Assessment of the contralateral routing of signal system in unilateral cochlear implantation.

OBJECTIVES: The purpose of this study was to evaluate the contribution of a contralateral routing of signal (CROS) system in unilateral cochlear implants (CI) users. DESIGN: Single-centre prospective interventional study. SETTING: Tertiary referral centre. PARTICIPANTS: Eight unilateral cochlear implants patients with >30% speech perception in silence and >6 months' implantation. MAIN OUTCOME MEASURES: Free-field speech perception assessed by 'vowel-consonant-vowel' pseudoword test and free-field spatial localisation by Fournier lists on five loudspeakers (in silence and in noise). Subjective benefit assessed on the abbreviated profile of hearing aid benefit (APHAB) questionnaire. These tests were performed on the 1st and 15th day of the trial (denoted by D1 and D15, respectively). RESULTS: Contralateral routing of signal-cochlear implants provided significant improvement in speech perception at D1 and D15 in silence (P, respectively, 0.03 and 0.025) and in noise (P 0.012 and 0.036). No improvement in spatial localisation was demonstrated. The abbreviated profile of hearing aid benefit quality of life questionnaire administered at D15 showed overall benefit and a significant difference in ease of communication with versus without contralateral routing of signal. By 6 months, however, 75% of the patients (6/8) had abandoned the system due to trouble in noise (5/6), trouble with the device's wiring (3/6) and onset of headache (4/6). CONCLUSION: Contralateral routing of signal-cochlear implants is an interesting novel option, restoring a binaural effect and providing improved speech perception and non-negligible comfort of hearing in certain patients, without the medical and economic costs of bilateral cochlear implants. However, the drawbacks (especially the difficulty of modulating the signal-to-noise ratio) do not presently allow it to be an effective alternative to bilateral cochlear implants.

Is liver transaminases assessment an appropriate tool for the screening of non-alcoholic fatty liver disease in at risk obese children and adolescents?

Pediatric obesity has increased dramatically all over the world and nonalcoholic fatty liver disease (NAFLD) is one of the most frequent complications associated with excess adiposity. NAFLD causes serum transaminase elevation and liver disease, which could end up in fibrosis, cirrhosis and eventually hepatocellular carcinoma. NAFLD seems to be associated with the metabolic complications of obesity, mainly insulin resistance. The aim of the present article is to review the role of serum liver enzyme assessment as a suitable non invasive predictor of NAFLD in children. Although serum liver enzyme elevation does not accurately measure liver damage, it may be a valuable and non invasive test to screen NAFLD in children and adolescents and a marker to control NAFLD evolution. To detect NAFLD in obese children and adolescents, transaminases serum concentrations should be routinely determined in these patients. In this sense, it seems necessary to obtain transaminase reference standards for children and adolescents.

[Hypertension high resolution consultation. A year of experience]. / Consulta de alta resolución (CAR) de HTA: experiencia de un año.

By High Resolution Consultation (HRC) we mean an ambulatory process of assistance fulfilled in a single day, by which treatment and diagnosis are established after all complementary tests have been carried out. Once diagnosed, the patient is discharged and resent to the doctor who had previously remitted him/ her. In the Cáceres sanitary area, with distances longer than 100- 120 km. and precarious local road communications, the introduction of hypertension (HTA) HRC has brought along important savings of sanitary and economical resources and it is perceived by the user as highly satisfactory. We have carried out an observational one- year study of our HCR HTA, in which 90 patients have been evaluated, out of which 74.4% came from primary assistance and 25.6% from specialized assistance. Once diagnosed, 61 patients were discharged and sent to receive primary assistance and 29 were kept in our outpatient nephrology consultation, justified by severe and/ or rebellious HTA in 11 cases and by renal failure in 16 cases; two of these patients are still being tested. Taking into account that in a traditional consultation a patient would need two or three visits and one or two days for complementary tests, our HTA HRC (by which patients are tested and diagnosed in a single day), brings along savings of one or two consultations and two to four relocations for new consultations and diagnostic explorations. In one year of HTA- HRC with 90 patients, we have saved from 212 to 302 consultations and from 302 to 604 relocations in comparison to the traditional organization and we have thus generated from 100 to 150 places for first appointments.

