Vision, visuo-cognition and postural control in Parkinson's disease: An associative pilot study

Publication date: July 2016
Source:Gait & Posture, Volume 48
Author(s): E. Hill, S. Stuart, S. Lord, S. Del Din, L. Rochester
IntroductionImpaired postural control (PC) is common in patients with Parkinson's disease (PD) and is a major contributor to falls, with significant consequences. Mechanisms underpinning PC are complex and include motor and non-motor features. Research has focused predominantly on motor and sensory inputs. Vision and visuo-cognitive function are also integral to PC but have largely been ignored to date. The aim of this observational cross-sectional pilot study was to explore the relationship of vision and visuo-cognition with PC in PD.MethodsTwelve people with PD and ten age-matched healthy controls (HC) underwent detailed assessments for vision, visuo-cognition and postural control. Vision assessments included visual acuity and contrast sensitivity. Visuo-cognition was measured by visuo-perception (object identification), visuo-construction (ability to copy a figure) and visuo-spatial ability (judge distances and location of object within environment). PC was measured by an accelerometer for a range of outcomes during a 2-min static stance. Spearman's correlations identified significant associations.ResultsContrast sensitivity, visuo-spatial ability and postural control (ellipsis) were significantly impaired in PD (p=0.017; p=0.001; and p=0.017, respectively). For PD only, significant correlations were found for higher visuo-spatial function and larger ellipsis (r=0.64; p=0.024) and impaired attention and reduced visuo-spatial function (r=−0.62; p=0.028).ConclusionsVisuo-spatial ability is associated with PC deficit in PD, but in an unexpected direction. This suggests a non-linear pattern of response. Further research is required to examine this novel and important finding.



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Vision, visuo-cognition and postural control in Parkinson's disease: An associative pilot study

Publication date: July 2016
Source:Gait & Posture, Volume 48
Author(s): E. Hill, S. Stuart, S. Lord, S. Del Din, L. Rochester
IntroductionImpaired postural control (PC) is common in patients with Parkinson's disease (PD) and is a major contributor to falls, with significant consequences. Mechanisms underpinning PC are complex and include motor and non-motor features. Research has focused predominantly on motor and sensory inputs. Vision and visuo-cognitive function are also integral to PC but have largely been ignored to date. The aim of this observational cross-sectional pilot study was to explore the relationship of vision and visuo-cognition with PC in PD.MethodsTwelve people with PD and ten age-matched healthy controls (HC) underwent detailed assessments for vision, visuo-cognition and postural control. Vision assessments included visual acuity and contrast sensitivity. Visuo-cognition was measured by visuo-perception (object identification), visuo-construction (ability to copy a figure) and visuo-spatial ability (judge distances and location of object within environment). PC was measured by an accelerometer for a range of outcomes during a 2-min static stance. Spearman's correlations identified significant associations.ResultsContrast sensitivity, visuo-spatial ability and postural control (ellipsis) were significantly impaired in PD (p=0.017; p=0.001; and p=0.017, respectively). For PD only, significant correlations were found for higher visuo-spatial function and larger ellipsis (r=0.64; p=0.024) and impaired attention and reduced visuo-spatial function (r=−0.62; p=0.028).ConclusionsVisuo-spatial ability is associated with PC deficit in PD, but in an unexpected direction. This suggests a non-linear pattern of response. Further research is required to examine this novel and important finding.



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Vision, visuo-cognition and postural control in Parkinson's disease: An associative pilot study

Publication date: July 2016
Source:Gait & Posture, Volume 48
Author(s): E. Hill, S. Stuart, S. Lord, S. Del Din, L. Rochester
IntroductionImpaired postural control (PC) is common in patients with Parkinson's disease (PD) and is a major contributor to falls, with significant consequences. Mechanisms underpinning PC are complex and include motor and non-motor features. Research has focused predominantly on motor and sensory inputs. Vision and visuo-cognitive function are also integral to PC but have largely been ignored to date. The aim of this observational cross-sectional pilot study was to explore the relationship of vision and visuo-cognition with PC in PD.MethodsTwelve people with PD and ten age-matched healthy controls (HC) underwent detailed assessments for vision, visuo-cognition and postural control. Vision assessments included visual acuity and contrast sensitivity. Visuo-cognition was measured by visuo-perception (object identification), visuo-construction (ability to copy a figure) and visuo-spatial ability (judge distances and location of object within environment). PC was measured by an accelerometer for a range of outcomes during a 2-min static stance. Spearman's correlations identified significant associations.ResultsContrast sensitivity, visuo-spatial ability and postural control (ellipsis) were significantly impaired in PD (p=0.017; p=0.001; and p=0.017, respectively). For PD only, significant correlations were found for higher visuo-spatial function and larger ellipsis (r=0.64; p=0.024) and impaired attention and reduced visuo-spatial function (r=−0.62; p=0.028).ConclusionsVisuo-spatial ability is associated with PC deficit in PD, but in an unexpected direction. This suggests a non-linear pattern of response. Further research is required to examine this novel and important finding.



