Population-Based Prediction of Fitting Levels for Individual Cochlear Implant Recipients

2014 ◽  
Vol 20 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Feddo B. van der Beek ◽  
Jeroen J. Briaire ◽  
Johan H.M. Frijns
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Predictive Models ◽  
Linear Models ◽  
Dynamic Range ◽  
Population Based ◽  
Design Data ◽  
Data Set ◽  
Closed Set

Objectives: This study analyzed the predictability of fitting levels for cochlear implant recipients based on a review of the clinical levels of the recipients. Design: Data containing threshold levels (T-levels) and maximum comfort levels (M-levels) for 151 adult subjects using a CII/HiRes 90K cochlear implant with a HiFocus 1/1 J electrode were used. The 10th, 25th, 50th, 75th and 90th percentiles of the T- and M-levels are reported. Speech perception of the subjects, using a HiRes speech coding strategy, was measured during routine clinical follow-up. Results: T-levels for most subjects were between 20 and 35% of their M-levels and were rarely (<1/50) below 10% of the M-levels. Furthermore, both T- and M-levels showed an increase over the first year of follow-up. Interestingly, levels expressed in linear charge units showed a clear increase in dynamic range (DR) over 1 year (29.8 CU; SD 73.0), whereas the DR expressed in decibels remained stable. T-level and DR were the only fitting parameters for which a significant correlation with speech perception (r = 0.34, p < 0.01, and r = 0.33, p < 0.01, respectively) could be demonstrated. Additionally, analysis showed that T- and M-level profiles expressed in decibels were independent of the subjects' across-site mean levels. Using mixed linear models, predictive models were obtained for the T- and M-levels of all separate electrode contacts. Conclusions: On the basis of the data set from 151 subjects, clinically applicable predictive models for T- and M-levels have been obtained. Based on one psychophysical measurement and a population-based T- or M-level profile, individual recipients' T- and M-levels can be approximated with a closed-set formula. Additionally, the analyzed fitting level data can serve as a reference for future patients. i 2014 S. Karger AG, Basel

Prognostic value of weight loss in patients with amyotrophic lateral sclerosis: a population-based study

2020 ◽  
Vol 91 (8) ◽  
pp. 867-875 ◽  
Author(s):  
Mark R Janse van Mantgem ◽  
Ruben P A van Eijk ◽  
Hannelore K van der Burgh ◽  
Harold H G Tan ◽  
Henk-Jan Westeneng ◽  
...  
Keyword(s):  
Weight Loss ◽  
Amyotrophic Lateral Sclerosis ◽  
Body Weight ◽  
Prognostic Value ◽  
Population Based ◽  
Data Set ◽  
Population Based Study ◽  
Risk Of Death ◽  
Lateral Sclerosis

ObjectiveTo determine the prevalence and prognostic value of weight loss (WL) prior to diagnosis in patients with amyotrophic lateral sclerosis (ALS).MethodsWe enrolled patients diagnosed with ALS between 2010 and 2018 in a population-based setting. At diagnosis, detailed information was obtained regarding the patient’s disease characteristics, anthropological changes, ALS-related genotypes and cognitive functioning. Complete survival data were obtained. Cox proportional hazard models were used to assess the association between WL and the risk of death during follow-up.ResultsThe data set comprised 2420 patients of whom 67.5% reported WL at diagnosis. WL occurred in 71.8% of the bulbar-onset and in 64.2% of the spinal-onset patients; the mean loss of body weight was 6.9% (95% CI 6.8 to 6.9) and 5.5% (95% CI 5.5 to 5.6), respectively (p<0.001). WL occurred in 35.1% of the patients without any symptom of dysphagia. WL is a strong independent predictor of survival, with a dose response relationship between the amount of WL and the risk of death: the risk of death during follow-up increased by 23% for every 10% increase in WL relative to body weight (HR 1.23, 95% CI 1.13 to 1.51, p<0.001).ConclusionsThis population-based study shows that two-thirds of the patients with ALS have WL at diagnosis, which also occurs independent of dysphagia, and is related to survival. Our results suggest that WL is a multifactorial process that may differ from patient to patient. Gaining further insight in its underlying factors could prove essential for future therapeutic measures.

