A comparison of the University of New Brunswick Test of Prosthetic Function and the Assessment of Capacity for Myoelectric Control

BACKGROUND

Valid outcome measures are required for gathering evidence on when, how and using which prosthetic components to start prosthetic fitting to children with congenital upper limb deficiencies and those following acquired upper limb amputation. We have been using the University of New Brunswick Test of Prosthetic Function (UNB, which measures skill and spontaneity of prosthetic use) in our country since 1996, and the Assessment of Capacity for Myoelectric Control (ACMC, which was developed for persons using a myoelectric prosthesis) since 2008.

AIM

We wanted to explore whether the UNB and the ACMC measure the same construct (i.e., assess convergent validity), and whether the ACMC can also be used for assessing children and adolescents who use a body-powered upper-limb prosthesis.

DESIGN

Observational.

SETTING

Inpatient.

POPULATION

All the 19 children and adolescents who were visiting the outpatient clinic for rehabilitation of children with upper limb deficiencies and amputations at our institute from January 2010 to December 2011 and had a myoelectric (15 participants) or body-powered prosthesis (4 participants).

METHODS

The participants were assessed by the age-appropriate UNB subtest; 60 assessments were performed in total. Two tests (moving a plastic glass half-full with water from table to the sink, and tying apron at the back) were added to obtain the ACMC scores.

RESULTS

Simple and autocorrelation-adjusted correlation and regression analyses demonstrated that ACMC score is highly positively correlated with UNB spontaneity and skill score in children and adolescents who use a myoelectric prosthesis. Neither of the two associations could be observed in children and adolescents who use a body-powered prosthesis.

CONCLUSION

The results suggest that both tests can be used for assessing children and adolescents who use a myolectric prosthesis, but only the UNB appears to be appropriate for those who use a body-powered prosthesis.

CLINICAL REHABILITATION IMPACT

This small study indicates that either the ACMC or the UNB are applicable for assessing children and adolescents who use a myolectric upper-limb prosthesis because of congenital upper limb deficiencies or acquired upper limb amputation, but only the UNB seems to be applicable for those children or adolescents who use a body-powered prosthesis.

Remote programming of MED-EL cochlear implants: users' and professionals' evaluation of the remote programming experience

CONCLUSION

Remote programming is safe and is well received by health-care professionals and cochlear implant (CI) users. It can be adopted into clinic routine as an alternative to face-to-face programming.

OBJECTIVES

Telemedicine allows a patient to be treated anywhere in the world. Although it is a growing field, little research has been published on its application to CI programming. We examined hearing professionals' and CI users' subjective reactions to the remote programming experience, including the quality of the programming and the use of the relevant technology.

METHODS

Remote CI programming was performed in Italy, Sweden, and Russia. Programming sessions had three participants: a CI user, a local host, and a remote expert. After the session, each CI user, local host, and remote expert each completed a questionnaire on their experience.

RESULTS

In all, 33 remote programming sessions were carried out, resulting in 99 completed questionnaires. The overwhelming majority of study participants responded positively to all aspects of remote programming. CI users were satisfied with the results in 96.9% of the programming sessions; 100% of participants would use remote programming again. Although technical problems were encountered, they did not cause the sessions to be considerably longer than face-to-face sessions.

Comprehensive hemodynamic performance and frequency of patient-prosthesis mismatch of the St. Jude Medical Trifecta bioprosthetic aortic valve

BACKGROUND AND AIM OF THE STUDY

The study aim was to evaluate the performance of a new stented pericardial bioprosthesis, the Trifecta (St. Jude Medical, St. Paul, MN, USA), for aortic valve replacement (AVR) with respect to valvular hemodynamics and frequency of patient-prosthesis mismatch (PPM). PPM has been reported in a wide range of bioprosthetic valves following AVR, and has been associated with multiple adverse outcomes. It was hypothesized that the Trifecta aortic valve would have superior hemodynamics and an acceptable incidence of PPM following AVR.

METHODS

A prospective cohort study was performed between January 2010 and May 2012, following 75 patients (mean age 71.9 _ 11.1 years) who had undergone AVR with a Trifecta valve for aortic stenosis (88%) or regurgitation (12%) at the authors' institutions. Intraoperative three-dimensional and Doppler transesophageal echocardiography were used to evaluate hemodynamic variables before and after AVR, as well as pre-discharge.

