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Fulltext The different faces of facial nerve schwannomas

Abdullah A, Mahmud MR, Sabir HA, Saim L

Med J Malaysia, 2003 Aug;58(3):450-3.
PMID: 14750390

Facial nerve schwannomas are rare benign tumors. The tumor can arise anywhere along the course of the facial nerve. The most common presentation for this tumor is a slowly progressive facial nerve paralysis. Sensorineural hearing loss (SNHL) and tinnitus are later symptoms. The symptoms and signs depend on the site of tumor along the nerve. We report three cases of facial nerve schwannomas with different clinical presentations. Appropriate management of a facial nerve schwannoma should be based on the site and extent of the tumor and status of the nerve function.
Histopathology of the inner ear in unoperated acoustic neuroma

Mahmud MR, Khan AM, Nadol JB

Ann Otol Rhinol Laryngol, 2003 Nov;112(11):979-86.
PMID: 14653368

Although hearing loss is the most common presenting symptom in patients with acoustic neuroma, the pathophysiology of hearing loss associated with acoustic neuroma is unknown. Although primary dysfunction of the auditory nerve is intuitively logical, available histopathologic and clinical data suggest that although neural degeneration is common, it alone does not adequately account for hearing loss in many cases. The purpose of this study was to evaluate 11 cases of unoperated unilateral acoustic neuromas. Temporal bones were identified by means of a search mechanism provided by the National Temporal Bone, Hearing, and Balance Pathology Resource Registry and were prepared for light microscopy by standard techniques. Quantification of spiral ganglion cells, hair cells, stria vascularis, and spiral ligament was accomplished for each specimen. In addition, the maximum diameter and volume of each tumor were calculated from histopathologic sections. Increasing tumor size did predict a reduced spiral ganglion count. However, although there was a tendency for decreasing spiral ganglion cell count and for increasing tumor size to predict a higher pure tone average and lower speech discrimination score, these correlations did not reach statistical significance. In tumor ears in which the speech discrimination score was 50% or less, there was always significant degeneration of other structures of the inner ear in addition to neurons, including hair cells, the stria vascularis, and the spiral ligament. Endolymphatic hydrops and eosinophilic precipitate in the perilymphatic spaces were found in 2 of 3 such cases. It is concluded that acoustic neuromas appear to cause hearing loss, not only by causing degeneration of the auditory nerve, but also by inducing degenerative changes in the inner ear. It is hypothesized that the proteinaceous material seen histologically may represent the products of up-regulated genes in acoustic neuroma, some of which may interfere with normal cochlear function.
Preoperative high resolution CT and MR imaging in cochlear implantation

Abdullah A, Mahmud MR, Maimunah A, Zulfiqar MA, Saim L, Mazlan R

Ann Acad Med Singap, 2003 Jul;32(4):442-5.
PMID: 12968546

INTRODUCTION: Accurate preoperative imaging of the temporal bone in patients receiving cochlear implants is important. High resolution computed tomography (HRCT) and magnetic resonance (MR) imaging are the 2 preoperative imaging modalities that provide critical information on abnormalities of the otic capsule, pneumatisation of the mastoid, middle ear abnormalities, cochlear ducts patency and presence of cochlear nerve.
MATERIALS AND METHODS: The HRCT and MR imaging in 46 cochlear implant patients in our department were reviewed.
RESULTS: Majority of our patients [34 patients (73.9%)] showed normal HRCT of the temporal bone; 5 (10.9%) patients had labyrinthitis ossificans, 2 (4.3%) had Mondini's abnormality and 2 (4.3%) had middle ear effusion. One patient each had high jugular bulb, hypoplasia of the internal auditory canal and single cochlear cavity, respectively.
CONCLUSION: The above findings contribute significantly to our surgical decisions regarding candidacy for surgery, side selection and surgical technique in cochlear implantation.
Vestibular nerve section in a child with intractable Menière's disease

See GB, Mahmud MR, Zurin AA, Putra SH, Saim LB

Int J Pediatr Otorhinolaryngol, 2002 May 31;64(1):61-4.
PMID: 12020915

Clinical presentation of Menière's disease in children is not as typical as in adults. The triad of vertigo, tinnitus and deafness are not usually elicited, diagnosis often being made after years of follow up and batteries of investigation. A case of Menière's disease in a 3-year-old boy is presented. The diagnosis was only obvious at the age of 8 when the triad of vertigo, deafness and tinnitus were present. His disease progressed despite a trial of intratympanic gentamicin injections and endolymphatic sac decompression. Vestibular nerve section was subsequently performed for his intractable disease. Following the procedure he was asymptomatic and able to attend school.