Contributions of Coding Efficiency of Temporal-Structure and Level Information to Lateralization Performance in Young and Early-Elderly Listeners.

The performance of a lateralization task based on interaural time or level differences (ITDs or ILDs) often varies among listeners. This study examined the extent to which this inter-listener variation could be accounted for by the coding efficiency of the temporal-structure or level information below the stage of interaural interaction. Young listeners (20s to 30s) and early-elderly (60s) listeners with or without mild hearing loss were tested. The ITD, ILD, TIME, and LEVEL tasks were intended to measure sensitivities to ITDs, ILDs, the temporal structure of the stimulus encoded by the neural phase locking, and the stimulus level, respectively. The performances of the ITD and ILD tasks were not significantly different between the age groups, while the elderly listeners exhibited significantly poorer performance in the TIME task (and in the LEVEL with a high-frequency stimulus only) than the young listeners. Significant correlations were found between thresholds for the ILD and LEVEL tasks with low- and high-frequency stimuli and for the ITD and TIME tasks for the high-frequency stimulus, implying peripheral coding efficiency as a major factor determining lateralization performance. However, we failed to find a correlation between the ITD and TIME tasks for the low-frequency stimulus, despite a large range of threshold values in the TIME task. This implies that in a low frequency region, the peripheral coding efficiency of the stimulus temporal structure is a relatively minor factor in the ITD-based lateralization performance.

Bilateral cervical fistulas from heterotopic salivary gland tissues.

A 24-year-old male was referred to our department with intermittent clear drainage in both sides of the middle neck that did not increase while eating. On physical examination, there were fistulas in both sides of the neck, anterior to the sternocleidomastoid muscles. Fistulography revealed a 9-mm-long sinus from the left fistula, extending in the medial-caudal direction. On the right side, cannulation was not possible. Surgical excision of the lesion was performed on both sides, and the pathological examination revealed heterotopic salivary gland tissue (HSGT). From a literature review of reports of bilateral neck HSGT, we found that it is often associated with a family history of HSGT and other congenital anomalies. However, our case was different from the previously reported cases in that, although it was a bilateral case, it lacked any family history of HSGT or other congenital anomalies. Clinicians should include HSGT in the differential diagnosis of neck sinuses. © 2015 S. Karger AG, Basel.

How independent are the pitch and interaural-time-difference mechanisms that rely on temporal fine structure information?

The temporal fine structure (TFS) of acoustical signals, represented as the phase-locking pattern of the auditory nerve, is the major information for listeners performing a variety of auditory tasks, e.g., judging pitch and detecting interaural time differences (ITDs). Two experiments tested the hypothesis that processes for TFS-based pitch and ITD involve a common mechanism that processes TFS information and the efficiency of the common mechanism determines the performance of the two tasks. The first experiment measured the thresholds for detecting TFS-based pitch shifts (Moore and Moore, J Acoust Soc Am 113:977-985, 2003) and for detecting ITD for a group of normal-hearing listeners. The detection thresholds for level increments and for interaural level differences were also measured. The stimulus was a harmonic complex (F0 = 100 Hz) that was spectrally shaped for the frequency region around the 11th harmonic. We expected a positive correlation between the pitch and ITD thresholds, based on the hypothesis that a common TFS mechanism plays a determinant role. We failed to find evidence for a positive correlation, hence no support for the above hypothesis. The second experiment examined whether perceptual learning with respect to detecting TFS-based pitch shifts via training would transfer to performance in other untrained tasks. The stimuli and tasks were the same as those used in the first experiment. Generally, training in the pitch task improved performance in the (trained) pitch task, but degraded the performance in the (untrained) ITD task, which was unexpected on the basis of the hypothesis. No training effect was observed in the other untrained tasks. The results imply that the pitch and ITD processes compete with each other for limited neural resources.

Maxillary Swing Approach for Removal of Palatal Carcinoma: A Modified Procedure.

INTRODUCTION: We report a modification of the maxillary swing approach to remove a palatal tumor while preserving the anterior alveolar area. METHODS: Case report using clinical records. RESULTS: The patient was a 54-year-old male. TNM grade was T4bN0M0, and invasion to the base of the pterygoid process was seen. Two courses of induction chemotherapy were administered prior to the operation. Because there was no evidence of anterior maxillary invasion, the maxillary swing approach was chosen. The left anterior maxilla was cut and swung laterally, preserving the blood supply. After removal of the palatal tumor, the maxilla was repositioned and the defect was restored with an anterior lateral thigh flap. Postoperative course was typical, and facial appearance, speech, and masticatory function were satisfactory. CONCLUSIONS: This technique is particularly useful for preserving appearance as well as speech and mastication.

Heterogeneity of odorant identification impairment in patients with Alzheimer's Disease.

