A Pilot Study to Assess the Vestibular Apparatus Function with Videonystagmography During Chronic Otitis Media with Effusion.

OBJECTIVE: To assess the effect of chronic middle ear effusion (CMEE) on balance and equilibrium. MATERIAL AND METHODS: Prospective study controlling two groups of children. The active arm consisted of children having a unilateral or bilateral CMEE that persisted for at least 3 months. The control group consisted of children presenting with normal middle ear. Children and parents in both groups were questioned about any symptom of vertigo, dizziness, disequilibrium or child's tendency to fall. ENT exam included an assessment with pneumatic and microscopic otoscopy, evaluation of the vestibular system with the Romberg test, the Fukuda test, the head-shaking test and the Starwalk test. RESULTS: The study group consisted of 15 children (mean = 6.5 years, SD = 2; 10 females and 5 males). The control group consisted also of 15 children (mean = 7.2 years, SD = 1.8; 8 females and 7 males). The duration of MEE was between 3 and 12 months (mean = 8 months). Three children (20%) in the study group had a history of vertigo, imbalance, disequilibrium and/or tendency to fall. None of the children in the control group had such a history (p = 0.22); Five children in the study group had abnormal head-shaking test, Fukuda and/or Starwalk tests (33.33%). Two children in the control group had such a finding (13.33%) (p = 0.39). Romberg test was normal in all children in both groups. In the study group, one child showed positional and spontaneous nystagmus on VNG testing. Another one showed positional nystagmus. Hence, 2 children had abnormal findings on VNG (13.33%). In the control group, VNG was normal in all children (p = 0.46). Tympanometry showed a type B curve in 26 ears, a type C curve in 3 ears and type A in one ear. In the control group all patients presented a type A curve. CONCLUSION: This paper describes the first study using VNG in a population of children with CMEE. The presence of balance disturbances associated or not with hearing loss is of paramount importance to the clinician as to the indications of myringotomy with a tube intervention.

Molecular genetics of the Usher syndrome in Lebanon: identification of 11 novel protein truncating mutations by whole exome sequencing.

BACKGROUND: Usher syndrome (USH) is a genetically heterogeneous condition with ten disease-causing genes. The spectrum of genes and mutations causing USH in the Lebanese and Middle Eastern populations has not been described. Consequently, diagnostic approaches designed to screen for previously reported mutations were unlikely to identify the mutations in 11 unrelated families, eight of Lebanese and three of Middle Eastern origins. In addition, six of the ten USH genes consist of more than 20 exons, each, which made mutational analysis by Sanger sequencing of PCR-amplified exons from genomic DNA tedious and costly. The study was aimed at the identification of USH causing genes and mutations in 11 unrelated families with USH type I or II. METHODS: Whole exome sequencing followed by expanded familial validation by Sanger sequencing. RESULTS: We identified disease-causing mutations in all the analyzed patients in four USH genes, MYO7A, USH2A, GPR98 and CDH23. Eleven of the mutations were novel and protein truncating, including a complex rearrangement in GPR98. CONCLUSION: Our data highlight the genetic diversity of Usher syndrome in the Lebanese population and the time and cost-effectiveness of whole exome sequencing approach for mutation analysis of genetically heterogeneous conditions caused by large genes.

Cochlear implant programming: a global survey on the state of the art.

The programming of CIs is essential for good performance. However, no Good Clinical Practice guidelines exist. This paper reports on the results of an inventory of the current practice worldwide. A questionnaire was distributed to 47 CI centers. They follow 47600 recipients in 17 countries and 5 continents. The results were discussed during a debate. Sixty-two percent of the results were verified through individual interviews during the following months. Most centers (72%) participated in a cross-sectional study logging 5 consecutive fitting sessions in 5 different recipients. Data indicate that general practice starts with a single switch-on session, followed by three monthly sessions, three quarterly sessions, and then annual sessions, all containing one hour of programming and testing. The main focus lies on setting maximum and, to a lesser extent, minimum current levels per electrode. These levels are often determined on a few electrodes and then extrapolated. They are mainly based on subjective loudness perception by the CI user and, to a lesser extent, on pure tone and speech audiometry. Objective measures play a small role as indication of the global MAP profile. Other MAP parameters are rarely modified. Measurable targets are only defined for pure tone audiometry. Huge variation exists between centers on all aspects of the fitting practice.