RESULTS

Echocardiographic evaluation showed a preoperative average mean gradient (MG) of 40.6 ± 21.6 mmHg, an average peak gradient (PG) of 72.1 ± 19.4 mmHg, and an average effective orifice area index (EOAI) of 0.39 ± 0.20 cm2/m2. Postoperative mean pressure gradient measurements showed a postoperative average MG of 8.76 ± 3.75 mmHg (p < 0.001), an average PG of 19.4 ± 8.6 mmHg (p < 0.001), and EOAI of 1.09 ± 0.36 cm2/m2 (p < 0.001), which demonstrated a significantly improved hemodynamic performance across all valve sizes. Postoperative MG versus measured EOAI demonstrated a fairly linear relationship (R2 = 0.0703), rather than a rapid increase in MG with EOAI < 0.85 and < 0.65, as was seen with previous valve designs. Severe PPM (defined as EOAI ≤ 0.65 cm2/m2) was found in four patients (6%), while moderate PPM (EOAI > 0.65 and < 0.85 cm2/m2) was seen in 11 patients (16%).

CONCLUSION

The Trifecta pericardial valve demonstrated excellent hemodynamic performance at all valve sizes, and resulted in very low postoperative transvalvular pressure gradients and PPM, without the need for aortic root enlargement.

Comparative study of femoral sizing between intraoperative measurement and CT-based PSI in total knee arthroplasty

BACKGROUND

Appropriate femoral sizing in total knee arthroplasty (TKA) is an important factor for flexion. An oversized femoral component will decrease flexion gap and postoperative flexion. By using custom cutting blocks technique with computed tomography (CT) imaging to design cutting blocks will help determine sizing of each patient. The differences of femoral sizing between intraoperative measurement and custom cutting blocks technique are still questionable.

OBJECTIVE

To compare femoral component sizing between custom cutting blocks technique and conventional technique.

MATERIAL AND METHOD

Retrospective cross-sectional study was collected from 2,321 patients underwent primary TKA with the same prosthesis design in Bangkok between January 2012 and December 2012. The population was separated into three groups, group A, 2,053 patients operated by orthopedic surgeons in Bangkok by conventional instrument femoral sizing, group B, 218 patients operated by senior experienced arthroplasty surgeon (Chotanaphuti T) at Phramongkutklao Hospital using the same measurement technique as group A, and group C, 50 patients operated by Chotanaphuti T using custom cutting blocks technique for femoral sizing. The femoral component sizes were assigned from small to large size as number 1 to 6. Chi-square test and Fisher's exact test was used to determine the significant differences between amount of patients of each group.

RESULTS

In group A, femoral components were selected in size 1 (n = 157; 8%), 2 (n = 576; 28%), 3 (n = 737; 36%), 4 (n = 431; 21%), 5 (n = 144; 7%), and 6 (n = 8; 0.4%) respectively. In group B, femoral components were selected in size 1 (n = 31; 14%), 2 (n = 55; 25%), 3 (n = 64; 29%), 4 (n = 31; 140%), 5 (n = 37; 180%), and 6 (n = 0; 0%) respectively. In group C, femoral components were selected in size 1 (n = 7; 14%), 2 (n = 19; 38%), 3 (n = 11; 220%), 4 (n = 12; 24%), 5 (n = 1; 20%), and 6 (n = 0; 0%) respectively. The most chosen size of group A and B were No. 3, but for group C was No. 2, which was smaller than the first two group by one size. There were statistical difference in group A versus group B (p < 0.0001), and group B versus group C (p = 0. 009), but not difference in group A versus group C (p = 0. 096).

CONCLUSION

Custom cutting blocks technique chooses a femoral component closer to knee anatomy of the patients and smaller than intraoperative technique. There are several possible causes, which include variable of level or sagittal angle error of distal femoral bone cut.