Alzheimer's disease (AD) patients exhibit olfactory dysfunction. However, the olfactory declineti precise nature is not fully understood. One hundred patients (60 AD, 28 amnestic mild cognitive impairment (aMCI), 12 Normal) were enrolled. All participants underwent olfactory function testing using an odour stick identification test for Japanese (OSIT-J). OSIT-J scores were significantly correlated with recall. We classified OSIT-J odorants into three groups: Category I, odorants that were difficult for normal aged subjects to identify; Category II, odorants that became harder to accurately identify with cognitive decline; and Category III, odorants that even AD patients could identify. We defined a "cognitive subset" consisting of six Category II OSIT-J odorants (perfume, rose, Japanese cypress, curry, India ink and gas leak odour). The ability to identify "cognitive subset" odours was significantly better indicator of cognitive status than the ability to identify "non-cognitive subset", which consisted of the six remaining items. The ability to identify the gas leak odorant was decreased early in the aMCI stage, suggesting a need to reconsider the odours used to signal gas leaks. The "cognitive subset" would provide a more convenient and effective biomarker for diagnosing dementia in clinical settings.

A case of tracheo-innominate artery fistula successfully treated with endovascular stent of the innominate artery.

Tracheo-innominate artery fistula (TIF) is a rare but life-threatening complication of tracheostomy. We describe a 44-year-old man who was admitted for a pressure ulcer infection with a third tracheostomy in place. He showed massive hemoptysis from the TIF, followed by cardiopulmonary arrest. The cuff of the tube was hyperinflated; however, even a slight movement of the tube resulted in recurrent massive hemorrhage. Thus, an endovascular stent graft was placed. Our case shows that sentinel bleeding may be found prior to TIF, and an endovascular repair can be a lifesaving temporizing option, when the hemorrhage was not controlled by hyperinflating the cuff of the tube.

Factors that account for inter-individual variability of lateralization performance revealed by correlations of performance among multiple psychoacoustical tasks.

This study explored the source of inter-listener variability in the performance of lateralization tasks based on interaural time or level differences (ITDs or ILDs) by examining correlation of performance between pairs of multiple psychoacoustical tasks. The ITD, ILD, Time, and Level tasks were intended to measure sensitivities to ITD; ILD; temporal fine structure or envelope of the stimulus encoded by the neural phase locking; and stimulus level, respectively. Stimuli in low- and high-frequency regions were tested. The low-frequency stimulus was a harmonic complex (F 0 = 100 Hz) that was spectrally shaped for the frequency region around the 11th harmonic. The high frequency stimulus was a "transposed stimulus," which was a 4-kHz tone amplitude-modulated with a half-wave rectified 125-Hz sinusoid. The task procedures were essentially the same between the low- and high-frequency stimuli. Generally, the thresholds for pairs of ITD and ILD tasks, across cues or frequencies, exhibited significant positive correlations, suggesting a common mechanism across cues and frequencies underlying the lateralization tasks. For the high frequency stimulus, there was a significant positive correlation of performance between the ITD and Time tasks. A significant positive correlation was found also in the pair of ILD and Level tasks for the low- frequency stimulus. These results indicate that the inter-listener variability of ITD and ILD sensitivities could be accounted for partially by the variability of monaural efficiency of neural phase locking and intensity coding, respectively, depending of frequency.

Diffuse large B-cell lymphoma in the sphenoid sinus mimicking fibrous dysplasia in CT and MRI.

We present a 70-year-old man with lymphoma who presented with a right eye movement disorder. CT examinations showed 'ground-glass' appearance extending around the right sphenoid sinus which suggested fibrous dysplasia. However, biopsy from the mass histologically proved it to be diffusing large B-cell lymphoma and positron emission tomography examinations revealed increased fluorodeoxyglucose (FDG) uptake around the right sphenoid bone and multiple spinal bones. After chemotherapy for lymphoma, abnormal FDG uptake disappeared from the body.

Effect of the canalith repositioning procedure on subjective visual horizontal in patients with posterior canal benign paroxysmal positional vertigo.

CONCLUSION: Substantial numbers of patients with posterior canal benign paroxysmal positional vertigo (p-BPPV) have signs of utricular dysfunction at baseline. This improves after performing the canalith repositioning procedure. OBJECTIVE: To evaluate the changes of subjective visual horizontal (SVH) in patients with p-BPPV before and after treatment with the canalith repositioning procedure. METHODS: Twenty-six patients with p-BPPV were treated with the canalith repositioning procedure, Epley's maneuver, according to the affected side. Baseline SVH measurements were taken before performing the Dix-Hallpike maneuver and Epley's maneuver, for comparison with measurements taken just after Epley's maneuver, and 2 weeks after Epley's maneuver. RESULTS: Among 26 patients with p-BPPV, 11 (42%) showed abnormal deviation of SVH at baseline. Just after performing Epley's maneuver, the number of patients who showed an abnormal deviation of SVH decreased significantly to 15% (4 of 26 patients; p < 0.05). Two weeks after performing Epley's maneuver, only two patients (8%) showed an abnormal deviation of SVH (p < 0.001).