scholarly journals NEUROANATOMÍA DEL SAURÓPODO TITANOSAURIO NARAMBUENATITAN PALOMOI DEL CRETÁCICO SUPERIOR DE PATAGONIA, ARGENTINA.

2020 ◽  
Author(s):  
Ariana Paulina-Carabajal ◽  
Leonardo Filippi ◽  
Fabien Knoll
Keyword(s):  
Semicircular Canal ◽  
Upper Cretaceous ◽  
Semicircular Canals ◽  
Lateral View ◽  
Phylogenetic Position ◽  
Posterior Semicircular Canal ◽  
X Ray ◽  
Anterior Semicircular Canal ◽  
X Ray Computed ◽  
The Brain

this taxon has uncertain phylogenetic relationships within the clade. An X-ray Computed Tomography (CT) scan of the holotypebraincase allowed the first reconstruction of the brain and inner ear of this taxon, making it possible to compare the neuroanatomy with thatof closely related forms. Except for the slightly sigmodal shape of the endocast in lateral view—considered a basal condition—, the brainshows derived titanosaurian traits such as a poorly developed dorsal expansion and a single exit for Cranial Nerve (CN) XII. In contrast, the innerear exhibits slender and long semicircular canals (the anterior semicircular canal is distinctly longer than the posterior semicircular canal), whichis a character present in more basal representatives of the group, such as Sarmientosaurus. We consider, however, the morphology of theinner ear as an unreliable indicator of phylogenetic position. Furthermore, there is a remarkable similarity between the morphology of theendocast of Narambuenatitanand the possible saltasaurid from (FAM 03.064), from the Upper Cretaceous of Fox-Amphoux-Métisson, France,suggesting saltasaurine affinities for the Argentinean taxon.

scholarly journals First palaeoneurological study of a sauropod dinosaur from France and its phylogenetic significance

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7991 ◽  
Author(s):  
Fabien Knoll ◽  
Stephan Lautenschlager ◽  
Xavier Valentin ◽  
Verónica Díez Díaz ◽  
Xabier Pereda Suberbiola ◽  
...  
Keyword(s):  
Upper Cretaceous ◽  
Cranial Nerves ◽  
Semicircular Canals ◽  
Phylogenetic Position ◽  
Cerebral Vein ◽  
Southern France ◽  
X Ray ◽  
Computed Tomographic ◽  
X Ray Computed ◽  
The Brain

Despite continuous improvements, our knowledge of the palaeoneurology of sauropod dinosaurs is still deficient. This holds true even for Titanosauria, which is a particularly speciose clade of sauropods with representatives known from numerous Cretaceous sites in many countries on all continents. The data currently available regarding the palaeoneurology of titanosaurs is strongly biased towards Gondwanan forms (Argentina above all, but also India, Malawi and Australia). In contrast, the palaeoneurology of Laurasian titanosaurs is known only from a few taxa from Spain and Uzbekistan, despite the discovery in other countries of Laurasia of a number of neurocranial remains that would lend themselves well to investigations of this kind. To fill in this gap in our knowledge, we subjected a titanosaurian braincase from the uppermost Upper Cretaceous of southern France to X-ray computed tomographic scanning, allowing the generation of 3D renderings of the endocranial cavity enclosing the brain, cranial nerves and blood vessels, as well as the labyrinth of the inner ear. These reconstructions are used to clarify the phylogenetic position of the specimen from the Fox-Amphoux-Métisson site. A combination of characters, including the presence of two hypoglossal rami on the endocast, the average degree of development of the dorsal-head/caudal-middle-cerebral vein system and the relatively short and subequal lengths of the ipsilateral semicircular canals of the labyrinth, are particularly revealing in this respect. They suggest that, compared with the few other Laurasian titanosaurs for which in-depth palaeoneurological data are available, the French taxon is more derived than the distinctly more ancient, possibly non-lithostrotian titanosaur from the Uzbek site of Dzharakuduk but more basal than derived saltasaurids, such as the coeval or slightly more recent forms from the Spanish locality of Lo Hueco.

scholarly journals Braincase and Inner Ear Anatomy of the Late Carboniferous Tetrapod Limnoscelis dynatis (Diadectomorpha) Revealed by High-Resolution X-ray Microcomputed Tomography

2021 ◽  
Vol 9 ◽  
Author(s):  
Jozef Klembara ◽  
Marcello Ruta ◽  
Miroslav Hain ◽  
David S. Berman
Keyword(s):  
High Resolution ◽  
Semicircular Canals ◽  
Sister Group ◽  
Microcomputed Tomography ◽  
Data Matrix ◽  
Phylogenetic Position ◽  
Published Data ◽  
X Ray ◽  
Character Weighting ◽  
Anterior Semicircular Canal

