Management of diplopia secondary to neurosurgical injury of the orbital roof

BACKGROUND: Diplopia related to neurosurgical procedures is often consecutive to oculomotor nerve lesions. We hereby report an oculomotor dysfunction secondary to an orbital roof effraction and its treatment. HISTORY AND SIGNS: Following surgery for a left anterior communicating artery aneurysm, a 45-year-old woman reported vertical diplopia associated with a left orbital hematoma. The diagnosis of third cranial nerve palsy was excluded by orbital imaging which revealed an orbital roof defect with incarceration of the levator palpebrae and superior rectus. THERAPY AND OUTCOME: As neurosurgeons advised against muscle adhesiolysis, diplopia was corrected by a two-step procedure on the oculomotor muscles. We first corrected horizontal and torsional deviations by operating on the healthy eye, before correcting the vertical deviation on the fellow eye. This two-step extraocular muscle surgery allowed restoration of binocular single vision in a useful field of gaze. CONCLUSIONS: Diplopia can occur as a rare orbital complication during neurosurgical procedures. Surgery of extraocular muscles can provide good functional results

Reconstruction fronto-orbitaire complexe avec prothèse en PEEK et expansion cutanée : à propos d'un cas [Complex fronto-orbital reconstruction with a PEEK prosthesis and skin expansion: about a case].

INTRODUCTION: Reconstructions of the fronto-orbital area remain a challenge to the reconstructive surgeon, due to the functional and esthetic impact. OBSERVATION: The authors present a case of a complex fronto-orbital reconstruction with a PEEK (PolyEtherEtherKetone) implant, associated with a skin expansion. DISCUSSION: With a follow-up of over three years, the cosmetic result is excellent. The authors believe that this technique is reliable, fast with long-term good results.

La thérapie actuelle du rhabdomyosarcome orbitaire de l'enfant [Update of orbital rhabdomyosarcoma therapy in children]

INTRODUCTION: Rhabdomyosarcoma is the most frequent primitive orbital malignant tumor in children. If the treatment is started as soon as possible after discovery of the disease, the vital prognosis is considerably better than otherwise. The goal of this paper is to present the new therapeutic protocol and to report our experience in this field. MATERIAL AND METHOD: During the past 35 years, 102 cases of orbital tumors were collected in children under 15 years of age: 5 cases of rhabdomyosarcoma were cared for in our department. At the time of tumor diagnosis, the age of our patients ranged from 3 weeks to 13 years. After a biopsy or excision biopsy, all our cases were treated by chemotherapy with or without radiotherapy. Medication was mostly vincristine, ifosfamide and actinomycine D. When the result of the treatment was not satisfactory, carboplatine and epirubicine, vincristine as well as ifosfamide were given. Radiotherapy was performed only in particular cases or in recurrences. CONCLUSION: Rhabdomyosarcoma is a highly malignant tumor. Although rare, it is the most frequent of malignant tumors in children. It is important to keep it in mind in order to perform a biopsy enabling quick diagnosis and treatment following the modern protocol giving the highest chances of survival to these patients: about 98% in 3 years.

Metodologia para reconhecimento de três solos por sensores: laboratorial e orbital

O presente trabalho teve como objetivo estabelecer um método para a utilização de dados espectrais, obtidos em laboratório e imagens do Landsat 5, no reconhecimento e discriminação de três classes de solos do estado de São Paulo. Foram coletadas amostras de solo e obtidos os dados de reflectância por espectrorradiômetro em laboratório como padrão de um Latossolo Vermelho distroférrico (LVdf), um Argissolo Vermelho-Amarelo (PVA) e Neossolo Quartzarênico (RQ). Foram extraídos dados de reflectância das imagens, com os quais se efetuou a classificação digital pelo classificador Spectral Angular Mapper. As curvas espectrais obtidas por espectrorradiômetro em laboratório mostraram três padrões distintos de comportamento espectral, baseados nas diferenças da forma das curvas, feições de absorção dos minerais do solo e na intensidade de reflectância. O LVdf apresentou menor albedo em virtude da textura argilosa e maiores teores de Fe, ao contrário dos solos mais arenosos PVA e RQ. As bandas de absorção características da caulinta (2.200 nm), OH- e água (1.400 e 1.900 nm) ocorreram em todos os solos. Solos arenosos, como o RQ, apresentaram uma curva espectral com tendência positiva. A linha do solo mostrou distinção espectral, tanto com dados orbitais como terrestres, indicando que cada solo tem uma tendência individual. Os padrões espectrais obtidos em laboratório foram importantes para a eficiência do método na detecção dos mesmos nas imagens de satélite. Os solos avaliados podem ser discriminados e reconhecidos pela interpretação quantitativa em imagens. O método mostrou-se eficiente como auxílio no mapeamento de solos no nível semidetalhado de alta intensidade.

