Unión cráneo-cervical - anatomía normal y correlación con imágenes / Cranio Cervical Junction - Anatomy and Imaging Correlation

La solicitud de estudios de imagen en pacientes con trauma cervical es muy frecuente en la práctica diaria. Esa patología es causa relativamente frecuente de discapacidad en pacientes jóvenes junto con el trauma encéfalo craneano. En un porcentaje no despreciable de los casos, las lesiones traumáticas comprometen la unión cráneo- cervical y en esos pacientes, la morbi-mortalidad es más significativa. La transición entre el cráneo y el raquis se basa en un conjunto de estructuras óseas relacionadas por articulaciones muy móviles y estabilizadas por un grupo de ligamentos y músculos que le brindan al mismo tiempo gran solidez. Para una correcta interpretación de los estudios de imagen de uso corriente en la clínica, es fundamental un sólido conocimiento anatómico de la unión cráneo-cervical y sus componentes. Es el objetivo de esta revisión, sistematizar la anatomía de la unión cráneo-cervical con especial énfasis en sus ligamentos, analizar la fisiología de sus movimientos y el concepto de estabilidad para luego realizar una correlación con tomografía computada multi-detector y resonancia magnética.

The request of imaging techniques in patients with cervical spine trauma is very common in clinical practice. Cervical trauma is a relatively common cause of disability in young patients. In a significant percentage of cases traumatic injuries compromise the cranio-cervical junction with more important morbidity and mortality in this group of patients. The transition between the skull and the spine is based on a set of bony structures, high mobility joints, and stabilization mechanism formed by a group of ligaments and muscles. A solid anatomical knowledge of the cranio-cervical junction and its components is essential for a correct interpretation of current high resolution imaging studies. The goal of this review is highlight the anatomy of the cranio-cervical junction with special emphasis on the ligaments, analyze the biomechanics of their movements and the concept of stability. At last but not leastwe will establish a correlation with multidetector computed tomography and high-resolutionmagnetic resonance imaging.

Measurement of the Mechanical Deformation of Organ of Corti in a Model of Acute Endolymphatic Hydrops / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Endolymphatic hydrops has been considered as an important histologic substrate of Meniere's disease. A permanent displacement of basilar membrane (BM) by increased endolymphatic pressure has been thought to be an explanation for hearing change. Direct observation of histological sections of temporal bones, however, suggested that stereocilia and tectorial membrane decoupling is more associated with pressure induced by mechanical deformation of the organ of Corti rather than with the displacement of BM. METERIALS AND METHOD: 26 cochleae from 13 female pigmented ginea pigs were harvested. One cochlea per each animal was injected with artificial perilymph. The other one was used as control. After fixation, followed by embedding and mid-modiolar sectionning, specimens were observed with a microscope. Morphometric parameters of each row and turn of the organ of Corti were measured and quantified. RESULTS: The average area and height of the organ of Corti were significantly smaller in the apical turn of the experimental group (p<0.05). The lengths of outer hair cell and Deiters cell in the apical turn were also significantly reduced in the experimental group (p<0.05). The angle between the outer hair cell and Deiters cell was smaller in the apex and in the 3rd turn of the experimental group (p<0.05). CONCLUSION: Results show that compression and deformation of the organ of Corti, especially in the apical turn, is a prominent feature in the acute endolymphatic hydrops model. We suggest that the deformation of organ of Corti is the primary cause of hydrops that induce the decoupling of tectorial membrane and stereocilia rather than the displacement of BM.

Avaliação radiológica da transição crânio-vertebral / Radiological evaluation of the craniovertebral junction

A transição crânio-vertebral compreende o occiput, o atlas, o axis, suas articulações e suporte ligamentar. Para sua avaliação, além do estudo radiológico convencional, são necessários exames com parâmetros específicos - campo de visão, espessura de corte e deslocamento adequados na tomografia computadorizada e na ressonância magnética de alta resolução -, bem como estudo dinâmico que viabilize a análise da estabilidade da transição crânio-vertebral e da repercussão sobre a transição bulbo-medular. Este trabalho tem como objetivo revisar a técnica utilizada para estudo da transição crânio-vertebral, os parâmetros da semiologia radiológica e avaliação das entidades que mais freqüentemente a comprometem. Revisamos a literatura e exemplificamos com imagens do arquivo didático do Serviço de Radiologia da Med Imagem do Hospital da Beneficência Portuguesa de São Paulo, casos demonstrativos da anatomia normal, principais entidades patológicas congênitas e adquiridas da transição crânio-vertebral, através de radiologia convencional, tomografia computadorizada e ressonância magnética. Na prática diária, afecções da transição crânio-vertebral são detectadas por tomografia computadorizada e ressonância magnética do encéfalo e da coluna cervical. O conhecimento dessas entidades é fundamental para indicação de exames específicos que possibilitem estudo detalhado da transição crânio-vertebral, fornecendo subsídios para programação terapêutica quando indicada.

Histochemical Staining of PetaNADPH Diaphorase in Mongolian Gerbil and CJU/A Mouse Cochleae / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Nitric oxide (NO) is an inorganic, gaseous free radical that carries a variety of messages between cells. The histochemical demonstration of neuronal betaNADPH-d is the demonstration of the presence of NOS. The purpose of this study was to identify the existence of NOS and the difference of the expression of betaNADPH-d in mouse and gerbil cochleae. MATERIALS AND METHODS: Each of the eight cochleae of Mongolian gerbil (Meriones unguiculatus) and mice (CJU/A) were fixed by cardiac perfusion with 4% paraformaldehyde in 0.1M phosphate buffer solution. The en-bloc cochleae were incubated after decalcification, and stained with betaNADPH-d and counterstained with acid fuchsin. The relative intensity of staining was decided in the same location of cochlea. RESULTS: Most supporting cells were strongly stained except Claudius cells and Boettcher's cells in gerbil. However, Boettcher's cells were strongly stained in mice. Outer hair cells, inner hair cells, basial membrane and lining cells of spiral limbus were strongly stained. Interdental cells of spiral limbus, inner border cells and intermediate cells of stria vascularis were moderately stained. Tectorial membrane and amorphous layer of basial membrane were not stained. CONCLUSION: Using betaNADPH-d staining, this study documents the presence of nitric oxide synthase in mice and gerbil cochleae and the difference of staining between two species.