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Tinnitus Without Hearing Loss Causes

If you have tinnitus, your first stop toward a solution may have been to visit an audiologist for hearing testing. However, hearing loss is not always the cause of tinnitus. Consider how you can have tinnitus without hearing loss causes. These causes include behavioral and environmental associations.

Smoking
Over the years, scientists have discovered that smoking is to blame for a wide variety of medical ailments. Tinnitus without hearing loss causes include smoking. The longer that you have smoked tobacco, the greater your risk of having tinnitus. This is because nicotine acts as an irritant to the nerve endings and receptors in your ears. Chewing tobacco may also have this effect and be a cause of tinnitus without hearing loss.

Medications
Many over the counter and prescription medications are a part of tinnitus without hearing loss causes. Aspirin is a commonly used medication that may trigger tinnitus in some people. Anti-malaria drugs and malaria treatments such as quinine also cause ringing in the ears in some individuals. Diuretic drugs and chemotherapy agents may also cause tinnitus.

Food Additives and Supplements
Tinnitus without hearing loss causes includes food additives and supplements such as NutraSweet. This food additive is an artificial sweetener that is added to chewing gum, candies, diet soft drinks and other foods to replace sugar. In some sensitive individuals, consumption of foods containing NutraSweet may cause tinnitus. The more of the additive that is consumed, the more tinnitus you may experience.

TMJ
Temporomandibular joint syndrome, or TMJ, is a common cause of tinnitus. In TMJ, the jaw is out of alignment. The actions of chewing, talking or yawning may cause air pockets to build up within the sinuses around the ears. You may hear clicking or popping as you move your jaws. This is the sound of the air pocket trying to escape. These efforts can also trigger tinnitus in some people.

Earwax
A buildup of earwax may cause some people to experience a sensation of tinnitus. A piece of impacted earwax can also cause tinnitus. Earwax blockages are preventable, but once one develops, a medical professional will need to remove it in order to prevent damage to the ear.

Head Injuries
Traumatic brain injuries are also a common cause of tinnitus. A sudden impact to the brain can cause swelling in the blood vessels that service the ears. Stroke and high blood pressure can also cause tinnitus.

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CT Scan Imaging of the Human Fetal Labyrinth: Case Series Data Throughout Gestation

Objectives: The inner ear in humans reaches its final configuration and its adult size during fetal life. According to the literature, this occurs between 18 and 25 weeks of amenorrhea (WA). Our goal is to clarify the course of inner ear size development. Methods: Using computed tomography (CT) scanner, we studied 13 measurements in the inner ear of a collection of 153 fetuses from 21 to 40 WA. Results: We found no side-related differences or sexual dimorphism in the measurements. Cochlear and vestibular bone measurements did not show growth from 21 to 40 WA, with the exception of the lateral semicircular canal (LSCC) bony island, which grows until 25 WA. Internal auditory canal (IAC) and cochlear aqueduct (CA) growth are correlated with gestational age. As our cochlear measurements are similar to those of infants and adults, in accordance with the literature we conclude that the cochlea has reached its adult size before 21 WA. The continuous growth of the IAC and CA is linked to petrous ossification that continues during fetal gestation and after birth. Conclusion: We confirm that the cochlea reaches its adult size during the second trimester of fetal life.

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Test-retest and Interrater Reliability of the Video Head Impulse Test in the Pediatric Population

Objective: Determine reliability of horizontal and vertical video head impulse test (vHIT) and effect of maturation on angular vestibular ocular reflex (AVOR) gain estimations and peak head velocities of individual canals in typically developing children and adolescents. Design: Reliability study. Setting: University research laboratory Subjects: Two normal adults mean age 51.5 ± 0.5 years and 28 typically developing children and adolescents mean age 10 ± 3.5 years (range, 4.33–17.25 years). Main Outcome Measures: Mean AVOR gain estimate and peak head impulse velocity for individual canals. Results: In adult sample, mean AVOR gain estimates were 1.00 to 1.04 for lateral and 1.07 to 1.13 for vertical canals. In pediatric sample, mean AVOR gain estimates were 1.00 to 1.04 for lateral and 1.03 to 1.08 vertical canals. Mean AVOR gain intrarater reliability scores (intraclass correlation coefficient [ICC] ≥ 0.821 ≤ 0.945) and interrater reliability scores (ICC ≥ 0.800 ≤ 0.971) had good consistency. For each canal, across each age group, the range of percentage of trials with peak head velocities greater than 100 degrees/s was 32 to 49% right lateral, 31 to 49% left lateral, 0 to 11% right anterior, 3 to 4% left anterior, 1 to 7% right posterior, and 2 to 8% left posterior. Children aged less than 12 years, required 10 to 49% more trials compared with adults to obtain five valid, filtered trials. Adolescents required a similar number of trials compared with adults. Conclusion: In pediatric population, vHIT is a reliable clinical test to quantify individual canal function using high velocity head impulses. With children, it was difficult to acquire head impulse velocities of greater than 100 degrees/s especially in the plane of the vertical canals. These higher head velocities are required to reveal asymmetry in compensatory eye movements.

