Carl Verschuur

Symptoms, anxiety and handicap in dizzy patients: Development of the Vertigo symptom scale

Questionnaires assessing symptoms, anxiety and handicap were completed by 127 vertiginous patients. Factor analysis identified four distinct symptom clusters which formed the basis for the construction of scales quantifying the number and frequency of symptoms of: (a) vertigo (of long and short duration); (b) autonomic sensations and anxiety arousal; and (c) somatization. Scores on the vertigo severity scale were significantly related to clinical diagnosis and had near-zero correlations with measures of anxiety. Vertigo severity, autonomic signs and depressed mood each independently contributed to variance in handicap, taking precedence over the relationship between handicap and trait and state anxiety. Our findings suggest that the familiar association between anxiety and vertigo may be mediated principally by autonomic symptomatology arising as a result of somatopsychic and psychosomatic processes.

Auditory localization abilities in bilateral cochlear implant recipients.

Objective: To quantify binaural advantage for auditory localization in the horizontal plane by bilateral cochlear implant (CI) recipients. Also, to determine whether the use of dual microphones with one implant improves localization. Methods: Twenty subjects from the UK multicenter trial of bilateral cochlear implantation with Nucleus 24 K/M device were recruited. Sound localization was assessed in an anechoic room with an 11-loudspeaker array under four test conditions: right CI, left CI, binaural CI, and dual microphone. Two runs were undertaken for each of five stimuli (speech, tones, noise, transients, and reverberant speech). Order of conditions was counterbalanced across subjects. Results: Mean localization error with bilateral implants was 24° compared with 67° for monaural implant and dual microphone conditions (chance performance is 65°). Normal controls average 2 to 3° in similar conditions. Binaural performance was significantly better than monaural performance for all subjects, for all stimulus types, and for different sound sources. Only small differences in performance with different stimuli were observed. Conclusions: Bilateral cochlear implantation with the Nucleus 24 device provides marked improvement in horizontal plane localization abilities compared with unilateral CI use for a range of stimuli having different spectral and temporal characteristics. Benefit was obtained by all subjects, for all stimulus types, and for all sound directions. However, binaural performance was still worse than that obtained by normal hearing listeners and hearing aid users with the same methodology. Monaural localization performance was at chance. There is no benefit for localization with dual microphones.

Evaluation of bilaterally implanted adult subjects with the nucleus 24 cochlear implant system.

Objective: To evaluate the speech perception benefits of bilateral implantation for subjects who already have one implant. Study Design: Repeated measures. Patients: Thirty adult cochlear implant users who received their second implant from 1 to 7 years with a mean of 3 years after their first device. Ages ranged from 29 to 82 years with a mean of 57 years. Setting: Tertiary referral centers across the United Kingdom. Main Outcome Measures: Monosyllabic consonant-nucleus-consonant words and City University of New York sentences in quiet with coincident speech and noise and with the noise spatially separated from the speech by ±90°. Results: At 9 months, results showed the second ear in noise was 13.9 ± 5.9% worse than the first ear (p < 0.001); a significant binaural advantage of 12.6 ± 5.4% (p < 0.001) over the first ear alone for speech and noise from the front; a 21 ± 6% (p < 0.001) binaural advantage over the first ear alone when noise was ipsilateral to the first ear; no binaural advantage when noise was contralateral to the first ear. Conclusions: There is a significant bilateral advantage of adding a second ear for this group. We were unable to predict when the second ear would be the better performing ear, and by implanting both ears, we guarantee implanting the better ear. Sequential implantation with long delays between ears has resulted in poor second ear performance for some subjects and has limited the degree of bilateral benefit that can be obtained by these users. The dual microphone does not provide equivalent benefit to bilateral implants.