The Analysis of Two-Factor Interactions in Fixed Effects Linear Models

1993 ◽  
Vol 18 (1) ◽  
pp. 1-40 ◽  
Author(s):  
Robert J. Boik
Keyword(s):  
Fixed Effects ◽  
Linear Models ◽  
Null Distribution ◽  
P Value ◽  
Omnibus Test ◽  
F Test ◽  
Data Set ◽  
Moment Functions ◽  
Product Interaction

This article considers two related issues concerning the analysis of interactions in complex linear models. The first issue concerns the omnibus test for interaction. Apparently, it is not well known that the usual F test for interaction can be replaced, in many applications, by a test that is more powerful against a certain class of alternatives. The competing test is based on the maximal product interaction contrast F statistic and achieves its power advantage by focusing solely on product contrasts. The maximal product interaction F test is reviewed and three new results are reported: (a) An extended table of exact critical values is computed, (b) a table of moment functions useful for approximating the p-value corresponding to an observed maximal F statistic is computed, and (c) a simulation study concerning the null distribution of the maximal F statistic when data are unbalanced or covariates are present is reported. It is conjectured that lack of balance or presence of covariates has no effect on the null distribution. The simulation results support the conjecture. The second issue concerns follow-up tests when the omnibus test is significant. It appears that researchers, in general, do not perform coherent follow-up tests on interactions. To make it easier for researchers to do so, an exposition on the use of product interaction contrasts and partial interactions in complex fixed-effects models is provided. The recommended omnibus and follow-up tests are illustrated on an educational data set analyzed using SAS ( SAS Institute, 1988 ) and SPSS (1990) .

scholarly journals Intracochlear Position of Cochlear Implants Determined Using CT Scanning versus Fitting Levels: Higher Threshold Levels at Basal Turn

2016 ◽  
Vol 21 (1) ◽  
pp. 54-67 ◽  
Author(s):  
Feddo B. van der Beek ◽  
Jeroen J. Briaire ◽  
Kim S. van der Marel ◽  
Berit M. Verbist ◽  
Johan H.M. Frijns
Keyword(s):  
Speech Perception ◽  
Cochlear Implants ◽  
Dynamic Range ◽  
Ct Scanning ◽  
Electrode Position ◽  
Insertion Depth ◽  
Threshold Levels ◽  
Lower Amplitude ◽  
Standard Profile

Objectives: In this study, the effects of the intracochlear position of cochlear implants on the clinical fitting levels were analyzed. Design: A total of 130 adult subjects who used a CII/HiRes 90K cochlear implant with a HiFocus 1/1J electrode were included in the study. The insertion angle and the distance to the modiolus of each electrode contact were determined using high-resolution CT scanning. The threshold levels (T-levels) and maximum comfort levels (M-levels) at 1 year of follow-up were determined. The degree of speech perception of the subjects was evaluated during routine clinical follow-up. Results: The depths of insertion of all the electrode contacts were determined. The distance to the modiolus was significantly smaller at the basal and apical cochlear parts compared with that at the middle of the cochlea (p < 0.05). The T-levels increased toward the basal end of the cochlea (3.4 dB). Additionally, the M-levels, which were fitted in our clinic using a standard profile, also increased toward the basal end, although with a lower amplitude (1.3 dB). Accordingly, the dynamic range decreased toward the basal end (2.1 dB). No correlation was found between the distance to the modiolus and the T-level or the M-level. Furthermore, the correlation between the insertion depth and stimulation levels was not affected by the duration of deafness, age at implantation or the time since implantation. Additionally, the T-levels showed a significant correlation with the speech perception scores (p < 0.05). Conclusions: The stimulation levels of the cochlear implants were affected by the intracochlear position of the electrode contacts, which were determined using postoperative CT scanning. Interestingly, these levels depended on the insertion depth, whereas the distance to the modiolus did not affect the stimulation levels. The T-levels increased toward the basal end of the cochlea. The level profiles were independent of the overall stimulation levels and were not affected by the biographical data of the patients, such as the duration of deafness, age at implantation or time since implantation. Further research is required to elucidate how fitting using level profiles with an increase toward the basal end of the cochlea benefits speech perception. Future investigations may elucidate an explanation for the effects of the intracochlear electrode position on the stimulation levels and might facilitate future improvements in electrode design.