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Otology, Neurotology, and Skull Base Surgery: Clinical Reference Guide: Theodore R. McRackan and Derald E. Brackmann; San Diego, CA: Plural Publishing, 2015.

No abstract available

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New Web-based Tool for Generating Scattergrams to Report Hearing Results

No abstract available

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Click Stimulus Electrocochleography Versus MRI With Intratympanic Contrast in Ménière's Disease: A Systematic Review

Objective: To evaluate the diagnostic value of electrocochleography compared with magnetic resonance imaging (MRI) with intratympanic gadolinium administration to diagnose endolymphatic hydrops in patients with Ménière's disease. Data Sources: An electronic search was performed in the PubMed, EMBASE, and Cochrane databases on September 15, 2015. A systematic search was conducted. Articles were included if written in English, Dutch, German, or French language. Study Selection: Original studies reporting on the diagnostic value of electrocochleography compared with MRI with intratympanic gadolinium administration, were included. Data Extraction: The methodological quality of the studies was independently assessed by two reviewers using an adjusted version of the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. The results of the diagnostic values of both tests were extracted. Data Synthesis: We performed analyses for the sensitivity, specificity, positive predictive value, and negative predictive value of compared electrocochleography with MRI with intratympanic gadolinium administration in patients with definite Ménière's disease. Conclusion: The results of this systematic review, based on a very low number of patients, show there is a relative low sensitivity and negative predictive value for click stimulus electrocochleography compared with MRI with intratympanic gadolinium administration for detecting endolymphatic hydrops in patients with definite Ménière's disease.

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Neutrophil to Lymphocyte Ratio as a Predictive Marker of Vestibular Schwannoma Growth

Objective: To examine the predictive value of neutrophil to lymphocyte ratio (NLR) for vestibular schwannoma (VS) growth. Study Design: Retrospective case-control study. Setting: Tertiary, referral center. Patients: Patients with sporadic VS and available NLR obtained within 1 year from the diagnosis were divided into two groups with growing or non-growing tumor. Patients with known conditions affecting NLR were excluded. Interventions: NLR and tumor growth as determined by linear measurements on serial magnetic resonance imaging. Main Outcome Measures: VS growth, demographic factors, and NLR were compared using multi-variant logistic regression and Receiver Operating Characteristic (ROC) curve analysis. Results: A total of 161 patients fulfilled the inclusion criteria, 79 with growing VS (men:women ratio = 43:36, mean age, 61.8 years) and 82 with non-growing tumors (men:women ratio = 37:45, mean age, 64.9 years). Mean NLR for the group with growing VS was 3.34 (SD [standard deviation] = 1.5) and 2.31 (SD = 0.76) for the group with non-growing VS (p = 0.001; 0.03 when adjusted for all parameters). The optimal cut-off point was NLR = 3.05 with positive predictive value 83.8% and 100% for NLR greater than 5.3. ROC analysis of the adjusted data for age, sex, and side, gave an area under the curve of 0.768, indicating NLR as a good independent predictive marker. Interestingly, the size of tumor was statistically significantly higher for the growing VS group (p = 0.001). Conclusion: Despite the low specificity of low NLR, our results indicate high NLR as a good predictive marker for VS growth. Confirmation by prospective studies will have a significant impact on patients’ management.

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Secondary Endolymphatic Hydrops After Acoustic Trauma

Objective: This study applied an inner ear test battery in patients with secondary hydrops after acoustic trauma to assess the inner ear deficits. Study Design: Retrospective study. Setting: University hospital. Methods: Twenty patients with secondary hydrops after acoustic trauma were assigned to Group A. The interval between noise exposure and the testing time varied from 1 month to 3 years (median 3 months). Another 20 patients without progressive hearing loss for at least 3 years after acoustic trauma were assigned to Group B. There were no significant differences between the two groups in terms of age, sex, laterality, and noise source. Before treatment, all patients received audiometry, and caloric, ocular vestibular-evoked myogenic potential (VEMP), and cervical VEMP (cVEMP) tests. Results: Percentages of abnormal mean hearing level (MHL), cVEMP test, oVEMP test, and caloric test were 75%, 75%, 61%, and 43% in Group A, and 35%, 57%, 61%, and 39% in Group B, respectively. Both groups exhibited a significantly declining sequence in inner ear function. Comparison of the abnormalities in the inner ear test battery between Groups A and B revealed a significant difference in percentages of abnormal MHL, but not in those of abnormal cVEMP, oVEMP, and caloric tests. Conclusion: Secondary hydrops after acoustic trauma occurs mainly on the cochlear part, but less on the vestibular part probably because previous acoustic trauma, i.e., firearms have severely damaged the vestibular partition.