Objective assessment of listening effort in the oscillatory EEG: comparison of different hearing aid configurations

An objective estimate of listening effort could support the hearing aid fitting procedure. Most of the digital hearing aids have already hearing aid settings which are supposed to reduce the listening effort, but the effects of these settings on the individual's listening effort remain unclear. In this study, we propose an objective estimate of listening effort using electroencephalographic data. The new method is based on the phase distribution of the ongoing oscillatory EEG activity. We hypothesize that for a non-effortful listening environment the phase is rather uniformly distributed on the unit circle than for a demanding condition. To prove if the phase is uniformly distributed around the unit circle, the Rayleigh Test was applied to the phase of the EEG. This method was tested in 14 hearing impaired subjects (moderate hearing loss, 65.64 ±7.93 yrs, 7 female). The tested hearing aid settings were a directional microphone combined with a noise reduction algorithm in a medium and a strong setting, the noise reduction setting turned off as well as a setting using omnidirectional microphones. Noise embedded sentences (Oldenburg Sentence Test, OlSa) were used as test materials. The task of the subject was to repeat each sentence. The results indicate that the objective estimate of listening effort maps the subjectively rated effort and for a listening situation like the presented one, the strong setting of the directional microphone requires the smallest effort.

Enlargement of the aortic annulus during aortic valve replacement: a review

The main goal of aortic valve replacement (AVR) is to obtain relief from the fixed left ventricular (LV) obstruction by replacing the aortic valve with a prosthesis, either mechanical or biological, of adequate size. Most currently available prostheses provide satisfactory hemodynamic performance, but small-sized prostheses may be associated with high transvalvular gradients and suboptimal effective orifice area that result in prosthesis-patient mismatch (PPM), and thus are far from ideal for use in young, active patients. The avoidance of PPM is advisable as it has been repeatedly associated with increased mortality, decreased exercise tolerance and an impaired regression of LV hypertrophy after AVR for severe aortic stenosis. Enlargement of the aortic annulus (EAA) has proved to be a valuable method to prevent PPM in the presence of a diminutive aortic root. This review outlines the various techniques described for EAA, presenting technical details, long-term results and major procedure-related complications, and discussing the current role of EAA in patients requiring AVR.

[What's new about total knee arthroplasty]

Osteoarthritis of the knee is one of the most common problems in the orthopedic practice and its surgical technique is still challenging. This Mini-Review presents patient specific cutting blocks for the implantation of a total knee arthroplasty.

Modern prescription theory and application: realistic expectations for speech recognition with hearing AIDS

A major decision at the time of hearing aid fitting and dispensing is the amount of amplification to provide listeners (both adult and pediatric populations) for the appropriate compensation of sensorineural hearing impairment across a range of frequencies (e.g., 160-10000 Hz) and input levels (e.g., 50-75 dB sound pressure level). This article describes modern prescription theory for hearing aids within the context of a risk versus return trade-off and efficient frontier analyses. The expected return of amplification recommendations (i.e., generic prescriptions such as National Acoustic Laboratories-Non-Linear 2, NAL-NL2, and Desired Sensation Level Multiple Input/Output, DSL m[i/o]) for the Speech Intelligibility Index (SII) and high-frequency audibility were traded against a potential risk (i.e., loudness). The modeled performance of each prescription was compared one with another and with the efficient frontier of normal hearing sensitivity (i.e., a reference point for the most return with the least risk). For the pediatric population, NAL-NL2 was more efficient for SII, while DSL m[i/o] was more efficient for high-frequency audibility. For the adult population, NAL-NL2 was more efficient for SII, while the two prescriptions were similar with regard to high-frequency audibility. In terms of absolute return (i.e., not considering the risk of loudness), however, DSL m[i/o] prescribed more outright high-frequency audibility than NAL-NL2 for either aged population, particularly, as hearing loss increased. Given the principles and demonstrated accuracy of desensitization (reduced utility of audibility with increasing hearing loss) observed at the group level, additional high-frequency audibility beyond that of NAL-NL2 is not expected to make further contributions to speech intelligibility (recognition) for the average listener.

