Roberto A. Cueva

Combination therapy (intratympanic dexamethasone + high-dose prednisone taper) for the treatment of idiopathic sudden sensorineural hearing loss.

Background: Idiopathic Sudden Sensorineural Hearing Loss (ISSNHL), commonly defined as greater than 20 dB of unilateral hearing loss in at least 3 frequencies occurring within 3 days, has a reported incidence of 5 to 20 per 100,000 patients per year. Untreated, it has a recovery rate of 32 to 65%. Although accepted therapy is high-dose prednisone taper (HDPT), recent publications suggest that intratympanic dexamethasone (IT-Dex) therapy may improve hearing recovery. Methods: This multicenter, double-blinded, placebo-controlled, randomized study seeks to compare hearing results in ISSNHL patients who have received HDPT alone, IT-Dex alone, or IT-Dex and HDPT (combination therapy). Fifty-one patients with a less than 6-week history of ISSNHL were randomized to 1 of 3 arms and followed prospectively. Group A (17 patients) received IT-Dex therapy with placebo taper, whereas Group B (18 patients) were administered HDPT and placebo intratympanic injections. Patients in Group C (16 patients) were administered IT-Dex and HDPT, otherwise known as combination therapy. Injections (IT-Dex/placebo) and audiograms were performed weekly for 3 weeks, and a final audiogram was obtained 4 weeks after the final injection. Results: Patients receiving combination therapy (IT-Dex + HDPT) in Group C had an average improvement in speech discrimination score of 44 percentage points and a 40-dB improvement in pure-tone average (PTA). Patients in Group C had statistically significant improvements in speech discrimination score compared with Group B patients (HDPT alone; p < 0.05). When defining a significant improvement in PTA as greater than 15 dB, there was a statistically significant difference between the groups in the proportion of patients achieving hearing improvement. Furthermore, the proportion of patients achieving a significant PTA improvement in Group C was statistically greater than patients in Group B (p < 0.02). Logistic regression analysis indicates that patients receiving combination therapy demonstrated better odds of hearing recovery than patients in both of the other groups (p < 0.05), when all 3 groups were adjusted for age, vertigo, initial hearing levels, and time delay between onset of hearing loss and treatment. Lastly, combination therapy patients recovered their hearing more quickly than patients in the other groups (p < 0.05). Conclusion: The results of this study suggest that ISSNHL patients treated with IT-Dex + HDPT (combination therapy) have a higher likelihood of hearing recovery than those treated with HDPT alone.

Auditory Brainstem Response versus Magnetic Resonance Imaging for the Evaluation of Asymmetric Sensorineural Hearing Loss

Objectives/Hypothesis: Auditory brainstem response (ABR) testing and magnetic resonance imaging (MRI) are compared for the evaluation of patients with asymmetric sensorineural hearing loss (SNHL). MRI with gadolinium administration is the current gold standard for identifying retrocochlear lesions causing asymmetric SNHL. The study seeks to determine the sensitivity and specificity of ABR in screening for possible retrocochlear pathology. Most important among SNHL etiologies are neoplastic lesions such as vestibular schwannomas, cerebellopontine angle (CPA) tumors, as well as multiple sclerosis, stroke, or other rare nonneoplastic causes. The study results will allow the author to recommend a screening algorithm for patients with asymmetric SNHL.

Comparison of growth patterns of acoustic neuromas with and without radiosurgery.