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Non-Ototoxic Local Delivery of Bisphosphonate to the Mammalian Cochlea: Erratum

No abstract available

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Correlation of CT, MR, and Histopathology in Incomplete Partition-II Cochlear Anomaly

Objective: To correlate the computed tomography (CT) and magnetic resonance imaging (MR) findings in a patient with incomplete partition-type II (IP-II) anomaly with histopathology in a similar human temporal bone specimen. To discover the histologic correlate of a common finding on MR of an “apparent” interscalar septum (IS). Patients: A patient with sensorineural hearing loss and imaging findings characteristic of IP-II, and a patient with histopathologic IP-II anomaly. Intervention: High-resolution CT, MR, and review of postmortem temporal bone histopathology. Main Outcome Measure: Correlation of temporal bone histopathology with CT and MR findings. Results: Consistent findings of IP-II anomaly on CT, absence of the IS between the more distal turns and flattening of the interscalar ridge between the distal basal turn and the middle turn, were present. The signal void surrounding the cochlea on MR also demonstrated flattening of the interscalar ridge. However, a thin band-like area of low T2 signal was seen, which could be mistaken for an IS. Correlation with temporal bone histopathology revealed that the modiolus was foreshortened, and the spiral ganglion neuron dendritic processes continued toward the upper middle turn through the osseous spiral lamina, likely accounting for the MR finding. Conclusion: Correlation of CT, MR, and histopathology in IP-II shows an “apparent” segmentation representing a continuum of neurosensory elements in approximately the same location of the expected location of a normal IS. Care should be taken when interpreting MR imaging in isolation. Understanding the bony outline of the cochlea on imaging may prove to be complementary.

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Reliability and Normative Data for the Dynamic Visual Acuity Test for Vestibular Screening

Hypothesis: The purpose of this study was to determine reliability of computerized dynamic visual acuity (DVA) testing and to determine reference values for younger and older adults. Background: A primary function of the vestibular system is to maintain gaze stability during head motion. The DVA test quantifies gaze stabilization with the head moving versus stationary. Commercially available computerized systems allow clinicians to incorporate DVA into their assessment; however, information regarding reliability and normative values of these systems is sparse. Methods: Forty-six healthy adults, grouped by age, with normal vestibular function were recruited. Each participant completed computerized DVA testing including static visual acuity, minimum perception time, and DVA using the NeuroCom inVision System. Testing was performed by two examiners in the same session and then repeated at a follow-up session 3 to 14 days later. Intraclass correlation coefficients (ICCs) were used to determine inter-rater and test–retest reliability. Results: ICCs for inter-rater reliability ranged from 0.323 to 0.937 and from 0.434 to 0.909 for horizontal and vertical head movements, respectively. ICCs for test–retest reliability ranged from 0.154 to 0.856 and from 0.377 to 0.9062 for horizontal and vertical head movements, respectively. Overall, raw scores (left/right DVA and up/down DVA) were more reliable than DVA loss scores. Conclusion: Reliability of a commercially available DVA system has poor-to-fair reliability for DVA loss scores. The use of a convergence paradigm and not incorporating the forced choice paradigm may contribute to poor reliability.

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Cochlear Implant Outcomes in Cochlea Nerve Aplasia and Hypoplasia

Objective: To assess cochlear implant (CI) outcomes, and factors affecting outcomes, for children with aplasia/ hypoplasia of the cochlea nerve. We also developed a new grading system for the nerves of the internal auditory meatus (IAM) and cochlea nerve classification. Study Design: Retrospective patient review. Setting: Tertiary referral hospital and cochlear implant program. Patients: Children 0 to 16 years inclusive with a CI who had absent/hypoplastic cochlea nerve on magnetic resonance imaging (MRI). Intervention: Cochlear implant. Main Outcome Measures: MRI, trans-tympanic electrical auditory brainstem response, intraoperative electrical auditory brainstem response, Neural Response Telemetry, Categories of Auditory Perception score, Main mode of communication. Results: Fifty CI recipients (26 males and 24 females) were identified, 21 had bilateral CIs, 27 had developmental delay. MRI showed cochlea nerve aplasia in 64 ears, hypoplasia in 25 ears, and a normal nerve in 11 ears. Main mode of communication was analyzed for 41 children: 21 (51%) used verbal language (15 speech alone, 5 speech plus some sign, 1 bilingual in speech and sign), and 20 (49%) used sign language (10 sign alone, 9 sign plus some speech, 1 tactile sign). Seventy-three percent of children used some verbal language. Cochlea nerve aplasia/ hypoplasia and developmental delay were both significant factors affecting main mode of communication. Categories of Auditory Performance scores were available for 59 CI ears; 47% with CN Aplasia (IAM nerve grades 0–III) and 89% with CN hypoplasia (IAM nerve grade IV) achieved Categories of Auditory Performance scores of 5 to 7 (some verbal understanding) (p = 0.003). Conclusion: Our results are encouraging and useful when counselling families regarding the likelihood of language outcomes and auditory understanding.

