate the efficiency of electrical stimulation in the muscle maintenance and nerve regeneration after end-to-side neurorrhaphy (ESN). METHODS: Sixty male Wistar rats (Rattus norvegicus) were divided into four experimental groups. Control group (Control), Denervated Group (Denervated); Group with End-to-side neurorrhaphy (ESN); Group with End-to-side neurorrhaphy and electrical stimulation (ESN + ES). We perform electrical stimulation in rats after they had undergone muscle reinnervation by ESN. We collected morphometric and functional data. RESULTS: When comparing the mass of the treated side of cranial tibial muscle (CTM) and that of normal side of CTM, the group ESN + ES (26.12%) exhibited lower mass loss than that of group ESN (37.23%). The peroneal functional index showed that group ESN + ES equaled that of the Control group and showed an evolution of 60.5% while group ESN showed an evolution of 9.5%. In measuring maximum strength of CTM, the group ES + ESN outperformed group ESN. The muscle and nerve morphometry showed superiority of group ES+ESN over ESN group in all parameters. CONCLUSION: Electrical stimulation is an effective means of maintaining functional muscle and nerve regeneration after end-to-side neurorrhaphy.

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.

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.

Anatomic variation of cranial parasympathetic ganglia

Having broad knowledge of anatomy is essential for practicing dentistry. Certain anatomical structures call for detailed studies due to their anatomical and functional importance. Nevertheless, some structures are difficult to visualize and identify due to their small volume and complicated access. Such is the case of the parasympathetic ganglia located in the cranial part of the autonomic nervous system, which include: the ciliary ganglion (located deeply in the orbit, laterally to the optic nerve), the pterygopalatine ganglion (located in the pterygopalatine fossa), the submandibular ganglion (located laterally to the hyoglossus muscle, below the lingual nerve), and the otic ganglion (located medially to the mandibular nerve, right beneath the oval foramen). The aim of this study was to present these structures in dissected anatomic specimens and perform a comparative analysis regarding location and morphology. The proximity of the ganglia and associated nerves were also analyzed, as well as the number and volume of fibers connected to them. Human heads were dissected by planes, partially removing the adjacent structures to the point we could reach the parasympathetic ganglia. With this study, we concluded that there was no significant variation regarding the location of the studied ganglia. Morphologically, our observations concur with previous classical descriptions of the parasympathetic ganglia, but we observed variations regarding the proximity of the otic ganglion to the mandibular nerve. We also observed that there were variations regarding the number and volume of fiber bundles connected to the submandibular, otic, and pterygopalatine ganglia.

Oseopercepción: la sensibilidad mediada por los implantes oseointegrados / Osseoperception: the sensibility mediated by osseointegrated implants

En la búsqueda de soluciones al problema de la edentación parcial o total, los implantes dentales se han ganado un lugar destacadodebido a su predecibilidad, estética, comodidad y función mejorada respecto a otras opciones restauradoras. El anclaje óseode los implantes brinda estabilidad a la restauración y tiene la capacidad de transmitir las fuerzas directamente al hueso. Estoúltimo permite, a su vez, poner en marcha una nueva modalidad sensorial descripta recientemente como oseopercepción. Estainformación periférica provoca un reordenamiento de los mapas sensitivos y motores en la corteza cerebral, lo que implica unamejoría en la percepción consciente del estímulo respecto a la situación de edentación y nueva información para el ajuste de lafunción motora mandibular. La evidencia experimental demuestra que las rehabilitaciones sobre implantes dentales presentanumbrales de detección táctil pasivos y activos aumentados en comparación con los dientes naturales. Se discute si esta capacidaddiscriminativa proviene de receptores residuales del ligamento periodontal o si depende de brotes de nuevas fibras nerviosas en lainterfase hueso-implante o bien de otros receptores ubicados a distancia de los mismos.

aesthetics, comfort and better function when compared to other restorative solutions. The bone anchored implants give stabilityto the restoration, and allow the transmission of forces directly to the bone. This fact is the basis of a new sensorial modalitycalled osseoperception. This new peripheral information leads to rearrangements of sensory-motor cortical maps, which improvesthe conscious perception of stimuli with respect to the edentulous situation and permit adjustment of motor mandible function.The passive and active tactile thresholds are higher in osseointegrated implants than in natural teeth. It is still unknown whetherthis discriminative ability depends on remnant receptors from the periodontal ligament, on the sprouting of nerve fibres in thebone-implant interface, or on other receptors placed not so close to the implants.

