Anatomy of the transmastoid endolymphatic sac decompression in the management of Ménière’s disease.

Ménière’s disease affects 1 in 1000 people and produces vertigo and hearing loss (Morrison, 1981). Endolymphatic sac decompression has been advocated on the basis that endolymphatic hydrops is the underlying pathology. The endolymphatic sac is said to be the terminal dilatation of the membranous labyrinth. It has been proposed that endolymph flows from the semicircular canals and cochlea to the endolymphatic sac. Portman (1927) devised a procedure for ‘decompressing’ the endolymphatic sac by removal of the bone from the posterior cranial fossa to relieve the symptoms of Ménière’s disease. Surgery on the endolymphatic sac remains controversial. Shea (1979) and Bagger-Sjöbäck et al (1990, 1993) have studied the endolymphatic sac using different techniques. There are discrepancies in the results between the two studies. The hypothesis that the endolymphatic sac can be safely approached and decompressed by a transmastoid route was tested. A total of thirteen cadaver heads and ten isolated temporal bones were used. A series of dissections were performed to examine the endolymphatic sac, perform measurements and analyse surgical approaches to the sac. Histological and electron microscopic study were performed. The lumen of the endolymphatic sac was not always identifiable in the dura of the posterior cranial fossa or it frequently lay over the sigmoid sinus. In the dura of the posterior cranial fossa where the endolymphatic sac is located was a thickening of the dura. This thickening was present even in the absence of the endolymphatic sac. The endolymphatic sac can be safely approached by a transmastoid approach, if there is an extraosseous component to the endolymphatic sac. The proximal endolymphatic sac can be approached by posterior cranial fossa route

Oral and Maxillofacial Surgery

Oral and maxillofacial surgery is a specialized branch of dentistry that deals with the surgical management of various head and neck pathologies. The specialty focuses on reconstructive surgery of the oro-facial region, surgery of facial trauma, the oral cavity and jaws, dental implants as well as cosmetic surgery. As such, surgeons in this field require extensive knowledge of not only these various surgical procedures but also head and neck anatomy. This book provides comprehensive information on both. Its goal is to educate oral and maxillofacial surgeons to enable them to treat a wide range of conditions and diseases using the most current surgical trends

Revision topics in otology

This e book covers all important topics in otology. Frequently asked exam questions are discussed in detail in this e book. This book will help students of otolaryngology during their exam preparations. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down

Modelling, Simulation and Data Analysis in Acoustical Problems

Modelling and simulation in acoustics is currently gaining importance. In fact, with the development and improvement of innovative computational techniques and with the growing need for predictive models, an impressive boost has been observed in several research and application areas, such as noise control, indoor acoustics, and industrial applications. This led us to the proposal of a special issue about “Modelling, Simulation and Data Analysis in Acoustical Problems”, as we believe in the importance of these topics in modern acoustics’ studies. In total, 81 papers were submitted and 33 of them were published, with an acceptance rate of 37.5%. According to the number of papers submitted, it can be affirmed that this is a trending topic in the scientific and academic community and this special issue will try to provide a future reference for the research that will be developed in coming years

Clinical applications of otoacoustic emissions in assessment of olivocochlear dysfunction

The efferent olivocochlear system provides feedback to the sensory receptors and afferent nerves of the cochlea. This study examined efferent auditory effects in humans by measurement of otoacoustic emissions during contralateral acoustic stimulation. Results were analyzed with a view to optimizing protocols for non-invasive clinical assessment of olivocochlear dysfunction. An experimental paradigm for assessing the loss of olivocochlear innervation was applied to vestibular nerve section patients whose olivocochlear bundle had been severed for treatment of peripheral labyrinthine disorders. Control patients were studied, who had undergone a similar surgical procedure for vascular decompression of the vestibular nerve, but without section of the olivocochlear fibres. The role of middle ear reflexes was investigated in patients with unilateral section of the middle ear muscle tendons for treatment of myoclonus. Patients with pathological lesions along the olivocochlear pathway from cochlea to cortex were also investigated. Normal subjects demonstrated significant and repeatable inhibition of otoacoustic emission amplitude during contralateral white noise at least 25dB above sensation level in normal subjects. The test was sensitive to olivocochlear disruption via vestibular nerve section, lesions of the olivary nuclei, or cerebello-pontine angle. Cases with a history of noise exposure also showed a loss of inhibitory effects. Control cases with lesions not affecting the olivocochlear pathway maintained normal levels of inhibition. The findings support the conclusion that otoacoustic emissions provide a means of evaluating efferent function, and that surgical or pathological disruption of the olivocochlear system results in a significant loss of efferent auditory effects

Diseases of the Brain, Head and Neck, Spine 2020–2023

This open access book offers an essential overview of brain, head and neck, and spine imaging. Over the last few years, there have been considerable advances in this area, driven by both clinical and technological developments. Written by leading international experts and teachers, the chapters are disease-oriented and cover all relevant imaging modalities, with a focus on magnetic resonance imaging and computed tomography. The book also includes a synopsis of pediatric imaging. IDKD books are rewritten (not merely updated) every four years, which means they offer a comprehensive review of the state-of-the-art in imaging. The book is clearly structured and features learning objectives, abstracts, subheadings, tables and take-home points, supported by design elements to help readers navigate the text. It will particularly appeal to general radiologists, radiology residents, and interventional radiologists who want to update their diagnostic expertise, as well as clinicians from other specialties who are interested in imaging for their patient care