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Microsurgical Anatomy of the Internal Acoustic Meatus as Seen Using the Retrosigmoid Approach

Hypothesis: To show via a retrosigmoid approach the bony labyrinth anatomy and its relationship with the internal acoustic meatus so as to provide guidelines for a safer drilling to the fundus using this approach. Background: Few studies deal with the complex anatomy of petrous bone structures as observed by a retrosigmoid approach. Methods: Ten retrosigmoid approaches were performed bilaterally on five fresh cadaveric heads. Afterward high-resolution computed tomographic scans were obtained. Measurements of landmarks and distances between important topographic structures of the pyramid were obtained on its surface using a navigation system. Semicircular canals, vestibular aqueduct, and internal acoustic meatus were dissected to show their anatomy and relationships. Results: The anatomy of the inner ear structures was shown. Opening of the internal acoustic meatus was accomplished without injury to the labyrinth in 9 out of 10 sides. The distance between the drilled bone of the internal acoustic meatus and the vestibule was calculated on the postoperative computed tomographic scan. The mean value was 1.43 mm (SD, 0.30 mm; range, 1.0–1.8 mm). Conclusion: A better knowledge of the anatomy of the semicircular canals and of the vestibular aqueduct as observed by a retrosigmoid approach, together with their relationships to the fundus and other petrous bone landmarks, can be useful to get a general orientation in acoustic neuroma surgery. Using this information together with the neuronavigation, we were able to successfully open the internal acoustic meatus without entering labyrinthine structures in 90% of the study dissections.

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Assessment of Cochlear Trauma During Cochlear Implantation Using Electrocochleography and Cone Beam Computed Tomography

Objective: To assess cochlear trauma during cochlear implantation by electrocochleography (ECoG) and cone beam computed tomography (CBCT) and to correlate intraoperative cochlear trauma with postoperative loss of residual hearing. Methods: ECoG recordings to tone bursts at 250, 500, 750, and 1000 Hz and click stimuli were recorded before and after insertion of the cochlear implant electrode array, using an extracochlear recording electrode. CBCTs were conducted within 6 weeks after surgery. Changes of intraoperative ECoG recordings and CBCT findings were correlated with postoperative threshold shifts in pure-tone audiograms. Results: Fourteen subjects were included. In three subjects a decrease of low-frequency ECoG responses at 250, 500, 750, and 1000 Hz occurred after insertion of the electrode array. This was associated with no or minimal residual hearing 4 weeks after surgery. ECoG responses to click stimuli were present in six subjects and showed a decrease after insertion of the electrode array in three. This was associated with a mean hearing loss of 21 dB in postoperative pure-tone audiograms. Scalar dislocation of the electrode array was assumed in one subject because of CBCT findings and correlated with a decrease of low-frequency ECoG responses and a complete loss of residual hearing. Conclusion: Hearing loss of ≤11 dB is not associated with detectable decrease in ECoG recordings during cochlear implantation. However, in a majority of patients with threshold shifts of >11 dB or complete hearing loss, an intraoperative decrease of high- or low-frequency ECoG signals occurs, suggesting acute cochlear trauma.

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Cochlear Histopathologic Findings in Patients With Systemic Lupus Erythematosus: A Human Temporal Bone Study

Hypothesis: We hypothesized that, in archived human temporal bone samples from patients with systemic lupus erythematosus (SLE), a pathologic condition exists in the stria vascularis and cochlear hair cells. Background: Sensorineural hearing loss is a common feature in SLE patients. However, the pathophysiologic mechanism of cochlear dysfunction is unclear. Methods: We examined 15 temporal bone samples from 8 SLE patients, along with 17 samples from 10 age-matched healthy control patients. The samples were serially sectioned in the horizontal plane and stained with hematoxylin and eosin. We determined the area of the stria vascularis in a midmodiolar section of each cochlear turn. Then, we made cytocochleograms and calculated the percentage of missing inner and outer hair cells. Results: The area of the stria vascularis in our SLE group was significantly smaller than in our control group. The number of remaining inner hair cells in our SLE group was smaller than in our control group; however, the difference did not reach statistical significance. The loss of outer hair cells in our SLE group was significantly higher than in our control group. There was a tendency toward a positive correlation between the loss of cochlear hair cells and the duration of SLE. Conclusion: The stria vascularis and cochlear hair cells are affected in SLE patients. Our findings could provide the histopathologic basis for the cochlear dysfunction, including sensorineural hearing loss, experienced by SLE patients.

