China
Africa
Explore chapters and articles related to this topic
Anatomy and Physiology of Balance
Published in R James A England, Eamon Shamil, Rajeev Mathew, Manohar Bance, Pavol Surda, Jemy Jose, Omar Hilmi, Adam J Donne, Scott-Brown's Essential Otorhinolaryngology, 2022
Nishchay Mehta, Andrew Forge, Jonathan Gale
The vestibular system is housed in the labyrinth of each ear. The main components of the vestibular system are three semicircular canals and two otolith organs (utricle and saccule). The three semicircular canals (superior, posterior, and lateral) detect angular acceleration in orthogonal planes. The utricle and saccule detect linear acceleration in primarily horizontal and vertical planes, respectively, as well as head position in relation to gravity.
Cranial Neuropathies I, V, and VII–XII
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
The utricle and saccule sense linear acceleration of the head. Both are expansions of the membranous labyrinth and contain a macula, which consists of hair cells covered by an otolithic membrane (lying on top of the hair cells) and otoconia (composed of calcium carbonate crystals or otoliths) on the surface. The movement of the otoliths deflects the hair cells.
Paper 3
Published in Amanda Rabone, Benedict Thomson, Nicky Dineen, Vincent Helyar, Aidan Shaw, The Final FRCR, 2020
Amanda Rabone, Benedict Thomson, Nicky Dineen, Vincent Helyar, Aidan Shaw
The case describes a mycotic aortic aneurysm. These are usually saccular, and features include interruption of arterial wall calcification, adjacent inflammatory changes and lymphadenopathy. There can be extension into the adjacent vertebrae and retroperitoneal collections. The most likely causative organisms are Staphylococcus aureus and salmonella.
A comprehensive finite element model for studying Cochlear-Vestibular interaction
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Junfeng Liang, Zhang Ke, Paige V. Welch, Rong Z. Gan, Chenkai Dai
Because of the lack of material property data of the inner ear and experimental results on the chinchilla inner ear functional parameters, such as pressure and velocity, the material properties used in the model are adjusted until BM movement and cupula displacement following the predicting pattern. This is similar to an inverse problem-solving strategy. Meanwhile, the results are presented in terms of non-dimensional values. Some of the results, for example, otolith transfer function, are highly related to the material properties, without further given the accurate material properties, we can only evaluate the relative effect. Therefore, the data present here should be considered as conceptual instead of actual physical values. Another drawback of the model is that the vestibule is simplified by combining the utricle and the saccule. The effect of head rotation on the BM, should not be affected because it is not related to the lymphatic connection. However, this may affect the cupula displacement when an acoustic wave was applied. This is limited by the availability of geometry information of membranous labyrinth. µCT image allows reconstruction of the bony membranous labyrinth with high resolution but is unable to detect the soft tissue. An imaginary saccule can be inserted between the current vestibule and the cochlea. The variation of its dimension and location may impose an effect on the results. This work will be included in our future study.
Intratympanic gentamicin injection for refractory ménière's disease (MD) has potential effect in preventing contralateral MD occurrence
Published in Acta Oto-Laryngologica, 2021
Yongzhen Wu, Yujuan Zhou, Jing Yu, Zijun Song, Chunfu Dai, Jing Wang
Gentamicin is an ototoxic drug. Its distribution in the inner ear of guinea pigs was shown to have a gradient [13]. Its concentration was found to be the highest in the vestibular saccule of the inner ear, mainly in type I and II hair cells and transitional cells, followed by the ampulla of the semicircular canal. The lowest concentration was in the cochlea. Therefore, low-dose gentamicin is often used for tympanic injection as the good choice for chemical labyrinth ablation. Such treatment could help inactivate peripheral vestibular organs to the degree and the number of recurrent vertigo attacks in MD patients while preserving to a great extent the cochlear function. In this study, patients with unilateral refractory MD were followed-up for two years after a single ITG injection. We found that the improvement rate of vertigo has reached 88.5%, which is consistent with the results in other study [14]. Therefore, ITG injection is a very effective treatment for controlling the vertigo symptoms in MD patients.
Subclinical vestibular dysfunction in type 1 diabetes mellitus
Published in Hearing, Balance and Communication, 2021
Abdollah Moossavi, Moslem Shaabani, Ensieh Nasli Esfahani, Mohsen Vahedi, Zakaria Enayati
Kocdor et al. [23] demonstrated that DM may have a selective and deleterious effect on human vestibular sensory epithelia, manifested as a lower density of type 1 vestibular hair cells, and that cochlear and facial nerve damage may precede vestibular damage, which reflects the chronological order effect of DM. Furthermore, others have reported differences among the vestibular organs, such as higher rate of glucose utilization for the utricle and saccule than the semicircular canal ampulla [55], smaller capillary diameter and greater capillary length of utricular macula than posterior canal ampulla [56], and normally greater density of capillaries beneath the neuro-epithelium in the utricle than in the saccule [19]. The saccule has also been shown to be preferentially affected by age-related degenerative changes and in certain pathological conditions of the inner ear [23]. Taken together, these finding are consistent with the idea that DM might also have a selective or chronological order effect on the vestibular system, with the otolith system damage preceding the semicircular canals.