Development of vestibular evoked myogenic potentials and audiometry for the clinical diagnosis of superior canal dehiscence syndrome

Often in Audiology and Neurotology the focus is on disorders characterized by loss of hearing and vestibular function. A complementary approach is to look at the manifestations of abnormally augmented auditory or vestibular functions, commonly named auditory and vestibular hypersensitivity. The present thesis deals with several aspects of a prototype of hypersensitivity syndrome, the superior canal dehiscence syndrome (SCDS). This relatively rare syndrome is characterized by cochlear and vestibular hypersensitivity to sound and vibrations, but also to pressure stimulation which normally has no influence on hearing or balance. By use of a recently introduced vestibular test method, vestibular evoked myogenic potentials (VEMP), it is possible to obtain an objective measure of vestibular sensitivity to sound and vibrations. The thesis describes the background to the research field presenting: the normal function of the ear, the function in presence of conditions giving sound/vibration and pressure hypersensitivity (third mobile window syndromes), a detailed description regarding the superior canal dehiscence syndrome and the vestibular evoked myogenic potentials. The thesis then presents and discuss in details the four scientific papers which are the core of this research project. In the first paper a new vestibular evoked myogenic method is presented. This method, based on low frequency bone conducted stimulation, showed a high diagnostic ability for SCDS, especially valuable in those sporadic conditions when other methods, based on sound stimulation, cannot be applied. The second paper presents a new approach for testing the cochlear hypersensitivity to body sounds. This phenomenon, expressed clinically by the symptom autophony, is particularly evident in SCDS. The study showed that it is possible to retrieve a measure of the internal body sound hypersensitivity by means of a specific audiometric application based on the delivery of bone conducted stimuli at distance sites and not at the mastoid as normally performed. The third paper is a comparative study on the actual ocular VEMP (oVEMP) methods investigating their diagnostic ability for SCDS in a large cohort of dizzy patients. The study confirmed the diagnostic superiority of oVEMP evoked by sound stimuli over the two other methods based on oVEMP evoked by bone conducted stimuli. In the fourth paper SCDS the diagnostic ability of sound induced VEMP protocols is studied. The testing is performed at reduced stimulus intensity levels according to the newly released recommendation on acoustic stimulation restrictions during VEMP testing. Specifically, VEMP was tested at sound intensity levels compatible with safe acoustic exposure levels in audiological testing. The study showed that these reduced sound levels did not affect the diagnostic accuracy of VEMP for SCDS. This is clinically relevant, as it will make it possible to carry out a SCDS diagnosis even among patients affected by abnormal acoustic susceptibility

The Organization of Soil Fragments

AbstractKubiëna (1938) was the first to introduce the concept of fabric in soil micromorphology, so this term has been used in soil micromorphology for a long time. The term "fabric" was initially applied to rocks by geologists and petrologists. This type of fabric is defined as the "factor of the texture of a crystalline rock which depends on the relative sizes, the shapes, and the arrangement of the component crystals" (Matthews and Boyer 1976). This definition has been adapted for soil micromorphology and its latest definition has been given by Bullock et al. (1985) as: "soil fabric deals with the total organization of a soil, expressed by the spatial arrangement of the soil constituents (solid, liquid, and gaseous), their shape, size, and frequency, considered from a configurational, functional and genetic view-point". In conclusion, the soil micromorphologist should consider the fabric as an arrangement and∕or organization of soil constituents

Observation of Soils: From the Field to the Microscope

AbstractAs emphasized by W. Kubiëna, "… there exists no other method capable of revealing the nature and complexity of soil polygenesis in so much detail as thin-section micromorphology and at the same time enabling one to follow and explain its formation...". This sentence, cited by Fedoroff (1971), highlights the aim of soil micromorphology: looking at a soil from the inside and at various scales, from the optical microscope to synchrotron imaging. Soils constitute multiscalar objects by definition, from their soilscape (at the landscape scale), to their profile and its horizons to the atomic interactions between the smallest minerals and organic molecules. Micromorphology enters the soil investigations at the multi-centimetre scale (see "File 3") at which the thin section is made

The Future of Soil Micromorphology

AbstractThe advancement of technology opens up new opportunities to soil micromorphology. Although a description using an optical microscope of the fabric and the various constituents of soils will be always necessary to investigate soil evolution, the uncovered thin section leaves soil material on which analyses can be performed. Since the 1970s, it was possible to observe thin sections at high resolution with the scanning electron microscope in its backscattered electron mode (see "10.1007/978-3-030-67806-7_1#Sec7"). It was also possible to generate chemical images with electron microprobes. But these conventional techniques, as well as new ones, greatly improve the study of matter interactions in soils, not only by enhancing the spatial resolution with incredible precision but also by providing chemical and mineralogical images, which substantially increased the accuracy of micromorphological diagnostics. By coupling morphological and chemical approaches, including stable isotope imaging in soil material, the future of soil micromorphology will undoubtedly offer new opportunities to solve specific problems, especially in the field of organomineral interactions in soils. It is wise to say that soil micromorphology, with its analytical and holistic approaches, will make it possible to build the necessary solid foundations needed for investigations that are increasingly oriented towards nanoscale objects: it will remind us that the trees should not hide the forest

