David R. Friedland

Temporal Bone Fractures: Traditional Classification and Clinical Relevance

Objectives/Hypothesis: The objectives were to evaluate the clinical relevance of traditional temporal bone radiographic descriptors and to investigate the efficacy of an alternative fracture classification scheme.

Choice of ear for cochlear implantation: the effect of history and residual hearing on predicted postoperative performance.

Objective This study used mathematical formulas predicting cochlear implant outcomes to investigate the effects of implantation in the poorer ear on postoperative speech recognition. Design Retrospective cohort study with mathematical and statistical analyses. This study used the University of Iowa formula for predicting outcomes derived from implantation of the better ear on the basis of duration of deafness and preoperative speech understanding, applying this predictive model to a cohort of patients undergoing implantation in the poorer ear at The Johns Hopkins Medical Center. Setting Tertiary referral center with active cochlear implant program. Patients Postlingually deafened adults (n = 58) with preoperative Central Institute for the Deaf sentence scores less than or equal to 40%. Intervention Cochlear implantation with all three Food and Drug Administration–approved devices. Main Outcome Measure Postoperative monosyllabic word recognition scores and correlations between actual and predicted results. Results There was good statistical correlation between the predicted postoperative performance using the University of Iowa formula and the actual performance of our cohort of patients undergoing implantation in the poorer ear (r = 0.50, p < 0.0001). In addition, as a population, our cohort had a mean postoperative consonant-nucleus-consonant word score of 41.8%, which was statistically the same as that predicted by the University of Iowa formula (43.6%). Conclusions The postoperative performance of cochlear implant patients is most closely correlated with duration of deafness. However, our results indicate that this measure may not be ear specific and is more reflective of the total auditory receptivity of the patient. These observations help to form guidelines for choice of ear for implantation.

Audiometric pattern as a predictor of cardiovascular status: Development of a model for assessment of risk

This study hypothesizes that low‐frequency hearing loss is associated with underlying cardiovascular disease. The objective of this study was to use a mathematical model of hearing thresholds to predict cardiovascular status.

Case-Control Analysis of Cochlear Implant Performance in Elderly Patients

OBJECTIVE To characterize speech perception performance in elderly cochlear implant users compared with younger adult users. DESIGN Case-control retrospective analysis from January 1, 1999, to January 28, 2008. SETTING Tertiary care, academic practice cochlear implant program. PATIENTS Medical records for 78 patients with age at implantation of 65 years or older were analyzed for ear-specific preimplantation speech perception performance, length of deafness, age at implantation, and 1-year postimplantation speech perception performance. A subset of 28 elderly patients with complete data was matched to 28 younger adult patients (age at implantation, 18-64 years) for preimplantation performance using the Hearing in Noise Test-Quiet scores (mean, 22% and 23%, respectively). MAIN OUTCOME MEASURE One-year postimplantation performance on word and sentence testing. RESULTS Within the elderly cohort, the Consonant-Nucleus-Consonant and Hearing in Noise Test-Quiet scores were not affected by age. The Hearing in Noise Test-Noise scores trended downward with increasing age but did not reach statistical significance (P = .052). Of the matched older and younger patients, 55 of 56 showed improvement in their 1-year postimplantation compared with preimplantation Hearing in Noise Test-Quiet scores, with better preimplantation performance predictive of better postimplantation performance, independent of age at implantation (P = .02). Group comparisons, however, revealed poorer postimplantation scores overall for the elderly patients compared with the younger ones for the Hearing in Noise Test-Quiet (70% vs 83%; P = .02) and the Consonant-Nucleus-Consonant test (38% vs 53%; P = .02). CONCLUSIONS Elderly patients benefit significantly from cochlear implantation. Compared with a younger cohort matched for preimplantation performance, however, their postimplantation scores are significantly lower on some measures. These results may provide guidelines for candidacy and counseling regarding elderly patients with cochlear implants.