Simulating the effect of interaural mismatch in the insertion depth of bilateral cochlear implants on speech perception

A bilateral advantage for diotically presented stimuli has been observed for cochlear implant (CI) users and is suggested to be dependent on symmetrical implant performance. Studies using CI simulations have not shown a true "bilateral" advantage, but a "better ear" effect and have demonstrated that performance decreases with increasing basalward shift in insertion depth. This study aimed to determine whether there is a bilateral advantage for CI simulations with interaurally matched insertions and the extent to which performance is affected by interaural insertion depth mismatch. Speech perception in noise and self-reported ease of listening were measured using matched bilateral, mismatched bilateral and unilateral CI simulations over four insertion depths for seventeen normal hearing listeners. Speech scores and ease of listening reduced with increasing basalward shift in (interaurally matched) insertion depth. A bilateral advantage for speech perception was only observed when the insertion depths were interaurally matched and deep. No advantage was observed for small to moderate interaural insertion-depth mismatches, consistent with a better ear effect. Finally, both measures were poorer than expected for a better ear effect for large mismatches, suggesting that misalignment of the electrode arrays may prevent a bilateral advantage and detrimentally affect perception of diotically presented speech.

Computer navigation is a useful intra-operative tool for joint line measurement in total knee arthroplasty

BACKGROUND

Restoration of the native joint line in total knee arthroplasty is important in restoring ligamentous balance and normal knee kinematics. Failure to achieve this could lead suboptimal outcomes. The purpose of this study was to analyze the clinical and functional outcome of patients who demonstrated joint line changes after computer-assisted (CAS) total knee arthroplasty (TKA).

METHODS

One hundred sixty-eight patients (168 knees) underwent CAS TKA by two surgeons at a single institution with 2 years follow-up. The final change in joint line was calculated from the verified tibial resection and distal femoral cuts. Group A patients had joint line changes of less than 4mm and Group B patients had joint line changes of more than 4mm. Post-operative Oxford scores, Knee scores, Function scores and SF-36 scores were obtained at 6 months and 2 years post TKA.

RESULTS

There was significant linear correlation between joint line changes and Oxford scores (P=0.0001), Function scores (P=0.0001) and Knee scores (P=0.0001) at 6 months and Oxford scores (P=0.0001) alone at 2 years with increasing joint line changes having poorer outcome scores. Group A compared to Group B patients demonstrated better Oxford scores (P=0.0001), Function scores (P=0.0001), Knee scores (P=0.0001) and total SF-36 scores (P=0.003) at 6 months as well as better Oxford scores (P=0.0001) and Knee scores (P=0.014) at 2 years.

CONCLUSIONS

CAS is a useful intra-operative tool for assessing the final joint line in TKA. Outliers in joint line changes of ≥4 mm are associated with poorer clinical outcome scores.

LEVEL OF EVIDENCE

Prognostic Study, Level II-1.

Listening effort with cochlear implant simulations

PURPOSE

Fitting a cochlear implant (CI) for optimal speech perception does not necessarily optimize listening effort. This study aimed to show that listening effort may change between CI processing conditions for which speech intelligibility remains constant.

METHOD

Nineteen normal-hearing participants listened to CI simulations with varying numbers of spectral channels. A dual-task paradigm combining an intelligibility task with either a linguistic or nonlinguistic visual response-time (RT) task measured intelligibility and listening effort. The simultaneously performed tasks compete for limited cognitive resources; changes in effort associated with the intelligibility task are reflected in changes in RT on the visual task. A separate self-report scale provided a subjective measure of listening effort.

RESULTS

All measures showed significant improvements with increasing spectral resolution up to 6 channels. However, only the RT measure of listening effort continued improving up to 8 channels. The effects were stronger for RTs recorded during listening than for RTs recorded between listening.

CONCLUSION

The results suggest that listening effort decreases with increased spectral resolution. Moreover, these improvements are best reflected in objective measures of listening effort, such as RTs on a secondary task, rather than intelligibility scores or subjective effort measures.

Relation of distortion-product otoacoustic emission input-output functions to loudness

The aim of this study is to further explore the relationship between distortion-product otoacoustic emission (DPOAE) measurements and categorical loudness scaling (CLS) measurements using multiple linear regression (MLR) analysis. Recently, Thorson et al. [J. Acoust. Soc. Am. 131, 1282-1295 (2012)] obtained predictions of CLS loudness ratings from DPOAE input/output (I/O) functions using MLR analysis. The present study extends that work by (1) considering two different (and potentially improved) MLR models, one for predicting loudness rating at specified input level and the other for predicting the input level for each loudness category and (2) validating the new models' predictions using an independent set of data. Strong correlations were obtained between predicted and measured data during the validation process with overall root-mean-square errors in the range 10.43-16.78 dB for the prediction of CLS input level, supporting the view that DPOAE I/O measurements can predict CLS loudness ratings and input levels, and thus may be useful for fitting hearing aids.

