Cochlear schwannomas.

Schwannomas arising solely from the cochlear nerve and limited to the internal auditory canal are rare. Only three prior cases have been specifically described in the literature. We report a 38-year-old male with and asymmetric audiogram and poor discrimination. Magnetic resonance imaging revealed a 3-mm mass occupying the inferior portion of the internal auditory canal. Discrimination improved following a course of steroids, but thresholds did not. The patient underwent a translabyrinthine removal of the tumor, which was confirmed to involve only the cochlear nerve. It is important to obtain evidence regarding the possibility that a tumor confined to the internal auditory canal is a cochlear schwannoma. If so, surgery can be deferred until hearing is no longer functional or tumor growth mandates removal.

Bone cement reconstruction of the ossicular chain: a preliminary report.

OBJECTIVE: To determine the feasibility and efficacy of using a bone cement, Oto-Cem, to reconstruct the ossicular chain. STUDY DESIGN: Prospective clinical trial on nine consecutively chosen adult patients with ossicular chain defects. PATIENTS AND SETTING: Nine patients with ossicular chain defects involving the long process of the incus were treated at the Carolina Ear and Hearing Clinic. The ossicular chain was reconstructed using bone cement by itself or in conjunction with a stapes prosthesis. MAIN OUTCOME MEASURES: Preoperative audiograms were compared with audiograms 3, 6, and 12 months after reconstruction. RESULTS: There was a mean pure-tone average (PTA) improvement of 15 dB in patients undergoing incus to stapes suprastructure reconstruction with the bone cement. The incus to mobile footplate reconstruction (using a stapes prosthesis attached to the newly reconstructed incus) resulted in a 34-dB PTA postoperative improvement. Two of the three patients with incus to oval window repairs experienced a 10-dB improvement in PTA. One of the three patients experienced a loss in speech discrimination and a 2-dB loss in PTA. CONCLUSIONS: Despite the limited number of patients, this preliminary study demonstrates the effectiveness of Oto-Cem in reconstructing a foreshortened incus. There was a substantial hearing improvement in all but one patient in the incus to stapes or the incus to footplate categories.

Needle placement with transtympanic electrocochleography.

Electrocochleography (ECoG) is an objective, electrophysiologic test useful in the clinical diagnosis of endolymphatic hydrops, or Meniere's disease. The purpose of this study was to determine if the position of the needle, using transtympanic methodology, gives a variable SP/AP (summating potential/action potential) response. SP/AP ratios were obtained during routine tympanoplasty procedures. After the tympanic membrane remnant was removed using a lateral graft technique, precise needle placement was obtained at the medial and lateral round window niches, as well as on the promontory. SP/AP ratios were obtained in these three needle positions. There was no significant difference in the SP/AP ratio responses despite the location of needle placement. The use of transtympanic electrocochleography can give very good wave form morphology and consistent results. Therefore, if elevated SP/AP ratios do occur, they are thought to be due to a pathologic process of the ear and not needle placement.

Electrocochleography in retrosigmoid vestibular nerve section for intractable vertigo caused by Menière's disease.

Interest in electrocochleography has increased in recent years because of the discovery of an elevated summating potential to action potential amplitude ratio (SP/AP ratio) in patients with endolymphatic hydrops caused by Menière's disease or perilymph fistula. It was the purpose of this investigation to determine whether the intraoperative SP/AP ratio will decrease after vestibular nerve section in patients with intractable Meniere's disease. Fourteen patients with medically intractable classic Menière's disease underwent retrosigmoid vestibular nerve section. Intraoperative transtympanic electrocochleography was performed with alternating click stimuli presented at 95 dB HL. In all patients the SP/AP ratio was recorded before the skin incision ("baseline" condition) and after the dura was closed ("closing" condition). Statistical analysis was applied to the recorded data. In 11 (79%) patients, the SP/AP ratio was found to be elevated above 0.30 in the baseline state. In 13 (93%) patients, the SP/AP ratio decreased more than 25% after the nerve was sectioned. These results were highly statistically significant (p < 0.001). We conclude that the SP/AP ratio does decrease in patients with Menière's disease after undergoing retrosigmoid vestibular nerve section and offer a possible explanation.

Work-related, noise-induced hearing loss: evaluation including evoked potential audiometry.

This article reviews the evaluation of 246 workers (492 ears) who underwent otologic and audiologic testing as part of a worker's compensation claim for work-related, noise-induced hearing loss. Tinnitus was present in 58% of the patients, but was rarely a major symptom. Other otologic symptoms or a history of ear disease were virtually nonexistent. Standard audiometry showed a downsloping, high-frequency sensorineural hearing loss in 85% of the ears tested, with only 37% having a characteristic "noise notch" at 4000 or 6000 hertz. Asymmetric hearing loss was not uncommon, with 48 patients (20%) undergoing magnetic resonance scanning, all of whom showed no central lesion responsible for the loss. Proven malingering was surprisingly uncommon (9%). In this study, evoked response audiometry was a valuable adjunct to confirm behavioral thresholds in the evaluation of possible work-related, noise-induced hearing loss. The middle latency response was more effective than the auditory brainstem response as a result of the high-frequency steepness of the audiometric curve.

Use of surgery and postoperative radiation in the treatment of advanced squamous cell carcinoma of the pyriform sinus.

Forty-seven patients with very advanced cancer of the pyriform sinus were treated with surgery and immediate postoperative radiation in a planned sequential manner. Eradication of the cancer above the clavicles was obtained in 81% of the patients, with a treatment mortality of 8%. Most of the patients' tumors were resected with primary closure, which obviated the need for complicated reconstructive procedures. The survival rate of 23% at 2 years and the high rate of distant metastasis reflect the aggressive biologic behavior of this cancer. The need to find an adjuvant treatment that will act upon the systemic spread of this cancer is obvious.

Fibroblast implantation enhances wound healing as indicated by breaking strength determinations.

Irradiation of normal tissues at the dose/time factor employed in the treatment of solid tumors impairs the subsequent healing of surgical wounds made in those tissues. Irreversible radiation damage to regional fibroblasts is one cause of impaired healing. This study was conducted to determine whether syngeneic guinea pig fibroblasts, harvested from tissue culture when injected into irradiated guinea pig skin at the time of wound closure, could improve wound healing. Breaking strength determinations indicate that irradiated wounds demonstrate enhanced wound healing if implanted with fibroblasts.