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Cost–Utility Analysis of Cochlear Implantation in Australian Adults

Objectives: Sequential and simultaneous bilateral cochlear implants are emerging as appropriate treatment options for Australian adults with sensory deficits in both cochleae. Current funding of Australian public hospitals does not provide for simultaneous bilateral cochlear implantation (CI) as a separate surgical procedure. Previous cost-effectiveness studies of sequential and simultaneous bilateral CI assumed 100% of unilaterally treated patients’ transition to a sequential bilateral CI. This assumption does not place cochlear implantation in the context of the generally treated population. When mutually exclusive treatment options exist, such as unilateral CI, sequential bilateral CI, and simultaneous bilateral CI, the mean costs of the treated populations are weighted in the calculation of incremental cost–utility ratios. The objective was to evaluate the cost–utility of bilateral hearing aids (HAs) compared with unilateral, sequential, and simultaneous bilateral CI in Australian adults with bilateral severe to profound sensorineural hearing loss. Research Design: Cost–utility analysis of secondary sources input to a Markov model. Setting: Australian health care perspective, lifetime horizon with costs and outcomes discounted 5% annually. Intervention: Bilateral HAs as treatment for bilateral severe to profound sensorineural hearing loss compared with unilateral, sequential, and simultaneous bilateral CI. Main Outcome Measures: Incremental costs per quality adjusted life year (AUD/QALY). Results: When compared with bilateral hearing aids the incremental cost–utility ratio for the CI treatment population was AUD11,160/QALY. The incremental cost–utility ratio was weighted according to the number of patients treated unilaterally, sequentially, and simultaneously, as these were mutually exclusive treatment options. Conclusion: No peer-reviewed articles have reported the incremental analysis of cochlear implantation in a continuum of care for surgically treated populations with bilateral severe to profound sensorineural hearing loss. Unilateral, sequential, and simultaneous bilateral CI were cost-effective when compared with bilateral hearing aids. Technologies that reduce the total number of visits for a patient could introduce additional cost efficiencies into clinical practice.

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Response to Letter to the Editor: Comment on “Usher's Syndrome: Evaluation of the Vestibular System with Cervical and Ocular Vestibular Evoked Myogenic Potentials and the Video Head Impulse Test”

No abstract available

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Economic Evaluation of Treatments for Pediatric Bilateral Severe to Profound Sensorineural Hearing Loss: An Australian Perspective

Objectives: In Australia, surgical treatment options for children with bilateral severe to profound sensorineural hearing loss exist in a continuum ranging from unilateral cochlear implantation (CI), sequential bilateral CI through to simultaneous bilateral CI, depending on the condition. When treatment options are mutually exclusive, the mean costs and benefits of each treatment group are summed together to obtain the total mean costs and benefits. This enables an incremental analysis of treatment options in the context of the treated populations. The objective was to evaluate the cost-utility of current Australian CI treatment practices in children using domestic costs and consequences when compared with bilateral hearing aids (HAs). Research Design: Economic evaluation including a Markov model based on secondary sources. Setting: The base case modeled a government health payer perspective over a child's lifetime. Primary and secondary school education costs were also assessed. Intervention: Bilateral HAs compared with CI, including unilateral, sequential bilateral, or simultaneous bilateral CI weighted according to treatment. Main Outcome Measures: Incremental costs per quality adjusted life year. Results: Approximately 42% of children in Australia with unilateral CI did not transition to sequential bilateral nor undergo simultaneous bilateral implantation. This differs from previous economic evaluations that assumed 100% of children transitioned to sequential bilateral CI treatment or were treated with simultaneous bilateral CI. The incremental cost utility of unilateral cochlear implantation compared with HAs was AUD 21,947/QALY. The weighted average incremental cost utility of the combined cochlear implantation treatment groups was AUD 31,238/QALY when compared with HAs. Conclusion: Previous economic evaluations of cochlear implantation assumed 100% of unilaterally treated patients would transition to sequential bilateral or be treated with simultaneous bilateral implantation. This approach does not take into account the total treated population, where a proportion of patients are treated with unilateral CI. CI was cost effective when compared with HAs, and included children treated with unilateral, sequential bilateral, and simultaneous bilateral CI. The model was sensitive to the number of assessment and habilitation visits. Alternative health service models with cost efficiencies are needed to reduce after care costs.

