Pretreatment Hearing Levels Research Articles

Differences in Clinical Results After LINAC-Based Single-Dose Radiosurgery Versus Fractionated Stereotactic Radiotherapy for Patients With Vestibular Schwannomas

To evaluate the outcomes of patients with vestibular schwannoma (VS) treated with fractionated stereotactic radiotherapy (FSRT) vs. those treated with stereotactic radiosurgery (SRS). This study is based on an analysis of 200 patients with 202 VSs treated with FSRT (n = 172) or SRS (n = 30). Patients with tumor progression and/or progression of clinical symptoms were selected for treatment. In 165 out of 202 VSs (82%), RT was performed as the primary treatment for VS, and for 37 VSs (18%), RT was conducted for tumor progression after neurosurgical intervention. For patients receiving FSRT, a median total dose of 57.6 Gy was prescribed, with a median fractionation of 5 x 1.8 Gy per week. For patients who underwent SRS, a median single dose of 13 Gy was prescribed to the 80% isodose. FSRT and SRS were well tolerated. Median follow-up time was 75 months. Local control was not statistically different for both groups. The probability of maintaining the pretreatment hearing level after SRS with doses of < or =13 Gy was comparable to that of FSRT. The radiation dose for the SRS group (< or =13 Gy vs. >13 Gy) significantly influenced hearing preservation rates (p = 0.03). In the group of patients treated with SRS doses of < or =13 Gy, cranial nerve toxicity was comparable to that of the FSRT group. FSRT and SRS are both safe and effective alternatives for the treatment of VS. Local control rates are comparable in both groups. SRS with doses of < or =13 Gy is a safe alternative to FSRT. While FSRT can be applied safely for the treatment of VSs of all sizes, SRS should be reserved for smaller lesions.

Correlation between Audiovestibular Function Tests and Hearing Outcomes in Severe to Profound Sudden Sensorineural Hearing Loss

This study investigated whether audiovestibular function tests, namely auditory brain stem response (ABR) and vestibular-evoked myogenic potential (VEMP) tests were correlated to hearing outcomes after controlling the effects of other potential confounding factors in severe to profound sudden sensorineural hearing loss (SSHL). Eighty-eight patients with severe to profound SSHL were enrolled in this study. Pretreatment hearing levels, results of audiovestibular function tests, and final hearing outcomes were recorded from retrospective chart reviews. Other factors, including age, gender, delay of treatment, vertigo, diabetes mellitus, and hypertension, were collected as well. Comparative analysis between multiple variables and hearing outcomes was conducted using the cumulative logits model in overall subjects. Further, multivariate analysis of prognostic factors was conducted in the stratified groups of severe (70 dB HL <hearing level < or =90 dB HL) and profound (hearing level >90 dB HL) SSHL. Multivariate analysis showed that pretreatment hearing levels, presence of vertigo, and results of ABR and VEMP testing were significant outcome predictors in the overall subjects. Stratification analysis demonstrated that both the presence of ABR and VEMP waveforms were significantly correlated with better hearing outcomes in the group of severe SSHL [ABR: adjusted odds ratio (aOR) = 14.7, 95% confidence interval (CI) = 1.78 to 122, p = 0.01; VEMP: aOR = 5.91, 95% CI = 1.18 to 29.5, p = 0.03], whereas the presence of vertigo was the only significant negative prognostic factor in the group of profound SSHL (aOR = 0.24, 95% CI = 0.06 to 0.95, p = 0.04). Other variables, including age, gender, diabetes mellitus, hypertension, and delay of treatment, were not significantly related to hearing outcomes in both groups (p > 0.05). A predictive hearing recovery table with the combined ABR and VEMP results was proposed for the group of severe SSHL. ABR and VEMP tests should be included in the battery of neurootological examinations in patients with severe SSHL because the presence of both waveforms might indicate favorable hearing outcomes. The presence of vertigo might portend a worse prognosis in patients with profound SSHL. A presumed table in predicting hearing outcomes was suggested for patients with severe SSHL.