Soft Cochlear Implantation: Rationale for the Surgical Approach

Recent advances in cochlear implant technology have focused renewed attention on the preservation of residual hearing. The focus on preservation of residual hearing is driven by the concept of electroacoustic stimulation. This option depends on the insertion of a short cochlear implant electrode into the basal region of the cochlea while preserving native function in the apical region. The desire to preserve residual hearing has led to the development of the soft-surgery cochlear implantation technique. Here, the authors evaluate its various components. Avoiding entry of blood into the cochlea and the use of hyaluronate seem to be reasonably supported, whereas the use of topical steroids is unlikely to be beneficial. The site of entry into the cochlea, the use of contoured or straight devices, and the depth of insertion are also evaluated. The authors highlight the importance of systematic recording of outcomes and surgical events.

Feasibility of auditory cortical stimulation for the treatment of tinnitus.

Objectives: To investigate the feasibility and safety of an implantable epidural cortical stimulator for the treatment of severe tinnitus. Study Design: Prospective, controlled, single-blinded study of cortical stimulation for 4 weeks, and then an open-label stimulation period. Setting: Tertiary care referral center. Patients: Adults (n = 8) with constant tinnitus of at least 1 year with a tinnitus reaction questionnaire score greater than 33. Tinnitus was predominantly unilateral with a frequency less than 8,000 Hz. Interventions: Surgical implantation of an investigational epidural electrode over the posterior superior temporal gyrus using functional magnetic resonance imaging targeting. A 2-week stimulation period alternated with a 2-week sham period in random order to which subjects were blinded. This was followed by continuous stimulation with parameter adjustments to maximize tinnitus suppression. Main Outcome Measure: Subjective rating of tinnitus severity, loudness, and device efficacy. Objective measures of hearing thresholds, tinnitus frequency, loudness, and minimum masking levels. Outcome measures using the Tinnitus Handicap Questionnaire, Tinnitus Reaction Questionnaire, and Beck Depression Inventory. Results: There were no effects of stimulation during the 4-week blinded period. With continuous chronic stimulation, 2 patients had persistent reduction of pure-tone tinnitus, and 6 patients had short periods of total tinnitus suppression.Significant improvements in the Beck Depression Inventory and tinnitus questionnaires were found, although objective measures of tinnitus loudness remained fairly stable. No surgical or stimulation-related complications were noted. Conclusion: Chronic electrical stimulation of the secondary auditory cortex seems safe and warrants further investigation as a potential therapeutic intervention for the suppression of tinnitus.

Cranial thickness in superior canal dehiscence syndrome: implications for canal resurfacing surgery.

Objective: To use morphometric analyses of cranial thickness to investigate 2 cases of unanticipated calvarial bone resorption in superior canal dehiscence (SCD) resurfacing surgery. Design: Retrospective morphometric analysis of high-resolution computed tomography (CT) temporal bone scans in normal and control subjects with accompanying case reports. Setting: Tertiary care referral center. Patients: Two patients with SCD and failed resurfacing because of bone resorption. Temporal bone CT scans from 30 sex-matched controls. Intervention: Resurfacing of SCD via a middle fossa approach using a split thickness calvarial graft from the craniotomy site. Main Outcome Measure: Mean cross-sectional area of the middle fossa craniotomy bone flap and mean cranial thicknessat 30 and 45 degrees above the middle fossa floor. Results: Two patients had delayed failure of SCD resurfacing surgery as manifested by return of symptoms. High-resolution CT scans in both, and intraoperative confirmation in one, confirmed resorption of the bone graft. Measurements of cross-sectional area of the middle fossa craniotomy onhigh-resolution CT scans demonstrated significantly reduced values in the two SCD patients as compared with normal controls (Mann-Whitney U test, p < 0.05). Cranial thickness outside the squamous temporal bone was reduced but did notreach statistical significance. Conclusion: Morphometric measurements of the calvarium have demonstrated that the squamous temporal bone is thinner in patients with SCD as compared with controls. Thus, the process leading to defects in the tegmen extends beyond the petrous pyramid. This suggests that there may be extratemporal factors leading to the development of a dehiscence. These findings also have implications for the surgical treatment of this disorder. Resurfacing methods may have a higher failure rate as the bone graft has reduced mass and maybe prone to resorption. Canal plugging methods may provide amore definitive means of addressing the dehiscent labyrinth than resurfacing.

