The accurate diagnosis of inner ear anomalies on CT and/or MRI is of importance for understanding the pathogenesis of hearing impairment as well as balance disorders. Furthermore, it is possible to comprehend the molecular pathophysiology in some inner ear anomaly disorders in which a causative gene has been detected. Enlargement of the vestibular aqueduct (EVA) is the most common malformation of the inner ear. EVA can be observed in various disorders, including DFNB4/Pendred syndrome caused by SLC26A4 mutations, branchio-oto-renal/branchio-oto (BOR/BO) syndrome caused by mutations in EYA1, SIX1 or SIX5, and distal renal tubular acidosis caused by mutations in ATP6V1B1 or ATP6V0A4. SLC26A4 mutations can be responsible for EVA as well as incomplete partition type II and dilated vestibule. Characteristic phenotypes of EVA include fluctuating hearing loss and repetitive vertigo. However, such symptoms are not necessarily recognized in patients with the BOR/BO syndrome. The CHARGE syndrome is a disorder characterized by coloboma, heart defect, choanal atresia, retarded growth and development, genital hypoplasia and ear anomalies. Aplasia and hypoplasia of the semicircular canals are the most prevalent anomalies in the CHARGE syndrome. Other disorders associated with inner ear anomalies, including DFNX2 and the Usher syndrome, are mentioned in the review article.
Three hundred sixty-seven vertiginous patients with overlap consultation and 164 patients without overlap consultation were analyzed. The rate of patients with overlap consultation gradually increased with age. little difference between the overlap consultation and the first consultation was seen with the choice of the medical institution, and little difference was seen between both groups regarding the kinds of diseases causing vertigo. Most vertiginous patients visited the first medical institution within one month after the onset of the disease. For the overlap consultation, patients visited the institutions at various periods after the onset. Although emotional and functional scores of the Dizziness Handicap Inventory in the overlap consultation group were statistically significantly higher than in the no overlap group, there was no difference in the physical scores. The incidence of positional or positioning nystagmus in the overlap consultation group was higher than in the no overlap group. There was statistical significance in only the total tracing length of stabilometry between both groups. The patients with overlap consultation demonstrated some characteristics, and various factors had some influences on their care-seeking behavior.
Age-related hearing loss is a well-known condition and many studies have been performed on the possibility of its prevention and treatment. Recent studies have revealed similar physiological aging changes in the equilibrium function, while little is known about its pathogenesis, prevention and treatment. In the present study, we observed the effects of medical treatment, such as vasoactive drugs, vitamins, radical scavengers, etc., on the equilibrium function in the patients, who were treated for age-related hearing loss and not aware of balance disorders retrospectively, in order to determine whether age-related balance disorders were treatable or not. Stabilometry was performed in 16 patients (5 males and 10 females, aged 70-87 (77.1±5.6) years), at the time of the first visit, 2 months and 4 months after drug therapy. As a result, a significant improvement in various parameters of stabilometry was observed. These results may indicate the possibility of the prevention and treatment of age-related balance disorders as with age-related hearing loss.
Introduction: From fiscal year 2011, the Japan Society for Equilibrium Research started a certification system for doctors consulting regarding dizziness, and it is predicted that an increasing number of clinic doctors will be certified as consulting doctors for this purpose in the future. Further, the importance of clinic doctors involved in primary care as consulting doctors for dizziness is anticipated to increase. We investigated vertiginous outpatients who visited our ENT clinic. Subjects: For the 4 years from January 2010 to December 2013, 810 out of 16,903 patients (4.8%) who visited our clinic complained of dizziness. Results: The patients consisted of 239 males and 571 females aged 6-97 years, with a male-to-female ratio of 1: 2.4. Among the 810 patients who visited our clinic with a complaint of dizziness, the presence of nystagmus was examined using an infrared CCD camera in 366 patients (45%), and these patients were diagnosed as having the following conditions: the most common vertiginous disease was benign paroxysmal positional vertigo in 208 (25.7%), followed by other peripheral vestibular disorders in 66 (8.1%) and Meniere's disease in 57 (7.0%). Many of the patients with nystagmus visited our clinic early after the onset of dizziness, and 75.4% of the patients with dizziness visited within seven days after onset.
Objective: To investigate the background of hospitalized patients with Meniere's disease over a ten-year period. Methods: A retrospective study was conducted of the medical records of patients with Meniere's disease who were hospitalized in our hospital between January 2001 and December 2010. Results: Twenty people were hospitalized during this period; 3 of them were re-hospitalized. Therefore, the total was 23 cases in 10 years. All of them were hospitalized due to vertigo attacks. Their ages ranged from 44 to 78 years. There was no difference in the length of hospitalization between the patients under 65 y.o. and those 65-and-over. The distribution of the onset time suggests a high incidence in daytime. The highest onset season was winter with 12 cases. Concerning the clinical findings, 12 patients showed nystagmus beating toward the affected ear at the time of hospitalization. The hearing improved after hospitalization in 4 patients. However, there was no difference in the types of medications. The number of the patients who had smoked was 25%, which was almost equal to the national average. Forty-five percent of the patients had a drinking habit, which exceeded the national average. Regarding the patients' personalities, most of them were cheerful or gentle. Most patients (27.8%) slept 7 hours a day, and no single case reported less than 6 sleep hours. Office workers at 35.0% accounted for the occupation of the majority. Conclusion: This study revealed the tendency of aging of the patients with Meniere's disease. It became clear that the severe vertigo attacks that needed hospitalization were more likely occur in the daytime and in winter. Recently, the lack of sleep had been considered as one of the causes of Meniere's disease. However, this study suggested the quality of sleep is also an important factor.