Incidence and impact of prosthesis-patient mismatch after transcatheter aortic valve implantation

BACKGROUND AND AIM OF THE STUDY

The study aim was to investigate the incidence of patient-prosthesis mismatch (PPM) with new catheter valves, and its influence on the patients' clinical state. At present, few echocardiographic data are available on the incidence and impact of PPM with the CoreValve and Sapien prostheses for transcatheter aortic valve implantation (TAVI).

METHODS

The reliability of effective orifice area (EOA) measurements was assured by awaiting an interval of six months after TAVI. Of 256 survivors after TAVI, 149 complete echocardiographic data sets were available for the assessment of the indexed EOA (iEOA). In total, 106 CoreValve prostheses and 43 Sapien prostheses were implanted in this high-risk cohort (mean age 81 +/- 6 years, mean logistic EuroSCORE 20 +/- 13%).

RESULTS

The overall incidence of PPM (iEOA < 0.85 cm2/m2) was 61%. Patients with a larger body surface area were more likely to develop PPM (p = 0.001), while the prosthesis type, native annulus diameter, preoperative EOA, gender and prosthesis size had no influence. The mean aortic gradient was significantly higher in patients with PPM. A reduction in the left ventricular end-diastolic diameter was seen in all patients, without significant differences between groups. There were no differences in postoperative NYHA class or self-assessed health state between patients with or without PPM.

CONCLUSION

PPM was common after TAVI in the presented cohort, presumably because the native calcium masses narrow the outflow area available for blood flow. As expected for low gradients, there was no impairment of left ventricular dimension regression or clinical state of the patients, even if severe PPM was present. Based on the presented data, it is assumed that PPM might be less relevant in TAVI patients.

Current fit of medial and lateral unicompartmental knee arthroplasty

Whether failure in unicompartmental knee arthroplasty (UKA) is related to implant design remains unclear. We hypothesize that current available UKAs fit within 2 mm. Forty-eight CTs of cadaveric knees were compared to current available UKA brands. Overall no-fit compared to at least one component within 2 mm is high (91.7%) and worse for males (100%) compared to females (833%). Good fit was observed for the medial but not for the lateral tibia plateau. Seven males (29.2%) had larger dimensions of more than 2 mm. For the widest UKA brand, 12 (57%) males and 2 females (8. 3%) had lateral femoral condyles 3 mm larger. Current UKA's in our sample population fit less on the lateral tibia and on femoral condyles.

Primary total hip arthroplasty with a retained intramedullary femoral nail

Retained intramedullary femoral nails can pose a problem for the implantation of the femoral component during total hip arthoplasty (THA) and they must often be removed. A patient with a retained Küntscher femoral nail implanted 47 years previously presented in our outpatient clinic for a THA. Since removal of the nail was impossible without severe damage to the femur, we chose to perform an extended trochanteric osteotomy, to cut the proximal part of the nail and to implant a cemented short stem with its tip in the hollow end of the nail.

Examination of anticipated chemical shift and shape distortion effect on materials commonly used in prosthetic socket fabrication when measured using MRI: a validation study

The quality of lower-limb prosthetic socket fit is influenced by shape and volume consistency during the residual limb shape-capturing process (i.e., casting). Casting can be quantified with magnetic resonance imaging (MRI) technology. However, chemical shift artifact and image distortion may influence the accuracy of MRI when common socket/casting materials are used. We used a purpose-designed rig to examine seven different materials commonly used in socket fabrication during exposure to MRI. The rig incorporated glass marker tubes filled with water doped with 1 g/L copper sulfate (CS) and 9 plastic sample vials (film containers) to hold the specific material specimens. The specimens were scanned 9 times in different configurations. The absolute mean difference of the glass marker tube length was 1.39 mm (2.98%) (minimum = 0.13 mm [0.30%], maximum = 5.47 mm [14.03%], standard deviation = 0.89 mm). The absolute shift for all materials was <1.7 mm. This was less than the measurement tolerance of +/-2.18 mm based on voxel (three-dimensional pixel) dimensions. The results show that MRI is an accurate and repeatable method for dimensional measurement when using matter containing water. Additionally, silicone and plaster of paris plus 1 g/L CS do not show a significant shape distortion nor do they interfere with the MRI image of the residual limb.