Somatic and psychological factors contributing to handicap in people with vertigo

Questionnaires assessing symptoms, disability and handicap, predisposition to anxiety, and current anxiety and depression were completed by 127 people attending neuro-otology clinics with a major complaint of vertigo or dysequilibrium. Definite signs of vestibular dysfunction (spontaneous or positional nystagmus, or canal paresis) were found in 56% of the sample, but the presence or absence of abnormal vestibular test results was unrelated to diagnosis, reported symptoms, handicap and psychological status. Two-thirds of employed respondents admitted to occupational difficulties, and more than one in seven had left work because of vertigo. Although the number of people in the sample with a predisposition to anxiety was not unusually high, over a third of the sample had abnormally elevated levels of current anxiety. Multiple regression analyses indicated that disability was determined mainly by physical factors (vertigo severity and duration, age and sex). Handicap was influenced by a mixture of somatic and psychological variables, including the severity of autonomic symptoms. Anxiety and depression were only indirectly related to the severity and duration of the vertigo, insofar as this contributed to handicap. The partial dissociation between these different aspects of patient well-being suggests a need for separate evaluation and differing management of problems at each level of functioning.

Markers of inflammatory status are associated with hearing threshold in older people: findings from the Hertfordshire Ageing Study.

BACKGROUND Age-related hearing loss is a common disabling condition but its causes are not well understood and the role of inflammation as an influencing factor has received little consideration in the literature. OBJECTIVE To investigate the association between inflammatory markers and hearing in community-dwelling older men and women. DESIGN Cross-sectional analysis within a cohort study. SETTING The Hertfordshire Ageing Study. PARTICIPANTS A total of 343 men and 268 women aged 63-74 years on whom data on audiometric testing, inflammatory markers and covariates were available at follow-up in 1995. MAIN OUTCOME MEASURES Average hearing threshold level (across 500-4,000 Hz) of the worst hearing ear and audiometric slope in dB/octave from 500 to 4,000 Hz. RESULTS Older age, smoking, history of noise exposure and male gender (all P < 0.001) were associated with higher mean hearing threshold in the worse ear in univariate analysis. After adjustment for these factors in multiple regression models, four measures of immune or inflammatory status were significantly associated with hearing threshold, namely white blood cell count (r = 0.13, P = 0.001), neutrophil count (r = 0.13, P = 0.002), IL-6 (r = 0.10, P = 0.05) and C-reactive protein (r = 0.11, P = 0.01). None of the inflammatory markers was associated with maximum audiometric slope in adjusted analyses. CONCLUSIONS Markers of inflammatory status were significantly associated with degree of hearing loss in older people. The findings are consistent with the possibility that inflammatory changes occurring with ageing may be involved in age-related hearing loss. Longitudinal data would enable this hypothesis to be explored further.

A Retrospective Analysis of the Contribution of Reported Factors in Cochlear Implantation on Hearing Preservation Outcomes.

Introduction Preservation of residual hearing is essential to perceive acoustic stimulation from hybrid cochlear implants (CI). Preservation is a good marker of atraumatic surgery and residual hearing may be exploited further or enhanced in future therapies, making complete hearing preservation a desirable goal for all current CI surgeries. There is large variability in the amount of hearing preserved and the timeframe over which it is lost after CI. The increase in numbers of patients with high levels of residual hearing at implantation means that understanding the variables affecting its preservation is more important than ever. Data Sources An English search term with generic and specific items concerning hearing preservation and cochlear implantation was searched on the Web of Science service. The search timeframe was limited to 2000 to 2014, with no language limitations on results. Study Selection Hearing preservation, retrospective CI outcome studies which reported pre- and post-surgical pure-tone audiometry (PTA) were identified and selected. Data Extraction PTA thresholds were extracted from audiograms or tables and converted into a low-frequency hearing preservation (LFHP) score. Data for 21 factors associated with hearing preservation were collected from studies. Data Synthesis Factors were included in a hearing preservation model if they had both a significant bivariate correlation with LFHP and a significant Kruskal-Wallis H test result (for ordinal data) or a significant multiple regression analysis result (for scale data). Conclusions Seven factors were found to have a significant effect on hearing preservation: insertion site, progressive versus stable hearing loss, insertion angle of electrode, use of intraoperative topical steroids, use of steroids (via any route/timing), hearing etiology, and electrode array type. The best hearing preservation options are given.

