The Diagnostic Value of Multifrequency Tympanometry in Patients with Ménière's Disease: A Prospective Analysis.

INTRODUCTION: Diagnosing Ménière's disease (MD) by its characteristics such as episodes of vertigo, fluctuating hearing loss, and tinnitus with aural fullness remains challenging. Available tests evaluating the presence of endolymphatic hydrops (EH) are often expensive or time assuming. An in-office quick and simple non-invasive diagnostic test is multifrequency tympanometry (MFT). It can measure conductance at 2 kHz probe tones, which was demonstrated to reflect variations in cochlear pressure. Previous studies investigating MFT as a diagnostic test for MD showed conflicting outcomes possibly biased by their retrospective design. METHODS: We prospectively collected MFT results (Y width) in patients with dizziness and compared MFT test results in affected (group 1) and unaffected (group 2) ears of 37 MD subjects and in control ears of 33 non-MD subjects (group 3). RESULTS: The mean value of the Y width in affected ears was 315.6 ± 70.2 daPa compared to 292.3 ± 98.6 daPa in unaffected ears in MD subjects and 259.4. ± 60.6 daPa in the non-MD group. A positive test result (i.e., a Y width of 235 daPa or more) was found in 35 ears in the MD group, 21 times involving the affected ear and 14 times involving the unaffected ear, compared to 16 in the non-MD group. No significant differences between the three groups could be demonstrated (p > 0.05). We found a sensitivity of 58.3% and specificity of 66.3% for detecting EH in an affected ear in MD subjects. CONCLUSION: There is a trend towards increased conductance tympanometry in affected ears. However, we noticed a high false positive rate of MFT and do not support standardized use of MFT as an additional diagnostic tool for detecting EH in MD patients. A negative test result on the contrary is unlikely related to EH.

[Atypical pain and a unilateral swelling of the neck: a patient with TIPIC-syndrome]. / Atypische pijn en een eenzijdige zwelling in de hals.

BACKGROUND: TIPIC-syndrome (Transient Perivascular Inflammation of the Carotid Artery) as a cause of a painful lump in the neck is not often described in the literature. This self-limiting perivascular inflammation of the carotid bifurcation is relatively unknown. CASE: We describe a 50-year old patient, in whom a CT-scan that was performed because of unilateral pain in the neck and paranasal sinuses revealed the unexpected diagnosis of TIPIC-syndrome. CONCLUSION: Knowledge of the symptoms at presentation and the following clinical course of TIPIC-syndrome can prevent unnecessary use of additional tests.

Vestibular schwannoma manifesting with hemifacial spasm in a young woman: clinical considerations and tumor removal with hearing preservation. 2-Dimensional operative video.

Hemifacial spasm (HFS) is a rare presentation of vestibular schwannoma. The authors present their experience with a 27-year-old woman who presented with normal hearing and HFS, which was the single neurological manifestation of an 18-mm vestibular schwannoma. In this challenging situation, the treatment goals were maximal tumor removal with preservation of hearing and facial nerve function and cure of the HFS. The authors achieved these goals, performing complete tumor removal via a retrosigmoid approach, assisted with neurophysiological monitoring and a 45°-angle QEVO endoscope. In the video, they explain the clinical, radiological, and surgical considerations and demonstrate the surgical technique. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID2099.

Temporal bone anatomy characteristics in superior semicircular canal dehiscence.

