A Paradoxical Clinical Coincidence: Benign Paroxysmal Positional Vertigo and Bilateral Vestibulopathy.

Benign paroxysmal positional vertigo (BPPV) and bilateral vestibulopathy (BVL) are two completely different forms of vestibular disorder that occasionally occur in the same patient. We conducted a retrospective review searching for that coincidence in our database of the patients seen over a 15-year period and found this disorder in 23 patients, that is 0.4%. More frequently they occurred sequentially (10/23) and BPPV was diagnosed first. Simultaneous presentation occurred in 9/23 patients. It was subsequently studied, but in a prospective manner, in patients with BPPV on all of whom a video head impulse test was performed to search for bilateral vestibular loss; we found it was slightly more frequent (6/405). Both disorders were treated accordingly, and it was found that the results follow the general trend in patients with only one of those disorders.

Cochlear Implantation With a Dexamethasone Eluting Electrode Array: Functional and Anatomical Changes in Non-Human Primates.

OBJECTIVES: The aim of this study was to determine whether the dexamethasone-eluting electrode (DEXEL) has a protective anti-inflammatory effect in a normal hearing implanted cochlea, as well as its performance and safety. DESIGN: Ten healthy and normal hearing cynomolgus macaques (Mf) were divided into two cohorts: DEXEL group (DG) (CONCERTO CI device containing a DEXEL) and conventional CI group (CG) (unmodified CONCERTO CI device). The electrode was inserted into the scala tympani via the round window with an angle of insertion of 270 degrees. Auditory, impedance, electrically evoked compound action potential (eCAP), and recovery of function measurements were recorded monthly until sacrifice at 6 months post-implantation. A histologic analysis was also performed. RESULTS: At 6 months, measurement of auditory brainstem responses revealed a mean threshold shift, as well as a mean impedance value, lower in the DEXEL group. The minimum eCAP for the remaining active contacts in the DEXEL group was 68% of that in the conventional CI group. Also at 6 months, the eCAP amplitude produced by a stimulating current of 800 cu (eCAP) was almost 2.5-fold higher in the DEXEL group than in the conventional CI group (1338.86 ±â€Š637.87 µV versus 545.00 ±â€Š137.37 µV; p = 0.049). Tissue reactions, in particular fibrosis and ossification, were more common in the conventional CI group. CONCLUSIONS: The CI electrode array equipped with a dexamethasone-eluting component tested in macaques evidence that delivery of dexamethasone to the inner ear may produce rapid and long-lasting improvement of hearing with fewer neural tissue reactions.

Correlation between High-Resolution Computed Tomography Scan Findings and Histological Findings in Human Vestibular End Organs and Surgical Implications.

BACKGROUND: Histological study of vestibular end organs has been challenging due to the difficulty in preserving their structures for histological analysis and due to their complex geometry. Recently, radiology advances have allowed to deepen the study of the membranous labyrinth. SUMMARY: A review and analysis of surgical implications related to the anatomy of the vestibular end organ is performed. Radiological advances are key in the advancement of the knowledge of the anatomy and pathology of the vestibule. Thus, application of such knowledge in the development or improvement of surgical procedures may facilitate the development of novel techniques. Key Messages: During the last few decades, the knowledge of the anatomy of the auditory system through histology and radiology had improved. Technological advances in this field may lead to a better diagnosis and therapeutic approach of most common and important diseases affecting the inner ear.

Prelingual Deaf Children Treated With Cochlear Implant: Monitoring Performance With Percentiles.

