Objective To evaluate the association between neuroimaging and outcome in infants with congenital cytomegalovirus (cCMV), focusing on qualitative MRI and quantitative diffusion-weighted imaging of... Show moreObjective To evaluate the association between neuroimaging and outcome in infants with congenital cytomegalovirus (cCMV), focusing on qualitative MRI and quantitative diffusion-weighted imaging of white matter abnormalities (WMAs).Methods Multicentre retrospective cohort study of 160 infants with cCMV (103 symptomatic). A four-grade neuroimaging scoring system was applied to cranial ultrasonography and MRI acquired at <= 3 months. WMAs were categorised as multifocal or diffuse. Temporal-pole WMAs (TPWMAs) consisted of swollen or cystic appearance. Apparent diffusion coefficient (ADC) values were obtained from frontal, parieto-occipital and temporal white matter regions. Available follow-up MRI at >= 6 months (N=14) was additionally reviewed. Neurodevelopmental assessment included motor function, cognition, behaviour, hearing, vision and epilepsy. Adverse outcome was defined as death or moderate/severe disability.Results Neuroimaging scoring was associated with outcome (p<0.001, area under the curve 0.89 +/- 0.03). Isolated WMAs (IWMAs) were present in 61 infants, and WMAs associated with other lesions in 30. Although TPWMAs and diffuse pattern often coexisted in infants with IWMAs (p<0.001), only TPWMAs were associated with adverse outcomes (OR 7.8; 95% CI 1.4 to 42.8), including severe hearing loss in 20% and hearing loss combined with other moderate/severe disabilities in 15%. Increased ADC values were associated with higher neuroimaging scores, WMAs based on visual assessment and IWMAs with TPWMAs. ADC values were not associated with outcome in infants with IWMAs. Findings suggestive of progression of WMAs on follow-up MRI included gliosis and malacia.Conclusions Categorisation of neuroimaging severity correlates with outcome in cCMV. In infants with IWMAs, TPWMAs provide a guide to prognosis. Show less
Objectives: Misplacement of the electrode array is associated with impaired speech perception in patients with cochlear implants (CIs). Translocation of the electrode array is the most common... Show moreObjectives: Misplacement of the electrode array is associated with impaired speech perception in patients with cochlear implants (CIs). Translocation of the electrode array is the most common misplacement. When a CI is translocated, it crosses the basilar membrane from the scala tympani into the scala vestibuli. The position of the implant can be determined on a postoperative CT scan. However, such a scan is not obtained routinely after CI insertion in many hospitals, due to radiation exposure and processing time. Previous studies have shown that impedance measures might provide information on the placement of the electrode arrays. The electrode impedance was measured by dividing the plateau voltage at the end of the first phase of the pulse by the injected current. The access resistance was calculated using the so-called access voltage at the first sampled time point after the start of the pulse divided by the injected current. In our study, we obtained the electrode impedance and the access resistance to detect electrode translocations using electrical field imaging. We have investigated how reliably these two measurements can detect electrode translocation, and which method performed best. Design: We calculated the electrode impedances and access resistances using electrical field imaging recordings from 100 HiFocus Mid-Scala CI (Advanced Bionics, Sylmar, CA) recipients. We estimated the normal values of these two measurements as the baselines of the implant placed in the cochlea without translocation. Next, we calculated the maximal electrode impedance deviation and the maximal access-resistance deviation from the respective baselines as predictors of translocation. We classified these two predictors as translocations or nontranslocations based on the bootstrap sampling method and receiver operating characteristics curves analysis. The accuracy could be calculated by comparing those predictive results to a gold standard, namely the clinical CT scans. To determine which measurement more accurately detected translocation, the difference between the accuracies of the two measurements was calculated. Results: Using the bootstrap sampling method and receiver operating characteristics-based optimized threshold criteria, the 95% confidence intervals of the accuracies of translocation detections ranged from 77.8% to 82.1% and from 89.5% to 91.2% for the electrode impedance and access resistance, respectively. The accuracies of the maximal access-resistance deviations were significantly larger than that of the maximal electrode impedance deviations. The location of the translocation as predicted by the access resistance was significantly correlated with the result derived from the CT scans. In contrast, no significant correlation was observed for the electrode impedance. Conclusions: Both the electrode impedance and access resistance proved reliable metrics to detect translocations for HiFocus Mid-Scala electrode arrays. The access resistance had, however, significantly better accuracy and it also reliably detected the electrode-location of translocations. The electrode impedance did not correlate significantly with the location of translocation. Measuring the access resistance is, therefore, the recommended method to detect electrode-array translocations. These measures can provide prompt feedback for surgeons after insertion, improving their surgical skills, and ultimately reducing the number of translocations.In the future, such measurements may allow near-real-time monitoring of the electrode array during insertion, helping to avoid translocations. Show less
Objectives: The impact of the newly introduced cochlear implantation criteria of the United Kingdom and Flanders (Dutch speaking part of Belgium) was examined in the patient population of a... Show moreObjectives: The impact of the newly introduced cochlear implantation criteria of the United Kingdom and Flanders (Dutch speaking part of Belgium) was examined in the patient population of a tertiary referral center in the Netherlands. We compared the patients who would be included/excluded under the new versus old criteria in relation to the actual improvement in speech understanding after implantation in our center. We also performed a sensitivity analysis to examine the effectiveness of the different preoperative assessment approaches used in the United Kingdom and Flanders. Design: The selection criteria were based on preoperative pure-tone audiometry at 0.5, 1, 2, and 4 kHz and a speech perception test (SPT) with and without best-aided hearing aids. Postoperatively, the same SPT was conducted to assess the benefit in speech understanding. Results: The newly introduced criteria in Flanders and the United Kingdom were less restrictive, resulting in greater percentages of patients implanted with CI (increase of 30%), and sensitivity increase of 31%. The preoperative best-aided SPT, used by both countries, had the highest diagnostic ability to indicate a postoperative improvement of speech understanding. We observed that patient selection was previously dominated by the pure-tone audiometry criteria in both countries, whereas speech understanding became more important in their new criteria. Among patients excluded by the new criteria, seven of eight (the United Kingdom and Flanders) did exhibit improved postoperative speech understanding. Conclusions: The new selection criteria of the United Kingdom and Flanders led to increased numbers of postlingually deafened adults benefitting from CI. The new British and Flemish criteria depended on the best-aided SPT with the highest diagnostic ability. Notably, the new criteria still led to the rejection of candidates who would be expected to gain considerably in speech understanding after implantation. Show less