INTRODUCTION: Superior semicircular canal dehiscence (SCD) remains difficult to diagnose despite advances in high-resolution computed tomography (HRCT) imaging. We hypothesize possible associations between gross temporal bone anatomy and sub-millimeter pathology of the semicircular canals, which may supplement imaging and clinical suspicion. This pilot study investigates differences in gross temporal bone anatomic parameters between temporal bones with and without SCD. METHODS: Records were reviewed for 18 patients referred to an otology clinic complaining of dizziness with normal caloric stimulation results indicative of non-vestibular findings. Eleven patients had normal temporal bone anatomy while seven had SCD. Three-dimensional reconstruction of every patient's temporal bone anatomy was created from patient-specific computational tomography images. Surface area (SA), volume (V), and SA to V ratios (SA:V) were computed across temporal bone anatomical parameters. RESULTS: SCD temporal bones have significantly smaller V, and larger temporal bone SA. Mean (±SD) V was 21,484 ± 3,921 mm3 in temporal bones without SCD and 16,343 ± 34,471 mm3 for those with SCD. Their respective SA were 13,733 ± 1,603 mm2 and 18,073 ± 3,002 mm2. Temporal bone airspaces and lateral semicircular canals did not demonstrate significant differences where SCD was and was not present. Plots of MVwarm response against computed SCD temporal bone anatomic parameters (SA, V and SA:V) showed moderate to strong correlations: temporal bone SA:V (r = 0.64), temporal bone airspace V (r = 0.60), temporal bone airspace SA (r = 0.55), LSCC SA (r = 0.51), and LSCC-to-TM Distance (r = 0.65). CONCLUSIONS: This analysis demonstrated that SCD is associated with decreased temporal bone volume and density. The defect in SCD does not appear to influence caloric responses.

Removal of dental implants displaced into the maxillary sinus: A case series.

PURPOSE: To present a retrospective case series of displaced dental implants in the maxillary sinus. MATERIALS AND METHODS: Patients with unintentional displacement of dental implants in the maxillary sinus over a 5-year period who underwent or were candidates for surgical implant removal were included. The patients' characteristics, medical history, clinical and imaging results, and post-removal outcome were retrospectively assessed. RESULTS: Out of 14 patients, 13 underwent surgical removal. In one case the implant spontaneously exiled into the nose before surgery. The timespan between dental implantation and presentation ranged from 3 months to 9 years. Imaging evaluation showed a displaced implant (100%), oroantral fistula (65%), complete opacification of the maxillary sinus (28%), circumferential opacification (21%), isolated maxillary sinus outflow obstruction (7%) and a sinus which appeared normal (43%). Symptoms and signs included nasal obstruction (36%), purulent secretions (36%), facial pain (21%), tenderness on percussion (21%) and foul smell (14%). Two patients (14%) were asymptomatic. Intraoperative inspection of nine sinuses revealed mucosal changes and purulent secretions in 55% of patients. In all cases the implant had migrated from the maxillary sinus floor towards the natural ostium. Endoscopic removal was carried out successfully in all operated cases. All sinuses eventually healed. CONCLUSIONS: Migration of displaced implants and mucosal changes may occur over a short period, eventually causing secondary sinusitis. We therefore favour surgical removal. Surgery should be as close as possible to displacement in order to minimise mucosal inflammation and to prevent unnecessary manipulation during surgical removal. Conflict of interest statement: None of the authors report any financial interests or potential conflict of interests.

The mechanism of direct stimulation of the cochlea by vibrating the round window.

BACKGROUND: Active middle ear implants such as the vibrant sound bridge (VSB) have been placed on the round window (RW) in patients with conductive or mixed hearing loss, with satisfactory hearing results. Several observations show that the mechanism of RW stimulation is not completely understood. The purpose of the present study was to compare different coupling procedures between the transducer and the RW in order to contribute to an understanding of the mechanism of RW stimulation. METHODS: Five fat sand rats underwent ablation of the left ear and opening of the right bulla, followed by baseline measurements of thresholds of auditory nerve brainstem evoked responses (ABR) to air and bone conduction click stimuli. Subsequently the malleus and incus were removed from the right middle ear, modeling a conductive hearing loss in which the VSB on the RW is indicated. In the next stage of the experiment, a rod attached to the bone vibrator was placed gently on the RW membrane and then on saline fluid applied to the RW niche. ABR thresholds were recorded following both placements. RESULTS: Mean baseline ABR threshold in response to air conduction stimuli was 48 ± 4 dB; mean ABR threshold when the rod was placed on the dry RW membrane was 99 ± 12 dB; mean ABR threshold when the rod was in the saline on RW niche was 79 ± 7 dB. CONCLUSIONS: ABR thresholds were better (lower) with stimulation of fluid on the RW membrane compared to direct stimulation of the RW, providing further evidence of a direct fluid pathway.

Experimental exploration of the soft tissue conduction pathway from skin stimulation site to inner ear.