Early hearing aid fitting in children: challenges and results

A universal programme of newborn/early hearing screening was introduced fifteen years ago in the northern part of Belgium (Flanders) by the Government Health Service 'Kind en Gezin' (Child and Family). Since then, large numbers of hearing-impaired babies have been fitted with conventional hearing aids at a very young age, mostly before the age of 2-3 months. As a result of the early hearing screening programme, the decision to proceed with a cochlear implant is now taken much earlier. Fitting hearing aids in very young children is always part of a continuous diagnostics approach based on cross-checks and a combination of objective and subjective audiometry. It is also a component of a multidisciplinary approach, with parents as the essential party. Fitting hearing aids in very young children cannot be separated from this approach. This article therefore stresses the positive evolution of the last fifteen years in the context of three basic elements for helping young children with hearing loss and their families: diagnostics, fitting hearing aids and treatment. Early screening and the consequent early diagnosis of hearing loss in neonates triggered the transformation of support arrangements for young children with hearing loss and their families.

[The fitting of prostheses for children with a lower limb amputation]

The fitting of prostheses in child or adolescent amputees enables them to reconstruct a real life project. In most cases, the functional possibilities are very close to normal. The young patient is supported throughout, from the pre-operative consultation to the long-term monitoring of the prosthesis.

Satisfaction and problems experienced with transfemoral suspension systems: a comparison between common suction socket and seal-in liner

OBJECTIVE

To compare a seal-in liner with the common suction socket with regards to patient satisfaction and problems experienced with the prosthesis.

DESIGN

Retrospective survey.

SETTING

A medical and engineering research center and a department of biomechanical engineering.

PARTICIPANTS

Men (N=90) with traumatic transfemoral amputation who used both suspension systems participated in the study.

INTERVENTION

Two prosthetic suspension systems: a seal-in liner and common suction socket.

MAIN OUTCOME MEASURES

Two questionnaires were completed by each subject to evaluate their satisfaction and problems experienced with the 2 suspension systems. Satisfaction and problems with the prosthetic suspension systems were analyzed in terms of fitting, donning and doffing, sitting, walking, stair negotiation, appearance, sweating, wounds, pain, irritation, pistoning, edema, smell, sound, and durability.

RESULTS

The study revealed that the respondents were more satisfied with a seal-in liner with regards to fitting, sitting, and donning and doffing. Overall satisfaction increased with the use of a seal-in liner compared with the suction socket (P<.05). However, satisfaction with the prosthesis showed no significant differences in terms of walking (flat and uneven surfaces), appearance, and stair negotiation. Furthermore, problems experienced differed significantly between the 2 suspension systems (P<.05). Sweating, wounds, pain, irritation, pistoning, edema, smell, and sound were less problematic with the use of a seal-in liner, whereas durability was significantly better with the suction socket.

CONCLUSIONS

The results of the survey suggest that satisfaction and problems with prosthetic suspension in persons with transfemoral amputation can be improved with a seal-in liner compared with the suction socket, provided that the durability of the liner is enhanced.

How some ridge shapes affect the fit of denture bases

Polymerization shrinkage can result in poor denture fit. The aim of this study was to determine the accuracy of heat-polymerized acrylic bases on simulated edentulous metal ridges having simplified and standardized geometric configurations. Analysis of variance was used to explore the relationship between fit and ridge-slope/ridge-convergences. The outcome of that analysis revealed that the discrepancies between the base plates decreased significantly (p < 0.05) as both the ridge slope decreased and the anterior-sagital convergence increased. These geometric correlations can help clinicians to anticipate potential areas of sore spots on residual ridges when delivering complete dentures.

Perceptual acclimatization post nonlinear frequency compression hearing aid fitting in older children

PURPOSE

In this study, the authors evaluated the effect of frequency compression hearing aids on speech perception ability and the time course and magnitude of acclimatization-related changes.