Modelo experimental comportamental e histológico da regeneração do nervo facial em ratos / Behavioral and histologic experimental model of facial nerve regeneration in rats

O estabelecimento de modelos experimentais é o passo inicial para estudos de regeneração neural. OBJETIVO: Estabelecer modelo experimental de regeneração do nervo facial. MATERIAIS E MÉTODOS: Ratos Wistar com secção completa e sutura do tronco do nervo facial extratemporal, com análise comportamental e histológica até 9 semanas. FORMA DE ESTUDO: Estudo prospectivo experimental. RESULTADOS: Progressiva recuperação clínica e histológica dos animais. CONCLUSÃO: Estabelecemos um método aceitável para o estudo de regeneração do nervo facial em ratos.

To setup an experimental model is the first step to study neural regeneration. AIM: Setting up an experimental model on facial nerve regeneration. MATERIAL AND METHODS Wistar rats with complete sectioning and suturing of the extratemporal facial nerve trunk; with a behavioral and histological analysis for 9 weeks. STUD DESIGN: Experimental prospective study. RESULTS: Progressive clinical and histological recovery of the animals. CONCLUSION: Our method is acceptable to study facial nerve regeneration in rats.

Agrupamento de sensações somatossensoriais com estimulação de corrente senoidal / Clustering of somatosensory sensations during sinusoidal current stimulation

Fibras finas (FF) aferentes primárias mediam a percepção de sensações relacionadas à dor e à temperatura, e as fibras grossas (FG) ao tato. O objetivo deste trabalho é avaliar percepções relacionadas às FF (picada, pontada, agulhada, queimação) e às FG (aperto, pressão, vibração e movimento)evocadas por estimulação elétrica senoidal com 5 Hz e 2 kHz, respectivamente. O dedo indicador da mão esquerda de 150 voluntários, sem doença neurológica conhecida e medicação, foram estimulados nessas frequências com intensidades decorrente igual ao limiar de sensibilidade (LS) e 1,5 vezes LS.O voluntário escolheu das 8 palavras, 3 que mais se aproximavam à sua percepção do estímulo. Outro grupo de 60 voluntários foi utilizado como controle, sendo que as 3 palavras foram escolhidas sem nenhuma estimulação. O valor de “1” foi atribuído à palavra escolhida, e “0” à não selecionada. As sensações foram agrupadas utilizando-se o vizinho mais próximo (single linkage) e a correlação entre variáveis binárias(tetrachloric correlation). Os resultados indicam uma tendência a sensações de fibras grossas sem estimulação, sendo que 5 Hz evoca principalmente as sensações de fibras finas e 2 kHz as de fibras grossas. A exceção foi a sensação de FF queimação, a qual se mostrou inconsistente em ambos os grupos.

Thin fibers mediate the perception related to temperature and painful sensations, and thick fibers the perception related to touch. This work tries to evaluate the perceptions related to thin (prick, pang, twinge and burning) and thick fibers (squeeze, pressure, movement and vibration) evoked by sinusoidal stimulation with 5 Hz and2 kHz, respectively. The left index fingers of 150 volunteers, without known neurological problems or under medication, were stimulatedat these frequencies and at current intensities equal to the sensory threshold and 1.5 times the sensory threshold. The volunteers chose three words out of eight that better represented the sensation felt during the stimulus. Another group of 60 volunteers was used as control, for which the three words were chosen with no stimulation. The value “1” was attributed to each sensation chosen and “0” forthe others. The sensations were clustered using the single linkage nearest neighbor method and the tetrachloric correlation between binary variables. The results showed a tendency to thick fiber sensations with 2 kHz or no stimulation, while 5 Hz evoked thin fiber sensations. The exception was the FF sensation of burning, which did not fit into any group.

Perceptions and electric senoidal current stimulation

OBJETIVO: Estudar a relação entre as sensações evocadas por estimulação elétrica por corrente senoidal (ESCS). MÉTODO: 100 voluntários normais foram estudados. ESCS a 5 Hz e 2 kHz foram aplicadas no dedo indicador esquerdo com uma e 1,5 vezes o limiar sensorial. Listas de oito palavras (4 relacionadas a fibras grossas, 4 a fibras finas) foram apresentadas após cada estimulação e foi solicitado que o sujeito escolhesse as 3 palavras que mais se aproximassem das sensações experimentadas. Às palavras escolhidas foi dado o escore 1. Os resultados finais para análise foram obtidos da soma dos escores para as palavras relacionadas aos diferentes sistemas de fibras. RESULTADOS: Para ESCS a 5 Hz sensações relacionadas a fibras finas foram significantemente mais escolhidas, já para estimulações a 2 kHz sensações relacionadas a fibras grossas foram significantemente mais escolhidas. CONCLUSÃO: Estes resultados mostram um relação entre diferentes percepções e diferentes freqüências de correntes elétricas senoidais.

