Chemotherapy of bilateral acoustic neuromas

Decision making in acoustic neuroma management: the only hearing ear

Patients with acoustic neuroma in their only hearing ear are not frequently seen in clinical practice. Managing this group of patients is a challenge to both patient and surgeon. In this study we report on five cases of acoustic neuroma in an only hearing ear. Our decision for nonsurgical management of those patients with regular follow-up using auditory brainstem responses and magnetic resonance imaging is discussed. Other management options currently available are considered as well.

Suggested response criteria for phase II antitumor drug studies for neurofibromatosis type 2 related vestibular schwannoma

Neurofibromatosis type 2 (NF2) is a tumor suppressor gene syndrome characterized by multiple schwannomas, especially vestibular schwannomas (VS), and meningiomas. Anticancer drug trials are now being explored, but there are no standardized endpoints in NF2. We review the challenges of NF2 clinical trials and suggest possible response criteria for use in initial phase II studies. We suggest two main response criteria in such trials. Objective radiographic response is defined as a durable 20% or greater reduction in VS volume based on post-contrast T1-weighted MRI images collected with 3 mm or finer cuts through the internal auditory canal. Hearing response is defined as a statistically significant improvement in word recognition scores using 50-word recorded lists in audiology. A possible composite endpoint incorporating both radiographic response and hearing response is outlined. We emphasize pitfalls in response assessment and suggest guidelines to minimize misinterpretations of response. We also identify research goals in NF2 to facilitate future trial conduct, such as identifying the expectations for time to tumor progression and time to measurable hearing loss in untreated NF2-related VS, and the relation of both endpoints to patient prognostic factors (such as age, baseline tumor volume, and measures of disease severity). These data would facilitate future use of endpoints based on stability of tumor size and hearing, which might be more appropriate for testing certain drugs. We encourage adoption of standardized endpoints early in the development of phase II trials for this population to facilitate comparison of results across trials of different agents.

Management of acoustic neuroma in the only hearing ear

Patients with acoustic neuroma in their only hearing ear are not frequently seen in clinical practice. Managing this group of patients is a challenge to both the patient and surgeon. In this study we report on five cases of acoustic neuroma in an only hearing ear. Our decision for conservative management of those patients with regular follow-up using auditory brain stem response and magnetic resonance imaging is discussed. Other management options currently available are reviewed as well.

Vestibular schwannoma and the only hearing ear

With the recent advances in the management of vestibular schwannomas, it is possible not only to save the facial nerve function but also preserve hearing in a small percentage of cases. Difficulties arise while managing patients with vestibular schwannoma in their only hearing ear. In this article we summarize our experience in managing seven of these patients. We recommended a watch and wait policy with a regular follow-up with audiometric testing and gadolinium-enhanced magnetic resonance imaging (MRI). Gamma knife radiosurgery is advised in cases with deterioration of hearing or increase in tumour size. Surgery is usually avoided unless there are brainstem compression symptoms.

Bilateral acoustic neuromas

This article reviews 12 patients with bilateral acoustic neuromas. The sex incidence was equal and the mean age at diagnosis was 26.2 years. The family history was positive in nine of the patients. Five patients have had incomplete surgical removal of acoustic neuromas on both sides. Two of them are completely deaf and the other three have severe sensorineural hearing loss in one ear and no hearing in the other ear. In five patients the tumour on one side has been operated on and the other side is being observed with at least short-term preservation of good hearing. The remaining two patients died of intra-cranial complications, one of them post-operatively. Four patients developed facial palsy immediately following surgery and one developed facial weakness 6 months after surgery. Guidelines are discussed for the care of these patients including the timing of surgery and alternative treatment options (observation, radio-surgery and chemotherapy). This is essentially a group of young individuals who have had multiple operations for bilateral acoustic tumours and associated manifestations and for whom the disease and the sequelae of treatment can be tragic.

Recovery from repeated sudden hearing loss with corticosteroid use in the presence of an acoustic neuroma

Sensorineural hearing loss of sudden onset may be the presenting symptom in up to 14% of patients with acoustic neuroma. We present the first reported case of sudden hearing loss in an only hearing ear with recovery to normal levels after steroid therapy on four separate occasions. Evaluation revealed a 1.5-cm acoustic neuroma. After middle cranial fossa decompression, a fifth episode with recovery after steroid use was documented. A review of the recent literature is presented, emphasizing the possible causation of sudden sensorineural hearing loss with recovery to normal in patients with acoustic neuroma. Modalities of therapy for the dilemma of the acoustic neuroma in an only hearing ear are discussed, including surgery, radiotherapy, and chemotherapy. An aggressive approach to the evaluation of the cause of sudden hearing loss is suggested.

A case of neurofibromatosis 2 presenting with a mononeuritis multiplex

A patient with neurofibromatosis 2 had an asymmetrical peripheral neuropathy. A nerve biopsy specimen revealed neurofibromatous changes, and the neuropathy may have been a direct consequence of neurofibromatosis. An apparent clinical response to immunosuppressive treatment and plasma exchange is also reported.

Oral manifestations of neurofibromatosis types I and II

The disease known as neurofibromatosis is now recognized to consist of distinct variants that differ from each other genetically, microscopically, and clinically. Neurofibromatosis type I (NF-I) is often referred to as von Recklinghausen's disease of skin, and its features are well known. Neurofibromatosis type II (NF-II) is a much more uncommon manifestation that probably results from a structural defect in chromosome 22, as opposed to NF-I, which is related to chromosome 17. Although neurofibromas occur in NF-II, neurilemmomas and acoustic neuromas are the predominant neural tumors; bilateral acoustic neuromas are the hallmark of the disease. NF-II largely afflicts the central nervous system and has a more gradual onset than and different clinical features from NF-I. One case each of NF-I and NF-II is presented, with emphasis on oral manifestations. Diagnostic techniques, treatment, and prognosis are reviewed.

Radiosurgery of acoustic neurinomas

Eighty-five patients with acoustic neurinomas underwent stereotactic radiosurgery with the gamma unit at the University of Pittsburgh (Pittsburgh, PA) during its first 30 months of operation. Neuroimaging studies performed in 40 patients with more than 1 year follow-up showed that tumors were smaller in 22 (55%), unchanged in 17 (43%), and larger in one (2%). The 2-year actuarial rates for preservation of useful hearing and any hearing were 46% and 62%, respectively. Previously undetected neuropathies of the trigeminal (n = 12) and facial nerves (n = 14) occurred 1 week to 1 year after radiosurgery (median, 7 and 6 months, respectively), and improved at median intervals of 13 and 8 months, respectively, after onset. Hearing loss was significantly associated with increasing average tumor diameter (P = 0.04). No deterioration of any cranial nerve function has yet developed in seven patients with average tumor diameters less than 10 mm. Radiosurgery is an important treatment alternative for selected acoustic neurinoma patients.