Effect of BAEP monitoring on hearing preservation during acoustic neuroma resection.

We measured the effect of brainstem auditory evoked potential (BAEP) monitoring on hearing preservation in acoustic neuroma resection in 90 consecutive patients with monitoring compared with 90 historical controls matched for tumor size and preoperative hearing status. In small tumors (less than 2 cm), BAEP monitoring was associated with a higher rate of hearing preservation and a greater chance that the hearing preserved was clinically useful. Changes in the BAEP intraoperatively showed a good correlation with postoperative hearing status.

Stereotactic radiosurgery using the gamma knife for acoustic neuromas.

PURPOSE: To assess the efficacy and toxicity of stereotactic radiosurgery using the gamma knife for acoustic neuromas. METHODS AND MATERIALS: Between January 1990 and January 1993, 36 patients with acoustic neuromas were treated with stereotactic radiosurgery using the gamma knife. The median maximum tumor diameter was 21 mm (range: 6-32 mm). Tumor volumes encompassed within the prescribed isodose line varied from 266 to 8,667 mm3 (median: 3,135 mm3). Tumors < or = 20 mm in maximum diameter received a dose of 20 Gy to the margin, tumors between 21 and 30 mm received 18 Gy, and tumors > 30 mm received 16 Gy. The dose was prescribed to the 50% isodose line in 31 patients and to the 45%, 55%, 60%, 70%, and 80% isodose line in one patient each. The median number of isocenters per tumor was 5 (range: 1-12). RESULTS: At a median follow-up of 16 months (range: 2.5-36 months), all patients were alive. Thirty-five patients had follow-up imaging studies. Nine tumors (26%) were smaller, and 26 tumors (74%) were unchanged. No tumor had progressed. The 1- and 2-year actuarial incidences of facial neuropathy were 52.2% and 66.5%, respectively. The 1- and 2-year actuarial incidences of trigeminal neuropathy were 33.7% and 58.9%, respectively. The 1- and 2-year actuarial incidence of facial or trigeminal neuropathy (or both) was 60.8% and 81.7%, respectively. Multivariate analysis revealed that the following were associated with the time of onset or worsening of facial weakness or trigeminal neuropathy: (a) patients < age 65 years, (b) dose to the tumor margin, (c) maximum tumor diameter > or = 21 mm, (d) use of the 18 mm collimator, and (e) use of > five isocenters. The 1- and 2-year actuarial rates of preservation of useful hearing (Gardner-Robertson class I or II) were 100% and 41.7% +/- 17.3, respectively. CONCLUSION: Stereotactic radiosurgery using the gamma knife provides short-term control of acoustic neuromas when a dose of 16 to 20 Gy to the tumor margin is used. Preservation of useful hearing can be accomplished in a significant proportion of patients.

Usher's syndrome with unusual otologic manifestations.

Usher's syndrome is characterized by a congenital hearing loss and retinitis pigmentosa. Ocular symptoms and signs are usually established at adolescence, and the hearing loss, the onset of which is at a young age, generally remains stable. The following case is of interest, therefore, because the hearing loss that had been present since birth progressed suddenly to total bilateral deafness in adulthood. There were no ocular symptoms at any time; the classic findings of retinitis pigmentosa were disclosed only on routine examination of the eyes.

Improved preservation of facial nerve function with use of electrical monitoring during removal of acoustic neuromas.

Continuous spontaneous electromyographic activity and responses to electrical stimulation of the facial nerve in the surgical field were monitored in 48 patients undergoing primary removal of an acoustic neuroma. The operative and postoperative results in these patients were compared with the results in 48 patients who were matched for age and size of tumor and who underwent the same surgical procedure without intraoperative monitoring. Eighty-three percent of the patients had preoperative evidence of facial neuropathy, which was more severe with larger tumors. Postoperative facial nerve function was most accurately predicted on the basis of the extent of facial neuropathy on preoperative electrophysiologic testing. Anatomic preservation of the facial nerve in patients with large tumors was substantially improved in the monitored patients (67%) in comparison with those without monitoring (33%). No difference was noted in facial nerve function in the two groups of patients immediately postoperatively. By 3 months, the degree of improvement in the monitored group exceeded that in those who were not monitored, particularly in patients with medium-sized and large tumors.

Childhood sinusitis.