The Clinical Correlation between Anterior Inferior Cerebellar Artery and Sudden Sensorineural Hearing Loss

Background and Objectives The influence of anterior inferior cerebellar artery (AICA) loop on sudden sensorineural hearing loss (SSHL) remains controversial. The objective of this study was to evaluate the correlation between the anatomical type of AICA loop and SSHL. Subjects and Method We reviewed the medical records of 69 ears from 60 patients with SSHL between January 2005 and April 2008, retrospectively. AICA loops were classified according to the Chavda classification method by magnetic resonance imaging. According to the extension depth of the loop in the internal auditory canal, it was classified as type I, II and III. The loop was classified as S (small diameter) and L (large diameter) by comparing the thickness of the loop with adjacent facial nerves. Results The predominant type of AICA loop was type I (68.1%) and type S (78.3%). There was no significant correlation between the pretreatment hearing level, extension depth and diameter. There was also no significant correlation between the rate of hearing recovery by Siegel's criteria and diameter. However, there was significant correlation between the rate of hearing recovery by Siegel's criteria and the types of the extension depth (p

Risk Factors of Ototoxicity After Cisplatin-Based Chemo-Irradiation in Patients With Locally Advanced Head-and-Neck Cancer: A Multivariate Analysis

Cisplatin chemo-irradiation is increasingly used in locally advanced squamous cell carcinoma of the head and neck. The objective of this study is to determine risk factors of ototoxicity due to intra-arterial high-dose cisplatin chemoradiation. A prospective analysis of hearing thresholds at low and (ultra) high frequencies obtained before, during, and after treatment in 146 patients. Treatment consisted of intra-arterial infusion of high-dose cisplatin (150 mg/m(2), four courses) with sodium thiosulfate rescue and concurrent radiation therapy (70 Gy). Patient and chemoradiation variables were studied in a multivariate analysis. After treatment, 23% of the ears were under consideration for hearing aids because of therapy. Twenty-two percent of the patients developed an increase in air-bone gap >10 dB during or after therapy. In the multivariate explanatory analysis, cumulative dose of cisplatin and radiation therapy, and young age displayed a causal relationship with increased sensorineural hearing loss during and after therapy (p < 0.001). In the multivariate prediction analysis, pretreatment hearing level of the concerning ear was identified as an independent predictive factor for hearing capability after therapy (p < 0.0001). Both cisplatin and radiation therapy were proven to induce sensorineural hearing loss, in this study with short-term follow-up. Of all patient and treatment variables studied, the patients pretreatment hearing level appeared to be the main predictive factor for hearing capability after high-dose intra-arterial cisplatin chemoradiation.

Low-dose radiosurgery for large vestibular schwannomas: long-term results of functional preservation

The author conducted a study to assess the long-term results obtained in patients who underwent GKS for large vestibular schwannomas (> 3 cm in diameter). Facial and cochlear nerve functions were evaluated. Twenty consecutive large tumors in 18 patients (including two cases of neurofibromatosus Type 2 [NF2]) were followed for more than 6 years. There were eight tumors that were more than 4 cm in maximum diameter. Microsurgery had already been performed prior to GKS in 11 patients (nine recurrent and two residual tumors). Four patients (including one with NF2) died during the follow-up period of other diseases or by accident. Fourteen of 15 tumors were stable or decreased in size. Microsurgery was performed in one patient 2 years after radiosurgery. Facial nerve function was preserved in all patients and hearing preserved in four of five patients with cochlear nerve function prior to radiosurgery. No adverse effects of radiosurgery have been observed to date. Gamma knife surgery seems to have a place in the low-dose treatment of selected large vestibular schwannoma in patients with a reasonable chance of retaining facial function and pretreatment hearing level. Patients with severe brainstem compression should first be undergo microsurgery.