Pedofeatures Associated to Soil Processes

AbstractAs stipulated by G. Stoops, "the aim of micropedology is to contribute to solving problems related to the genesis, classification and management of soils, including soil characterization in palaeopedology and archaeology. The interpretation of features observed in thin sections is the most important part of this type of research, based on an objective detailed analysis and description" (Stoops et al. 2018). To answer such questions, two major books contributed to the comparative knowledge necessary to tackle this objective: the first one was published in 1985 and used micromorphology to distinguish between different classes of soils (Douglas and Thompson 1985); the second one is an extensive guide of more than 1000 pages to the interpretation of micromorphological features encountered in thin sections of soil (Stoops et al. 2018). The aim of this Atlas is neither to be a substitution for these books nor a way to enter directly into the interpretation of soil genesis and classification. Nonetheless, this chapter presents the imprints of major soil processes that can be easily deduced from specific features observed in thin sections. These processes involve the dynamics of (a) clay, both translocation and swelling, (b) water, such as waterlogging, evaporation, and its role as ice and frost, (c) carbonate, gypsum, and iron oxyhydroxides, and finally (d) biogeochemical reactions within the solum

Ankle Audiometry: A Clinical Test for the Enhanced Hearing Sensitivity for Body Sounds in Superior Canal Dehiscence Syndrome

Introduction: The aim of this study was to develop a clinical test for body sounds\u27 hypersensitivity in superior canal dehiscence syndrome (SCDS). Method: Case-control study, 20 patients affected by SCDS and body sounds\u27 hypersensitivity and 20 control matched subjects tested with a new test called ankle audiometry (AA). The AA consisted of a psychoacoustic hearing test in which the stimulus was substituted by a controlled bone vibration at 125, 250, 500, and 750 Hz, delivered at the medial malleolus by a steel spring-attached bone transducer prototype B250. For each subject, it was defined an index side (the other being non-index), the one with major symptoms in cases or best threshold for each tested frequency in controls. In 3 patients, the AA was measured before and after SCDS surgery. Results: The AA thresholds for index side were significantly lower in SCDS patients (115.6 \ub1 10.5 dB force level [FL]) than in control subjects (126.4 \ub1 8.56 dB FL). In particular, the largest difference was observed at 250 Hz (-16.5 dB). AA thresholds in patients were significantly lower at index side in comparison with non-index side (124.2 \ub1 11.4 dB FL). The response obtained with 250 Hz stimuli outperformed the other frequencies, in terms of diagnostic accuracy for SCDS. At specific thresholds\u27 levels (120 dB FL), AA showed relevant sensitivity (90%) and specificity (80%) for SCDS. AA did not significantly correlate to other clinical markers of SCDS such as the bone and air conducted hearing thresholds and the vestibular evoked myogenic potentials. The AA thresholds were significantly modified by surgical intervention, passing from 119.2 \ub1 9.7 to 130.4 \ub1 9.4 dB FL in 3 patients, following their relief in body sounds\u27 hypersensitivity. Conclusion: AA showed interesting diagnostic features in SCDS with significantly lower hearing thresholds in SCDS patients when compared to healthy matched subjects. Moreover, AA could identify the affected or more affected side in SCDS patients, with a significant threshold elevation after SCDS surgery, corresponding in body sounds\u27 hypersensitivity relief. Clinically, AA may represent a first objective measure of body sounds\u27 hypersensitivity in SCDS and, accordingly, be an accessible screening test for SCDS in not tertiary audiological centers

Transitional care management in patients with auto-inflammatory diseases: experience of cooperation of a paediatric and adult centre

Abstract Objectives Auto-inflammatory Diseases (AIDs) are a group of diseases with a strong genetic component, inducing an inappropriate activation of innate immunity. The patients with pediatric onset will face the transitional care (TC) from a pediatrician to an adult care setting, during the critical phase of the adolescence. That implies a risk of failure and drop out, due to the different approach of pediatrician compared to the adult doctor. To describe the model of TC for AIDs from a paediatric to adult centre of two hospitals in Rome, and to pointing out the different steps emerged from specific experiences. Methods In November 2020, a Board of paediatricians and internists discussed their experience to identify "hot topics" for a successful management of TC. Results The Board agreed on the optimal time for the transition (12–18 years). Specific elements to be considered are the reached level of emotional and intellectual maturity, and the clinical stability of the disease. Conclusions The TC of patients with chronic AIDs, requires a strong cooperation to define the adequate follow-up, and to guarantee the compliance to the treatment. This model allows us to investigate AIDs complex cases, requiring a long period of observations

