Tinnitus and acoustic neuromas: analysis of the effect of surgical excision on postoperative tinnitus.

In this retrospective review of the 160 acoustic neuroma cases treated at The University of Iowa between 1980 and 1991, follow-up information was obtained for 82% by telephone interview. Postoperative tinnitus was a symptom reported by 75% of the acoustic neuroma patients. Overall, among patients with tinnitus preoperatively, the condition postoperatively was absent in 45%, lessened in 17%, unchanged in 30%, and greater in 8%. Detailed results are compared to other series and significant differences in the depth of comparison described.

Diatrizoate and dextran treatment of sudden sensorineural hearing loss.

Many treatments have been proposed to manage sudden sensorineural hearing loss. The University of Iowa has used a protocol of intravenous radiopaque contrast and volume expander for the last 10 years in the treatment of sudden sensorineural hearing loss. A retrospective analysis of these cases was performed to review the efficacy of this treatment with respect to the natural history of the disease, as reported in previous studies. Sixty-four percent of 39 cases showed audiometric improvement in their pure-tone averages, speech reception thresholds, and speech discriminations while receiving treatment. Forty-eight percent of these showed improvement after their first treatment doses. Eighty percent of patients who presented more than 7 days after the onset of their hearing loss showed audiometric improvement with treatment, whereas 71 percent of patients presenting before 7 days showed audiometric improvement. However, the patients who presented earlier showed more marked improvement. Speech discrimination with the W-22 word list was a predictor of early recovery. Patients with measurable speech discrimination scores on presentation uniformly improved with treatment, even if their pure-tone average was profound. Our findings were suggestive of a pathophysiologic mechanism for some cases of sensorineural hearing loss for which intravenous contrast is efficacious. Although our findings were far from conclusive in this uncontrolled study, these initial results support the use of these agents in a rigorous clinical trial.

Indium 111-labeled white blood cell scintigraphy as an unreliable indicator of malignant external otitis resolution.

The field of otolaryngology-head and neck surgery has seen many advances in the treatment and prognosis of malignant external otitis (MEO). However, establishing the resolution of the infection remains problematic. A recent report suggests that indium 111-labeled white blood cell scintigraphy may be a reliable and timely indicator of resolution of infection. We present a case of a false-negative white blood cell scan in a patient with persistent MEO. A discussion of this case and a review of the literature illustrate that there continues to be no "gold standard" for establishing MEO resolution.

Mondini dysplasia and congenital cytomegalovirus infection.

We report a case of bilateral temporal bone anomalies in a child with symptomatic congenital cytomegalovirus infection and severe, bilateral sensorineural hearing loss identified at 3 months of age. High-resolution temporal bone computed tomography (HRCT) revealed bilateral findings of a short, malformed cochlea lacking an interscalar septum, a short and wide internal auditory canal, and an enlarged vestibular aqueduct, features diagnostic of bilateral Mondini dysplasia. To determine the importance of this observation, we completed HRCT in five additional children between 7 months and 9 years of age who had evidence of symptomatic congenital cytomegalovirus infection. One child with profound sensorineural hearing loss had severe bilateral temporal bone dysplasia with a small cochlea lacking an interscalar septum, an abnormal vestibule, and a large cochlear aqueduct. Of the remaining four children, hearing thresholds ranged from normal to profoundly decreased, but their HRCT scans were normal to visual inspection. When inner ear dimensions of these temporal bones were compared with norms established by Pappas and coworkers, however, seven of the eight ears had short cochleas and narrow lateral semicircular canals, and three ears had short or narrow vestibules. These results indicate that congenital cytomegalovirus infection may cause anomalies or growth disturbances of the temporal bone.

Lightning injury of the tympanic membrane.

A number of cases of otologic injuries by lighting strikes have been described in the otolaryngological literature. The mechanism of these injuries remains uncertain. We report 3 cases of lightning injury that presented to us. Analysis of these cases suggests that the mechanism of injury is direct conduction of electricity from the scalp to the soft tissues of the external auditory canal to the tympanic membrane. The conduits of the electrical surge are the subcutaneous blood vessels, smaller vessels being damaged more than larger vessels. Since the tympanic membrane central vessels are smaller than the canal vessels, the central area of the tympanic membrane would be most vulnerable, and this is seen clinically. A review of the literature supports this proposed mechanism of injury.