OBJECTIVES: To develop a percentile ranking system driven by speech recognition data obtained from different groups of patients treated with a cochlear implant to serve as a tool to monitor the progress of these patients. STUDY DESIGN: Prospective study. SETTING: Tertiary referral center. PATIENTS: Diagnosed with a bilateral, profound sensorineural hearing loss treated with a unilateral cochlear implant. INTERVENTION: Diagnostic. MAIN OUTCOME MEASURE: Six different percentiles (p) were classified taking into account the correlation between speech recognition outcome scores and age at implantation, with reference to the onset of hearing loss. RESULTS: Four hundred sixteen prelingual patients were included. These subjects were divided into subgroups depending on age at implantation.Prelingual group, from the fifth year after implantation, p50 centered on the following percentages of correct words in each subgroup: 100, 94.6, 91.4, 91.0, 79.2, and 63.1% in children implanted under 12 months, 1, 2, 3, 4 to 6, 7 to 10 years, respectively. After a 12-year follow-up, a significant negative correlation between age at implantation and speech recognition was observed in both prelinguals (Rhos=-0.578, p<0.001). CONCLUSION: A percentile system was developed to monitor the postimplant progress of prelingual deaf implanted patients, with potential applications in patient follow-up and handling circumstances that may deteriorate results.

Effects of Implantation and Reimplantation of Cochlear Implant Electrodes in an In Vivo Animal Experimental Model (Macaca fascicularis).

OBJECTIVES: The objectives of this study were to evaluate the effect of reimplanting a cochlear implant electrode in animal normal-hearing cochlea to propose measures that may prevent cochlear injury and, given its close phylogenetic proximity to humans, to evaluate the macaque as a model for electroacoustic stimulation. DESIGN: Simultaneous, bilateral surgical procedures in a group of 5 normal-hearing specimens (Macaca fascicularis) took place in a total of 10 ears. Periodic bilateral auditory testing (distortion product otoacoustic emissions and auditory brainstem evoked responses [ABR]) took place during a 6-month follow-up period. Subsequently, unilateral explantation and reimplantation was performed. Auditory follow-up continued up to 12 months, after which animals were sacrificed and both temporal bones extracted for histological analysis. RESULTS: Implantation and reimplantation surgeries were performed without complications in 9 of 10 cases. Full insertion depth was achieved at reimplantation in four of five ears. Auditory evaluation: Statistically significant differences between implanted and reimplanted were observed for the frequencies 2000 and 11,000 Hz, the remaining frequencies showed no differences for distortion product otoacoustic emission. Before the procedure, average thresholds with click-stimuli ABR of the five animals were 40 dB SPL (implanted group) and 40 dB SPL (reimplanted group). One week after first implantation, average thresholds were 55 dB SPL and 60 dB, respectively. After 12 months of follow-up, the average thresholds were 72.5 dB SPL (implanted group) and 65 dB SPL (reimplanted group). Hearing loss appeared during the first weeks after the first implantation and no deterioration was observed thereafter. Differences for ABR under click stimulus were not significant between the two ear groups. Similar results were observed with tone-burst ABR. A 15 dB shift was observed for the implanted group preoperatively versus 1-week post surgery and an additional 17.5 dB shift was seen after 12-month follow-up. For the reimplanted group, a 20 dB shift was observed within the first week post reimplantation surgery and an additional 5 dB after 6 months follow-up. Statistical analysis revealed significant differences between the implanted and reimplanted ear groups for frequencies 4000 Hz (p = 0.034), 12000 Hz (p = 0.031), and 16,000 Hz (p = 0.031). The histological analysis revealed that the electrode insertion was minimally traumatic for the cochlea, mainly indicating rupture of the basilar membrane in the transition area between the basal turn and the first cochlear turn only in Mf1 left ear. CONCLUSIONS: With application of minimally traumatic surgical techniques, it is possible to maintain high rates of hearing preservation after implantation and even after reimplantation. Partial impairment of auditory thresholds may occur during the first weeks after surgery, which remains stable. Considering the tonotopic distribution of the cochlea, we found a correlation between the histological lesions sites and the auditory findings, suggesting that a rupture of the basilar membrane may impact hearing levels. The macaque was observed to be a functionally and anatomically an excellent animal model for cochlear implantation.