Multiwavelength observations of 3C 454.3. I. The AGILE 2007 November campaign on the "Crazy Diamond"

[Abridged] We report on a multiwavelength observation of the blazar 3C 454.3 (which we dubbed "crazy diamond") carried out on November 2007 by means of the astrophysical satellites AGILE, INTEGRAL, Swift, the WEBT Consortium, and the optical-NIR telescope REM. 3C 454.3 is detected at a $\sim 19-\sigma$ level during the 3-week observing period, with an average flux above 100 MeV of $F_{\rm E>100MeV} = (170 \pm 13) \times 10^{-8}$ \phcmsec. The gamma-ray spectrum can be fit with a single power-law with photon index $\Gamma_{\rm GRID} = 1.73 \pm 0.16$ between 100 MeV and 1 GeV. We detect significant day-by-day variability of the gamma-ray emission during our observations, and we can exclude that the fluxes are constant at the 99.6% ($\sim 2.9 \sigma$) level. The source was detected typically around 40 degrees off-axis, and it was substantially off--axis in the field of view of the AGILE hard X-ray imager. However, a 5-day long ToO observation by INTEGRAL detected 3C 454.3 at an average flux of about $F_{\rm 20-200 keV} = 1.49 \times 10^{-3}$ \phcmsec with an average photon index of $\Gamma_{\rm IBIS} = 1.75 \pm 0.24$ between 20--200 keV. Swift also detected 3C 454.3 with a flux in the 0.3--10 keV energy band in the range $(1.23-1.40) \times 10^{-2}$ \phcmsec{} and a photon index in the range $\Gamma_{\rm XRT} = 1.56-1.73$. In the optical band, both WEBT and REM show an extremely variable behavior in the $R$ band. A correlation analysis based on the entire data set is consistent with no time-lags between the gamma-ray and the optical flux variations. Our simultaneous multifrequency observations strongly indicate that the dominant emission mechanism between 30 MeV and 30 GeV is dominated by inverse Compton scattering of relativistic electrons in the jet on the external photons from the broad line region.Comment: Accepted for publication in ApJ. Abridged Abstract. 37 pages, 14 Figures, 3 Table

Development and implementation of the AIDA International Registry for patients with Periodic Fever, Aphthous stomatitis, Pharyngitis, and cervical Adenitis syndrome

Objective: Aim of this paper is to illustrate the methodology, design, and development of the AutoInflammatory Disease Alliance (AIDA) International Registry dedicated to patients with the Periodic Fever, Aphthous stomatitis, Pharyngitis, and cervical Adenitis (PFAPA) syndrome. Methods: This is a physician-driven, non-population- and electronic-based registry proposed to gather real-world demographics, clinical, laboratory, instrumental and socioeconomic data from PFAPA patients. Data recruitment is realized through the on-line Research Electronic Data Capture (REDCap) tool. This registry is thought to collect standardized information for clinical research leading to solid real-life evidence. The international scope and the flexibility of the registry will facilitate the realization of cutting-edge study projects through the constant updating of variables and the possible merging and transfer of data between current and future PFAPA registries. Results: A total of 112 centers have already been involved from 23 countries and 4 continents starting from August 24th, 2021, to April 6th, 2022. In total 56/112 have already obtained the formal approval from their local Ethics Committees. The platform counts 321 users (113 principal investigators, 203 site investigators, two lead investigators, and three data managers). The registry collects retrospective and prospective data using 3,856 fields organized into 25 instruments, including PFAPA patient's demographics, medical histories, symptoms, triggers/risk factors, therapies, and impact on the healthcare systems. Conclusions: The development of the AIDA International Registry for PFAPA patients will enable the on-line collection of standardized data prompting real-life studies through the connection of worldwide groups of physicians and researchers. This project can be found on NCT 05200715

Discovery of Powerful Gamma-Ray Flares from the Crab Nebula

The well known Crab Nebula is at the center of the SN1054 supernova remnant. It consists of a rotationally-powered pulsar interacting with a surrounding nebula through a relativistic particle wind. The emissions originating from the pulsar and nebula have been considered to be essentially stable. Here we report the detection of strong gamma-ray (100 MeV-10 GeV) flares observed by the AGILE satellite in September, 2010 and October, 2007. In both cases, the unpulsed flux increased by a factor of 3 compared to the non-flaring flux. The flare luminosity and short timescale favor an origin near the pulsar, and we discuss Chandra Observatory X-ray and HST optical follow-up observations of the nebula. Our observations challenge standard models of nebular emission and require power-law acceleration by shock-driven plasma wave turbulence within a ~1-day timescale.Comment: 23 pages (including Supporting On-line Material), 8 figures, 1 table. Version published in Science Express on January 6, 2011 (available at http://www.sciencemag.org/content/early/2011/01/05/science.1200083