Near nerve potential of sural nerve in leprosy

Na hanseníase, as fibras de pequeno calibre são acometidas antes que as fibras mais grossas, ocasião em que o estudo da condução torna-se anormal. Neste estudo, utilizou-se a técnica de registro com eletrodos justa-nervo com a finalidade de aumentar a precocidade e a acurácia diagnóstica, devido à sua capacidade de detectar potenciais oriundos de fibras com cerca de 3-6 mm. Contrário às nossas expectativas, o componente principal do potencial sensitivo do nervo sural foi anormal em todos os pacientes, enquanto a velocidade de condução mínima foi normal ou discretamente alterada em 3 pacientes. Além disso, os resultados são sugestivos de degeneração axonal e não mielinopatia, como seria esperado em uma doença que compromete inicialmente a bainha de mielina. Para um melhor entendimento da fisiologia e fisiopatologia, e para aumentar a precocidade diagnóstica, é fundamental estudar casos bem precoces e correlacionar os dados neurofisiológicos com a respectiva anatomia patológica.

Bases neurofisiológicas para el manejo clínico del complejo dentinopulpar / Neurophysiological basis for the clinical management of the dentino pulpal complex

El complejo dentinopulpar cuenta con una inervación muy abundante. Por el foramen apical de cada diente humano pasan de1000 a 2000 fibras nerviosas. De ellas el 75 por ciento son amielínicas –fibras C- y el 25 por ciento mielínicas -la mayoría Aδ y pocas Aβ -. Lasramificaciones de las fibras Aδ penetran de 100 a 200 micrómetros en aproximadamente la mitad de los túbulos dentinarios,inervando la porción más interna de la dentina. Las terminaciones de las fibras nerviosas funcionan como receptores. Existiríantres grupos de receptores intradentarios: nociceptores específicos, receptores polimodales y posiblemente mecanorreceptores.Los dos primeros proveen información de alerta frente al daño tisular y su estimulación produce sensaciones dolorosas. Lasfibras Aδ intradentales median el dolor agudo intenso, pasajero, típico de la sensibilidad dentinaria. Diversos estímulos (térmicos,mecánicos, osmóticos, etc.) provocan flujo de líquido dentro de los túbulos dentinarios y es este flujo el que estimula a lasfibras nerviosas dentinopulpares. La permeabilidad de la dentina expuesta es una de las variables más importantes en la sensibilidaddentinaria. Las fibras intradentales C median el dolor sordo, difuso, mal localizado y prolongado. Hay pocas evidencias deque los estímulos mecánicos puedan causar una sensación diferente a la dolorosa cuando se aplican al complejo dentinopulpar.Existen también algunas fibras nerviosas autonómicas que tendrían función en la regulación del flujo vascular pulpar...

The dental pulp and dentin are very innervated. Between one and two thousand nerve fibers pass through the apical foramen of ahuman tooth. 75 percent of them are amielinic C-fibers and the rest are mielinic fibers, most of them from the Aδ and some from the Aβtypes. The Aδ endings penetrate 100 –200 micrometers in near half the dentin tubules, innervating the inner portion of the dentin.The endings of the nerve fibers act like receptors. There are three types of intradental receptors: specific nociceptors, polimodalreceptors and probably mechanoreceptors. The first two types provide information about threat of tissue damage and theirstimulation leads to painful sensations. Intradental Aδ fibers mediate sharp temporary pain characteristic of dentin sensibility.Many stimuli (thermal, mechanic, osmotic, etc.) produce fluid flow inside the dentinal tubules, and this flow stimulates dentinopulpalnerve fibers. The permeability of the exposed dentin is one of the main variables in dentin sensibility. Intradental C-fibers mediatedull, bad localized, diffuse pain. There is little evidence that the mechanical stimuli produce a sensation different than pain whenapplied to the dentinopulpal complex. There are some intradental autonomic fibers that may play a role in pulpal blood flowregulation...

An un usual course of the Nervus Conarii in the pineal glandof the tinamid bird Crypturellus parvirostris. A case report

The pineal gland is innervated by postganglionic sympathetic nerves from the superior cervical ganglion. As theaxons enter the gland, they synapse with the pinealocytes. In this report, we describe a case in which the conarii nervewas observed crossing the distal portion of the ascending branch of the venous sinus, thus penetrating the capsule ofthe pineal gland. The nerve observed consisted of a bundle of unmyelinated axons and collagen fibers which aresurrounded by endothelial cells. This is the first report of a completely engulfed and detached conarii nerve within avenous sinus.