Comportamento espectral dos solos na paisagem a partir de dados coletados por sensores terrestre e orbital

Parte da variabilidade dos índices de produção agrícola está associada com as características do solo e da paisagem. Dessa forma, práticas de manejo, como a adubação, devem levar em consideração esta variabilidade. O sensoriamento remoto é uma ferramenta que pode fornecer, de maneira rápida, informações para o manejo do solo, pois relaciona a radiação eletromagnética com os atributos do solo. Assim, este trabalho teve como objetivo avaliar o comportamento espectral, em dois níveis de aquisição de dados (terrestre e orbital), de diferentes classes de solos ao longo de toposseqüências na região de São Carlos e Ibaté, SP. Para isso, amostras de terra georreferenciadas foram coletadas em 319 pontos, em três profundidades. Em seguida, obtiveram-se os dados radiométricos em laboratório, na faixa espectral entre 450 e 2.500 nm. Os mesmos locais amostrados na camada superficial, no campo, foram avaliados na imagem de satélite. A partir dos resultados obtidos, pode-se concluir que: (a) teores de areia grossa, argila e matéria orgânica, e cor tiveram relação com a reflectância dos solos; (b) ao longo das vertentes ocorrem variações nos dados espectrais dos solos; e (c) solos da mesma ordem taxonômica, porém com classes texturais diferentes, apresentam diferentes comportamentos espectrais, podendo ser discriminados por sensoriamento remoto.

Metastases orbitaires de melanome malin. [Orbital metastasis in malignant melanoma]

We report the case of a 60-year-old man presenting bilateral progressive proptosis with diplopia, weight loss, tachycardia, nervosity, and stomach pain. These signs seemed at first to favor a diagnosis of Graves'ophthalmopathy. Thyroid tests were negative and the initial orbital CT scan was considered normal. A new radiological investigation 4 months later in our hospital revealed typical hypertrophy of the extraocular muscles compatible with orbital metastasis. The systemic investigations demonstrated a pulmonary tumor, multiple hepatic lesions, and several pigmented nodules of gastric mucosa. The pathology of pulmonary and gastric specimens confirmed the diagnosis of malignant melanoma. The primary lesion remains unknown. The authors discuss the differential diagnoses of orbital metastasis and the radiological characteristics of orbital metastasis in malignant melanoma.

Accuracy and predictability in use of AO three-dimensionally preformed titanium mesh plates for posttraumatic orbital reconstruction: a pilot study.

The aim of this study was to prospectively evaluate the accuracy and predictability of new three-dimensionally preformed AO titanium mesh plates for posttraumatic orbital wall reconstruction.We analyzed the preoperative and postoperative clinical and radiologic data of 10 patients with isolated blow-out orbital fractures. Fracture locations were as follows: floor (N = 7; 70%), medial wall (N = 1; 1%), and floor/medial wall (N = 2; 2%). The floor fractures were exposed by a standard transconjunctival approach, whereas a combined transcaruncular transconjunctival approach was used in patients with medial wall fractures. A three-dimensional preformed AO titanium mesh plate (0.4 mm in thickness) was selected according to the size of the defect previously measured on the preoperative computed tomographic (CT) scan examination and fixed at the inferior orbital rim with 1 or 2 screws. The accuracy of plate positioning of the reconstructed orbit was assessed on the postoperative CT scan. Coronal CT scan slices were used to measure bony orbital volume using OsiriX Medical Image software. Reconstructed versus uninjured orbital volume were statistically correlated.Nine patients (90%) had a successful treatment outcome without complications. One patient (10%) developed a mechanical limitation of upward gaze with a resulting handicapping diplopia requiring hardware removal. Postoperative orbital CT scan showed an anatomic three-dimensional placement of the orbital mesh plates in all of the patients. Volume data of the reconstructed orbit fitted that of the contralateral uninjured orbit with accuracy to within 2.5 cm(3). There was no significant difference in volume between the reconstructed and uninjured orbits.This preliminary study has demonstrated that three-dimensionally preformed AO titanium mesh plates for posttraumatic orbital wall reconstruction results in (1) a high rate of success with an acceptable rate of major clinical complications (10%) and (2) an anatomic restoration of the bony orbital contour and volume that closely approximates that of the contralateral uninjured orbit.