[Assessment of the new Ballard score to estimate gestational age]. / Valoración del test de Ballard en la determinación de la edad gestacional.

BACKGROUND AND OBJECTIVES: The New Ballard Score (NBS) is commonly used to estimate gestational age (GA) in the newborn. The aims of this study were: a) to determine the reliability of the NBS; b) to estimate the agreement between two methods of GA assessment, NBS and ultrasonography (US) or last menstrual period (LMP); c) to estimate the agreement between NBS and US/LMP in distinct subgroups of neonates. PATIENTS AND METHODS: We performed a prospective, blind study. NBS was performed in neonates born in Hospital 12 Octubre, Madrid before the age of 48 hours. The level of agreement was estimated with two analytical parameters: the intraclass correlation coefficient (ICC) and the mean differences method (MD). RESULTS: Inter-observer agreement was very good (ICC > 0.8). Agreement between US/LMP and NBS was good (ICC = 0.6-0.8). In infants with lower weight or GA, and in those whose mothers had received prenatal corticosteroid therapy, NBS tended to overestimate GA compared with US/LMP (MD = 1.2-2.9). CONCLUSIONS: The agreement between two observers in NBS assessment was very good. The agreement between NBS and US/LMP was good, but differences of more than 2 weeks in GA were frequent. In very preterm newborns and in infants whose mothers had received prenatal corticosteroid therapy, NBS tends to overestimate GA.

[Binaural cochlear implantation: general concept, surgical technique and electrophysiology]. / Implantation cochléaire binaurale.

Cochlear implant have been proven to be safe and cost-effective in deafened adults. Generally, a single cochlear implants is proposed providing monaural audition. Some teams have published interesting results in patients wearing two cochlear implants. The cost of the surgical procedure is greatly increased for bilateral implantation. In an attempt to provide patients with binaural hearing and a better chance to improve their capacity for frequency discrimination without an excessive increase in cost, we developed an new concept and design for binaural cochlear implants. The aim of the present study was to establish the surgical technique for binaural cochlear implantation with a single internal receptor-stimulator. We report descriptive data on surgical procedures performed in two cadavers and in two deafened adults. The special implant is composed of a single receptor-stimulator and two electrode arrays: a short one implanted into the ipsilateral ear and a long one in the contralateral ear. A specially designed tool for endoscopic facial lifting was used to create subcutaneous tunnels from the ipsilateral to the contralateral ear. Insertion into cochleas was unremarkable. Additional time for surgery (compared with mean operative time for routine adult surgery in our unit), and surgical details are discussed. Binaural cochlear implantation is feasible, easy and not very time consuming. Studies are in progress to determine patient benefit. Obtaining auditory brainstem evoked potentials electrically in patients with binaural cochlear implants is possible and provides an interesting mode for in vivo analysis of the long-term effect of profound/total deafness on neural transmission. In our patients, results have demonstrated that neural response properties in auditory pathways are negatively related to duration of deafness.

Mismatch negativity: a tool for the assessment of stimuli discrimination in cochlear implant subjects.

OBJECTIVES: The performance of cochlear implants varies among users. This variability may be due to the ability to process auditory information. The mismatch negativity should provide an index of discrimination in cochlear implantees (Kraus N, McGee T, Carrell T, Sharma A. Neurophysiologic bases of speech discrimination. Ear Hear. 1995;16:19-37). Our aim was to analyze MMN in cochlear implant (Digisonic) subjects to assess electrode discrimination and to study the relationship between MMN and speech performance. METHODS: The mismatch was determined by stimulating three pairs of different electrodes. Two sessions were performed with both standard and deviant stimuli reversed. Speech recognition abilities were evaluated using 4 speech tests. The statistics included the results of 6 subjects. They indicated that MMN may be obtained when stimulating two different electrodes. A difference occurred between standard and deviant stimuli within a session but also when the response to the deviant stimulus was compared to the response of the same stimulus in a standard condition, validating the discrimination process. MMN latency was about 140 ms, and amplitude about -2.8 microV. No differences were shown with respect to electrode spacing. No relationship between MMN and speech performance was found. A clinical application of this method might be to assess the auditory processing of electrical stimuli in congenitally deaf subjects at the pre-implantation stage.