Performance Over Time of Congenitally Deaf and Postlingually Deafened Children Using a Multichannel Cochlear Implant

1992 ◽  
Vol 35 (4) ◽  
pp. 913-920 ◽  
Author(s):  
Holly Fryauf-Bertschy ◽  
Richard S. Tyler ◽  
Danielle M. Kelsay ◽  
Bruce J. Gantz
Keyword(s):  
Speech Perception ◽  
Word Recognition ◽  
Cochlear Implant ◽  
Deaf Children ◽  
Closed Set ◽  
Open Set ◽  
Northwestern University ◽  
Identification Test ◽  
Improved Performance ◽  
Over Time

The speech perception performance of 10 congenitally deaf and 3 postlingually deafened children who received the Cochlear Corporation multichannel cochlear implant was examined and compared. The children were tested preimplant and at 6-month intervals up to 2 years using the Monosyllable-Trochee-Spondee test (MTS), the Word Intelligibility by Picture Identification test (WIPI), and Phonetically Balanced Kindergarten (PB-K) or Northwestern University List 6 (NU-6) word lists. The postlingually deafened children exhibited significantly improved performance on open- and closed-set tests of word recognition after 6 months of implant use, a pattern similar to that of postlingually deafened adult implant users. In contrast, the congenitally deaf children did not exhibit measurably improved performance on speech perception tests until after 12 months or more of implant use. With as much as 18–24 months of use, however, some congenitally deaf children demonstrated limited open-set word recognition.

scholarly journals Patients with chronic periodontitis are more likely to develop upper urinary tract stone: a nation-wide population-based eight-year follow up study

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5287
Author(s):  
I-Shen Huang ◽  
Sung-En Huang ◽  
Wei-Tang Kao ◽  
Cheng-Yen Chiang ◽  
To Chang ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Chronic Periodontitis ◽  
Cox Regression ◽  
Population Based ◽  
Upper Urinary Tract ◽  
Research Database ◽  
Data Set ◽  
Urinary Tract Stone ◽  
The Relationship

Background The purpose of this study was to investigate the relationship between chronic periodontitis (CP) and upper urinary tract stone (UUTS) in Taiwan by using a population-based data set. Methods A total of 16,292 CP patients and 48,876 randomly-selected controls without chronic periodontitis were selected from the National research database and studied retrospectively. Subjects selected have not been diagnosed with UUTS previously. These subjects were prospectively followed for at least eight years. Cox regression models were used to explore the connection between risk factors and the development of UUTS. Results The CP patients have a greater chance of developing UUTS compared to controls (1761/16292, 10.8% vs. 4775/48876, 9.8%, p-values < 0.001). Conditioned logistic regression suggested CP increases the risk of UUTS development (HR 1.14, 95% CI [1.08–1.20], p < 0.001). After respective adjustment for age, gender, hypertension and diabetes, results showed that CP still increases the risk of developing UUTS (HR 1.14, 95% CI [1.08–1.20], p < 0.001). Conclusion By using a population-based database with a minimum eight 8 follow-up of CP in Taiwan, we discovered patients with CP are more likely to develop UUTS.

