Peripheral vestibular loss in noise-exposed firefighters.

Introduction: Occupational workers are increasingly aware of the risk of noise overexposure to the auditory system but lack awareness about potential risks to the vestibular system. The purpose of this study was to investigate changes in vestibular end organ function in a known at-risk noise-exposed population, firefighters compared to age- and sex-matched controls using electrophysiologic measures of cervical vestibular evoked myogenic potentials (cVEMP). Methods: A cross-sectional observational study compared cVEMP response characteristics in 38 noise-exposed firefighters. Firefighters were grouped by years of exposure in the fire service. The cVEMP responses were compared within firefighter groups and between firefighters and age- and sex-matched controls. Dependent variables included the response characteristics of amplitude, latency and threshold. Results: cVEMP response amplitudes were significantly decreased in firefighters compared to their age- and sex-matched controls. Threshold of the cVEMP responses were significantly higher in firefighters compared to controls and firefighters had a higher incidence of absent cVEMP responses compared to controls. Response amplitudes decreased with increasing years in the fire-service at an increased rate compared to their age- and sex-matched controls. Latency of the cVEMP response was not significantly different in firefighters compared to controls. These findings are consistent with both animal and human studies suggesting noise-induced changes in the sacculocollic pathway. Discussion: In the absence of any reported vestibular symptoms or auditory indicators of noise-induced hearing loss, these early effects on the vestibular system point to a potential hidden vestibular loss.

Recognizing a Mediastinal Mass: A Case of Primary Mediastinal Large B-Cell Lymphoma With Pruritus in a 23-Year-Old Adult Male Sailor.

Primary mediastinal large B-cell lymphoma (PMBCL) is a rare, non-Hodgkin, B-cell lymphoma thought to originate from thymic B cells, which occurs primarily in young adults such as in the active duty population. Primary mediastinal large B-cell lymphoma (PMBCL) presents as a large mediastinal mass, posing risks to the cardiopulmonary safety of patients and challenging the routine approach to diagnosis. We describe a case of a 23-year-old male sailor who presented to sick call on his ship while in port with shortness of breath, night sweats, 50-pound weight loss, and pruritic punched-out lesions on all extremities. An initial chest X-ray showed a large consolidation. After being seen in the pulmonary medicine clinic 5 weeks after his initial presentation, the patient was admitted to the intensive care unit after computed tomography of his chest revealed a mediastinal mass, causing compression of both the right bronchus and superior vena cava with a large pericardial effusion. Empiric high-dose dexamethasone was initiated before a formal diagnosis due to his significant risk for cardiopulmonary compromise. Following diagnosis and two cycles of chemotherapy, the patient was transferred to a medical oncology facility in the continental USA. This case demonstrates the need to educate all military providers to recognize the presentation of mediastinal masses in active duty service members and the importance of urgently escalating these patients to higher levels of care in order to avoid life-threatening complications.

The effects of stimulus modality, task complexity, and cuing on working memory and the relationship with speech recognition in older cochlear implant users.

INTRODUCTION: The role of working memory (WM) in speech recognition of older cochlear implant (CI) users remains unclear. This study 1) examined the effects of aging and CI on WM performance across different modalities (auditory vs. visual) and cuing conditions, and 2) assessed how specific WM measures relate to sentence and word recognition in noise. METHOD: Fourteen Older CI users, 12 Older acoustic-hearing (AH) listeners with age-appropriate hearing loss, and 15 Young normal-hearing (NH) listeners were tested. Participants completed two simple span tasks (auditory digit and visual letter span), two complex WM tasks (reading span and cued-modality WM with simultaneously presented auditory digits and visual letters), and two speech recognition tasks (sentence and word recognition in speech-babble noise). RESULTS: The groups showed similar simple span performance, except that Older CI users had lower auditory digit span than Young NH listeners. Both older groups had similar reading span performance, but scored significantly lower than Young NH listeners, indicating age-related declines in attentional and phonological processing. A similar group effect was observed in the cued-modality WM task. All groups showed higher recall for auditory digits than for visual letters and the advantage was most evident without modality cuing. All groups displayed greater cuing benefits for visual recall than for auditory recall, suggesting that participants consistently allocated more attention to auditory stimuli regardless of cuing. For Older CI users, after controlling for the previously reported spectral resolution, auditory-uncued WM performance was significantly correlated with word recognition but not sentence recognition. CONCLUSIONS: Complex WM was significantly affected by aging but not by CI. Neither aging nor CI significantly affected modality cuing benefits in the WM task. For Older CI users, complex auditory WM with attentional control may better reflect the cognitive load of speech recognition in noise than simple span or complex visual WM.

Psychoacoustic and Demographic Factors for Speech Recognition of Older Adult Cochlear Implant Users.

Purpose This study aimed to evaluate the effects of aging and cochlear implant (CI) on psychoacoustic and speech recognition abilities and to assess the relative contributions of psychoacoustic and demographic factors to speech recognition of older CI (OCI) users. Method Twelve OCI users, 12 older acoustic-hearing (OAH) listeners age-matched to OCI users, and 12 younger normal-hearing (YNH) listeners underwent tests of temporal amplitude modulation detection, temporal gap detection in noise, and spectral-temporal modulated ripple discrimination. Speech reception thresholds were measured for sentence recognition in multitalker, speech-babble noise. Results Statistical analyses showed that, for the small sample of OAH listeners, the degree of hearing loss did not significantly affect any outcome measure. Temporal resolution, spectral resolution, and speech recognition all significantly degraded with both age and the use of a CI (i.e., YNH better than OAH and OAH better than OCI performance). Although both were significantly correlated with OCI users' speech recognition, the duration of CI use no longer had a significant effect on speech recognition once the effect of spectral-temporal ripple discrimination performance was taken into account. For OAH listeners, the only significant predictor of speech recognition was temporal gap detection performance. Conclusion The preliminary results suggest that speech recognition of OCI users may improve with longer duration of CI use, mainly due to higher perceptual acuity to spectral-temporal modulated ripples in acoustic stimuli.