Neuroanatomy of the nodosaurid Struthiosaurus austriacus (Dinosauria: Thyreophora) supports potential ecological differentiations within Ankylosauria

Nodosauridae is a group of thyreophoran dinosaurs characterized by a collar of prominent osteoderms. In comparison to its sister group, the often club-tailed ankylosaurids, a different lifestyle of nodosaurids could be assumed based on their neuroanatomy and weaponry, e.g., regarding applied defensive strategies. The holotype of the nodosaurid Struthiosaurus austriacus consists of a single partial braincase from the Late Cretaceous of Austria. Since neuroanatomy is considered to be associated with ecological tendencies, we created digital models of the braincase based on micro-CT data. The cranial endocast of S. austriacus generally resembles those of its relatives. A network of vascular canals surrounding the brain cavity further supports special thermoregulatory adaptations within Ankylosauria. The horizontal orientation of the lateral semicircular canal independently confirms previous appraisals of head posture for S. austriacus and, hence, strengthens the usage of the LSC as proxy for habitual head posture in fossil tetrapods. The short anterior and angular lateral semicircular canals, combined with the relatively shortest dinosaurian cochlear duct known so far and the lack of a floccular recess suggest a rather inert lifestyle without the necessity of sophisticated senses for equilibrium and hearing in S. austriacus. These observations agree with an animal that adapted to a comparatively inactive lifestyle with limited social interactions.

Partial Duplication of the Lateral Semicircular Canal—A Novel Anatomical Malformation in a Child with Barakat Syndrome

Several known genetic causes of sensorineural deafness are associated with dysplasia of inner ear structures, including the cochlea and labyrinth. Here, we present a child with Barakat syndrome and sensorineural hearing loss, found to have multiple inner ear anomalies including partial duplication of the posterior limb of the left lateral semicircular canal. To our knowledge, duplication of the semicircular canal has not previously been reported. This finding expands our understanding of the range of anatomical variations observed in congenital inner ear malformations, and further characterizes the phenotypic manifestations of Barakat syndrome.

Are Hounsfield Unit Measurements of Bony Absorption Changes in Cholesteatoma Helpful?

Introduction High-resolution computed tomography (HRCT) scans of the temporal bone are used to assess the bony erosion of the middle-ear structures whenever cholesteatoma is suspected. Objective To study the differences in HRCT Hounsfield unit (HU) index measurements of middle-ear bony structures between an ears with and without cholesteatoma. Methods A retrospective study of 59 patients who underwent surgery due to unilateral cholesteatoma. The HRCT HU index of the scutum, of three middle-ear ossicles, of the lateral semicircular canal (LSCC), and of the fallopian canal was measured in both ears. A comparison was made between the cholesteatoma and the non-cholesteatomatous ear (control). All measurements were conducted by an otolaryngologist. To assess the interobserver bias, 10% of the samples were randomly and independently assessed by another otolaryngologist and a neuroradiologist who were blinded. Results The average HU index was lower in the ear with cholesteatoma when compared with the non-cholesteatomatous ear. While the differences were statistically significant regarding the measurements of the scutum (516.02 ± 311.693 versus 855.64 ± 389.999; p = 0.001), the malleus (1049.44 ± 481.765 versus 1413.47 ± 313.376; p = 0.01), and the incus (498.03 ± 264.184 versus 714.25 ± 405.631; p = 0.001), the differences in the measurements of the LSCC (1042.34 ± 301.066 versus 1154.53 ± 359.609; p = 0.69) and of the fallopian canal (467.19 ± 221.556 versus 543.51 ± 263.573; p = 0.108) were not significantly different between both groups. The stapes was immeasurable in both groups due to its small size. Conclusion Hounsfield unit index measurements are a useful tool that may aid in the diagnosis of early-stage cholesteatoma.

Peculiarities of clinical manifestations of perilymphatic fistulas and evaluation of the effectiveness of treatment in patients with middle ear cholesteatoma

By the analysis of the 410 histories of illnesses of patients in 38 (9,26 %) are set perilymphatic fistula of different localization. Clinical, radiological intraoperative differences and going are set near the choice of method reconstructively operation depending on the type of perilymphatic fistula. After motion the extensive is certain more aggressive perilymphatic fistula is widespread, especially in the cases of cholesteatoma destruction of bone wall of labyrinth and simultaneous adhesion with a membranous labyrinth. On the stage of preoperative diagnostics from data of КТ of temporal bones of perilymphatic fistula set for 21 (55,3 %) patients and determined almost for all patients with extensive widespread perilymphatic fistula (in 12 patients from 13) and in 9 patients with limit perilymphatic fistula. By the preoperative inspection the positive test of fistula was determined only in 7 % patients. After localization more often perilymphatic fistula was determined at the level of lateral semicircular canal – for 23 patients (60,5 %). Plural localization of perilymphatic fistula with the united defeat of bone wall two and more semicircular canals educed 5 patients (13,1 %). The open variant of tympanoplasty is executed in 30 patients (78,9 %). The closed variant of tympanoplasty is in 6 (15,8 %) patients. Early exposure of perilymphatic fistula after the presence of not staggered endost and in good time reconstructive surgical interference is conducted with optimal combined by microscopically-endoscopic visualization for patients with chronic otitis media with cholesteatome will allow saving a rumor and will prevent development of irreversible complications from the side of internal ear.