Current Trends in Pediatric Cochlear Implant Candidate Selection and Postoperative Follow-Up

2014 ◽  
Vol 23 (3) ◽  
pp. 309-325 ◽  
Author(s):  
Kristin Uhler ◽  
René H. Gifford
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
The United States ◽  
Test Battery ◽  
Current Trends ◽  
Northwestern University ◽  
Auditory Integration ◽  
Scheduling Protocols ◽  
Selection Of

Purpose In this article, the authors describe current pediatric cochlear implant (CI) assessment and postoperative scheduling protocols in the United States. Method A survey was conducted in 2 phases. Results Response rates were similar between Phase I (10%) and Phase II (13%). Across phases, nearly all respondents reported assessing speech perception both preoperatively and postoperatively. The most frequently used parent questionnaires were the Infant–Toddler Meaningful Auditory Integration Scale (Robbins, Renshaw, & Berry, 1991), the Meaningful Auditory Integration Scale (Robbins et al., 1991), and LittlEARS (Kuehn-Inacken, Weichboldt, Tsiakpini, Coninx, & D'Haese, 2003). The most commonly used speech perception measure for children <23 months of age was the Early Speech Perception Test–Low Verbal (ESP-LV; Moog & Geers, 1990). The most commonly used measures for children 24–35 months of age were the ESP-LV, the Northwestern University of Children's Perception of Speech (Elliot & Katz, 1980), and the Mr. Potato Head task (Robbins, 1993). For children >36 months of age, there was a wide variety of speech perception tests utilized. Patient follow-up visits were weekly or biweekly immediately following CI activation, then every 3 months for the remainder of the 1st year. After the 1st year, most children were seen semiannually. Conclusions Although trends emerged, there is a lack of consistency in the selection of speech perception measures utilized across centers for children <36 months of age. The development of a working group to establish a standard minimum pediatric test battery (similar to the adult Minimum Speech Test Battery) would promote uniformity in clinical protocols used to assess children who receive CIs.

scholarly journals A Longitudinal Study of Speech Perception Skills and Device Characteristics of Adolescent Cochlear Implant Users

2012 ◽  
Vol 23 (05) ◽  
pp. 341-349 ◽  
Author(s):  
Elizabeth J. Robinson ◽  
Lisa S. Davidson ◽  
Rosalie M. Uchanski ◽  
Christine M. Brenner ◽  
Ann E. Geers
Keyword(s):  
High School ◽  
Longitudinal Study ◽  
Speech Perception ◽  
Cochlear Implant ◽  
Dynamic Range ◽  
Elementary Grades ◽  
Comfort Levels ◽  
Technology Type ◽  
Over Time ◽  
Technology Map