Measures of the electrically evoked compound action potential threshold and slope in HiRes 90K(TM) users.

OBJECTIVES: To investigate electrically evoked compound action potentials (eCAPs) measured with the neural response imaging (NRI) 'SmartNRI' algorithm. NRI thresholds and slopes were examined according to three aspects: (1) site along the cochlea, (2) development of responses over time, and (3) influence of age/duration of deafness. METHODS: Thirty-four individuals implanted with the Advanced Bionics HiRes 90K(TM) device were included. The eCAP recordings were made from four electrodes along the array at first fitting and at frequent intervals up to at least 2 years. Slope and threshold (tNRI) of the amplitude growth function were measured and a range of explanatory variables were tested for significant effects on these measures using multi-factorial analysis of variance. RESULTS: Electrode position emerged as a significant effect for the tNRI measure, with lowest thresholds at the apical end of the array. Mean slope was greatest for the most apical electrode, but not significantly. Slope was significantly influenced by onset of deafness, with congenital hearing loss associated with steeper slopes than acquired hearing loss. There was also a highly significant effect of duration of device use, with a gradual increase in slope over the 2 years following device activation. DISCUSSION: The observed effects of electrode position are consistent with a model in which eCAP threshold is governed primarily by an effect of distance between electrode and neural interface (which is shorter towards the apex of the cochlea) and in which slope is governed primarily by density of surviving neural elements.

Down syndrome: an electrophysiological and radiological profile.

OBJECTIVES/HYPOTHESIS: To assess the hearing status of trisomy 21 patients by analyzing electrophysiological and radiological findings of any correlation between hearing impairment and major or minor inner ear malformations. STUDY DESIGN: Prospective radiological and electrophysiological study. METHODS: A group of 34 ears of Down syndrome subjects and 20 ears of a volunteer age- and sex-matched control group of 10 normal subjects were studied electrophysiologically by means of otoacoustic emissions and auditory brainstem response. Temporal bone computed tomography (CT) scans were carried out in both groups; radiological findings were compared. Inner ear structure measurements were applied attempting to disclose subtle bony labyrinthine anomalies. The findings from both groups were statistically analyzed employing the t test. RESULTS: The rate of sensorineural hearing loss (SNHL) in Down syndrome group was 41%. Temporal bone CT scans showed no ossicular malformation in all Down syndrome cases. Major inner ear abnormalities were disclosed in 5.8%; they corresponded to two cases of lateral semicircular canal dysplasia detected on CT images by visual inspection. The application of various inner ear structure measurements increased the overall detection rate of common inner ear malformations to 47%. A statistically significant correlation was found between hearing level and vestibule length (P = .009) and internal auditory canal length (P = .028). Vestibular aqueduct width was correlated to different otic abnormalities. CONCLUSIONS: SNHL is mainly secondary to the underestimated subtle inner ear malformations that are adequately demonstrated by adopting standardized inner ear structure measurements on petrous bone imaging. Vestibular height and internal auditory canal length were correlated to SNHL. LEVEL OF EVIDENCE: 3b.

A novel 5-bp deletion in Clarin 1 in a family with Usher syndrome.

BACKGROUND: To identify the genetic defect in a Lebanese family with two sibs diagnosed with Usher Syndrome. MATERIALS AND METHODS: Exome capture and sequencing were performed on DNA from one affected member using Agilent in solution bead capture, followed by Illumina sequencing. RESULTS: This analysis revealed the presence of a novel homozygous 5-bp deletion, in Clarin 1 (CLRN1), a known gene responsible for Usher syndrome type III. The deletion is inherited from both parents and segregates with the disease phenotype in the family. The 5-bp deletion, c.301_305delGTCAT, p.Val101SerfsX27, is predicted to result in a frameshift and protein truncation after 27 amino acids. Sequencing all the coding regions of the CLRN1 gene in the proband did not reveal any other mutation or variant. CONCLUSION: Here we describe a novel deletion in CLRN1. Our data support previously reported intra familial variability in the clinical features of Usher syndrome type I and III.