Search results for "Skull"

New skulls of the basal sauropodomorph Plateosaurus trossingensis from Frick, Switzerland: is there more than one species?

2021

The Triassic basal sauropodomorph Plateosaurus trossingensis is well-known from mass accumulations at the German localities of Trossingen and Halberstadt and the Swiss locality of Frick, and is significant especially regarding its ta-phonomy and proposed developmental plasticity. These implications, however, rely on the assumption that this material derives from a single species, which has been questioned. Here we describe new skull material from Frick including eight complete and six partial skulls, more than doubling the number of known skulls of P. trossingensis. This exceptional sample size allows for gaining a deeper understanding of variability that may occur in a single species. The …

Mismatch negativity (MMN) in freely-moving rats with several experimental controls.

2014

Mismatch negativity (MMN) is a scalp-recorded electrical potential that occurs in humans in response to an auditory stimulus that defies previously established patterns of regularity. MMN amplitude is reduced in people with schizophrenia. In this study, we aimed to develop a robust and replicable rat model of MMN, as a platform for a more thorough understanding of the neurobiology underlying MMN. One of the major concerns for animal models of MMN is whether the rodent brain is capable of producing a human-like MMN, which is not a consequence of neural adaptation to repetitive stimuli. We therefore tested several methods that have been used to control for adaptation and differential exogenou…

Über die Micromelerpetontidae (Amphibia: Temnospondyli). 1. Morphologie und Paläoökologie desMicromelerpeton credneri (Unter-Perm; SW-Deutschland)

1995

This paper presents a redescription of the most important features of the skull roof, palate, hyobranchial apparatus, and the postcranial skeleton ofMicromelerpeton credneri. It is possible to distinguish a temporal sequence of three morphotypes that can be differentiated by size and slight differences in the structure of the skull roof. They led a predaceous existence in the pelagial of three fairly deep lakes that had excellent potential for the preservation of fossils. Comparisons of the size-frequency distributions for specimens from different horizons indicate facultative paedomorphosis by means of progenesis. This phenomenon may be related to different trophic strategies and possible …

Lethal rupture of post-traumatic aneurysm of the vertebral artery case report.

2009

Abstract Traumatic aneurysms or dissections of the vertebral artery have been reported in patients who have suffered minor craniofacial injuries in traffic accidents. A case is reported of ruptured traumatic vertebral artery aneurysm due to closed head injury without without penetrating injuries or skull fractures. The macroscopic and histological findings relevant to the vertebral wall were compatible with post-traumatic aneurysm; the rupture of the wall was assumed to be caused by sepsis and local infiltration of inflammatory cells.

Concept and Treatment of Hydrocephalus in the Greco-Roman and Early Arabic Medicine

2007

In the ancient medical literature hydrocephalus was not often described although its existence and symptomatology were well known. Most detailed descriptions of hydrocephalus including the surgical treatment are extant in the encyclopaedic works on medicine of the physicians Oreibasios and Aetios from Amida from the 4th and 6th centuries AD, respectively. Because of their broad scientific interests, this type of physicians, typical for the late Roman empire, were known as philosophy-physicians (iota alpha tau rho o sigma o phi iota sigma tau alpha iota). They defined hydrocephalus in contrast to our present understanding as a fluid collection excluding abscesses visible as a bulging tumour …

Neumoencefalo a tensión tras herida en cuero cabelludo en portadora de válvula de derivación ventrículo-peritoneal: caso clínico y revisión de la lit…

2009

El neumoencéfalo se produce la mayoría de las veces por una solución de continuidad en el cráneo e incluso en las meninges. En ocasiones, ciertos factores pueden hacer que éste adopte las características de un neumoencéfalo a tensión provocando una clínica neurológica severa. Presentamos el caso de una paciente de 66 años portadora de una doble válvula de derivación ventrículo-peritoneal que acude a Urgencias con un cuadro de hipertensión intracraneal y que tras la exploración física y la tomografía computarizada se detecta una herida en cuero cabelludo y un neumoencéfalo a tensión. Este defecto en piel se hallaba justo en la zona del borde de una plastia craneal colocada tras la resección …

Orofacial clinical features in Arnold Chiari type I malformation: A case series

2017

Background Arnold Chiari malformation (ACM) is characterized by an anatomical defect at the base of the skull where the cerebellum and the spinal cord herniate through the foramen magnum into the cervical spinal canal. Among the subtypes of the condition, ACM type I (ACM-I) is particularly outstanding because of the severity of symptoms. This study aimed to analyze the orofacial clinical manifestations of patients with ACM-I, and discuss their demographic distribution and clinical features in light of the literature. Material and methods A case series with patients with ACM-I treated between 2012 and 2015 was described. The sample consisted of patients who were referred by the Department of…

Evaluation of strain values of critical anatomic regions for two different pterygomaxillary approaches in Le Fort I osteotomy: An experimental study

2017

WOS: 000405530400016

Head and Neck Paragangliomas

2016

Head and neck paragangliomas are highly vascularized neuroendocrine tumors derived from the extra-adrenal paraganglia of the autonomic nervous system. These tumors may occur either sporadically or in the context of a hereditary familial tumor syndrome, and multifocal presentations are observed, particularly in hereditary cases. Hereditary paragangliomas are mostly caused by mutations in the succinate dehydrogenase complex genes. Early imaging, with ultrasonography of the neck and magnetic resonance imaging (MRI) of the skull base, is essential for localizing and assessing the extent of the tumor, as well as for precise planning of the treatment approach. Views regarding the treatment of cho…

2017

Objective Computer-aided-surgery in ENT surgery is mainly used for sinus surgery but navigation accuracy still reaches its limits for skull base procedures. Knowledge of navigation accuracy in distinct anatomical regions is therefore mandatory. This study examined whether navigation accuracy can be improved in specific anatomical localizations by using hybrid registration technique. Study design Experimental phantom study. Setting Operating room. Subjects and methods The gold standard of screw registration was compared with automatic LED-mask-registration alone, and in combination with additional surface matching. 3D-printer-based skull models with individual fabricated silicone skin were u…