The braincase anatomy of the Pennsylvanian diadectomorph Limnoscelis dynatis is described in detail, based upon high-resolution X-ray microcomputed tomography. Both supraoccipitals and most of the prootics and opisthotics are preserved. The known portions of the left prootic, opisthotic, and supraoccipital enclose complete sections of the endosseous labyrinth, including the anterior, posterior, and lateral semicircular canals, the vestibule, the cochlear recess, and the canal for the endolymphatic duct. The fossa subarcuata is visible anteromedial to the anterior semicircular canal. The presumed endolymphatic fossae occur in the dorsal wall of the posteromedial portion of the supraoccipital. Both the fossa subarcuata and the fossa endolymphatica lie in the cerebellar portion of the cranial cavity. In order to investigate the phylogenetic position of L. dynatis we used a recently published data matrix, including characters of the braincase, and subjected it to maximum parsimony analyses under a variety of character weighting schemes and to a Bayesian analysis. Limnoscelis dynatis emerges as sister taxon to L. paludis, and both species form the sister group to remaining diadectomorphs. Synapsids and diadectomorphs are resolved as sister clades in ∼90% of all the most parsimonious trees from the unweighted analysis, in the single trees from both the reweighted and the implied weights analyses, as well in the Bayesian tree.

Evaluation of Vertical Semicircular Canal Function in Patients With Vestibular Schwannoma

2018 ◽  
Vol 128 (2) ◽  
pp. 113-120 ◽  
Author(s):  
Keishi Fujiwara ◽  
Hiroko Yanagi ◽  
Shinya Morita ◽  
Kimiko Hoshino ◽  
Atsushi Fukuda ◽  
...  
Keyword(s):  
Vestibular Schwannoma ◽  
Semicircular Canal ◽  
Vestibular Function ◽  
Semicircular Canals ◽  
Vestibular Nerve ◽  
Head Impulse Test ◽  
Posterior Semicircular Canal ◽  
Vestibulo Ocular Reflex ◽  
Anterior Semicircular Canal ◽  
Vertical Semicircular Canal

Objectives: The aim of this study was to investigate vertical semicircular canal function in patients with vestibular schwannoma (VS) by video head impulse test (vHIT). Methods: Fifteen patients with VS who had not received any treatment, including surgery or stereotactic radiotherapy, before vHIT examination were enrolled. Vestibulo-ocular reflex gain and catch-up saccade in vHIT were evaluated. Results: Dysfunction of anterior and posterior semicircular canals was detected by vHIT in 26.7% and 60.0%, respectively. Six patients (40.0%) demonstrated abnormalities referable to both vestibular nerve divisions. Abnormalities referable to the superior vestibular nerve were identified in 3 patients (20.0%), while 3 patients (20.0%) demonstrated a pattern indicative of inferior vestibular nerve involvement. Anterior semicircular canal vHIT produced fewer abnormalities than did either horizontal or posterior semicircular canal vHIT. Conclusions: Dysfunction of the semicircular canals, including the vertical canals, in patients with VS was detected by vHIT. The anterior semicircular canal was less frequently involved than the horizontal or posterior semicircular canal. The examination of the vertical canals by vHIT is useful in the evaluation of vestibular function in patients with VS.

Evolution of Treatment Maneuvers for Benign Paroxysmal Positional Vertigo

2016 ◽  
Author(s):  
Robert W. Baloh
Keyword(s):  
21St Century ◽  
Semicircular Canal ◽  
Benign Paroxysmal Positional Vertigo ◽  
Posterior Semicircular Canal ◽  
Initial Examination ◽  
Positional Vertigo ◽  
Anterior Semicircular Canal ◽  
Paroxysmal Positional Vertigo

Near the turn of the 21st century, as more physicians began performing the Epley and Semont maneuvers for treatment of benign paroxysmal positional vertigo (BPPV), it became apparent that the procedures could be done at the time of initial examination without the need for sedation or vibration. Furthermore, modified versions of the maneuvers evolved that were more effective and easier to perform. There are clear similarities in these modified repositioning maneuvers. BPPV nearly always results from otoconial debris within the posterior semicircular canal because this is the canal in which it is most easily trapped. Although less common, there are horizontal and anterior semicircular canal variants of BPPV, and otolithic debris can become attached to the cupula, producing a true cupulolithiasis. The nystagmus is in the plane of the affected canal; the nystagmus is transient when the debris is freely floating and persistent when debris is attached to the cupula.