Disappearing recurrent acoustic neuroma in an elderly woman.

Acoustic neuromas have been shown to grow more slowly, if at all, in the elderly. Reduction of tumor size has been rarely reported in intracranial masses thought to be acoustic neuromas. We present a biopsy-proven acoustic neuroma that involuted completely during a 4-year period of surveillance. Possible mechanisms of involution are discussed.

Gustatory otorrhea: Frey's syndrome of the external auditory canal.

A case of Frey's syndrome of the external auditory canal is reported. The patient presented with unilateral gustatory otorrhea and thickened external auditory canal skin. Histopathologic examination of the canal skin showed sudomotor gland hyperplasia. Symptoms were relieved with canal skin excision and skin graft.

Early diagnosis of otologic Wegener's granulomatosis using the serologic marker C-ANCA.

Wegener's granulomatosis is a systemic vasculitis that may involve any organ system. Otologic manifestations are common, and can be the presenting complaint. In the past, diagnosis often necessitated the development of characteristic pulmonary or renal disease. The identification of a new serologic marker, cytoplasmic pattern antineutrophil cytoplasmic autoantibody (C-ANCA), allows for the early diagnosis of Wegener's granulomatosis and gives the patient the best chance for remission with cytotoxic therapy. We report two patients with Wegener's granulomatosis who presented with refractory otitis media, one of whom subsequently developed facial nerve paralysis, in which an early diagnosis was facilitated by the use of the C-ANCA test. Otologic manifestations of Wegener's granulomatosis and the basis of the C-ANCA test are discussed.

Syndrome of inappropriate secretion of arginine vasopressin in patients with cancer of the head and neck.

The syndrome of inappropriate secretion of arginine vasopressin (AVP) known as the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is associated with a variety of malignant and nonmalignant diseases. Only 17 cases of SIADH have been reported in the literature in association with cancer isolated to the head and neck. A retrospective review of 1,436 patients with head and neck malignancy excluding skin cancer through The University of Iowa Tumor Registry revealed 60 patients with the diagnosis of either SIADH or hyposmolality. A chart review for each of these patients was then done to establish the diagnosis of SIADH through relevant laboratory values and by excluding other causes of hyposmolality and hyponatremia. In 43 of these patients (3%), SIADH was found to be associated only with the cancer of the head and neck. We conclude that the incidence of SIADH in patients with cancer of the head and neck is much higher than previously recognized. As elevated serum AVP levels may not be clinically apparent unless associated with excessive water ingestation, it is possible that an even higher percentage of patients may have increased serum AVP levels.

Tube-perilymph fistula. An experimental study.

Before exploratory tympanotomy, it is difficult to diagnose an idiopathic perilymph fistula (PLF) because of its variable presentations. An animal model tube-PLF on guinea pigs was established to evaluate the change of the sensitivity of the cochlea function and the value of the postural audiometry in PLF. A fine polyethylene tube (O.D. 0.6mm) was inserted into the scala tympani of the basal turn through the incised round window membrane in 10 experimental guinea pigs, and another 5 as controls. The hearing threshold (HT), action potential (AP) latency for stimulus of 105 dB SPL, difference of HT and AP latency from the test ear down to up were measured by electrocochleography (ECoG) immediately after operation and one week later. The HT, AP latency and postural audiometry showed no significant changes immediately but a significant difference one week later in HT (P less than 0.01) and postural audiometry, the AP latency also presented a significant delay (P less than 0.01). The results showed that the tube-PLF model may be a valuable method for studying chronic PLF.

The effect of hyperbaric oxygen on growth of human squamous cell carcinoma xenografts.

Hyperbaric oxygen is an important adjunct to the treatment of patients with head and neck cancer with existing or recurrent wound healing problems. Anecdotal clinical observations and a recent study of chemically induced oral cancer in hamsters have raised concern that hyperbaric oxygen therapy may accelerate tumor growth in such patients. This study evaluated the effect of hyperbaric oxygen therapy on the growth of human squamous cell carcinoma xenografts in a proved animal model. Fresh tumor specimens from three patients with head and neck squamous cell carcinoma of varying degrees of differentiation were first subcutaneously transplanted into a nude mouse host. Growing xenografts were then transplanted into one of three mouse groups. Half of the mice in each group were given hyperbaric oxygen therapy. The transplant volume as an index of tumor growth was measured in controls and mice given hyperbaric oxygen therapy six times during the 3-week course. Xenograft growth was almost linear in all mice. No statistical difference in overall group mean growth rates was observed in mice given hyperbaric oxygen or control mice regardless of the degree of tumor differentiation. Xenograft tissue from all mice was microscopically examined for tumor mitotic indices and degree of differentiation. This study suggests that hyperbaric oxygen therapy has no effect on established tumor xenograft growth.

