Unilateral Conductive Loss Research Articles

Audiologic and Surgical Outcomes of a Novel, Nonpercutaneous, Bone Conducting Hearing Implant

To assess the selection criteria, surgical technique, audiologic, and quality of life outcomes for a novel, nonpercutaneous bone conductor hearing aid. Retrospective case review. Secondary otology practice. Eighteen patients (16 adults and 2 children). Implantation of unilateral (n = 16) or bilateral (n = 2) devices. Mean preoperative and postoperative air conduction and bone conduction free-field testing, BKB-SIN aided and unaided at 0-degree 70 dB SPL, Speech, Spatial, and Qualities of Hearing Scale (SSQ), aided and unaided measures of localization and discrimination in single-sided deafness (SSD), surgical complications. Implants have been fixed under general or local anesthesia without perioperative complications. Two patients noted minor skin irritation only. Audiologic gain was greatest for those with bilateral conductive loss (21.9 ± 10.4 dB HL). For those with bilateral and unilateral mixed loss, gain was 6.2 ± 5.3 dB HL and 5.5 ± 6.5 dB HL, respectively. A greater improvement was seen with BKB-SIN at 70 dB SPL at 0 with all groups except for SSD, gaining statistically significant benefit. Localization and discrimination studies in patients with SSD or unilateral conductive loss failed to detect benefit from aiding. SSQ scores show an improvement in all domains for each patient group. The surgical procedure requires no specialized equipment and can be performed as a day case. This device complements treatment for patients requiring bone conduction aids and presents as an alternative to conventional percutaneous bone-anchored implants.

Conventional behind-the-ear hearing aids after subtotal petrosectomy with blind sac closure

To overcome the limitations of monaural hearing resulting from a subtotal petrosectomy and blind sac closure by fitting of a behind-the-ear hearing aid. Three patients were fitted with aids. Patient satisfaction and the decision to buy the aids were recorded. Three patients reported good hearing result despite the absence of the middle ear structures. For patients troubled by the limitations imposed on hearing with a unilateral conductive loss following a subtotal petrosectomy and blind sac closure, a behind-the-ear aid is a simple and easy option to try, if the residual canal allows fitting of the aid.

Management of otosclerosis in the UK.

The last 30 years has seen a gradual change in the management of otosclerosis. The aim of this study is to evaluate the current practice among British otolaryngology consultants using a questionnaire, and to compare it with the practice reported in a survey 8 years ago. A total of 353 valid responses (64.5%) were available for analysis. The overall trend is towards centralization, with a reduction in the number of surgeons undertaking stapes surgery (49.9%). The majority of consultants (81.3%) who undertake stapes surgery would operate for a unilateral conductive loss and 75.1% would undertake bilateral stapes surgery. Stapedotomy is the operation of choice (82%), with a few consultants performing partial or rarely total stapedectomies. Postoperative restrictions and follow-up times vary widely amongst surgeons, with the senior surgeons tending to be more conservative than the younger consultants.

Neuro-otological profile of Episodic Vertigo

Episodic Vertigo Comprises a large group of patients seen in any neurootology unit. A total of 118 subjects were reviewed who attended the neurootology unit. Vertigo of shorter duration was noted in 78 and of longer duration in 40 cases. 51 cases showed bilateral neurosensory deafness, 15 cases had bilateral and another one case had unilateral conductive loss. Spinovestibular tests were abnormal in all cases of vertigo of short duration but only 29 cases showed abnormal reflex in patients with a long duration of illness. Thermal vestibulometry revealed hyporeflexia in 33 cases, directional preponderance in 30 cases and 4 cases showed hyperreflexia 28 cases had peripheral lesions while 81 cases had central lesions. The acute cases showed significant improvement on follow up except cases with abnormality in thermal vestibulometry . The cases with positional nystagmus showed improvement with head and body balance exercises expect in those who received treatment with vestibulosedative and vestibular suppersive drugs. Hearing loss remained the same except in patients with middle ear disorders.

Auditory neuronal sizes after a unilateral conductive hearing loss

The left external auditory meatus was removed in 4-day-old CBA J mice; after killing at 45 days, serial sections of the cochleae and brain stem were prepared. From these, the cross-sectional areas of spiral ganglion neurons and of 14 auditory brain stem neuronal types were measured, using a total of 210 neurons of each of the 15 types from both the right and left sides. Nine neuronal types were significantly ( P < 0.01) on the left side: spiral ganglion neurons; globular, small spherical, large spherical, octopus, multipolar, and granule cells of the ventral cochlear nucleus; Purkinje-like cells of the dorsal cochlear nucleus; and spindle cells of the lateral superior olivary nucleus. Two neuronal types were significantly smaller ( P < 0.01) on the right: principal cells of the medial nucleus of the trapezoid body (superior olivary complex), and spindle-shape principal neurons of the central nucleus of the inferior colliculus. The left ventral cochlear nucleus had significantly smaller volume ( P < 0.01) than the right but right and left dorsal cochlear nuclear volumes did not differ significantly ( P > 0.05). Right and left sides were not significantly different ( P > 0.05) for the following neuronal types: fusiform cells and coarse- and fine-Nissl deep cells of the dorsal cochlear nucleus, and rostral bipolar cells of the medial superior olivary nucleus. Neurons affected by unilateral conductive loss were not significantly different ( P > 0.05) from the same cells in mice with bilateral conductive losses; neurons not affected by unilateral conductive loss were not significantly diferent ( P > 0.05) from the same cells in normal mice.

Audiometric Weber and Rinne test as compared pure-tone thresholds

Results of the audiometric Weber and Rinne tests were compared to pure tone thresholds in 185 Bantu patients. The frequency of 1000 Hz was selected as being most suitable for Weber and Rinne testing. The Weber was found to be of limited diagnostic value even with unilateral conductive losses whilst the Rinne displays a fair degree of efficiency and is of value as a routine supplement to audiometric threshold tests.

Studies in impedance audiometry. 3. Middle ear disorders.

Results of impedance audiometry were analyzed in 454 consecutive patients with conductive hearing loss. Completely successful results were obtained on 428 patients (94%). Tympanometry results indicated that type A patterns were usually associated with otosclerosis or other ossicular chain fixations and type B and C patterns were usually found in otitis media. Maximum static compliance values had only limited diagnostic value due to overlap between conductive and normal groups. Stapedial reflex could not be elicited in most patients. When reflexes were observed in otosclerotic ears, an unusual pattern characterized by negative deflections at onset and termination of a sound appeared. In a subgroup of 154 patients with unilateral conductive loss, results showed that amount of AC-BC gap necessary to abolish stapedial reflex was approximately 25 dB with sound in bad ear and approximately 5 dB with probe-tip in bad ear.