Profound Unilateral Sensorineural Hearing Loss Research Articles

Evolving applications in the use of bone-anchored hearing aids.

The bone-anchored hearing aid (BAHA) is an effective means of intervention, its use being well documented in persons with chronic conductive pathology and congenital aural anomalies. This article describes the standard guidelines (both auditory and extraauditory aspects) for patient selection and expands the criteria to include bilateral BAHA implantation, unilateral conductive hearing loss, and unilateral profound sensorineural hearing loss. The BAHA's development, design features, and patient outcomes are also reviewed. Suggestions are presented for fitting, counseling, and following BAHA users.

Preserved otoacoustic emission in a child with a profound unilateral sensorineural hearing loss

We report a case of profound unilateral sensorineural hearing loss with good response of otoacoustic emission. The patient was a 5-year-old boy, who was diagnosed to have unilateral hearing impairment on pure tone audiometry at the first visit. The affected ear showed the absence of auditory brainstem response; however, its transiently evoked otoacoutic emission and distortion product otoacoustic emission were considered to be normal. These findings indicated that the outer hair cell of cochlea was not impaired and that the impairment should be localized between inner hair cells, primary afferent fiber or its synapses, spiral ganglion of the cochlea and acoustic fiber, or at a combination of these areas. That is, evaluation of otoacoustic emission was useful in determining the region of impairment in sensorineural hearing loss. Further follow-up will be necessary to differentiate the present case from auditory neuropathy.

小児感音難聴の進行性 特に一側聾の反対側聴力について

小児感音難聴の進行性 特に一側聾の反対側聴力について

Auditory cortical responses in humans with profound unilateral sensorineural hearing loss from early childhood

We recorded auditory evoked magnetic fields from five patients with profound unilateral sensorineural hearing loss from early childhood, using a 122-channel whole-scalp neuromagnetometer. The stimuli were 50-ms 1-kHz tone bursts delivered to the healthy ear at interstimulus intervals (ISI) of 1, 2, and 4 s. As the normal-hearing controls, four patients had shorter latencies of N100m, the 100-ms response, over the hemisphere contralateral to the stimulation than over the ipsilateral hemisphere. With 1-s ISI, three patients had, instead of N100m, a deflection of opposite polarity at about 100 ms (P100m) after the stimulus onset. A 10-year-old patient had a prominent P100m response, did not produce a clear N100m at any ISI, but had a clear N50m at the 4-s ISI. Four patients had bilateral N200m deflections peaking about 200 ms after the stimulus onset; the fifth patient showed N200m over the right hemisphere. N200m was also observed in the three youngest controls in both hemispheres. The ISI dependence of NI00m amplitude and latency was similar in controls and patients. The amplitudes and latencies of N200m did not show any ISI dependence. In patients, the appearance of P100m-N200m deflections of auditory evoked fields, normally present in children, is more pronounced than in controls. The defect apparently delays the development of N100m, possibly by interfering with function of callosal connections.

Unilateral Sensorineural Hearing Loss Rehabilitation

The Audiant Bone Conductor has been heralded as an aid for use in conductive hearing loss; however, its possible use in unilateral sensorineural hearing loss (SNHL) has also been proposed. Between July 1987 and July 1989, profound unilateral sensorineural hearing loss has been rehabilitated in 43 patients using the Xomed Audiant Bone Conductor. Patients who were willing to participate in this clinical trial and who were felt to be good contralateral routing of signals (CROS) aid candidates were selected preoperatively. Audiometric followup, selection criteria, patient satisfaction, and complications are discussed.

Hearing loss due to mumps.

The possibility of mumps was considered in 33 children with profound unilateral sensorineural hearing loss of unknown origin. Fifteen gave a history of mumps, of whom 12 contracted the infection between the last normal and first abnormal hearing tests. Hearing should be tested after mumps infection.

The vestibular aqueduct syndrome: Computed tomographic appearance

We have recently examined three young patients with congenital unilateral profound sensorineural hearing loss. On computed tomography the only abnormality discovered was a remarkably enlarged vestibular aqueduct on the abnormal side. The vestibular aqueduct syndrome is an important cause of congenital hearing loss. Although this finding has been well illustrated with conventional multidirectional tomography, there has been little emphasis on the computed tomographic appearance.