Ménière Recognizes That Vertigo Can Originate from the Inner Ear

2016 ◽  
Author(s):  
Robert W. Baloh
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Blood Vessels ◽  
Semicircular Canal ◽  
Semicircular Canals ◽  
Underlying Disease ◽  
The Brain ◽  
Benign Course

Prosper Ménière was the first clinician to conclude that vertigo can result from diseases of the inner ear. The symptom of vertigo originally fell under the rubric of apoplectiform cerebral congestion, a disorder thought to result from overfilling of blood vessels in the brain. Ménière noted that patients with vertigo and hearing loss associated with damage to the inner ear often have a benign course, and aggressive treatments such as bleeding can be more dangerous than the underlying disease. The first hint that the semicircular canals may be related to balance rather than hearing was provided by a Frenchman, Marie Jean Pierre Flourens. He systematically cut each semicircular canal in the pigeon and noted that the animal’s head and body tended to move in the plane of the damaged canal. The gyrations of the animals described by Flourens made Ménière think that vertigo in humans might be a similar phenomenon.

scholarly journals A New Coordinate System for Magnetic Resonance Imaging of the Vestibular System

2022 ◽  
Vol 12 ◽  
Author(s):  
Weixing Liu ◽  
Gui Chen ◽  
Junyang Xie ◽  
Tianhao Liang ◽  
Chunyi Zhang ◽  
...  
Keyword(s):  
Coordinate System ◽  
Vestibular System ◽  
Semicircular Canal ◽  
Internal Auditory Canal ◽  
Semicircular Canals ◽  
Image Data ◽  
Mean Values ◽  
Medical Software ◽  
Anterior Semicircular Canal ◽  
Imaging Plane

Objectives: To develop and evaluate a new coordinate system for MRI of the vestibular system.Methods: In this study, 53 internal auditory canal MRI and 78 temporal bone CT datasets were analyzed. Mimics Medical software version 21.0 was used to visualize and three-dimensionally reconstruct the image data. We established a new coordinate system, named W–X, based on the center of the bilateral eyeballs and vertex of the bilateral superior semicircular canals. Using the W–X coordinate system and Reid's coordinate system, we measured the orientations of the planes of the anterior semicircular canal (ASCC), the lateral semicircular canal (LSCC), and the posterior semicircular canal (PSCC).Results: No significant differences between the angles measured using CT and MRI were found for any of the semicircular canal planes (p > 0.05). No statistical differences were found between the angles measured using Reid's coordinate system (CT) and the W–X coordinate system (MRI). The mean values of ∠ASCC & LSCC, ∠ASCC & PSCC, and ∠LSCC & PSCC were 84.67 ± 5.76, 94.21 ± 3.81, and 91.79 ± 5.22 degrees, respectively. The angle between the LSCC plane and the horizontal imaging plane was 15.64 ± 3.92 degrees, and the angle between the PSCC plane and the sagittal imaging plane was 48.79 ± 4.46 degrees.Conclusion: A new W–X coordinate system was developed for MRI studies of the vestibular system and can be used to measure the orientations of the semicircular canals.

MR imaging in the diagnosis of brain tumors

1993 ◽  
Vol 74 (3) ◽  
pp. 180-184
Author(s):  
I. V. Klyushkin ◽  
R. F. Bakhtiozin ◽  
M. M. Ibatullin ◽  
I. R. Chuvashaev ◽  
V. I. Zinin ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Diagnostic Method ◽  
Associate Professor ◽  
Posterior Cranial Fossa ◽  
Brain Diseases ◽  
X Ray ◽  
Chief Physician ◽  
X Ray Computed ◽  
Cranial Fossa ◽  
The Brain

Diagnosing brain diseases is one of the most difficult tasks in medicine. For the exclusion or detection of brain tumors, MRI is a valuable modern diagnostic method. It allows you to clarify the localization of the neoplasm within the brain, its relation to the surrounding tissues, to determine the presence of concomitant cerebral edema, vasculature, the shape, size, nature and structure of the tumor. In this respect, the center (chief physician associate professor IV Klyushkin) M3 RT MRI significantly exceeds the capabilities of X-ray computed tomography, especially in the diagnosis of tumors of the posterior cranial fossa and basal localization.

Netrin 1 is required for semicircular canal formation in the mouse inner ear

Development ◽  
2000 ◽  
Vol 127 (1) ◽  
pp. 13-22 ◽  
Author(s):  
M. Salminen ◽  
B.I. Meyer ◽  
E. Bober ◽  
P. Gruss
Keyword(s):  
Central Nervous System ◽  
Axon Guidance ◽  
Inner Ear ◽  
Semicircular Canal ◽  
Cell Walls ◽  
Semicircular Canals ◽  
Plate Formation ◽  
Multistep Process ◽  
Anterior Semicircular Canal ◽  
The Central Nervous System

The morphogenetic development of the mammalian inner ear is a complex multistep process, the molecular and cellular details of which are only beginning to be unraveled. We show here that mouse netrin 1, known to be involved in axon guidance and cell migration in the central nervous system, also plays a critical morphogenetic role during semicircular canal formation. netrin 1 is expressed at high levels in the otic epithelium, in cells that will come together to form a fusion plate, a prerequisite for the formation of semicircular canals. In netrin 1 mutant mice, fusion plate formation is severely affected resulting in a reduced anterior semicircular canal and the complete lack of the posterior and lateral canals. Our results suggest that netrin 1 facilitates semicircular canal formation through two different mechanisms: (1) it participates in the detachment of the fusion plate epithelia from the basement membrane, and (2) it stimulates proliferation of the periotic mesenchymal cells which then push the epithelial cell walls together to form the fusion plate.

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