DIAGNOSIS
A.–L. McDermott, S.N. Dutt, R.M. Irving, A.L. Pahor S. V. Chavda. Anterior inferior cerebellar artery syndrome: Fact or fiction. Clin Otolaryngol 2003;28:75–80
A prospective analysis of patients referred by Otolaryngologists from a tertiary hospital for detailed assessment of the posterior cranial fossa was undertaken. The objectives were to evaluate radiological characteristics of the anterior inferior cerebellar artery (AICA) within the cerebellopontine angle (CPA) and the internal auditory canal (IAC), and to correlate these characteristics with ipsilateral auditory symptoms. Three hundred and thirty–two consecutive adult patients who presented with unilateral auditory symptoms were studied. All patients were referred by the Department of Otolaryngology at City Hospital, Birmingham, from October 1999 to October 2001. Magnetic resonance imaging (MRI) with three–dimensional Fourier Transformation Constructive Interference in Steady State (3D F1–CISS) was the imaging strategy used to investigate each patient. Six hundred and sixty–four sides were studied and the AICA loop was identified in all patients. Using a simple anatomical classification to type the loops: there were 412 type I loops (within the CPA), 202 type II loops (at the porus acousticus, extending up to 50 % of IAC) and 50 type III loops (extending beyond 50 % of IAC). There was a statistically significant association with unilateral hearing loss and type II and III AICA loops (P = 0.016 and P = 0.006 respectively). An association between the presence of a large diameter vascular loop in the CPA and unilateral auditory symptoms was not found to be significant (P > 0.05).
TREATMENTS
Chong–Sun Kim, Sun O. Chang, Seung Ha Oh, Soon–Hyun Ahn, Chan Ho Hwang, Hyo Jeong Lee. Management of intratemporal facial nerve schwannoma. Otol Neurotol 2003;24:312–316
Objective: The aim of this study was to report a series of 18 racial nerve schwannomas, including 2 infantile cases.
Study Design: Retrospective case review.
Setting: Tertiary referral center.
Patients: Eighteen patients with facial nerve schwannoma, operated on between 1980 and 2000.
Intervention: Surgical treatments were performed in all cases.
Main Outcome Measures: The presenting symptoms and facial nerve function were graded using the House–Brackmann scale and eye closure.
Results: Facial nerve paralysis was the most common symptom, presenting in 94 % of cases, followed by hearing loss and mass lesion. In one case, the tumor was shaved, leaving the facial nerve intact. In the other cases, the facial nerve reconstruction with hypoglossal–facial anastomosis or interposition graft was performed. The postoperative facial function was House–Brackmann grade IV in most cases (88.2 %). In terms of the functional recovery classified by complete or incomplete eye closure, the moderate preoperative facial nerve palsy group showed a better functional outcome than severe group.
Conclusion: In cases with good facial nerve function, it would be better to consider an alternative method for preserving the facial nerve. Furthermore, when facial nerve paralysis has developed to more than House–Brackmann grade III, an immediate operation is recommended to obtain a good postoperative facial functional recovery.
Daniel P. Nadeau, Robert T. Sataloff. Fascicle preservation surgery for facial nerve neuromas involving the posterior cranial fossa. Otol Neurotol 2003;24:317–325
Objective: To assess facial nerve function after fascicle preservation surgery in cases of facial nerve neuroma involving the cerebellopontine angle.
Study Design: Retrospective case series and literature review.
Setting: Tertiary referral center.
Patients: Seven patients with facial nerve neuroma involving the posterior cranial fossa were reviewed from a single neurotologist's practice and combined with a review of 648 cases reported in the literature.
Interventions: Translabyrinthine resection was used in all patients for complete tumor removal. Nerve reconstruction was accomplished with fascicle preservation (three cases), cable nerve interposition grafting (three cases, one of which involved using cranial nerve VIII as the graft), or direct anastomosis (one case).
Main Outcome Measure: Facial nerve function as measured by the House–Brackmann grading system.
Results: A postoperative facial nerve (House–Brackmann) grade of II/VI was obtained in two of our three patients who underwent fascicle preservation reconstruction and in two of eight cases reported by other authors. One case reported elsewhere resulted in grade I/VI, and four other cases reported elsewhere achieved grade III/VI; only two cases were grade V/VI. There were no tumor recurrences at 5 to 19 years of follow–up.
Conclusion: Most cases of facial nerve neuroma require facial nerve resection. In rare cases, these tumors can be dissected away from the nerve fascicles, allowing the surgeon to preserve the facial nerve. This method resulted in better long–term postoperative facial nerve function (House–Brackmann grade II/VI vs. grade III/VI) compared with other techniques for patients in this small series, and no tumor recurrence.
Brian A. Neff, Thomas O. Willcox, Jr., Robert T. Sataloff. Intralabyrinthine schwannomas. Otol Neurotol 2003;24:299–307
Objective: To describe the patient presentation, radiographic findings, and treatment results in a series of eight patients with a diagnosis of intralabyrinthine schwannoma, and to review the presentation of other cases of intralabyrinthine schwannoma in the English otolaryngologic literature.
Methods: Retrospective review of patient records, operative reports, and radiologic studies, and review of the literature.
Results: Eight patients with a variety of otologic symptoms including progressive hearing loss, episodic vertigo, and tinnitus were found to have a schwannoma involving the vestibule or cochlea. Surgery was performed to remove the tumors from four patients with nonserviceable hearing. The patients experienced significant improvement in their vertigo and tinnitus after surgery. Observation and serial magnetic resonance imaging were adequate treatment of the four patients with serviceable hearing. In the literature review, 447 cases of intralabyrinthine schwannoma were identified, and the presentations were similar to those in the cases described here.