Objective: To compare the natural history of acoustic neuroma growth to the reported growth rate of acoustic neuromas after radiosurgical therapy, a retrospective review and meta-analysis of the literature was performed. The retrospective review was of one hundred eleven patients (average age, 71 yr) who chose to have their acoustic neuromas managed conservatively in our institution. These patients underwent serial magnetic resonance imaging for assessment of tumor growth for an average period of 38 months. Growth patterns if these untreated tumors were compared to that of radiosurgically treated acoustic neuromas reported in the literature. Data Sources: The English-language literature on the topic was searched systematically by Medline and Pubmed using the following key words: acoustic neuroma, vestibular schwannoma, conservative management, conservative treatment, nonsurgical, age, elderly, growth, observation, untreated, radio-surgery, gamma knife, 13 Gy and 12 Gy. There were no limits to the year of publication. Study Selection: Articles that fulfilled inclusion criteria (methods) were studied in detail. Data Extraction: All the articles described in the study selection were used in the review. Conclusion: The average growth rate of the untreated tumors was 0.7 ± 1.4 mm/yr. Eighty-two percent grew less than 1 mm/yr, whereas 18% grew equal to or more than 1 mm/yr. Thirteen percent grew more than 2 mm/yr, with growth being noted at an average of 2.2 years after diagnosis. This represents an 87% control rate if tumor control rate is defined as less than 2-mm growth/yr. Meta-analysis indicates that tumor control rates range in the radiosurgical literature from 86% to 100%. The mean follow-up periods in the radiosurgical literature are generally not reported. Tumor control is not uniformly defined. Based on the results of this study, there is no discernable significant difference between growth patterns of untreated acoustic neuromas and those treated radiosurgically. To establish a significant difference, longer-term follow-up studies with larger sample sizes and tumor control rates are needed. Tumor control should be defined as zero growth.

Conservation surgery for glomus jugulare tumors ; the value of early diagnosis

The results of‐lateral cranial base surgery for glomus jugulare tumors are gratifying when normal anatomy and function can be preserved. The goal of conservation surgery is to preserve normal ear anatomy and cranial nerve function. In general, conservation surgery is tumor‐size dependent. Thus, excellent states of functional recovery depend upon accurate early diagnosis. This paper reviews the technical aspects of transtemporal conservation skull base tumor surgery while also reviewing our experience with nearly 100 glomus jugulare patients. Adjuvants to early diagnosis will be highlighted from a review of presenting symptoms, clinical signs, and related diagnosis. Our objective is to provoke a high index of suspicion in physicians charged with the responsibility of diagnosing these tumors. Diagnostic guidelines are proposed.

A comparison of direct eighth nerve monitoring and auditory brainstem response in hearing preservation surgery for vestibular schwannoma.

Objective: The objective of this study was to compare the effectiveness of direct eighth nerve monitoring (DENM) and auditory brainstem response (ABR) in facilitating hearing preservation during vestibular schwannoma resection. Study Design: This was a retrospective study. Setting: Tertiary referral center. Methods: We conducted a retrospective clinical study of the use of ABR and DENM during vestibular schwannoma removal. Tumors were removed through a retrosigmoid craniotomy. The rate of hearing preservation between the two monitoring modalities was compared. The additional outcome measures of facial nerve function and cerebral spinal fluid leak rate were also evaluated. Results: Hearing preservation was attempted in 77 patients with vestibular schwannomas. Tumor sizes ranged from 0.5 cm to 2.5 cm. Hearing was preserved in 71% of patients with tumors 1 cm or less and in 32% of patients with tumors between 1 and 2.5 cm when direct eighth nerve monitoring was used. Hearing preservation rates with ABR for tumors 1 cm or less were 41% and 10% in patients with tumors between 1 and 2.5 cm (p = 0.03) Facial nerve preservations rates were 94% (House-Brackmann 1–2) for tumors less than 2 cm. Conclusions: DENM provides significantly higher rates of hearing preservation during vestibular schwannoma resection when compared with ABR.

A prospective, multi-centered study of the treatment of idiopathic sudden sensorineural hearing loss with combination therapy versus high-dose prednisone alone: a 139 patient follow-up.