Background: For pediatric cochlear implant (CI) users, CI processor technology, map characteristics, and fitting strategies are known to have a substantial impact on speech perception scores at young ages. It is unknown whether these benefits continue over time as these children reach adolescence. Purpose: To document changes in CI technology, map characteristics, and speech perception scores in children between elementary grades and high school, and to describe relations between map characteristics and speech perception scores over time. Research Design: A longitudinal design with participants 8–9-yr-old at session 1 and 15–18-yr-old at session 2. Study Sample: Participants were 82 adolescents with unilateral CIs, who are a subset of a larger longitudinal study. Mean age at implantation was 3.4 yr (range: 1.7–5.4), and mean duration of device use was 5.5 yr (range: 3.8–7.5) at session 1 and 13.3 yr (range: 10.9–15) at session 2. Data Collection and Analysis: Speech perception tests at sessions 1 and 2 were the Lexical Neighborhood Test (LNT) presented at 70 dB SPL (LNT-70) and Bamford-Kowal-Bench sentences in quiet (BKB-Q) presented at 70 dB SPL. At session 2, the LNT was also administered at 50 dB SPL (LNT-50), and BKB sentences were administered in noise with a +10 dB SNR (BKB-N). CI processor technology type and CI map characteristics (coding strategy, number of electrodes, threshold levels, and comfort levels) were obtained at both sessions. Electrical dynamic range was computed, and descriptive statistics, correlations, and repeated-measures ANOVAs were employed. Results: Participants achieved significantly higher LNT and BKB scores, at 70 dB SPL, at ages 15–18 than at ages 8–9 yr. Forty-two participants had 1–3 electrodes either activated or deactivated in their map between test sessions, and 40 had no change in number of active electrodes (mean change: −0.5; range: −3 to +2). After conversion from arbitrary clinical map units to charge-per-phase in nanocoulombs (nC), no significant difference was found for T levels across time. Average comfort levels (C levels) decreased by 19 nC. Seventy-three participants (89%) upgraded their CI processor technology type. At both sessions, significant correlations were found between electrical dynamic range (EDR) and all speech perception measures except LNT-50 (r range: .31 to .47; p < 0.01). Similarly, significant correlations were also found between C levels and all speech perception measures (r range: .29 to .49; p < 0.01). At session 2, a significant correlation was found between processor technology type and the LNT-50 scores (r = .38; p < 0.01). Conclusions: Significant improvement in speech scores was observed between elementary grades and high school for children who had used a CI since preschool. On average, T levels (nC) and electrode function remained stable for these long-term pediatric users. Analyses of maps did not allow for the determination of the exact cause of C level reductions, though power limitations in new processor systems and changes in perceived loudness over time are possible. Larger EDRs and higher C levels were associated with better speech scores. Newer speech processor technology was associated with better speech scores at a softer level.

Effect of Increased IIDR in the Nucleus Freedom Cochlear Implant System

2007 ◽  
Vol 18 (09) ◽  
pp. 777-793 ◽  
Author(s):  
Laura K. Holden ◽  
Margaret W. Skinner ◽  
Marios S. Fourakis ◽  
Timothy A. Holden
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Dynamic Range ◽  
Sound Field ◽  
The Other ◽  
Threshold Levels ◽  
Speech In Noise ◽  
El Sistema ◽  
Initial Activation ◽  
Implant System

The objective of this study was to evaluate the effect of the increased instantaneous input dynamic range (IIDR) in the Nucleus Freedom cochlear implant (CI) system on recipients' ability to perceive soft speech and speech in noise. Ten adult Freedom CI recipients participated. Two maps differing in IIDR were placed on each subject's processor at initial activation. The IIDR was set to 30 dB for one map and 40 dB for the other. Subjects used both maps for at least one month prior to speech perception testing. Results revealed significantly higher scores for words (50 dB SPL), for sentences in background babble (65 dB SPL), and significantly lower sound field threshold levels with the 40 compared to the 30 dB IIDR map. Ceiling effects may have contributed to non-significant findings for sentences in quiet (50 dB SPL). The Freedom's increased IIDR allows better perception of soft speech and speech in noise. El objetivo de este estudio fue evaluar el efecto del rango dinámico aumentado instantáneo de ingreso (IIDR) en el sistema de implante coclear (IC) Nucleus Freedom, sobre la capacidad de sujetos implantados para percibir lenguaje a bajo volumen y lenguaje en ruido. Diez sujetos implantados con el IC Freedom participaron. En la activación inicial, dos mapas con una diferencia en cuanto al IIDR se colocaron en el procesador de cada sujeto. El IIDR fue ajustado a 30 dB para un mapa y a 40 dB para el otro. Los sujetos utilizaron ambos mapas por al menos un mes, antes de una evaluación de percepción del lenguaje. Los resultados revelaron puntajes significativamente más altos para palabras (50 dB SPL), para frases en balbuceo de fondo (65 dB SPL), y niveles umbrales en campo libre significativamente más bajos con el mapa de IIDR de 40 comparado con el de 30. Efectos tope pueden haber contribuido a los hallazgos no significativos para frases en silencio (50 dB SPL). El IIDR aumentado para Freedom permite mejor percepción para el lenguaje a bajo volumen y el lenguaje en medio de ruido.

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