Avaliação da mácula e camada de fibras nervosas peripapilar em olhos normais, glaucomatosos e com suspeita de glaucoma utilizando a tomografia de coerência óptica / Optical coherence tomography measurement of macular and peripapillar nerve fiber layer thickness in normal, glaucoma suspect and glaucomatous eyes

Esse estudo transversal avalia a espessura macular e da camada de fibras nervosas peripapilar em olhos normais, glaucomatosos e suspeitos com a unidade protótipo de tomografia de coerência óptica. Foram estudados 534 olhos, incluindo 166 normais, 196 com glaucoma inicial, 89 com glaucoma avançado e 83 olhos suspeitos. Todos os parâmetros da camada de fibras nervosas mostraram diferenças estatisticamente significativas entre olhos normais e com glaucoma inicial ou avançado (p = 0,0001). Este fato não aconteceu em relação aos parâmetros maculares. Houve diminuição da espessura macular e da camada de fibras nervosas em olhos glaucomatosos, sendo que a redução desta última parece ser superior.This cross-sectional study evaluates macular and peripapillary nerve fiber layer thickness in normal, glaucoma suspect and glaucomatous eyes. It was used prototype optical coherence tomography unit to measure macular and nerve fiber layer thickness. It was studied 534 eyes, including 166 normal, 83 of glaucoma suspects, 196 of early and 89 eyes of advanced glaucoma. All nerve fiber layer parameters were statistically significantly different comparing normals and either early or advanced glaucoma (p=0.0001). This did not happen for macular parameteres. Nerve fiber layer and macular thickness measurements were reduced in glaucoma, although nerve fiber layer thickness was more reduced...

Apoptosis of sensory neurons and satellite cells after sciatic nerve transection in C57BL/6J mice

The rate of axonal regeneration, after sciatic nerve lesion in adult C57BL/6J mice, is reduced when compared to other isogenic strains. It was observed that such low regeneration was not due just to a delay, since neuronal death was observed. Two general mechanisms of cell death, apoptosis and necrosis, may be involved. By using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) technique, we demonstrated that a large number of sensory neurons, as well as satellite cells found in the dorsal root ganglia, were intensely labeled, thus indicating that apoptotic mechanisms were involved in the death process. Although almost no labeled neurons or satellite cells were observed one week after transection, a more than ten-fold increase in TUNEL labeling was detected after two weeks. The results obtained with the C57BL/6J strain were compared with those of the A/J strain, which has a much higher peripheral nerve regeneration potential. In A/J mice, almost no labeling of sensory neurons or satellite cells was observed after one or two weeks, indicating the absence of neuronal loss. Our data confirm previous observations that approximately 40 percent of C57BL/6J sensory neurons die after sciatic nerve transection, and indicate that apoptotic events are involved. Also, our observations reinforce the hypothesis that the low rate of axonal regeneration occurring in C57BL/6J mice may be the result of a mismatch in the timing of the neurons need for neurotrophic substances, and production of the latter by non-neuronal cells in the distal stump

Analisador de fibras nervosas: um estudo sobre os resultados falso-positivo / Nerve fiber analyzer: a study on the false-positive results

Objetivos: Determinar a especificidade do analisador de fibras nervosas-GDx em um grupo de pacientes normais, assim como os índices que mais comumente mostram-se alterados em pacientes deste grupo. Métodos : Foram submetidos a exame oftalmológico completo 50 pacientes normais (näo-glaucomatosos) e na sequência obtida a análise da camada de fibras nervosas destes pacientes, utilizando-se o software GDx (LDT). Foram excluídos os olhos que näo perfaziam os critérios de inclusäo e utilizado apenas um olho de cada paciente após randomizaçäo, perfazendo um total de 34 olhos. Resultados e Conclusöes: Obtivemos 20 exames normais e 14 exames alterados. O índice com maior frequência de alteraçäo foi a simetria (85,71 por cento ), e os com menor frequência "inferior ratio" e "superior ratio" (0 por cento cada). A especificidade obtida foi de 58,8 por cento para 70,5 por cento após correçäo e análise dos dados. Devemos levantar a hipótese de um exame-falso positivo quando um paciente com exame ocular normal mostrar a simetria como único índice alterado ao GDx ,e lembrar do diagnóstico de glaucoma quando um paciente suspeito apresentar alteraçäo de"inferior ratio".

O cerebelo e a aprendizagem motora / The cerebellum and the motor learning

O circuito cerebelar básico, os aspectos anatomofisiológicos e estruturais e as divisöes do cerebelosäo descritos. A aprendizagem motora é caracterizada e seus possíveis mecanismos de controle säo mencionados.