Childhood sinusitis is difficult to diagnose. It is classified on the basis of duration of inflammation--acute or chronic--and cause of inflammation--infectious or noninfectious. Infectious sinusitis is often a result of obstruction of the osteomeatal complex. Inflammation in noninfectious sinusitis is similar to the inflammatory changes detected in respiratory mucosa of patients with asthma. Acute sinusitis is primarily an infectious process similar to a prolonged infection of the upper respiratory tract. Plain radiography has limited value for the diagnosis of acute sinusitis in children. The most effective treatment of acute sinusitis is administration of a beta-lactamase-resistant antibiotic. Chronic sinusitis may be infectious, noninfectious, or both. Coronal computed tomography of the sinuses and nasal endoscopy are the preferred methods for determining the presence of chronic sinusitis. When physicians prescribe therapy for chronic sinusitis, they need to consider whether the underlying cause is infectious, noninfectious, or both. Treatment of chronic infectious sinusitis is most effective when a beta-lactamase-resistant antibiotic is administered. Chronic noninfectious sinusitis may respond to topically intranasally applied corticosteroids. If medical treatment fails to resolve the disease within 3 months, surgical intervention may be necessary. Finally, although an association between asthma and sinusitis exists, a cause-and-effect relationship has not been established.

The canalith repositioning procedure for the treatment of benign paroxysmal positional vertigo: a randomized controlled trial.

OBJECTIVE: To compare the canalith repositioning procedure (CRP) with a sham maneuver for the treatment of benign paroxysmal positional vertigo. PATIENTS AND METHODS: We recruited 50 patients with a history of positional vertigo and unilateral positional nystagmus on physical examination (Dix-Hallpike maneuver). Patients were randomized to either the CRP (n = 24) or a sham maneuver (n = 26). Measured outcomes included resolution of vertigo and positional nystagmus at follow-up examination. RESULTS: The mean duration of follow-up was 10 days for both groups. Resolution of symptoms was reported by 12 (50%) of the 24 patients in the CRP group and by 5 (19%) of the 26 patients in the sham group (P = .02). The results of the Dix-Hallpike maneuver were negative for positional nystagmus in 16 (67%) of 24 patients in the CRP group and in 10 (38%) of 26 patients in the sham group (P = .046). CONCLUSION: The CRP is effective treatment of benign paroxysmal positional vertigo, and this procedure can be performed by general internists on outpatients with this disorder.

Predictors of response to transantral orbital decompression in severe Graves' ophthalmopathy.

OBJECTIVE: To identify factors that may help predict the outcome after transantral orbital decompression in Graves' ophthalmopathy. DESIGN: A retrospective study was conducted of 428 patients who had undergone an initial transantral orbital decompression for severe Graves' ophthalmopathy at the Mayo Clinic between November 1969 and May 1989. MATERIAL AND METHODS: With use of logistic regression analysis, we assessed the preoperative characteristics, the early postoperative results, and the follow-up questionnaire data (obtained a median of 9.5 years postoperatively) from 304 female and 124 male patients with Graves' ophthalmopathy who had undergone transantral orbital decompression at a median age of 53 years. RESULTS: On multivariate stepwise regression analysis, young age, male sex, and long duration of eye symptoms were predictors of severe initial proptosis (P < 0.001). The only independent predictors of greater postoperative recession of proptosis were severity of initial proptosis and longer interval between operation and postoperative examination (P < 0.001). Patients with the most reduction of proptosis had the greatest improvement in visual acuity but more chance for postoperative development of continuous diplopia. Failure of prior corticosteroid or orbital radiation therapy did not affect the degree of recession of proptosis or improvement in visual acuity. On multivariate analysis for predictors of long-term overall patient satisfaction, only young age of the patient was of borderline significance (P = 0.05), and the only significant predictor of satisfaction with the postoperative eye appearance was an operation done primarily for cosmetic purposes (P = 0.012). CONCLUSION: Although various factors may influence the outcome of orbital decompression in patients with Graves' ophthalmopathy, this study showed that the more pronounced the initial proptosis, the greater the degree of recession postoperatively. A higher degree of reduction of proptosis is associated with better visual acuity but also a greater likelihood of development of continuous diplopia.

Benign positional vertigo: incidence and prognosis in a population-based study in Olmsted County, Minnesota.