Lymphatic malformation: predictive factors for recurrence.

ABSTRACT OBJECTIVE: Although lymphatic malformations are often found to be well circumscribed when surgery is undertaken in early childhood, complete surgical excision can be difficult when the lesion is infiltrative. This study retrospectively evaluates these patients in an attempt to identify prognostic factors that may predict recurrence. STUDY DESIGN AND SETTING: A retrospective chart review was conducted covering the years 1991 to 1998. Seventeen patients were identified having undergone 32 surgical resections of tumors described as lymphatic malformations. Data abstracted from the charts included the site of the lesion, surgical and histologic assessment of encapsulation, and status at follow-up examination. RESULTS: Six of 17 patients developed a recurrence after surgery. Correlation between recurrence and histologic or operative impressions of encapsulation was significant by χ2 analysis (P < 0.01). CONCLUSION: On the basis of the findings of this case series, lymphatic malformations that are found to be nonencapsulated and infiltrative by intraoperative or histologic assessment are more likely to recur.

Cholesteatoma growth and proliferation: posttranscriptional regulation by microRNA-21.

Objectives: The goal of this study was to identify novel regulatory mechanisms controlling the growth and proliferation of cholesteatoma. Specifically, the potential role of microRNAs, regulators of protein translation, was studied in cholesteatoma. Study Design: This study represents a molecular biologic investigation characterizing and comparing microRNA and protein expression in cholesteatoma and normal postauricular skin. Methods: Cholesteatoma and normal skin were taken from patients at the time of surgery. Tissue was processed for RNA and protein extraction. Real-time reverse-transcriptase-polymerase chain reaction was used to assess levels of human microRNAs, reverse-transcriptase-polymerase chain reaction was used to confirm the presence of upstream regulators, and Western blot analyses were used to assess levels of downstream target proteins. Results: Among the microRNAs investigated, human microRNA-21 (hsa-miR-21) showed a 4.4-fold higher expression in cholesteatoma as compared with normal skin (p = 0.0011). The downstream targets of hsa-miR-21, PTEN and programmed cell death 4, were found to be greatly reduced in 3 of 4 cholesteatoma samples. Proposed upstream regulators of hsa-miR-21 expression (CD14, interleukin 6R, gp130, and signal transducer and activator of transcription 3) were present in all cholesteatoma tissues. Conclusion: MicroRNAs represent powerful regulators of protein translation, and their dysregulation has been implicated in many neoplastic diseases. This study specifically identified up-regulation of hsa-miR-21 concurrent with down-regulation of potent tumor suppressor proteins PTEN and programmed cell death 4. These proteins control aspects of apoptosis, proliferation, invasion, and migration. The results of this study were used to develop a model for cholesteatoma proliferation through microRNA dysregulation. This model can serve as a template for further study into potential RNA-based therapies for the treatment of cholesteatoma.

A modified Golgi staining protocol for use in the human brain stem and cerebellum.

The Golgi silver-impregnation method established itself as an important technique for distinguishing morphology at the individual neuron level. This technique has been especially useful for studying human neuroanatomy because it works on postmortem tissue but it is also unreliable and capricious. In this report, we describe a simple technique that was applied to human autopsy and tissue-bank material yielding useful results for the study of neuronal morphology in the brain stem and cerebellum. Human adult brain stems had been immersion-fixed in formalin for a period of time ranging from weeks to months. Brain stem tissue was cross-sectioned into 3-5mm thick slabs, centered about the cochlear nucleus. Slabs were processed under continuous vacuum (22-26 in. of Hg), a procedure that promoted penetration of reagents into the tissue. Tissue was sectioned using a Vibratome and mounted for light microscopy. The results demonstrated improved staining of neurons in the brain stem. Staining of the large synaptic endings of auditory nerve fibers called end bulbs of Held in the cochlear nucleus was especially evident. These results suggest that an age-graded series could be conducted to describe the development of these large auditory endings in humans.