1/298. The leaking labyrinthine lesion resulting from direct force through the auditory canal: report of five cases. The leaking labyrinthine lesion is treated by conservative methods or surgical procedures. With respect to the stapes, the surgical treatment is controversial. Five cases of middle ear injuries accompanying oval window rupture are reported herein. In each case, direct force through the auditory canal damaged not only the ossicular chain but also the oval window. Initial symptoms were sudden hearing loss with significant conductive disturbance and various degrees of unsteadiness. Spontaneous horizontal nystagmus directed toward the uninvolved ear was observed in each case. Tympanic cavities were promptly explored under general anesthesia and oval window injuries were confirmed. In each case, the damaged stapes was temporally removed from the oval window. Perilymphatic leakage was recognized in each case. Two patients had subluxation of the stapes with a paucity leakage. Three had complete luxation of the stapes with a relatively huge oval window fistula. Disrupted oval windows were repaired with temporalis muscle fascial grafts that were inserted under the middle ear mucosae surrounding the oval windows. The stapes were replaced in the repaired oval windows, and the ossicular chains were reconstructed without artificial grafts. Vestibular dysfunctions disappeared within 7 days, and satisfactory audiologic results were obtained in each case. ( info) |
2/298. Labyrinthine involvement in Langerhans' cell histiocytosis. BACKGROUND: Langerhans' cell histiocytosis, a rare condition caused by the proliferation of abnormal Langerhans' cells ('LCH cells') and an accompanying granulomatous infiltrate, can affect several organs including the ear. External and middle ear involvement are common with a reported incidence as high as 61%. The bony labyrinth is resistant to erosion by the granulation tissue, thereby protecting the cochlea and vestibular structures. Probably for this reason, involvement of the inner ear is rare, with few case reports in the literature. patients: We report two girls, one with bilateral and the other with unilateral mastoid involvement, in whom there was invasion of the labyrinth. The first girl had 'single system' LCH affecting only bone and developed an acute hearing loss due to invasion of the cochlea, while the second had both bone and skin involvement and labyrinthine involvement was diagnosed on imaging prior to the onset of labyrinthine symptoms. CONCLUSION: Inner ear involvement can lead to permanent deafness, which may be prevented by early institution of treatment. Threatened inner ear involvement requires urgent systemic medical therapy with steroids, possibly combined with chemotherapy. ( info) |
3/298. cholesteatoma extending into the internal auditory meatus. We report our experiences in managing a patient with cholesteatoma complicated by meningitis, labyrinthitis and facial nerve palsy. The antero-inferior half of the tympanum was aerated but the postero-superior portion of the tympanic membrane was tightly adherent to the promontry mucosa. An attic perforation was present at the back of the malleolar head. High-resolution computed tomography also uncovered a fistula in the lateral semicircular canal. Surgical exploration of the middle ear cavity demonstrated that both the vestibule and cochlea were filled with cholesteatoma, and the cholesteatoma extended into the internal auditory meatus through the lateral semi-circular canal fistula. The cholesteatoma was removed by opening the vestibule and cochlea with a preservation of the facial nerve. Post-operatively, an incomplete facial palsy remained, but has improved slowly. There is no sign of recurrence to date after a 3-year period of observation. ( info) |
4/298. Haemorrhage in the labyrinth caused by anticoagulant therapy: case report. We report a patient who experienced a severe vertiginous episode with bilateral tinnitus and progressive right-sided hearing loss. She had Marfan's disease and was on anticoagulant treatment. The fluid in the labyrinth gave higher signal than cerebrospinal fluid on T1-weighted images, suggesting haemorrhage. The radiological follow-up is discussed. ( info) |
5/298. A method for quantitative assessment of vestibular otopathology. BACKGROUND: Quantitative studies of the vestibular system using serial sections from human temporal bones have been limited because it has been generally difficult to reliably differentiate hair cells from supporting cells and type I from type II hair cells. OBJECTIVES: 1. To develop a new method to overcome the above limitations and permit quantitative assessments of types I and II vestibular hair cells in archival temporal bone sections. 2. To demonstrate that this method is reliable, valid, and repeatable. 3. To describe the advantages of this method compared with other traditional techniques. 4. To discuss the potential of this method to provide new insight into the etiology, pathology, and pathophysiology of vestibular disorders. STUDY DESIGN: Examination of archival human temporal sections prepared for conventional light microscopy. methods: The method used Nomarski (differential interference contrast) microscopy to permit visualization of the cuticular plate and stereociliary bundle, to allow unambiguous identification of hair cells. Types I and II hair cells were distinguished by their morphological characteristics. The method was used to measure the density of types I and II hair cells in each vestibular sense organ. Raw-density counts were corrected for potential double counting using Abercrombie's formula. RESULTS: Intrarater and interrater reliability was strong as judged by high Pearson and Spearman correlation values (P < .01). Abercrombie's formula was shown to be valid by comparison with counts made by an unbiased calibration technique using the optical disector principle (correlation coefficients > 0.9, P < .01). CONCLUSIONS: The method described in this report has several advantages when compared with alternative techniques such as surface preparations. The method is applicable to archival bones, permits simultaneous evaluation of the rest of the labyrinth, is relatively inexpensive, and does not preclude other techniques of study (e.g., polymerase chain reaction and immunostaining). Case studies of temporal bones with aminoglycoside ototoxicity and Meniere's disease are used to show how this method has the potential to provide new insight into the pathology and pathophysiology of vestibular disorders. ( info) |