A retrospective review of our population-based medical records linkage system for residents of Olmsted County, Minnesota, revealed 53 patients (34 women and 19 men; mean age, 51 years) with newly diagnosed benign positional vertigo in 1984. The age- and sex-adjusted incidence was 64 per 100,000 population per year (95% confidence interval, 46 to 81 per 100,000). The incidence of benign positional vertigo increased by 38% with each decade of life (95% confidence interval, 23 to 54%). One patient had an initial stroke during follow-up; thus, the relative risk for new stroke associated with benign positional vertigo was 1.62 (95% confidence interval, 0.04 to 8.98) in comparison with the expected occurrence based on incidence rates for an age- and sex-adjusted control population. The observed survival among the 53 Olmsted County residents with benign positional vertigo diagnosed in 1984 was not significantly different from that of an age- and sex-matched general population. Patients with benign positional vertigo seem to have a good prognosis.

Results of transantral orbital decompression in 428 patients with severe Graves' ophthalmopathy.

We reviewed records from 428 consecutive patients with severe Graves' ophthalmopathy to determine early and late results after transantral orbital decompression. Optic neuropathy was present in 217 (50.7%) patients. Post-operatively, 402 (89%) of 453 eyes with preoperative visual acuity worse than 20/20 improved or remained the same. Visual field scotomas improved or resolved in 245 (91%) of 269 eyes tested pre- and postoperatively. Preoperative papilledema resolved or improved in 99 (94%) of 105 eyes, and preoperative exposure keratitis improved or resolved in 178 (92%) of 195 eyes. Average proptosis reduction was 4.7 mm. Postoperatively, new diplopia developed in 74 (64%) of 116 patients who had no diplopia before orbital decompression, although 300 patients ultimately had strabismus surgery. At late follow-up (N = 293 patients), 226 (77%) had single vision and 44 (15%) had correction with prism. Complications included sinusitis (18 patients), lower eyelid entropion (38 patients), numb lip (23 patients), cerebrospinal fluid leaks (15 patients), and one frontal lobe hematoma (one patient). The average duration of follow-up was 8.7 years. Transantral orbital decompression effectively reduces proptosis and usually corrects optic neuropathy. In other circumstances, the benefits achieved and the side effects incurred must be carefully balanced for each patient before transantral orbital decompression is considered.

Impact of cranioplasty on headache after acoustic neuroma removal.

We reported previously the incidence of headache after the retrosigmoid removal of an acoustic neuroma as 23% at 3 months, declining to 9% at 2 years after surgery. In an attempt to reduce the incidence and the severity of these headaches, we made one change in our surgical procedure, which was to perform a cranioplasty with methyl methacrylate. Twenty-four patients underwent the cranioplasty and were followed for at least 3 months postoperatively. These patients were matched to 24 patients who did not undergo a cranioplasty. We found a 4% incidence of headache in the cranioplasty group and a 17% incidence in the matched group. No complications were related to this change in our procedure.

Conservative management of acoustic neuroma: an outcome study.

OBJECTIVE: This study analyzed selection criteria, clinical outcome, and tumor growth rates in patients with acoustic neuromas in whom the initial management strategy was observation. METHODS: A retrospective review of patients with conservatively managed unilateral acoustic neuromas was conducted. Minimum follow-up was 6 months. Patients with neurofibromatosis Type II were excluded. Differences in tumor growth rates were analyzed by use of the Wilcoxon rank sum test. RESULTS: Sixty-eight patients (31 men and 37 women) with a mean age of 67.1 years were followed for an average of 3.4 years after diagnosis. The reasons for a trial of observation included advanced age (55%), patient preference (21%), minimal symptoms (9%), poor general medical condition (7%), asymptomatic tumor (4%), and tumor in the only hearing ear (4%). Fifty-eight patients (85%) were successfully managed with observation alone. Ten patients (15%) ultimately required treatment (nine received microsurgical treatment and one patient underwent radiosurgical intervention) at a mean time interval of 4.0 years after diagnosis. Forty-eight tumors (71%) showed no growth and 20 (29%) enlarged during the study period. The mean tumor growth rate at the 1-year follow-up was significantly higher in the group requiring treatment (3.0 mm) than in the group not requiring treatment (0.36 mm) (P < 0.0001). Thus, the tumor growth rate at the 1-year follow-up was a strong predictor of the eventual need for treatment. CONCLUSION: Observation is a reasonable management strategy in carefully selected patients with acoustic neuromas. Diligent follow-up with serial magnetic resonance imaging is recommended, because some tumors will enlarge to the point at which active treatment is required.