A subcritical instability of wave-driven alongshore currents

The development of shear instabilities of a wave-driven alongshore current is investigated. In particular, we use weakly nonlinear theory to investigate the possibility that such instabilities, which have been observed at various sites on the U.S. coast and in the laboratory, can grow in linearly stable flows as a subcritical bifurcation by resonant triad interaction, as first suggested by Shrira eta/. [1997]. We examine a realistic longshore current profile and include the effects of eddy viscosity and bottom friction. We show that according to the weakly nonlinear theory, resonance is possible and that these linearly stable flows may exhibit explosive instabilities. We show that this phenomenon may occur also when there is only approximate resonance, which is more likely in nature. Furthermore, the size of the perturbation that is required to trigger the instability is shown in some circumstances to be consistent with the size of naturally occurring perturbations. Finally, we consider the differences between the present case examined and the more idealized case of Shrira et a/. [ 1997]. It is shown that there is a possibility of coupling between triads, due to the richer modal structure in more realistic flows, which may act to stabilize the flow and act against the development of subcritical bifurcations. Extensive numerical tests are called for.

Rehabilitation of orbital cavity after total orbital exenteration using oculofacial prostheses anchored by osseointegrated dental implants posed as a one-step surgical procedure

BACKGROUND: Total orbital exenteration is a radical surgical procedure, which typically involves the removal of the entire contents of the orbit including the periorbita, leaving the patient with a deep orbital deformity and results in devastating cosmetic, functional, and psychological consequences requiring difficult and challenging procedures for oculoplastic surgeons. Oculofacial prostheses retained by endosseous dental implants present an attractive and viable alternative when aesthetic and functional demands are beyond the capacity of local reconstructive efforts. PATIENTS AND METHODS: A 72-year-old woman presenting a malignant melanoma of the right eyelids and a 77-year-old man presenting a sebaceous carcinoma of the left upper eyelid underwent a total exenteration followed by positioning of endosseous implants (Straumann system Dental implants) as an integrated one-step combined surgical procedure. The oculofacial prosthesis was placed after epithelialization of the orbital cavity. RESULTS: The implants were perfectly osseointegrated without any complications, providing sufficient retention of the prostheses. A satisfactory aesthetic outcome has been achieved for both patients. CONCLUSIONS: Oculofacial prostheses anchored by osseointegrated dental implants placed as one-step surgical procedure ensure an adequate aesthetic result as well as a considerably decreased rehabilitation time and present a satisfactory solution when reconstruction is not a suitable option.

Inhibition of voltage-gated Na(+) currents in sensory neurones by the sea anemone toxin APETx2.

BACKGROUND AND PURPOSE: APETx2, a toxin from the sea anemone Anthropleura elegantissima, inhibits acid-sensing ion channel 3 (ASIC3)-containing homo- and heterotrimeric channels with IC(50) values < 100 nM and 0.1-2 µM respectively. ASIC3 channels mediate acute acid-induced and inflammatory pain response and APETx2 has been used as a selective pharmacological tool in animal studies. Toxins from sea anemones also modulate voltage-gated Na(+) channel (Na(v) ) function. Here we tested the effects of APETx2 on Na(v) function in sensory neurones.¦EXPERIMENTAL APPROACH: Effects of APETx2 on Na(v) function were studied in rat dorsal root ganglion (DRG) neurones by whole-cell patch clamp.¦KEY RESULTS: APETx2 inhibited the tetrodotoxin (TTX)-resistant Na(v) 1.8 currents of DRG neurones (IC(50) , 2.6 µM). TTX-sensitive currents were less inhibited. The inhibition of Na(v) 1.8 currents was due to a rightward shift in the voltage dependence of activation and a reduction of the maximal macroscopic conductance. The inhibition of Na(v) 1.8 currents by APETx2 was confirmed with cloned channels expressed in Xenopus oocytes. In current-clamp experiments in DRG neurones, the number of action potentials induced by injection of a current ramp was reduced by APETx2.¦CONCLUSIONS AND IMPLICATIONS: APETx2 inhibited Na(v) 1.8 channels, in addition to ASIC3 channels, at concentrations used in in vivo studies. The limited specificity of this toxin should be taken into account when using APETx2 as a pharmacological tool. Its dual action will be an advantage for the use of APETx2 or its derivatives as analgesic drugs.

Mineralocorticoid receptor is essential for corticosteroid-induced up-regulation of L-type calcium currents in cultured neonatal cardiomyocytes.

Despite the fact that mineralocorticoid receptor (MR) antagonist drugs such as spironolactone and eplerenone reduce the mortality in heart failure patients, there is, thus far, no unambiguous demonstration of a functional role of MR in cardiac cells. The aim of this work was to investigate the activation pathway(s) mediating corticosteroid-induced up-regulation of cardiac calcium current (ICa). In this study, using neonatal cardiomyocytes from MR or glucocorticoid receptor (GR) knockout (KO) mice, we show that MR is essential for corticosteroid-induced up-regulation of ICa. This study provides the first direct and unequivocal evidence for MR function in the heart.