Effect of stimulation rate on speech perception in adult users of the Med-El CIS speech processing strategy.

The primary aim of the study was to determine the effect of altering channel stimulation rate on the performance of adult cochlear implant users. Six adult users of the Med-El CIS processing strategy underwent tests of categorical identification of synthetic speech, tests of sentence recognition and tests of consonant recognition in three listening conditions: high channel stimulation rate (ranging from 1500 to 2020 pps/ch), a medium rate (800 pps/ch) and a low rate (400 pps/ch). Number of channels was held constant across rate conditions. With the categorical identification task, performance varied by acoustic cue type but did not vary with rate. With the consonant recognition task performance varied by phonological feature, but there was also no significant effect of rate. However, two subjects showed markedly reduced sentence scores at lower rates. Results suggests that higher stimulation rates with the CIS strategy may be beneficial to speech perception in some cases.

Trends in cochlear implant complications: implications for improving long-term outcomes.

Objectives To review worldwide data on cochlear implant adverse events, test for significant trends over a 10-year period and discuss possible reasons behind such trends. To evaluate the suitability of the Manufacturer and User Facility Device Experience (MAUDE) database for analysis of trends in cochlear implant adverse events. Study Design Retrospective analysis of cochlear implant adverse events reported to the U.S. Food and Drug Administration (FDA) as recorded on the MAUDE database. Data for each adverse event reported in the years 2000 (n = 237), 2005 (n = 1089), and 2010 (n = 2543) were evaluated and assigned to one of 14 categories according to report content. Incidence data were compared across the 3 sampling points to determine trends. Hypothesis Improvements in cochlear implant manufacturing processes and surgical techniques would result in a decrease in the proportion of CI adverse events because of primary device failure or surgical factors, relative to those with complex, multi-factorial or idiopathic origins, over the 10 year sampling period. Results and Conclusion Statistical analyses showed a significant increase over time in the proportion of CI adverse events that had multiple or unknown causes, particularly cases of gradual idiopathic loss of performance, as compared with those with a clearly defined underlying device-related or medical cause. Conclusions Findings suggest that there is an urgent need to undertake further research to investigate causes for idiopathic and gradual CI adverse events to continue the overall improvement in CI outcomes.

Inflammation is associated with a worsening of presbycusis: Evidence from the MRC national study of hearing

Abstract Objective: Inflammaging, a state of chronic inflammation in the elderly, is now thought to be a key element of the ageing process and contributor to age-related disease. In a previously published study, we identified a significant association between inflammation levels and severity of presbycusis among individuals aged 63 to 73 (ʽyounger old”) within an available audiometric range 0.5 to 4 kHz. Our aim was to see if this association would be identified among participants in the MRC national study of hearing, and whether the strength of the association would increase with greater age, or for very low or very high audiometric frequencies. Design: Cross-sectional analysis of cohort data. Study sample: Three hundred and sixty community-dwelling adults age 60 years and over, representing all those with white blood cell count and audiometric data available. Results: A significant independent association between (higher) WBC and (worse) hearing level was identified. This effect increased with age. The strongest association was among those over 75, for whom average hearing threshold levels among those with lower WBC was 17 dB better than those with higher WBC. Conclusions: The current findings support an association between inflammaging (a condition potentially amenable to pharmacological treatment or lifestyle management) and presbycusis.

Evaluation of a non-linear spectral subtraction noise suppression scheme in cochlear implant users

The aim of the study was to determine benefit to speech recognition in noise by adult cochlear implant users with the non-linear spectral subtraction (NSS) noise suppression strategy. Users of the Nucleus 22 or Nucleus 24 cochlear implant systems were tested with sentence materials combined with stationary noise at +5 and +10 dB signal to noise ratio (SNR), with and without NSS processing applied offline. Sentence scores were significantly higher with NSS processing, for both SNRs. The effect was greater at +5 dB SNR (12% improvement with NSS) than at +10 dB SNR (5% improvement with NSS). These results are promising and suggest that online implementation of NSS as part of cochlear implant processors has the potential to yield benefits for speech recognition in noise.