Binaural interaction of bone-conducted auditory brainstem responses in children with congenital atresia of the external auditory canal.
Adolescent; Audiometry; Auditory; Bilateral/congenital/physiopathology; Bone Conduction/*physiology; Brain Stem/*physiology; Child; Conductive/congenital/physiopathology; Ear; Ear Canal/*abnormalities/physiopathology; Evoked Potentials; Evoked Response; Hearing Loss; Humans; Middle/abnormalities; Preschool; Pure-Tone; Temporal Bone/abnormalities
Bilateral bone-conducted auditory brainstem responses (BC-ABRs) were recorded in children with atresia of the external auditory canal bilaterally (AECB) in order to compare the response characteristics to normal hearing adults. The binaural interaction component (BIC) of the ABR occurs when the sum of the monaural-evoked ABR amplitudes are different in amplitude when compared to the binaural-evoked ABR amplitude. Previous electrophysiological work from our lab has shown that children with AECB lateralize bone-conducted (BC) sound. Furthermore, we have found in normal-hearing adults that BICs exist using BC clicks. In adults, BC-BIC occurred in the latency region corresponding to waves IV-VI, whereas for children with AECB corresponding peak latencies occurred earlier. Same as normal-hearing adults, BC-ABR IV-V complex peak amplitudes for sum of the BC-monaural right and
Sheykholeslami Kianoush; Habiby Kermany Mohammad; Sebastein Schmerber; Kaga Kimitaka
International journal of pediatric otorhinolaryngology
2003
2003-10
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/s0165-5876(03)00197-6" target="_blank" rel="noreferrer noopener">10.1016/s0165-5876(03)00197-6</a>
Vestibular-evoked myogenic potentials in three patients with large vestibular aqueduct.
Adult; Auditory Threshold/*physiology; Auditory/*physiology; Bilateral/diagnosis/etiology; Child; Evoked Potentials; Female; Hearing Loss; Humans; Preschool; Saccule and Utricle/*physiopathology; Sensorineural/diagnosis/etiology; Tomography; Vestibular Aqueduct/*abnormalities/*physiopathology; Vestibular Diseases/complications/congenital/*physiopathology; Vestibular Function Tests; X-Ray Computed
An enlarged vestibular aqueduct (LVA) is a common congenital inner ear anomaly responsible for some unusual vestibular and audiological symptoms. Most of the cases show bilateral early onset and progressive hearing loss in children. The gross appearance on CT scan of the inner ear is generally normal. However, precise measurements of the inner ear components reveal abnormal dimensions, which may account for the accompanying auditory and vestibular dysfunction. Despite extensive studies on hearing and the vestibular apparatus, saccular function is not studied. To our knowledge this is the first report of saccular malfunction in three patients with LVA by means of vestibular evoked myogenic potentials. Conventional audiograms revealed bilateral severe sensorineural hearing loss in two patients and mixed type hearing loss in one patient. Two of the patients complained about vertigo and dizziness but vestibular assessments of the patients showed normal results. The diagnosis had been made by high-resolution CT scans and MR images of the skull that showed LVA in the absence of other anomalies. The VEMP threshold measured from the ear with LVA in two patients with unilateral enlargement of the vestibular aqueduct was 75-80 dB nHL whereas the threshold from normal ears was 95 dB nHL. The third patient with mixed type hearing loss and bilateral LVA had VEMP responses despite a big air-bone gap in the low frequency range. The VEMP in this patient was greater in amplitude and lower in threshold in the operated ear (the patient had a tympanoplasty which did not improve her hearing). These findings and results of other patients with Tullio phenomenon and superior semicircular canal dehiscence, who also showed lower VEMP threshold, confirmed the theory of a 'third window' that allows volume and pressure displacements, and thus larger deflection of the vestibular sensors, which would cause the vestibular organ to be more responsive to sound and pressure changes.
Sheykholeslami Kianoush; Schmerber Sebastien; Habiby Kermany Mohammad; Kaga Kimitaka
Hearing research
2004
2004-04
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/S0378-5955(04)00018-8" target="_blank" rel="noreferrer noopener">10.1016/S0378-5955(04)00018-8</a>