The effect of intra-tympanic dexamethasone on the vestibular function in patients with recurrent vertigo.

CONCLUSION: The low clinical efficacy of the treatment for patients included in this work correlates with no noticeable effect on the vestibular function. OBJECTIVE: To assess follow-up in patients with idiopathic and secondary Ménière's disease after treatment with intra-tympanic dexamethasone and correlate clinical findings with changes in the vestibular-ocular reflex elicited after stimulation of each of the six semicircular canals. METHODS: This is a single center retrospective review of patients presenting the clinical symptomatology of Meniérè's disease treated with intra-tympanic dexamethasone. An audiometric evaluation was performed in each patient before and after treatment. The study cohort was divided into two groups: those evaluated after a short period of time and after a long period of time. RESULTS: The study included 30 patients, mean age = 61 years. Differences in mean pure-tone average before and after treatment were non-significant for both treated (0.61 dB, p = 0.723) and untreated (0.59 dB, p = 0.609) ears. Vestibular-ocular reflex gain averages in the treated ear after treatment were 0.73 (superior semicircular canal), 0.86 (horizontal semicircular canal), and 0.69 (posterior semicircular canal). The gain did not vary significantly in the Superior (p = 0.194), the Horizontal (p = 0.646), or the Posterior Semicircular Canal (p = 0.820). Similar were obtained for the untreated ear.

Functional neuroimaging studies in asymmetric hearing loss.

This article presents an analysis of the impact of functional neuroimaging studies (positron emission tomography, PET) in asymmetric hearing loss based on the clinical expertise obtained from a group of 21 patients. In these patients, PET studies are performed at rest and after auditory stimulation in order to measure the increase in brain activity in the ipsi- and contralateral cortex, providing supporting evidence to recommend a specific treatment and the side to implant. In conclusion, PET is a useful tool for selected cases in which information on the metabolic status of the auditory pathway can drive the decision regarding the treatment of the most appropriate ear. However, in view of our small sample, further research is needed to confirm our results in this topic.

The vestibulo-ocular reflex assessment in patients with Ménière's disease: examining all semicircular canals.

UNLABELLED: Abstract Conclusion: The distribution of abnormal results is not uniform between different canals in each patient; the most frequent gain reduction is obtained for the posterior canal. Gain reduction reflects the disease duration and amount of hearing loss. OBJECTIVE: To test the hypothesis that the vestibulo-ocular reflex (VOR) evoked after stimulation of each semicircular canal behaves in a different manner in patients with unilateral definite Ménière's disease. METHODS: We studied the VOR evoked by rapid head-impulses in the plane of the 6 semicircular canals in 36 patients. It was evaluated with a video system that analyzes the head and eye velocity and the gain was the objective measure. RESULTS: In 12 (33.3%) patients the examination of both ears was normal for all the semicircular canals, in 12 patients the results from the affected ear were abnormal in at least 1 of the semicircular canals, in 11 (30.5%) patients the results were abnormal in at least 1 of the semicircular canals in both the affected and unaffected ears, and in 1 (2.9%) patient the results were abnormal only in the unaffected ear. The most frequent abnormal result was obtained from the posterior canal of the affected ear and from the coupled superior canal of the unaffected ear. The distribution of abnormal findings was dependent on the disease duration and hearing loss.

Recent onset disequilibrium mimicking acute vestibulopathy in early multiple sclerosis.

The differential diagnosis of patients with acute unilateral vestibulopathy rests in the proper clinical assessment and use of selected tests of vestibular function. In case of a central nervous system lesion as in Multiple Sclerosis, the case shown here, it is of particular importance to observe congruency between severity of symptoms and signs and, of topographic diagnosis. We report a case of a 37-year-old woman with recent onset disequilibrium that after careful analysis of the different test results several incongruences were found; this prompted a radiological study that provided the clue to diagnosis. After treatment the patient recovered completely not only clinically but also in vestibular deficit.