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Torticollis: A Symptom in Severe Otitis Media

No abstract available

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Word Recognition Variability With Cochlear Implants: The Degradation of Phonemic Sensitivity

Objective: Cochlear implants (CIs) do not automatically restore speech recognition for postlingually deafened adults. Average word recognition remains at 60%, and enormous variability exists. Understanding speech requires knowledge of phonemic codes, the basic sound units of language. Hearing loss may result in degeneration of these long-term mental representations (i.e., “phonemic sensitivity”), and CI use may not adequately restore those representations. This investigation examined whether phonemic sensitivity is degraded for CI users, and whether this degradation results in poorer word recognition. Study Design: Thirty adults with CIs and 20 normal-hearing controls underwent testing. Methods: Participants were assessed for word recognition in quiet, along with tasks of phonemic sensitivity using an audiovisual format to maximize recognition: initial consonant choice (ICC), in which they selected the word with the same starting sound as a target word, final consonant choice (FCC), in which they selected the word with the same ending sound, and backwards words, in which they repeated phonemes comprising words in backwards order. Results: Phonemic sensitivity was poorer for CI users than for normal-hearing controls for ICC and FCC. For CI users, ICC and FCC predicted 25% and 40% of variance in word recognition, respectively. Longer duration of CI use did not lead to greater restoration in phonemic sensitivity. Conclusion: Even for adults who presumably had developed refined phonemic representations, hearing loss can degrade those representations, which results in poorer word recognition. Cochlear implants do not adequately restore those representations. Findings suggest the need for rehabilitative efforts to improve CI users’ phonemic sensitivity.

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Quantitative Analysis of Psychiatric Disorders in Intractable Peripheral Vertiginous Patients: A Prospective Study

Objective: To investigate the correlation between psychological disorder and vestibular dysfunction in patients suffering from intractable peripheral vertigo. Study Design: Prospective study. Setting: In-patients in a university hospital. Methods: Prospective design of 26 intractable peripheral vertiginous patients with peripheral vestibular dysfunction and 20 controls recruited from the EENT hospital. Hospital Anxiety and Depression scale, Self-rating Anxiety scale, Self-rating Depression scale, Symptom Checklist-90 were used in this study. All vertigo patients received intratympanic gentamicin/dexamethasone administration or endolymphatic sac decompression. Pre- and posttreatment scores were collected and compared. All the results were statistically analyzed using Stata 8.0. t test or rank-sum test and paired-sample t test or rank-sum test were performed. Results: The outcomes of Hospital Anxiety and Depression scale, Self-rating Anxiety scale, Self-rating Depression scale, Symptom Checklist-90 were significantly greater in vertiginous group than that in normal controls (p  0.05). Conclusion: Increased anxiety/depression levels were noted in peripheral vertiginous patients compared with normal controls through psychiatric questionnaires, and then a significant decrease after the effective treatment of vertigo, suggesting that vertigo attack may contribute to psychological dysfunction. The intervention seemed to be more effective in lowering anxiety/depression levels among patients in earlier stage of Ménière's disease marked by pure-tone audiometry results.

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The Time Course of Deafness and Retinal Degeneration in a Kunming Mouse Model for Usher Syndrome

by Lu Yao, Lei Zhang, Lin-Song Qi, Wei Liu, Jing An, Bin Wang, Jun-Hui Xue, Zuo-Ming Zhang

Usher syndrome is a group of autosomal recessive diseases characterized by congenital deafness and retinitis pigmentosa. In a mouse model for Usher syndrome, KM^ush/ush_, discovered in our laboratory, we measured the phenotypes, characterized the architecture and morphology of the retina, and quantified the level of expression of pde6b and ush2a between postnatal (P) days 7, and 56. Electroretinograms and auditory brainstem response were used to measure visual and auditory phenotypes. Fundus photography and light microscopy were used to measure the architecture and morphology of the retina. Quantitative real-time PCR was used to measure the expression levels of mRNA. KM^ush/ush mice had low amplitudes and no obvious waveforms of Electroretinograms after P14 compared with controls. Thresholds of auditory brainstem response in our model were higher than those of controls after P14. By P21, the retinal vessels of KM^ush/ush mice were attenuated and their optic discs had a waxy pallor. The retinas of KM^ush/ush mice atrophied and the choroidal vessels were clearly visible. Notably, the architecture of each retinal layer was not different as compared with control mice at P7, while the outer nuclear layer (ONL) and other retinal layers of KM^ush/ush mice were attenuated significantly between P14 and P21. ONL cells were barely seen in KM^ush/ush mice at P56. As compared with control mice, the expression of pde6b and ush2a in KM^ush/ush mice declined significantly after P7. This study is a first step toward characterizing the progression of disease in our mouse model. Future studies using this model may provide insights about the etiology of the disease and the relationships between genotypes and phenotypes providing a valuable resource that could contribute to the foundation of knowledge necessary to develop therapies to prevent the retinal degeneration in patients with Usher Syndrome.