Current results of the retrosigmoid approach to acoustic neurinoma.

Since 1984 when cranial nerve monitoring became routinely performed at the Mayo Clinic, 255 patients have undergone 256 procedures using the retrosigmoid approach for the removal of acoustic neurinomas. Of these, 221 patients had some hearing before surgery and 52 maintained hearing following surgery. The anatomical continuity of the facial nerve was preserved in 237 of these 256 procedures. It was possible to perform a primary end-to-end anastomosis in seven of the remaining 19 patients, and one patient had a cable graft inserted. Thus, 95.7% of these patients were believed to have potential for spontaneous facial nerve function. Of the 11 patients in whom this was not possible, seven underwent early spinal accessory facial anastomosis, in two hypoglossal-facial anastomosis was performed, and two had no facial nerve procedures and have paralysis of the facial nerve. There were two deaths from a pulmonary embolus in the early postoperative period, both 4 days following otherwise uneventful surgery. The most common postoperative complication was cerebrospinal fluid leakage, which has not resulted in significant permanent morbidity although early repair for this problem is now routinely recommended. Other complications were quite rare and have generally not resulted in any major change in patient lifestyle or activity level. This review reconfirms that the retrosigmoid surgical treatment of acoustic tumors continues to be an acceptable treatment option.

Residual and recurrent acoustic neuromas.

A retrospective study was conducted on all 23 patients who underwent operation for residual or recurrent acoustic neuromas during the 10-year period January 1976 through December 1985. The most common symptoms at the time of reoperation were ataxia (16 patients), facial paresthesias (13 patients), and headaches (9 patients). Primary procedures had consisted of suboccipital posterior fossa approaches in 22 patients and a middle fossa approach in one. Reoperation for recurrent or residual tumor consisted of a retrosigmoid approach in 17 patients and a translabyrinthine or translabyrinthine/retrosigmoid approach in six patients. This study confirms that residual or recurrent acoustic tumors are not common. It also suggests that long-term follow-up, for at least 7 to 8 years, is indicated.

Intraoperative monitoring of the facial nerve.

Anatomic preservation of the facial nerve, with maximal facial function, is one of the goals of acoustic neuroma surgery. Application of electrophysiologic monitoring techniques is useful in achieving this goal. Preoperative electromyography and nerve conduction studies provide important prognostic information for preservation of the nerve and postoperative function. Intraoperative electromyography alerts the surgeon to facial nerve proximity and potential injury. Direct nerve stimulation is utilized to confirm the location and integrity of the nerve. Matched-pair analysis of two groups of patients demonstrated an increased ability to preserve the facial nerve with less postoperative facial deformity.

Low-dose intratympanic gentamicin and the treatment of Meniere's disease: preliminary results.

The most disabling symptom for most patients with unilateral Meniere's disease is vertigo. Eradication of the diseased end organ is effective in eliminating the vertigo. Labyrinthectomy remains the "gold standard"; unfortunately, residual hearing is sacrificed to obtain this end. The purpose of this study is to evaluate low-dose intratympanic gentamicin for the control of vertigo and for the preservation of hearing. A single dose of gentamicin (10-80 mg) was injected into the middle ear space of 23 patients with unilateral Meniere's disease as an office procedure. Eighty-four percent of the patients had no episodes of vertigo during the last 6 months of follow-up. Pure tone average and word discrimination scores were unchanged as a group. Ninety-five percent of patients had a hearing loss at 6 and 8 kHz that averaged 7.5 dB. Caloric function was reduced in 93%. Low-dose intratympanic gentamicin is a safe, simple, office procedure that is effective in controlling the definitive vertiginous episodes in most patients with unilateral Meniere's disease. Control of vertigo can be obtained with preservation of hearing.

Transtympanic gentamicin for Meniere's syndrome.