Conclusion: Intralabyrinthine schwannomas are rare tumors that arise from the distal portion of either the vestibular nerve or the cochlear nerve. Consequently, the cochlea, the semicircular canals, the vestibule, or a combination of these structures may become involved with these lesions. Transmastoid labyrinthectomy or a transotic approach can be used to remove intralabyrinthine tumors from patients with nonserviceable hearing and severe vertigo or tinnitus. In addition, these surgical approaches should be used if the tumor grows to involve the internal auditory canal. Observation is an appropriate option for patients who have serviceable hearing.
OUTCOMES
Valerie J. Lund, David Howard, William Wei, Margaret Spittle. Olfactory neuroblastoma: Past, present, and future? Laryngoscope 2003;113:502–507
Objective: To consider the long–term survival and outcomes in patients with olfactory neuroblastoma undergoing craniofacial resection.
Study Design: A single–center prospective cohort study.
Methods: All patients with olfactory neuroblastoma treated in a 23–year period with craniofacial resection (with or without radiotherapy) were analyzed; a multivariate analysis was included.
Results: Forty–two patients aged 12 to 70 years were assessed, 83 % of whom had received no preceding treatment. Craniofacial resection was used in all cases, combined with radiotherapy in 24 patients (57 %). Duration of follow–up ranged from 2 to 206 months (mean follow–up period, 57 mo). The disease–free actuarial survival and overall survival were 77 % and 61 % at 5 years and 53 % and 42 % at 10 years, respectively. A Cox regression analysis identified intracranial extension and orbital involvement as independent factors affecting outcome.
Conclusion: Craniofacial resection combined with radiotherapy offers the gold standard of care against which other approaches such as endoscopic resection must be judged.
Samuel S. Becker, Robert K. Jackler, Lawrence H. Pitts. Cerebrospinal fluid leak after acoustic neuroma surgery: A comparison of the translabyrinthine, middle fossa, and retrosigmoid approaches. Otol Neurotol 2003;24:107–112
Objective: To determine whether the choice of surgical approach affects the rate of postoperative cerebrospinal fluid leakage in patients who have undergone surgical resection of acoustic neuroma.
Study Design: Retrospective chart review.
Setting: Tertiary referral center.
Patients: Three hundred patients who underwent surgery for acoustic neuromas were selected by consecutive medical record number until 100 resections via each surgical approach (translabyrinthine, middle fossa, and retrosigmoid) had been gathered.
Main Outcome Measures: Surgical approach used, cerebrospinal fluid leak incidence, tumor size, patient age.
Results: Postoperative cerebrospinal fluid leak of any severity was observed in 13 % of translabyrinthine, 10 % of middle fossa, and 10 % of retrosigmoid patients. These difference in the rate of cerebrospinal fluid leakage were not statistically significant (p = 0.82). The majority of leaks were managed conservatively with fluid and activity restriction, often accompanied by a period of lumbar subarachnoid drainage. There was a need to return to the operating room for a definitive procedure in 4 % of translabyrinthine, 2 % of middle fossa, and 3 % retrosigmoid patients; again not statistically different among the approaches (p = 0.43). Tumor size was not correlated with cerebrospinal fluid leak rate (p = 0.13). Patient age, for patients older than 50 years, was suggestive of increased odds of cerebrospinal fluid leak (p = 0.06).
Conclusion: Neither surgical approach nor tumor size affects the rate of postoperative cerebrospinal fluid leakage or the necessity of managing a leak with a return to the operating room. Cerebrospinal fluid leakage rates have remained stable in recent decades despite numerous innovative attempts to improve dural closure, seal transected air cell tracts, and occlude anatomic pathways. The finding that leak rates were similar among three dissimilar surgical techniques suggests that factors other than techniques of wound closure, such as transient postoperative rises in cerebrospinal fluid pressure, may be responsible for these recalcitrant cases.
Kees Graamans, Johannes E. Van Dijk, Luuc W. Janssen. Hearing deterioration in patients with a non–growing vestibular schwannoma. Acta Otolaryngol 2003;123:51–54
Objective: The aim of this study was to document and analyse the course of several audiometric parameters in 49 patients with a non–growing unilateral vestibular schwannoma (VS).
Material and Methods: Patients received conservative management and absence of tumour growth was ascertained by means of serial magnetic imaging studies. Pure–tone audiometry and speech audiometry were performed at yearly intervals.
Results: Pure–tone audiometry revealed a significant increase in thresholds at all frequencies, except for 8.0 kHz. The maximum yearly threshold increase was 2.4 dB hearing level at 1.0 and 2.0 kHz. Speech audiometry revealed a significant decrease in maximum discrimination over the course of time. No significant changes were observed in the following parameters: the intensity level at which maximum discrimination was achieved; the roll–over index; the speech reception threshold; and the slope of the curve in the speech audiogram. No change was observed in the relation between pure–tone audiometry thresholds and speech audiometry scores. Apparently, the deterioration of pure–tone perception and speech discrimination ran parallel courses.
Conclusions: The results of this study indicate that hearing loss is a predominant symptom in patients with a non–growing VS. as is also known in patients with a growing lesion. Moreover, it seems unlikely that the hearing loss in VS patients is merely the result of mechanical influences on retrocochlear neural or vascular structures.