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Pile driving playback sounds and temporary threshold shift in harbor porpoises (Phocoena phocoena): Effect of exposure duration

High intensity underwater sounds may cause temporary hearing threshold shifts (TTSs) in harbor porpoises, the magnitude of which may depend on the exposure duration. After exposure to playbacks of pile driving sounds, TTSs in two porpoises were quantified at 4 and 8 kHz with a psychophysical technique. At 8 kHz, the pile driving sounds caused the highest TTS. Pile driving sounds had the following: pulse duration 124 ms, rate 2760 strikes/h, inter-pulse interval 1.3 s, duty cycle ∼9.5%, average received single-strike unweighted broadband sound exposure level (SELss) 145 dB re 1 μPa²s, exposure duration range 15-360 min (cumulative SEL range: 173–187 dB re 1 μPa²s). Control sessions were also carried out. Mean TTS (1–4 min after sound exposure stopped in one porpoise, and 12–16 min in the other animal) increased from 0 dB after 15 min exposure to 5 dB after 360 min exposure. Recovery occurred within 60 min post-exposure. For the signal duration, sound pressure level (SPL), and duty cycle used, the TTS onset SELcum is estimated to be around 175 dB re 1 μPa²s. The small increase in TTS between 15 and 360 min exposures is due to the small amount of sound energy per unit of time to which the porpoises were exposed [average (over time) broadband SPL ∼144 dB re 1 μPa].

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Kurtosis of room impulse responses as a diffuseness measure for reverberation chambers

This study presents a kurtosis analysis of room impulse responses as a potential room diffuseness measure. The early part of an impulse response contains a direct sound and strong reflections. As these reflections are sparse and strong, the sound field is unlikely to be diffuse. Such deterministic reflections are extreme events, which prevent the pressure samples from being distributed Gaussianly, leading to a high kurtosis. This indicates that the kurtosis can be used as a diffuseness measure. Two rooms are analyzed. A non-uniform surface absorption distribution tends to increase the kurtosis significantly in a small room. A full scale reverberation chamber is tested with different diffuser settings, which shows that the kurtosis calculated from broadband impulse responses from 125 Hz to 4 kHz has a good correlation with the Sabine absorption coefficient according to ISO 354 (International Organization for Standardization, Geneva, Switzerland, 2003).

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Design and analysis of air acoustic vector-sensor configurations for two-dimensional geometry

Acoustic vector-sensors (AVS) have been designed using the P-P method for different microphone configurations. These configurations have been used to project the acoustic intensity on the orthogonal axes through which the direction of arrival (DoA) of a sound source has been estimated. The analytical expressions for the DoA for different microphone configurations have been derived for two-dimensional geometry. Finite element method simulation using COMSOL-Multiphysics has been performed, where the microphone signals for AVS configurations have been recorded in free field conditions. The performance of all the configurations has been evaluated with respect to angular error and root-mean-square angular error. The simulation results obtained with ideal geometry for different configurations have been corroborated experimentally with prototype AVS realizations and also compared with microphone-array method, viz., Multiple Signal Classification and Generalized Cross Correlation. Experiments have been performed in an anechoic room using different prototype AVS configurations made from small size microphones. The DoA performance using analytical expressions, simulation studies, and experiments with prototype AVS in anechoic chamber are presented in the paper. The square and delta configurations are found to perform better in the absence and presence of noise, respectively.

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Optimized sound diffusers based on sonic crystals using a multiobjective evolutionary algorithm

Sonic crystals have been demonstrated to be good candidates to substitute for conventional diffusers in order to overcome the need for extremely thick structures when low frequencies have to be scattered, however, their performance is limited to a narrow band. In this work, multiobjective evolutionary algorithms are used to extend the bandwidth to the whole low frequency range. The results show that diffusion can be significantly increased. Several cost functions are considered in the paper, on the one hand to illustrate the flexibility of the optimization and on the other hand to demonstrate the problems associated with the use of certain cost functions. A study of the robustness of the optimized diffusers is also presented, introducing a parameter that can help to choose among the best candidates. Finally, the advantages of the use of multiobjective optimization in comparison with conventional optimizations are discussed.

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Supersonic intensity and non-negative intensity for prediction of radiated sound

Two numerical methods to identify the surface areas of a vibrating structure that radiate sound are presented. The supersonic intensity identifies only the supersonic wave components of the sound field contributing to far-field radiated sound. The supersonic intensity is calculated using a two-dimensional convolution between a spatial radiation filter and the sound field. To compute the spatial radiation filter, the shortest surface distance between two points on the structure is calculated using the geodesic distance method. The non-negative intensity is based on acoustic radiation modes and identifies the radiated sound power from a vibrating structure. Numerical models of a baffled plate, a cylinder and an engine crankcase are presented. The supersonic intensity is shown to be difficult to implement at low frequencies due to the size of the spatial radiation filter and accuracy of the surface distances. A cut-off coefficient associated with the acoustic wavenumber of the spatial radiation filter is used to reduce the aperture error. A comparison of the two intensity-based techniques both in terms of a sound power ratio and the modal assurance criterion is introduced to identify the optimal values of the cut-off coefficients that result in better convergence between the intensity techniques.

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