Estimated number and prevalence of patients with delayed endolymphatic hydrops in Japan: a nationwide survey.

BACKGROUND: Delayed endolymphatic hydrops (DEH) is a rare disease, and the actual number of patients in Japan remains unknown. OBJECTIVE: To investigate the number and prevalence of patients with DEH in Japan. METHODS: In total, 781 departments of otolaryngology in Japan were selected for survey by stratified random sampling according to the total number of hospital beds. We sent questionnaires to the target departments and collected data regarding the number of patients with DEH who visited those departments in 2019. RESULTS: The overall response rate was 68.0% (531 departments). The estimate number of patients with DEH in Japan was 962, and the prevalence was calculated to be 0.8 per 100,000 population. CONCLUSION: Patients with DEH were extremely rare in Japan. SIGNIFICANCE: This may be the first nationwide epidemiological study on the number and prevalence of patients with DEH in Japan or in the world.

A 14-year nationwide epidemiological analysis of delayed endolymphatic hydrops in Japan.

BACKGROUND: Delayed endolymphatic hydrops (DEH) is an inner ear disease that causes recurrent vertigo in the ipsilateral ear or fluctuating hearing in the contralateral ear due to endolymphatic hydrops secondary to preceding deafness. There are few reports of large, multicentre studies investigating the clinical-epidemiological characteristics of DEH. OBJECTIVE: This study aimed to clarify the characteristics of DEH in Japan. METHODS: Clinical data on 662 patients with DEH were analysed by nationwide, multicentre surveys conducted by the Peripheral Vestibular Disorders Research Group of Japan. RESULTS: The proportion of ipsilateral DEH (IDEH) was slightly higher than that of contralateral DEH (CDEH) at 55.4%. The time delay between onset of precedent deafness and onset of DEH was significantly longer for CDEH than for IDEH. The most common cause of precedent deafness was a disease of unknown cause with onset in early childhood (33.1%). Epidemiological characteristics were not significantly different between CDEH with and without vertigo. CONCLUSION: DEH appearing to be caused by viral labyrinthitis has a high rate of onset within 40 years of precedent deafness. Clinical and epidemiological characteristics of IDEH, CDEH with vertigo, and CDEH without vertigo were very similar. SIGNIFICANCE: The clinical-epidemiological characteristics of DEH in Japan were clarified.

Case Report: Response to Intra-arterial Cisplatin and Concurrent Radiotherapy Followed by Salvage Surgery in a Patient With Advanced Primary Sinonasal Low-Grade Non-intestinal Adenocarcinoma.

Background: The clinical usefulness of concurrent chemoradiotherapy before surgery in the treatment of primary, locally advanced sinonasal low-grade, non-intestinal type adenocarcinoma (LG non-ITAC) is unclear. Methods: We present the first case report of the efficacy of super-selective intra-arterial cisplatin (CDDP) infusion concurrent with conventional fractionated radiotherapy (RT) for LG non-ITAC in a Japanese patient. Results: A white, rugged-marginal mass that was histopathologically diagnosed as LG non-ITAC occupied the right nasal cavity. Based on the imaging findings, including computed tomography, magnetic resonance imaging, and positron emission tomography, the tumor was diagnosed as T4aN0M0, stage IVa. After treatment, the nasal tumor disappeared leaving only a small bulge in the medial wall of the middle turbinate. The patient also underwent right transnasal ethmoidectomy performed as salvage surgery. A histopathological examination revealed that the lesion was replaced by granulation tissue with lymphocytic infiltration and hemosiderin-laden macrophages, and no viable tumor cells remained. In the seven years after treatment, the patient has not experienced any local recurrence or regional or distant metastasis. Conclusions: Super-selective intra-arterial CDDP infusion concurrent with conventional fractionated RT followed by salvage surgery might be useful for the management of sinonasal LG non-ITAC.

Cerebral Hemodynamic Responses to the Sensory Conflict Between Visual and Rotary Vestibular Stimuli: An Analysis With a Multichannel Near-Infrared Spectroscopy (NIRS) System.

Sensory conflict among visual, vestibular, and somatosensory information induces vertiginous sensation and postural instability. To elucidate the cognitive mechanisms of the integration between the visual and vestibular cues in humans, we analyzed the cortical hemodynamic responses during sensory conflict between visual and horizontal rotatory vestibular stimulation using a multichannel near-infrared spectroscopy (NIRS) system. The subjects sat on a rotatory chair that was accelerated at 3°/s2 for 20 s to the right or left, kept rotating at 60°/s for 80 s, and then decelerated at 3°/s2 for 20 s. The subjects were instructed to watch white stripes projected on a screen surrounding the chair during the acceleration and deceleration periods. The white stripes moved in two ways; in the "congruent" condition, the stripes moved in the opposite direction of chair rotation at 3°/s2 (i.e., natural visual stimulation), whereas in the "incongruent" condition, the stripes moved in the same direction of chair rotation at 3°/s2 (i.e., conflicted visual stimulation). The cortical hemodynamic activity was recorded from the bilateral temporoparietal regions. Statistical analyses using NIRS-SPM software indicated that hemodynamic activity increased in the bilateral temporoparietal junctions (TPJs) and human MT+ complex, including the medial temporal (MT) area and medial superior temporal (MST) area in the incongruent condition. Furthermore, the subjective strength of the vertiginous sensation was negatively correlated with hemodynamic activity in the dorsal part of the supramarginal gyrus (SMG) in and around the intraparietal sulcus (IPS). These results suggest that sensory conflict between the visual and vestibular stimuli promotes cortical cognitive processes in the cortical network consisting of the TPJ, the medial temporal gyrus (MTG), and IPS, which might contribute to self-motion perception to maintain a sense of balance or equilibrioception during sensory conflict.

A tangible head model showing semicircular canals for demonstrating the physical treatment for BPPV.

CONCLUSIONS: It was shown that practicing with a tangible head model with semicircular canals is a useful educational tool for learning the physical treatment for BPPV. OBJECTIVES: To assess the efficacy of using a tangible head model with semicircular canals to teach the physical treatment for BPPV. METHODS: This study compared the number of canalith particles in the posterior semicircular canal that 20 participants could move from the ampulla to the utricle, before and after practicing with the tangible model. RESULTS: Before practicing with the model, they could move 2.5 (mean value) of 10 canalith particles. However, after practicing, they could move 6.6 (mean value) of 10 canalith particles. There was a statistical difference (p < 0.01) between the two trials.