Objective To compare combination therapy (high-dose prednisone taper (HDPT) + intratympanic dexamethasone (IT-Dex)) hearing recovery results in ISSNHL patients with those treated with HDPT alone. Design Prospective, multicentered trial. Setting Tertiary referral center. Patients Eighty ISSNHL patients with class C or D hearing. Intervention Eighty qualifying patients were treated with IT-Dex (10 mg/ml) every week for 3 weeks concomitant with HDPT (60 mg/d for 7 d with 7-d taper) and followed prospectively. Main Outcome Measure(s) Four-tone pure tone average (PTA) at 0.25, 0.5, 1, and 2 kHz and speech discrimination scores (SDS) 2 months posttreatment; Hearing results compared retrospectively with those of 59 ISSNHL treated with HDPT alone. Results Combination therapy and HDPT alone both provided a statistically significant benefit in audiometric parameters, especially if treated within 7 days of onset. However, 49% versus 29% (p = 0.02) of class D patients receiving combination therapy versus HDPT achieved serviceable hearing. Patients receiving combination therapy versus HDPT experienced a significantly greater improvement in PTA (34.1 ± 27 dB versus 12.0 ± 21 dB; p < 0.0001) and SDS (49.9.2 ± 38% versus 19.2 ± 36%; p < 0.0001) while achieving a significantly better final PTA (50.6 ± 28 dB versus 65.5 ± 29 dB; p = 0.005) and SDS (62.4 ± 40% versus 44.7 ± 41%; p = 0.01). Approximately 56% of class D and 40% of profound patients treated within 7 days with combination therapy achieved serviceable hearing. Conclusion Combination therapy offers ISSNHL patients the highest likelihood of achieving class A and B hearing. Differential results with combination therapy and HDPT compared with previous studies suggest time- and dose-dependent responses to the treatment of ISSNHL.

Approach design and closure techniques to minimize cerebrospinal fluid leak after cerebellopontine angle tumor surgery.

Objective: The purpose of the study was to identify specific aspects of surgical approach design and closure technique aimed at reducing the incidence of cerebrospinal fluid leak after cerebellopontine angle tumor surgery. Study Design: Retrospective case review. Setting: Tertiary referral center. Patients: All patients undergoing cerebellopontine angle tumor surgery at the study institution from January 1996 through September 2004. Main Outcome Measure: The presence or absence of cerebrospinal fluid leak after various surgical approaches for a wide variety of cerebellopontine angle tumors. Results: Three hundred forty three patients underwent surgery for cerebellopontine angle tumors at the study institution during the study period. Tumor types in descending order of frequency were as follows: acoustic neuroma, 244; cerebellopontine angle meningiomas, 33; petroclival meningiomas, 32; foramen magnum meningiomas, 10; epidermoid tumors, 9; facial nerve tumors, 6; hemangiopericytomas, 3; schwannomas of glossopharyngeal/spinal accessory nerves, 3; and unusual internal auditory canal tumors, 3. Surgical approaches used for tumor resection included translabyrinthine, retrosigmoid, combined transpetrosal, far lateral/transcondylar, middle cranial fossa, and extended middle cranial fossa. During the nearly 8-year study period, four postoperative cerebrospinal fluid leaks were encountered, resulting in a leak rate of 1.2%. Two of these patients required surgical repair of their leaks; the other two stopped spontaneously. The authors describe specific aspects of approach design and closure that appear to have a positive impact on postoperative cerebrospinal fluid leak rates. Conclusion: Attention to specific aspects of surgical approach design and wound closure results in a reduced incidence of cerebrospinal fluid leak after surgery for cerebellopontine angle tumors.

Extended middle fossa approach to the petroclival junction and anterior cerebellopontine angle.

Objectives: This article seeks to demonstrate the use of the extended middle cranial fossa approach in the treatment of tumors arising in the anterior cerebellopontine angle and petroclival region. Study Design: We conducted a retrospective chart review. Setting: Tertiary referral center. Patients: Ten-year retrospective chart review of over 800 skull base surgical cases demonstrated 16 cases in which the senior author used the extended middle cranial fossa as the sole approach to access the posterior cranial fossa, petroclival junction, or the anterior cerebellopontine angle. There were five males and 11 females, 13 meningiomas, 2 trigeminal schwannomas, and 1 brainstem glioma. Presenting symptoms were dependent on extent of brainstem compression and involvement of surrounding cranial nerves. The symptoms are broken down as follows: hydrocephalus, one; balance disturbance, three; diplopia, five; trigeminal neuralgia, two; hemifacial numbness, one; seizures, one; expressive aphasia, one; and hearing loss, two. Results: Of the 16 patients in this study, one patient needed postoperative care in a skilled nursing facility. Postoperative facial nerve weakness was not experienced in any patient. One patient developed a transient cerebrospinal fluid leak that resolved spontaneously. One patient developed a pseudomeningocele secondary to postoperative hydrocephalus. This was corrected with wound exploration and placement of a ventricular peritoneal shunt. Hearing was not maintained in one patient. Two patients developed new fourth nerve paresis and two patients developed new sixth nerve palsies. There were no postoperative infections and no deaths. Conclusions: The extended middle cranial fossa approach provides excellent access and exposure to tumors in the anterior cerebellopontine angle and petroclival junction. The approach allows more direct access to the area anterior to the internal auditory canal. The key to the approach is adequate bone removal of the petrous apex to provide exposure down to the inferior petrosal sinus and anteriorly to Meckels cave and the petroclival junction. Extradural elevation of the temporal lobe with suitable brain relaxation minimizes postoperative complications.

