Objectives/Hypothesis: Speech perception scores using cochlear implants have ranged widely in all published series. The underlying determinants of success in word recognition are incompletely defined. Although it has been assumed that residual spiral ganglion cell population in the deaf ear may play a critical role, published data from temporal bone specimens from patients have not supported this hypothesis. The depth of insertion of a multichannel cochlear implant has also been suggested as a clinical variable that may be correlated with word recognition. In the current study these correlations were evaluated in 15 human subjects. Study Design: Retrospective review of temporal bone histopathology-.Methods: Temporal bones were fixed and prepared for histological study by standard techniques. Specimens were then serially sectioned and reconstructed by two-dimensional methods. The spiral ganglion cells were counted, and the depth of insertion of the cochlear implant as measured from the round window was determined. Correlation analyses were then performed between the NU6 word scores and spiral ganglion cell counts and the depth of insertion. Results: The segmental and total spiral ganglion cell counts were not significantly correlated (P > .50) with NU6 word scores for the 15 subjects. Statistically significant correlations were not achieved by separate analysis of implant types. Similarly, no significant correlation between the depth of insertion of the electrode array and postoperative NU6 word score was identified for the group. Conclusion: Although it is unlikely that the number of residual spiral ganglion cell counts is irrelevant to the determination of word recognition following cochlear implantation, there are, clearly, other clinical variables not yet identified that play an important role in determining success with cochlear implantation.

Although hearing loss is the most common presenting symptom in patients with acoustic neuroma, the pathophysiology of hearing loss associated with acoustic neuroma is unknown. Although primary dysfunction of the auditory nerve is intuitively logical, available histopathologic and clinical data suggest that although neural degeneration is common, it alone does not adequately account for hearing loss in many cases. The purpose of this study was to evaluate 11 cases of unoperated unilateral acoustic neuromas. Temporal bones were identified by means of a search mechanism provided by the National Temporal Bone, Hearing, and Balance Pathology Resource Registry and were prepared for light microscopy by standard techniques. Quantification of spiral ganglion cells, hair cells, stria vascularis, and spiral ligament was accomplished for each specimen. In addition, the maximum diameter and volume of each tumor were calculated from histopathologic sections. Increasing tumor size did predict a reduced spiral ganglion count. However, although there was a tendency for decreasing spiral ganglion cell count and for increasing tumor size to predict a higher pure tone average and lower speech discrimination score, these correlations did not reach statistical significance. In tumor ears in which the speech discrimination score was 50% or less, there was always significant degeneration of other structures of the inner ear in addition to neurons, including hair cells, the stria vascularis, and the spiral ligament. Endolymphatic hydrops and eosinophilic precipitate in the perilymphatic spaces were found in 2 of 3 such cases. It is concluded that acoustic neuromas appear to cause hearing loss, not only by causing degeneration of the auditory nerve, but also by inducing degenerative changes in the inner ear. It is hypothesized that the proteinaceous material seen histologically may represent the products of up-regulated genes in acoustic neuroma, some of which may interfere with normal cochlear function.

No abstract

It is generally assumed that at least a minimal number of spiral ganglion cells is essential for successful speech perception with a cochlear implant. Although the insertion of a multichannel cochlear implant frequently results in loss of residual hearing in the implanted ear, this outcome does not imply that significant damage to residual populations of spiral ganglion cells has occurred. The purpose of the current study was to compare spiral ganglion cell counts in implanted and nonimplanted cochleas in 11 patients for whom both temporal bones were available and in whom a multichannel cochlear implant had been placed unilaterally. The temporal bones were processed for light microscopy by standard techniques. The cochleas were reconstructed by 2-dimensional methods. Spiral ganglion cell counts of the implanted and nonimplanted sides were compared by a paired t-test (2-tailed). The mean spiral ganglion cell counts for implanted and nonimplanted ears were not statistically different in the most basal three segments of the cochlea. However, the mean spiral ganglion cell count in segment 4 (apical segment) and the mean total spiral ganglion cell count were lower in the implanted cochleas than in the nonimplanted cochleas (p < .01). The results of this study suggest a modest decrease in the total spiral ganglion cell count in the implanted ears as compared to the nonimplanted ears, principally in the apical segment. Possible interpretations of this finding are discussed.

No abstract

The widely patent cochleovestibular communication is a distinct inner ear malformation, recognition of which may have important clinical implications. Estimates of spiral ganglion cells can be predicted from the number of cochlear turns. Although cochlear implantation is feasible in patients with this malformation, a higher risk of cerebrospinal fluid gushers, facial nerve injuries, meningitis, and poor performance would be predicted. A better understanding of the anatomy will allow more effective surgical planning and techniques and may have a significant impact in improving outcomes.

BACKGROUND: We assessed treatment uptake and completion for 6 months of isoniazid (6H) and 3 months of isoniazid plus rifapentine weekly (3HP) in a programmatic setting in Pakistan.METHODS: All household contacts were clinically evaluated to rule out TB disease. 6H was used for TB preventive treatment (TPT) from October 2016 to April 2017; from May to September 2017, 3HP was used for contacts aged ≥2 years. We compared clinical evaluation, TPT uptake and completion rates between contacts aged ≥2 years in the 6H period and in the 3HP period.RESULTS: We identified 3,442 contacts for the 6H regimen. After clinical evaluation, 744/1,036 (72%) started treatment, while 46% completed treatment. In contrast, 3,722 contacts were identified for 3HP. After clinical evaluation, 990/1,366 (72%) started treatment, while 67% completed treatment. Uptake of TPT did not differ significantly between the 6H and 3HP groups (OR 1.03, 95%CI 0.86–1.24). However, people who initiated 3HP had 2.3 times greater odds (95% CI 1.9–2.8) of completing treatment than those who initiated 6H after adjusting for age and sex.CONCLUSION: In programmatic settings in a high-burden country, household contacts of all ages were more likely to complete TPT with shorter weekly regimens, although treatment uptake rate for the two regimens was similar.

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is reported in up to 18.6% of patients treated with intravenous bisphosphonates and can result in significant morbidity. Most cases are managed by oral surgeons with only a handful of reports appearing in the otolaryngology literature. We present a unique case of extensive BRONJ involving the maxilla, sinuses, and skull base, complicated by sinusitis and an intracranial abscess. This is the first description of BRONJ involving the skull base. The pathogenesis and management of this process are reviewed.