METHOD

Participants included children ages 11-18 years. Speech perception ability was evaluated over well-controlled baseline, treatment, and withdrawal study phases. Study-worn hearing aids were individually fitted to all participants. The authors evaluated speech perception ability using outcomes of speech detection (/s/ and /[symbol in text]/ sounds), /s-[symbol in text]/ discrimination, and plural and consonant recognition.

RESULTS

Indices of change were discussed on a case-by-case basis across all study phases. Significant treatment effects were measured for all cases, on at least one measure, with some listeners displaying significant acclimatization trends following a trial of frequency compression.

CONCLUSION

Findings suggest that frequency compression provided varying outcomes, both in benefit and acclimatization, across listeners. For some, a period of acclimatization was necessary before change could be measured. For others, performance remained stable over the time course under evaluation, suggesting that some but not all children will experience improved speech recognition ability after a period of frequency compression hearing aid use.

Predicting the speech reception threshold of cochlear implant listeners using an envelope-correlation based measure

A modulation-based index is proposed for predicting speech intelligibility by cochlear implant (CI) listeners. The input to the proposed index are speech envelopes extracted using the individual CI user's daily strategy, and as such, this approach incorporates information about the number of active electrodes, shape of the compression function and electrical dynamic range. High correlation (r = 0.96) was achieved with the proposed index when evaluated with speech-reception thresholds (SRTs) obtained by CI users in steady and speech-masker conditions. This outcome suggests that the information contained in electrodograms seems to be sufficient for reliably predicting CI user's performance in noise. The proposed index can be used by clinicians to optimize the selection of fitting parameters of individual CI users for better performance in noise.

Left ventricular hypertrophy in isolated aortic stenosis: primetime for the ventricle

Aortic stenosis is the most common type of valvular heart disease and its recent increase is related to aging. The decreased aortic valve area imposes a chronic systolic pressure overload to the left ventricle. In response, the ventricle hypertrophies in an attempt to normalize the increased wall stress, but this response is not uniform in patients with similar degrees of stenosis and its regression after surgical correction is variable, suggesting that several factors, other than load, can explain these differences. These findings are particularly important since the presence of left ventricular hypertrophy after aortic valve replacement is an independent predictor of worse outcome, probably because it indicates irreversible remodeling. Age, gender, hypertension, patient-prosthesis mismatch and interstitial remodeling also play an important role in this setting, raising the possibility of intervention beyond valve replacement. The possibility of combining estrogen treatment, antihypertensive agents, antioxidants and modulators of the renin-angiotensin-aldosterone system with surgical treatment to promote reverse remodeling is very appealing. On the other hand, a preventive strategy to intervene earlier in patients with significant left ventricular mass and avoid patient-prosthesis mismatch, especially in the younger and those with systolic dysfunction, can have a significant impact on prognosis. Further evidence, with well designed clinical trials, is needed but the spotlight must be in the ventricle, not the valve.

Cochlear implantation and hearing preservation: Results in 21 consecutively operated patients using the round window approach

CONCLUSION

Prevalent hearing conservation may be achieved after round window (RW) cochlear implantation using soft and flexible electrode arrays if variations of RW anatomy, topography, and facial nerve position are considered. The most favorable electrode insertion depth remains to be established.

OBJECTIVES

We assessed the incidence of cochlear function after cochlear implant (CI) electrode insertion through the RW in our first 21 consecutively operated patients aimed at hearing conservation.

METHODS

Eleven patients had a preoperative low frequency hearing suitable for electro-acoustic stimulation. Hearing was preserved in an additional nine patients at their request with the intention to use full frequency CI stimulation. Anatomic variations of the RW were carefully considered using our temporal bone collection of micro-dissected ears. Electrode extension was assessed on X-ray by measuring the insertion angle of the first electrode and intra-cochlear length and correlated with audiometric data.

RESULTS

There was no incidence of total loss of residual hearing in any of the patients. A slight deterioration of low frequency thresholds occurred in some patients. Mean hearing loss at 125-500 Hz was 14.4 dB at 1 month following surgery and 15.6 dB after 1 year. Insertion angle (300-540°) and depth (17.5-28.5 mm) were not statistically correlated to hearing loss.