Meniere's disease (MD) is a clinically defined disorder, characterized by recurrent episodic vertigo with aural fullness, tinnitus, and sensorineural hearing loss. Most patients with MD maintain their normal daily activities by conservative approaches including a low salt diet and diuretics, but one third of them fail to control the vertigo attacks and progressive hearing loss occurs. The current study aimed to examine whether intratympanic injection of steroids was effective in the long term control of vertigo for patients with intractable MD. We conducted a retrospective outcome review of 21 patients with MD who were treated with an intratympanic injection of dexamethasone. Outcomes were determined by subjective assessment of vertigo control and by objective changes in the audiometric pure-tone average (PTA). We adopted the AAO-HNS guidelines that use a number of scales to define the frequency of vertiginous episodes at post injection and long term outcomes of treatment at 18 to 24 months after the last dexamethasone injection. At the 2-year follow up, complete control of vertigo (class A) was achieved in 8 patients (38%) and substantial control of vertigo (class B) in 6 (29%). The remaining 7 patients (33%) were classified as a failure (class D or E). The level of hearing was unchanged in 19 (90%), and increased or decreased in one patient each. These findings suggest that when the vertiginous symptoms still persist after 6 months of medical treatment, intratympanic steroid injections can be started, with the high probability of long term alleviation of vertigo attacks without causing hearing loss.
We have developed imaging analysis to visualize the endolymphatic space using 3-T magnetic resonance imaging (MRI) after intratympanic or intravenous injection of gadolinium (Gd). Investigation into the existence of endolymphatic hydrops (EH) among patients with Meniere's disease (MD) diagnosed according to the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria revealed that EH was frequently observed in patients with definite MD, suggesting MRI evaluation as a promising alternative to histologic confirmation of EH. Another investigation into the relationships between EH and other otological examinations, including vestibular evoked myogenic potential (VEMP), electrocochleography, and caloric response, demonstrated that results were related not only to the degree of EH, but also to the persistence of EH, i.e., duration of the disease. EH was detected on the MRI findings of patients with sudden deafness or fluctuating hearing loss, besides in those with MD. Moreover, EH was also found in patients with tinnitus or sensation of ear fullness, suggesting these symptoms as a potential first sign of early EH. MRI examination of EH can also be applied for preoperative evaluation for middle ear surgery, particularly otosclerosis. The existence of EH is a risk factor for severe vertigo following stapes surgery. The presence of EH in cases with otosclerosis could be clearly visualized in ears with and without EH-related symptoms. MRI is a sensitive technique for detecting EH, and could provide useful information to manage related symptoms and prevent complications following middle ear surgery.
Endolymphatic hydrops may be involved in the pathogenesis of Meniere's disease. However, the etiology remains to be clarified. Magnetic resonance imaging (MRI) facilitates visualization of the inner ear structure, and is useful for physiological and pharmacological evaluation. Recently, MRI of the fine structures of inner ears has been performed in humans, guinea pigs, and mice. In this study, we conducted high-magnetic-field MRI in mice to visualize endolymphatic hydrops. An endolymphatic hydrop model, PhexHyp-Duk/Y mice, was used, as well as a 7.05T MRI device (AVANCE III, 300 wb, ParaVison 5.1 PL2, Bruker GmbH). After intraperitoneal anesthesia, gadolinium contrast medium diluted with physiological saline at a ratio of 8 was administered into the tympanic cavity. Under mask anesthesia with sevoflurane, the body temperature was maintained by warm water (38°C) circulation. A 9-mm surface coil (Doty Co., Ltd.) was established in the external auditory canal. Using the 7.05T MRI device, inner ear imaging was performed. In the PhexHyp-Duk/Y mice, the presence of endolymphatic hydrops was confirmed.
Optical coherence tomography (OCT) visualizes the internal structures of a number of organs such as the eyes. Although visualization of the internal structures of the inner ear has been used to try and identify certain pathological conditions, attempts have had limited success owing to the thick bony capsule. After decalcifying the bony wall of the cochlea, we could clearly and widely visualize its internal structures with OCT. Specimens embedded in paraffin, sliced, and stained with hematoxylin and eosin (HE) were then examined under a light microscope. HE specimens exhibited several artifacts unrecognized in the OCT images, which were considered to be induced during the preparation process. This result suggests that our technique would be useful for examining cochlear pathologies without or prior to histological evaluations.
In vivo cellular imaging from tissue located deep in the brain or in the body remains challenging. To monitor molecular changes or neural activities from neural circuits in the deep brain area, we developed a confocal micro-endoscope system which can be used for fluorescence resonant energy transfer or Ca imaging. We adopted this system for the analyses of the basal ganglia and the cerebellum, and have shown its efficacy in the field of system neuroscience. In this paper, I briefly describe optical configurations for microendoscopy available to date and discuss the possible applications of the optic system mentioned above in the fields of neuroscience, otolaryngology and neuro-otology.