OBJECTIVES: Auditory sensation can be elicited by air conduction (AC) and by bone conduction (BC). It is also possible to elicit such responses by applying the standard clinical bone vibrator to the skin over soft tissue sites on the head, neck, or thorax of humans and animals. This mode of auditory stimulation has been called soft tissue conduction (STC). This study was designed to investigate the pathway between soft tissue sites and the ear. METHODS: The air in the middle ear was replaced with saline solution in an animal with unique anatomy--the fat sand rat, in which about 70% of a thin-walled inner ear bulges into the middle ear bulla cavity--while we recorded the auditory brain stem responses (ABRs) to AC, BC, and STC stimulation. RESULTS: This replacement of air with saline solution led to a significant improvement in STC threshold. With AC stimulation, the ABR threshold was elevated and the latency of the first ABR wave was prolonged. Consistent changes were not seen with BC stimulation. CONCLUSIONS: When the air (which has a very low acoustic impedance) that normally surrounds most of the inner ear is replaced with saline solution (which has an acoustic impedance similar to that of soft tissues), the STC threshold is improved. This improvement may be due to improved transmission of acoustic energy from the soft tissues to the inner ear.

Total lymphocyte count is a reliable surrogate marker for CD4 cell counts after the first year of antiretroviral therapy: data from an Indonesian cohort study.

Many studies have evaluated the total lymphocyte count (TLC) as a cheap surrogate marker for CD4 cells in HIV-infected patients not receiving antiretroviral therapy (ART). We assessed whether TLC can replace CD4 cell counts in evaluating the immunological response to ART. In a cohort of patients in Indonesia TLC, if measured after at least 1-year ART, correctly identified patients with <200 CD4 cells, and reliably excluded immunological failure, obviating the need for CD4 cell measurement in 43% of patients.

Combined effects of salicylic acid and furosemide and noise on hearing.

BACKGROUND: A major cause of the hearing loss following exposure to intense noise involves release of free radicals resulting from the elevated metabolism. The free radicals induce damage to several of the components of the cochlear amplifier including the outer hair cells and indirectly to the transduction currents. Salicylic acid induces a reversible hearing loss since it binds to the motor protein prestin in the outer hair cells, reducing electromotility. Furosemide also induces a reversible hearing loss since it reduces the endocochlear potential which is a major component of the cochlear transduction currents. On the other hand, each of these drugs also provides protection from a noise induced hearing loss if they are injected just before a noise exposure, probably as a result of the decreased metabolism induced in their presence, with release of lower levels of free radicals. In this study, both drugs were administered in order to assess whether their protective effects would be additive. METHODS: The study was conducted on normal hearing albino mice of the Sabra strain. They were injected with either salicylic acid alone (N = 11), or furosemide alone (N = 14), or both together (N = 14), or with saline control (N = 11) and exposed to broad band noise for 3.5 hours. An additional group of 9 mice was injected with both salicylic acid and furosemide, but not exposed to noise. The degree of the resulting hearing loss was assessed by recording thresholds of the auditory nerve brainstem evoked responses to broad band clicks before the injections and noise, and 7, 14 and 21 days after. RESULTS: The noise induced hearing loss in the mice injected with salicylic acid alone or furosemide alone was smaller than in those injected with saline, i.e. these drugs provided protection, as in previous studies in this laboratory. There was no threshold elevation after two weeks in the mice injected with both drugs without noise exposure, i.e. the effects of the two drugs given together was reversible. On the other hand, there was a significant hearing loss (i.e. threshold elevation) in the group which received both drugs and was also exposed to noise, with mean threshold elevations of 38.8 ± 19.0 dB and 28.3 ± 11.7 dB 7 days after noise exposure. CONCLUSIONS: This result is very surprising, if not paradoxical. Drugs which provide protection from a noise induced hearing loss when administered alone, not only do not provide protection when given together, but also induce a greater hearing loss when accompanied by noise. This observation may be related to the finding that the depression of the endocochlear potential normally caused by furosemide is reduced in the presence of salicylic acid, so that the protection usually provided by furosemide is not present when it is administered together with salicylic acid. Thus it seems that each drug may interfere with the protective action of the other when coupled with noise.