Clinical Characteristics of Deaf Children in Costa

Rica

Adriana Vega, MD (presenter); Mariela Arias, BS;Andres Obando-Valverde, MD; Julian Chaverri, MD

OBJECTIVE: 1) Determine the clinical characteristics amongCosta Rican deaf children by demographic distribution, etio-logical risk factors and audiometric screening results. 2) Com-pare among the data obtained and the reports in other countries.

METHOD: A retrospective case review at a tertiary academicmedical center was performed. 205 patients from the databaseof the deaf children clinic at the ENT Department, HospitalMexico, San Jose, Costa Rica, from October 2008 to January2010, were analyzed including sex, age of diagnosis, etiolog-ical and risk factors and audiometric tests results, using SPSSfor Windows.

RESULTS: 93 male (45%) and 111 female (55%) were in-cluded. In 79.9% (n�163) of the cases, the diagnosis of deaf-ness was done before the 4th year of age, in 10.3% (n�21),between 4 and 8 years and 9.9% (n�20) in children of 8 andmore. At the moment of diagnosis all patients had sensoneuralhearing loss (SNHL); according to the BIAP classification,70.6% had a very severe hearing loss (HL), 7.8% had a severeHL, 13.2% a moderate HL and 6.9% a mild HL. Related to theetiology, 97% (n�198) of all patients had a non-syndromicdeafness, meanwhile 3% (n�7) were related to a syndrome (4Usher, 1 Alport, 1 Moebius, 1 Waardenburg). An inner earmalformation was found in 4 patients (2 Cochlear aplasia, 1Mondini, 1 Cochlear hypoplasia) of 124 patients with a CTscan. Risk factors associated to pregnancy and birth wereidentified in 56 (27%) patients; a maternal infection waspresent in 24 (11.7%)cases and prematurity in 32 (12.8%). Afamily history of SNHL was present in 27.5 % (n�56) of allpatients.

CONCLUSION: Our findings are similar to the data reportedin other studies, except for the age of the diagnosis of thehearing loss and the incidence rate of syndromic deafness.

Clinical Role of Rotary Chair Test, ENG and CDP

Won-Ho Chung, MD, PhD (presenter); Hosuk Chu,MD

OBJECTIVE: The vestibular function tests are helpful to di-agnose dizzy patients. Among them, the bithermal caloric testis the most commonly used for localizing the permanent ves-tibular loss. However, normal caloric response does not indi-cate that the functional status of the vestibular system is nor-mal. We tried to classify functional status of vestibular systemin dizzy patients with normal caloric response by using othervestibular tests (rotary chair test, electronystagmography andposturography). These classifications might be used to evaluateand manage dizzy patients in terms of the functional (or active)status.

METHOD: A retrospective review of clinical records wasperformed in 69 dizzy patients with normal caloric response(canal paresis less than 30%). The vestibular function testsinclude bithermal caloric test, rotary chair test, slow harmonicacceleration (SHA) test, visual fixation (VFX) test, visual ves-tibulo-ocular reflex (VVOR) test, electronystagmography, andposturography. The abnormal findings in each test were clas-sified according to the possible location of vestibular impair-ment. The clinical characteristics in each group were evalu-ated.RESULTS: In a series of 69 patients, 26 patients (38%)showed abnormal findings only in rotary chair test, 14 patients(20%) only in posturography, and 29 patients (42%) had ab-normal results in two of the three tests simultaneously. Wefound four groups of abnormal vestibular testing in the patientswith normal caloric response. 1) Abnormal SHA test, such as(1) low gain and asymmetry, (2) phase lead and asymmetry,(3) low gain and phase lead without asymmetry. 2) AbnormalSHA test in asymmetry with normal gain and phase. 3. Ab-normal findings in vestibular components of posturography. 4.Abnormal findings in visual component of posturography, highgain in VFX test, and the abnormal oculomotor test in ENG.Eleven patients (16%) were included in the first group andregarded as unilateral vestibular loss. Second group (N�13,19%) was regarded as irritative vestibular imbalance. Thirdgroup was regarded as vestibular-spinal tract abnormality(N�14, 20%). The fourth group was classified as abnormalvisual-vestibular interactions (N�9, 13%). Overall, 68% of thepatients that showed abnormal tests with normal caloric re-sponse were classified according to our classifications andthese results were comparable to their subjective symptoms.CONCLUSION: We suggest new classification of abnormalvestibular functional status in dizzy patients with normal ca-loric response. These are comparable according their clinicalfeatures and thought to be helpful in managing and counselingthe patients.

Cochlear Implant Surgery: Incidents and Solutions

Cristina Sierra, PhD (presenter)

OBJECTIVE: Cochlear implant surgery is a relatively well-known technique between otologic surgeons; as with any othersurgical techniques, complications might occur. This retro-spective analysis is done in order to analyze serious incidentsrelated to surgery. The study describes the incidents involvedand techniques to avoid or overcome them.METHOD: From April 1991 until February 2010, 232 co-chlear implant surgeries have been performed by our depart-ment. From those 232 surgeries, we have found 25 patientswith serious incidents, most of them requiring revision surgery.RESULTS: More than 1 out of 10 patients (10.8%) sufferedserious incidents, most of them requiring revision surgery:11 p. (4.7%) with electronic failure of the implant, 4 p. (1.7%)in whom the introduction of the electrodes array was impos-

P226 Otolaryngology-Head and Neck Surgery, Vol 143, No 2S2, August 2010