Low-dose radiosurgery for large vestibular schwannomas: long-term results of functional preservation

Object. The author conducted a study to assess the long-term results obtained in patients who underwent GKS for large vestibular schwannomas (&gt; cochlear nerve functions were evaluated. Methods. Twenty consecutive large tumors in 18 patients (including two cases of neurofibromatosus Type 2 [NF2]) were followed for more than 6 years. There were eight tumors that were more than 4 cm in maximum diameter. Microsurgery had already been performed prior to GKS in 11 patients (nine recurrent and two residual tumors). Four patients (including one with NF2) died during the follow-up period of other diseases or by accident. Fourteen of 15 tumors were stable or decreased in size. Microsurgery was performed in one patient 2 years after radiosurgery. Facial nerve function was preserved in all patients and hearing preserved in four of five patients with cochlear nerve function prior to radiosurgery. No adverse effects of radiosurgery have been observed to date. Conclusions. Gamma knife surgery seems to have a place in the low-dose treatment of selected large vestibular schwannoma in patients with a reasonable chance of retaining facial function and pretreatment hearing level. Patients with severe brainstem compression should first be undergo microsurgery.

Medication for hearing loss after fractionated stereotactic radiotherapy (SRT) for vestibular schwannoma

Purpose: To investigate the effectiveness of corticosteroid treatments for patients showing decreases in hearing levels after stereotactic radiotherapy for vestibular schwannoma. Methods and Materials: Twenty-one patients experienced a hearing loss in pure-tone average at greater than 20 dB or less than 10 dB within 1 year after irradiation administration of 44 Gy/22 fractions followed by a 4 Gy boost. Eight received oral prednisone at a daily dose of 30 mg, which was gradually decreased (medicated group), and 13 received none (nonmedicated group). The average observation period was 26.7 ± 16.6 (range: 6–69) months. Results: Hearing recovery was seen after initial onset of the hearing loss in all 8 patients in the medicated group and in 2 of 13 patients in the nonmedicated group ( p = 0.001). The hearing recovery, that is, the change in pure-tone average (dB) at the last follow-up from the onset of hearing loss, was 9.8 ± 6.9 dB (recovery) in the medicated group and −9.4 ± 12.8 dB (further loss) in the nonmedicated group ( p = 0.0013). The hearing recovery rate, normalizing to the degree of the hearing loss before medication, was also significantly higher in the medicated group than in the nonmedicated group ( p = 0.0014). Conclusions: Corticosteroidal intake is suggested to be effective in improving hearing loss after stereotactic radiotherapy, at least in young patients having a useful pretreatment hearing level, if the treatment for hearing loss is administered immediately after the hearing loss is first detected.

小児突発性難聴の検討

Seven children (two boys and five girls) with idiopathic sudden deafness (SD) are reported. Juvenile SD accounts for 3.2% of 216 SD cases. Their ages ranged from 7 to 14 years (mean age 10.4 years). Children over 5 years of age were aware of the onset and complained of it. However, the diagnosis is sometimes so difficult that treatment in the very early stages is often not undertaken in such cases.The average pre-treatment hearing level was 81.7dB, and four cases (57%) complained of vertigo. The severity of hearing loss as well as the incidence of vestibular symptoms in juvenile SD seemed to be higher than in adult SD cases. All cases were initially treated with steroid-infusion therapy. In three cases were defibrinogenation therapy followed. Hearing improvement in the seven cases was as follows: 2 cases showed complete recovery, 2 cases showed remarkable improvement, 1 case showed slight improvement, and 1 case showed no improvement.Juvenile SD is rare but accounts for up to 5% of all SD cases. Proper and early diagnosis and the prompt start of appropriate treatment should be initiated to obtain excellent responses.

Analyses of neuro-otological complications after radiosurgery for acoustic neurinomas