Monothermal differential caloric testing in patients with Menière's disease.

The monothermal differential caloric test allows determination of vestibular recruitment and decruitment, variables which may help discriminate peripheral from central vestibular lesions. Previous reports indicated a strong association between vestibular recruitment and Menière's disease. This study examined patients having unilateral Menière's disease. Nystagmus beat frequency (NBF) and slow-component velocity (SCV) responses were recorded by electronystagmography (ENG). Electronystagmographic findings showing unilateral dysfunction were present in 54% of patients by slow-component velocity and in 31% by nystagmus beat frequency. Unilateral hypofunction was the most frequent lateralizing ENG finding. Absolute vestibular recruitment occurred in less than 10% of patients but relative recruitment was found in nearly 20% of patients. Slow-component velocity had higher sensitivity than nystagmus beat frequency, with excellent clinical concordance. Monothermal caloric testing as described in this study best detects peripheral vestibular disease in Meniere's patients using slow-component velocity to determine unilateral hypofunction and relative vestibular recruitment.

Homograft tympanoplasty: the Iowa experience.

Homograft tympanic membranes have been used in tympanoplasty for nearly 30 years. Reported anatomical success rates vary from 50 to 100 percent. One hundred and one homograft tympanoplasty procedures were performed at the University of Iowa over the 10-year period of July 1978 through June 1988. The anatomical success rate was 76 percent. Hearing results were satisfactory in 86 percent of cases. The homograft tympanic membrane, with or without ossicles, has proven to be a highly satisfactory modality for the reconstruction of the severely ravaged middle ear.

The osteo-mucoperiosteal flap in repair of cerebrospinal fluid rhinorrhea: a 20-year experience.

Chronic cerebrospinal fluid rhinorrhea (present for 2 months or longer) is a serious condition frequently encountered by the otolaryngologist-head and neck surgeon. The purpose of this report is that it can be successfully repaired transsinally, from below, with a high rate of success. Intracranial repair has been associated with reportedly high morbidity and failure rates. From 1967 to 1987, 16 patients underwent repair of chronic cerebrospinal fluid rhinorrhea in the cribriform plate or fovea ethmoidalis at the University of Iowa with an osteomucoperiosteal flap. Follow-up data from 1.6 to 22 years demonstrated no recurrent leaks in this group of patients. Minimal morbidity and no deaths were associated with the osteomucoperiosteal flap. On the basis of our experience, we recommend this technique, which can be performed by any experienced paranasal sinus surgeon, as superior to craniotomy for the repair of chronic cerebrospinal fluid rhinorrhea from cribriform plate and fovea ethmoidalis defects.

Audiologic results following reimplantation of cochlear implants.

Five patients using cochlear implants experienced internal device failure 6 weeks to 4 years following implantation. All devices were removed and new electrodes inserted. Single-channel implants were replaced with multichannel systems in three patients, while the others received identical multichannel implants. The performance on a uniform battery of audiologic tests was the same or better with the second implant in all patients. Replacement of intracochlear electrodes did not induce clinically apparent degeneration of auditory performance in this series.

Phonosurgery: indications and pitfalls.

Twenty-five patients underwent type 1 thyroplasty (external medialization of abducted true vocal cord) during a 2-year period 1986 to 1988) at the University of Iowa. The most common indication for thyroplasty was post-thyroidectomy vocal cord paralysis. Eighteen patients (72%) had either a good or an excellent initial result. Five patients were revised. Postrevision, 21 patients (84%) had achieved either a good or an excellent result. Complications were limited to one case of significant vocal cord edema and another instance of vocal cord hemorrhage. No patient required a tracheotomy. No prosthesis extruded. We feel that phonosurgery has the advantages over traditional Teflon injection of allowing the patient's head to be in a neutral position during the operation; of allowing local anesthesia; of permitting a predictable, graduated end point of the procedure; and of being infinitely adjustable, with preservation of the vocal cord mucosal wave.