Hearing preservation and vestibular schwannoma: intracochlear FLAIR signal relates to hearing level.

Objectives This study aimed to evaluate the relationship between cochlear signal on fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) sequences and hearing in patients undergoing hearing preservation surgery for vestibular schwannoma (VS) and to demonstrate a new classification system to be used in imaging evaluation of patients with VS. Methods A search of archived surgical cases at a single institution between January 1, 2006, and January 1, 2012, revealed 51 patients who underwent hearing preservation surgery for VS. Tumor size, patient age and sex, and preoperative and postoperative pure-tone average (PTA) and speech discrimination score (SDS) were recorded. Cochleae on the affected side were examined on preoperative FLAIR sequences and classified as limited hyperintensity (LH) or extensive hyperintensity (EH). Results Mean patient age was 51 years, and mean tumor size was 1.3 cm. Preoperative FLAIR sequences were classified into LH (n = 36) and EH (n = 15) categories. Preoperative PTA and SDS were 29.5 dB (SD, 16.7), 90% (SD, 14) and 40.6 dB (SD, 13.8), 80% (SD, 25) for LH and EH, respectively. On univariate analysis, preoperative PTA was superior in the LH group (p = 0.04). There was a trend toward superior preoperative SDS and postoperative PTA in the LH group, but these differences were not statistically significant (p = 0.08 and p = 0.06, respectively). Conclusion The current study is the first to demonstrate a distinct association between cochlear FLAIR signal and pretreatment hearing levels in patients with VS. A new classification system for evaluating cochlear FLAIR signal is proposed. Improvement in FLAIR sequences will allow further investigation of this association.

Hearing preservation in management of epidermoids of the cerebellopontine angle: CPA epidermoids and hearing preservation.

Objectives Surgical approaches for epidermoid cysts of the cerebellopontine angle (CPA) are dictated by tumor location. Previous reports have advocated the sacrifice of usable hearing to achieve maximal tumor resection in a single operation. The aim of the current study is to demonstrate the applicability of hearing preservation approaches in the neurotologic management of epidermoids of the CPA. Study Design Retrospective chart review. Methods A search of archived surgical cases at a single institution between January 1, 1997, and December 31, 2011, revealed 18 cases of epidermoid cysts involving the CPA. Results Eighteen patients with a mean age 40.9 years underwent surgery. Average tumor size was 4.47 cm, and presenting symptoms included headache, vertigo, cranial neuropathies, and seizures. Thirteen patients underwent a retrosigmoid approach, 2 translabyrinthine, 2 pterional, and 1 retrolabyrinthine/presigmoid. Complications included CSF leak, pseudomeningocele, meningitis, cranial nerve dysfunction, and persistent imbalance. All but 5 patients had long-term follow-up imaging to chronicle tumor residua/recurrence, varying from 6 to 149 months postoperatively. The average length of follow-up was 71.4 months, and residual tumor was common, with most patients demonstrating a focal or small area of residual tumor on follow-up imaging. Two patients had undergone previous surgery for epidermoid excision elsewhere. Two patients required reoperation for epidermoid regrowth, and the times between surgeries were 44 and 78 months. Of the patients who underwent a retrosigmoid approach, 9 had postoperative audiograms. All of these patients maintained hearing at or near their preoperative level except for 2 patients whose hearing declined and one whose hearing significantly improved. Conclusion Hearing preservation approaches for epidermoids of the CPA is a feasible option for long-term control of these tumors. Resection from a retrosigmoid approach can provide years of useful hearing, and the majority of patients do not require reoperation.