To find out the optimum treatment parameters and the proper indications for treatment of acoustic neurinomas, univariate and multivariate actuarial analyses of neuro-otological complications after stereotactic radiosurgery for acoustic neurinomas were performed. The subjects were 46 patients with acoustic neurinomas who underwent unilateral radiosurgery between June 1990 and June 1994 and were followed up at the University of Tokyo. Age ranged from 13 to 77 years (median, 54 years). Tumor diameter ranged from 0 to 25 mm (mean, 12 mm) at the cerebellopontine angle and from 2 to 15 mm (mean, 8.3 mm) in the internal auditory meatus. Maximum tumor doses ranged from 20 to 40 Gy (mean, 31.4 Gy), and peripheral doses from 12 to 25 Gy (mean, 16.8 Gy). One to eight isocenters were used (mean, 3.2). Median follow-up was 39 months. Eight events concerning neuro-otological complications were chosen, and the potential risk factors for them were analyzed by the actuarial analyses (univariate and multivariate). The events examined include hearing loss, vestibular function loss, facial palsy, and trigeminal nerve dysfunction. In order to point out potential risk factors for neuro-otological complications, univariate analyses were performed using both the Wilcoxon test and the log rank test, and multivariate analyses were performed with the Cox proportional hazards model. Variables nominated as potential risk factors were 1) demographic variables such as patient age and sex, 2) tumor dimensions, 3) treatment variables such as tumor doses and number of isocenters, and 4) pretreatment hearing levels. A variable with significant p-values (p < 0.05) in two or more of the three actuarial analyses (two univariate and one multivariate) was considered a possible risk factor. The possible variables that increase the risk for each event analyzed were: neurofibromatosis type II (NF2) and the number of isocenters for total hearing loss; experience of prior operation, the tumor diameter in the internal auditory meatus, and NF2 for hearing threshold elevation; peripheral tumor dose for vestibular function loss; patient age or midporus transverse tumor diameter (the two variables were correlated), and the number of isocenters for facial palsy; and the number of isocenters for trigeminal neuropathy. NF2 and the tumor diameter were the common risk factors for hearing loss in previous studies and ours. For the 5th/7th nerve dysfunction, the tumor diameter was the common risk factor. The risk of using more isocenters remains controversial. The difference in risk factors for hearing impairment and vestibular function loss suggests different mechanisms for the two. Further studies with larger populations and longer follow-up periods are required in order to draw conclusions on the risk factors in radiosurgery.

Gamma knife radiosurgery for acoustic tumors: multivariate analysis of four year results

In order to evaluate the results of radiosurgery for acoustic tumors and to identify optimum treatment parameters, an analysis of tumor control, as well as incidences of hearing loss, facial and trigeminal neuropathies was undertaken. Between August 1987 and August 1991, 134 patients with 136 acoustic tumors received stereotactic gamma knife radiosurgery at the University of Pittsburgh. Median follow-up was 24 months (range: 6–56 months). Tumor volumes ranged from 0.10 to 17.00 cm 3 (median = 2.75 cm 3). From one to ten isocenters were utilized per tumor treated (median = 3). Minimum tumor doses varied from 12 to 20 Gy (median = 17 Gy). The 4-year actuarial tumor control rate was 89.2 ± 6.0%. Some degree of hearing (by pure tone audiometry) was preserved in 71.0 ± 4.4% of patients. The actuarial rates for preservation of either pretreatment hearing level or useful hearing. were 34.4 ± 6.6% and 35.1 ± 97% respectively. Respectively, the actuarial incidences of postradiosurgery facial and trigeminal neuropathies were 29.0 ± 4.4% and 32.9 ± 4.5%, respectively. No significant factors affecting tumor control were identified. Multivariate analysis identified a significantly increased risk of hearing loss in patients with neurofibromatosis ( p = 0.0003) as well as decreased risks of facial and trigeminal neuropathies with both decreasing tumor diameter ( p = 0.001) and increasing number of isocenters treated ( p = 0.003). Radiosurgery is a safe and effective treatment for acoustic neuromas with acceptable morbidity that may be lowered by the use of multiple isocenter treatment techniques and by earlier treatment of small tumors.

Treatment of Syphilitic Hearing Loss

Twenty-nine patients with presumed syphilitic hearing loss, either congenital or acquired, were treated on one or more occasions according to a three-month protocol using penicillin and prednisone. Changes in hearing were carefully followed during treatment and for at least one year thereafter. Of 58 ears studied in 29 patients, 19 demonstrated significant partial improvement in hearing during treatment. However, 11 ears returned to pretreatment hearing levels after therapy, and only 8 ears, or 15%, maintained the hearing gains one year later. Enhanced discrimination occurred more commonly than gains in pure tone threshold. Long-term alternate day prednisone therapy was required to sustain hearing improvement in a small number of patients.