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ObjectiveWe compared the characteristics of air-conducted sound cervical vestibular evoked myogenic potential (ACS-cVEMP) and bone-conducted vibration cVEMP (BCV-cVEMP) among 3-month-old infants with normal hearing and sensorineural hearing loss (SNHL), and healthy adults to explore the feasibility and optimal strategies for infant vestibular screening.Methods29 infants (58 ears) were divided into two groups according to hearing (group I: normal hearing ears; group II: SNHL ears), 20 healthy adults were defined as group III. The results of response rate, P13 and N23 latency, P13-N23 interval, amplitudes, and corrected interaural asymmetry ratio (IAR) were recorded and compared among three groups.ResultsThe response rates of ACS-cVEMP in three groups were 88.89, 62.00, 100%, respectively. The P13 and N23 latencies, and P13-N23 interval did not differ significantly between group I and II (p = 0.866, p = 0.190, p = 0.252). A significant difference was found between group I and III (p = 0.016, p < 0.001, p < 0.001). No significant difference was observed in raw or corrected amplitude between group I and II (p = 0.741, p = 0.525), while raw and corrected amplitudes in group III were significantly larger than group I (p < 0.001, p < 0.001). For BCV-cVEMP, the response rates in three groups were 100, 86.36, 100%, respectively, No significant difference existed in the P13 and N23 latency, or P13-N23 interval between group I and II (p = 0.665, p = 0.925, p = 0.806), however, P13 and N23 latencies were significantly longer in group III than group I (p < 0.001, p = 0.018), but not in P13-N23 interval (p = 0.110). There was no significant difference in raw or corrected amplitude between group I and II (p = 0.771, p = 0.155) or in raw amplitude between group I and III (p = 0.093), however, a significant difference existed in corrected amplitude between group I and III (p < 0.001).ConclusionsCompared with adults, 3-month-old infants with normal hearing presented with equivalent response rates, shorter P13 and N23 latencies, smaller corrected amplitudes, and a wider IAR range for both ACS and BCV-cVEMP. SNHL infants had equivalent response rates of BCV-cVEMP, lower response rates of ACS-cVEMP than normal hearing infants. When responses were present, characteristics of ACS and BCV-cVEMP in SNHL infants were similar with normal hearing infants. ACS combined with BCV-cVEMP are recommended to improve the accuracy of vestibular screening.

Purpose This study aimed to describe the genetic and clinical characteristics of four Japanese patients with autosomal dominant optic atrophy (DOA) accompanied by auditory neuropathy and other systemic complications (i.e., DOA-plus disease). Methods Four patients from four independent families underwent comprehensive ophthalmic and auditory examinations and were diagnosed with DOA-plus disease. The disease-causing gene variants in the OPA1 gene were identified by direct sequencing. The genetic and clinical data of 48 DOA patients without systemic complications—that is, with simple DOA—were compared to those of DOA-plus patients. Results DOA-plus patients noticed a decrease in vision before the age of 14 and hearing impairment 3 to 13 years after the development of visual symptoms. Two patients had progressive external ophthalmoplegia, and one patient had vestibular dysfunction and ataxia. The DOA-plus phenotypes accounted for 13.3% (4/30) of the families with the OPA1 gene mutations. Each DOA-plus patient harbored one of the monoallelic mutations in the OPA1 gene: c.1334G>A, p.R445H, c.1618A>C, p.T540P, and c.892A>C, p.S298R. Missense mutations accounted for 100% (4/4) of the DOA-plus families and only 11.5% (3/26) of the families with simple DOA. Conclusions All the patients with the DOA-plus phenotype carried one of the missense mutations in the OPA1 gene. They all had typical ocular symptoms and signs of DOA in their first or second decade, and other systemic complications—such as auditory neuropathy, vestibular dysfunction, and ataxia—followed the ocular symptoms. We should consider the occurrence of extraocular complications in cases with DOA, especially when they carry the missense mutations in the OPA1 gene.

The living anatomy of the vestibular end-organs is still unknown, complex, and studying them is a challenge for researchers in basic science and in clinical medicine. This main reason is the fact that we cannot observe the vestibular end-organs in the living subjects by any modern diagnostic facilities such as CT and MRI. We can make the three-dimensional virtual histology of the vestibular end-organs based on high-resolution computed tomography (HR-CT) of a human temporal bone with the use of the direct volume rendering. The three-dimensional virtual histology is a volume rendering of these structures of interest, which currently includes the bone, soft tissues and air spaces of the temporal bone; the maculae of utricle and saccule, otolith, ampullae, and the ossicles. The three-dimensional volume rendering imaging can be sliced open at any section and the appropriate raw radiological image superimposed on the cleavage plane. The images stack can be resected in any arbitrary plane. This virtual histological technique is a powerful investigating tool for studying the complex anatomy of the vestibular end-organs of living subjects. We can research morphological conditions of the vestibular end-organs of normal functional status and pathological conditions like a retinal camera.

聴神経損傷患者における語音弁別力を調べる目的で聴覚検査を実施した。対象はいずれも聴性脳幹反応(ABR)に異常波形がみられ, ABRが無反応な4例とABRの遅い波の消失やI波-V波間の潜時の延長がみられた3例の2群に分けられた。検査結果は次の通りであった。(1)純音聴力検査では, 全例に軽度から中等度の閾値の上昇がみられた。(2)無意味単音節を用いた語音弁別検査では, 全例に正答率の低下が示されたが, ABRの遅い波の消失や潜時の延長がみられた例に比較してABRが無反応な例の方がより低下していた。(3)聴覚的言語理解検査では全例とも正常範囲であった。以上の結果より, 聴神経の損傷は聴覚的言語理解には影響しないが, 無意味単音節のような冗長度の低い言語情報の伝達に影響を及ぼすことが示唆された。, 国立情報学研究所で電子化