OBJECTIVES: Study the impact of transtympanic gentamicin on patients with unilateral Meniere's syndrome. Partial chemical labyrinthectomy is a relatively recent concept for the treatment of Meniere's syndrome. It uses the ototoxic effect of gentamicin to reduce the symptom of vertigo and maintain cochlear function. STUDY DESIGN: A prospective study using transtympanic gentamicin was begun in January 1994. Patients selected had failed medical therapy, but were not incapacitated. Patients had preinjection audiometric and electronystagmography data. Most had an imaging study. All had one injection, about half had more than one. Patients were seen 1 month after therapy and repeat studies were obtained. Repeat injection was performed if indicated. Follow-up from the chart or by telephone was obtained. Data were tabulated using the 1995 American Academy of Otologaryngology-Head and Neck Surgery guidelines. RESULTS: Through December 1996 43 patients with unilateral Meniere's syndrome were treated. The pretherapy function level was 3 through 5. After therapy the function level was 1 or 2. There was almost no change in cochlear function and no patient became deaf. Many patients had mild ataxia or dysequilibrium during the first 2 weeks following therapy. Most patients showed some decrease in labyrinthine function measured on electronystagmography. No attempt was made to ablate labyrinthine function. Seventeen of 18 patients had a vertigo index in the class A or B category after 2 years. CONCLUSIONS: Transtympanic gentamicin has become the treatment of choice for patients who fail medical therapy for Meniere's syndrome at the authors' institution.

Acoustic schwannoma and pregnancy: a DNA flow cytometric, steroid hormone receptor, and proliferation marker study.

For a long time, it has been speculated that pregnancy stimulates the growth of acoustic schwannomas. To test this hypothesis, immunohistochemical stains for estrogen receptor, progesterone receptor, and proliferating cell nuclear antigen (PCNA) were performed. Flow cytometric studies for DNA ploidy and S-phase fraction determinations were also performed. The study subjects included 6 female patients with unilateral acoustic tumors; at the time of tumor removal, 1 woman was pregnant and the other 5 women were 2 to 10 months postpartum. The age-sex-matched control group consisted of 6 men and 12 nonpregnant women, all with acoustic schwannomas similar in size to those of the study group. The study found no statistically significant association between the presence or quantity of estrogen or progesterone receptors and pregnancy, DNA ploidy, proliferation indices, or clinical data. Based on PCNA indices, large tumors tended to be less "biologically active" than small lesions (P < .01). The authors concluded that pregnancy does not significantly stimulate the cellular growth of acoustic schwannomas.

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.

Auditory monitoring during acoustic neuroma removal.

Preservation of hearing has become attainable for patients with small acoustic neuromas. Brain-stem auditory evoked response was monitored intraoperatively in 60 patients undergoing acoustic neuroma surgery via the posterior fossa approach. The overall rate of hearing preservation was 30% in the monitored group and 20% in 60 patients who were matched for tumor size and preoperative hearing level and underwent the same surgical procedure but without intraoperative brain-stem auditory evoked response monitoring. The rate of hearing preservation was correlated with tumor size: with tumors less than or equal to 1 cm, hearing was preserved in 82% of monitored and 36% of unmonitored patients; hearing was not preserved with tumors larger than 3 cm. Intraoperative brain-stem auditory evoked response monitoring appears to have improved the preservation of hearing during removal of small tumors.

Evaluation of posttonsillectomy hemorrhage and risk factors.

BACKGROUND: A 13-year retrospective study was undertaken to determine the incidence of posttonsillectomy hemorrhage, to evaluate potential risk factors, and to assess the efficacy and safety of ambulatory tonsillectomy. METHODS: From January 1985 to December 1997, 4662 patients underwent tonsillectomy at our institution. Ninety patients with posttonsillectomy bleeding were identified. For each patient with posttonsillectomy bleeding, 2 nonbleeding control subjects were selected and matched by age and sex to evaluate potential risk factors. RESULTS: Age was the only factor found to be statistically significant among the bleeding patients and the control group. The highest incidence (3.61%) of posttonsillectomy hemorrhage occurred in patients 21 to 30 years of age. In our experience, secondary hemorrhage was more common than primary hemorrhage, presenting most frequently on postoperative days 5 to 7. CONCLUSIONS: The incidence of posttonsillectomy bleeding in this review was 1.93%, and about half (47%) of the patients with posttonsillectomy hemorrhage returned to the operating room for hemorrhage control. The highest incidence (3.61%) of posttonsillectomy hemorrhage occurred in patients 21 to 30 years of age. Patients with posttonsillectomy hemorrhage, regardless of management, had a 12% incidence of subsequent hemorrhage. We found no difference in the incidence of posttonsillectomy bleeding between outpatient and inpatient procedures.