Measurement of Human Semicircular Canal Spatial Attitude

Located deep in the temporal bone, the semicircular canal is a subtle structure that requires a spatial coordinate system for measurement and observation. In this study, 55 semicircular canal and eyeball models were obtained by segmentation of MRI data. The spatial coordinate system was established by taking the top of the common crus and the bottom of the eyeball as the horizontal plane. First, the plane equation was established according to the centerline of the semicircular canals. Then, according to the parameters of the plane equation, the plane normal vectors were obtained. Finally, the average unit normal vector of each semicircular canal plane was obtained by calculating the average value of the vectors. The standard normal vectors of the and left posterior semicircular canal, superior semicircular canal and lateral semicircular canal were [−0.651, 0.702, 0.287], [0.749, 0.577, 0.324], [−0.017, −0.299, 0.954], [0.660, 0.702, 0.266], [−0.739, 0.588, 0.329], [0.025, −0.279, 0.960]. The different angles for the different ways of calculating the standard normal vectors of the right and left posterior semicircular canal, superior semicircular canal and lateral semicircular canal were 0.011, 0.028, 0.008, 0.011, 0.024, and 0.006 degrees. The technology for measuring the semicircular canal spatial attitudes in this study are reliable, and the measurement results can guide vestibular function examinations and help with guiding the diagnosis and treatment of BPPV.

Comparative Study of Preoperative Radiological Findings with Intraoperative Surgical Findings in Squamosal Type of Chronic Otitis Media

BACKGROUND Chronic otitis media (COM) of squamosal type is associated with cholestatoma with potential complications. Clinical examination and high resolution computed tomography (HRCT) scans are necessary to assess the disease site and extension. The purpose of the study was to compare the preoperative HRCT findings with the intraoperative surgical findings in squamosal type of chronic otitis media as well as various parameters in HRCT temporal bone and intraoperative findings. METHODS A prospective study was conducted on 30 patients aged between 18 and 60 years of both the genders who presented with chronic otitis media squamosal type, for a period of 22 months who attended the outpatient department of ENT. RESULTS HRCT findings and intraoperative findings were compared and results were analysed. Facial canal erosion (P - 0.0031), tegmen plate erosion (P - 0.0001), sigmoid sinus plate erosion (P - 0.002) were found to be statistically significant. Lateral semicircular canal fistula (P - 0.36) and ossicular status malleus (P - 1.000), incus (P - 0.949), stapes suprastructure (P - 0.984), and stapes footplate erosion (P - 0.977) were found to be statistically insignificant. CONCLUSIONS In our study, HRCT imaging for COM squamosal type, accurately depicted the soft tissue mass, erosion of tegmen plate, sigmoid sinus plate, scutum, lateral semicircular canal fistula, incus and suprastructure of stapes erosion and the same were found intraoperatively as well. Our study showed good comparison between the preoperative HRCT scans and the surgical findings in cholesteatoma cases. HRCT is confirmed to be valuable in the diagnosis and in guiding the surgical management of cholesteatoma. KEY WORDS Chronic Otitis Media, Cholesteatoma, HRCT Temporal Bone, Modified Radical Mastoidectomy

Vestibular Endolymphatic Hydrops Visualized by Magnetic Resonance Imaging and Its Correlation With Vestibular Functional Test in Patients With Unilateral Meniere's Disease

Background: Currently, 3 Tesla-MRI following intratympanic gadolinium injection has made it possible to assess the existence and the severity of hydrops in each compartment of the endolymphatic spaces in vivo. However, the relationship between vestibular endolymphatic hydrops (EH) visualized by MRI and vestibular functional tests, especially the correlation between caloric test, video-head impulse test, and semicircular canal hydrops, has not been well-investigated.Objective: The purpose of this study is to investigate the relationship between the severity of EH in each compartment of otoliths and semicircular canal and the results of vestibular functional tests.Methods: In this retrospective study, we performed three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) sequences following intratympanic gadolinium injection in 69 unilateral patients with definite Menière's disease. Vestibular and lateral semicircular canal hydrops was graded on MRI using a four grade criterion. All patients underwent pure-tone audiometry, cervical vestibular evoked myogenic potential (cVEMP), ocular vestibular evoked myogenic potential (oVEMP), caloric test and video head impulse test (vHIT). The latency, amplitude and asymmetry ratio of VEMP, canal paresis (CP) and vestibulo-ocular reflex (VOR) gain of lateral semicircular canal of vHIT were collected. The correlation analysis were performed between the parameters of function test and EH.Results: Vestibular EH showed correlations with the duration of disease (r = 0.360) and pure tone average (r = 0.326). AR of cVEMP showed correlations with Vestibular EH (r = 0.407). CP (r = 0.367) and VOR gain of lateral semicircular canal at 60 ms (r = 0.311) showed correlations with lateral semicircular canal hydrops.Conclusion: EH in different compartments is readily visualized by using 3D-FLAIR MRI techniques. The degree of vestibular EH correlated with AR of cVEMP and EH in the semicircular canal ampullar affects the caloric and vHIT response in patients with unilateral Meniere‘s disease.