6/298. Vestibular-evoked myogenic potentials in patients with dehiscence of the superior semicircular canal. Recently Minor and co-workers described patients with sound- and pressure-induced vertigo due to dehiscence of bone overlying the superior semicircular canal. Identifying patients with this "new" vestibular entity is important, not only because the symptoms can be very incapacitating, but also because they are surgically treatable. We present symptoms and findings for three such patients. On exposure to sounds, especially in the frequency range 0.5-1 kHz, they showed vertical/torsional eye movements analogous to a stimulation of the superior semicircular canal. They also showed abnormally large sound-induced vestibular-evoked myogenic potentials (VEMP), i.e. the short latency sternomastoid muscle response considered to be of saccular origin. The VEMP also had a low threshold, especially in the frequency range 0.5-1 kHz. However, in response to saccular stimulation by skull taps, i.e. when the middle ear route was bypassed, the VEMP were not enlarged. This suggests that the relation between the sound-induced and the skull tap-induced responses can differentiate a large but normal VEMP from an abnormally large response due to dehiscence of bone overlying the labyrinth, because only the latter would produce large sound-induced VEMP compared to those induced by skull taps. ( info) |
7/298. sound- and pressure-induced vertigo associated with dehiscence of the roof of the superior semicircular canal. In many types of peripheral vertigo, imaging is not part of the initial evaluation. We present a patient with sound- and pressure-induced vertigo associated with bony dehiscence of the roof of the superior semicircular canal. The diagnosis of this new entity can only be made by high-resolution coronal CT imaging of the temporal bones. In patients with this symptom complex, CT should be performed early in the diagnostic workup. ( info) |
8/298. Unilateral sensorineural hearing loss and its aetiology in childhood: the contribution of computerised tomography in aetiological diagnosis and management. OBJECTIVES: The objective of this study was to identify factors correlated with the CT outcome and to examine the contribution of the CT scan in the aetiological diagnosis and management of unilateral sensorineural hearing loss in childhood. methods: The records of 35 consecutively investigated patients by the audiology Department of Great Ormond Street Hospital between January 1996 and June 1998 were reviewed. The CT results, population sample characteristics, initiation of further investigations after the CT results and management decisions based on the CT results were tabulated and analysed. RESULTS: In a series of 35 consecutively investigated children with unilateral sensorineural hearing loss, 11 CT scans were identified as abnormal. The CT findings were: labyrinthitis ossificans (3), unilaterally dilated vestibular aqueduct (2), bilaterally dilated vestibular aqueduct (2), unilateral deformity of the cochlea ('Mondini') (1), unilateral severe labyrinthine dysplasia (1), unilateral markedly narrow internal acoustic meatus (1), bilaterally dilated lateral semicircular canals (1). The presence of progressive hearing loss was a significant predictor of abnormal CT outcome, while the severity of hearing loss was not. The CT scans offered valuable information regarding the aetiological diagnosis in all cases and, in addition, prompted the appropriate vestibular rehabilitation in three cases, further investigations in four (with dilated vestibular aqueduct) and hearing preservation counselling in two (bilateral DVA) (seven out of 35 = 20%). CONCLUSION: All children with unilateral sensorineural hearing loss should have a CT scan of the petrous pyramids/IAMs performed at some stage, as not only aetiology but also prognosis and management of these cases may be significantly influenced by the CT outcome. ( info) |
9/298. Cavernous angioma of the internal acoustic meatus--case report. A 39-year-old female presented with an intrameatal cavernous angioma manifesting as hearing loss and tinnitus in the right ear which progressed over 8 months. Magnetic resonance (MR) images revealed an intrameatal lesion as ultra-high intensity, nearly as bright as cerebrospinal fluid, on the T2-weighted images, and isointensity on the T1-weighted images. Computed tomography (CT) showed the mass accompanied by stippled patterns of calcification. The patient underwent surgery under a diagnosis of calcified acoustic neurinoma. Histological studies were compatible with cavernous angioma. Intrameatal cavernous angioma is a rare disease which requires differential diagnosis from the more common neurinoma or meningioma in this location. Intrameatal lesion with ultra-high intensity on T2-weighted MR imaging and stippled patterns of calcification on CT is more likely to be cavernous angioma than acoustic neurinoma. These neuroimaging features are important information in deciding the treatment strategy. ( info) |
10/298. Clinical study of elderly patients with Meniere's and related diseases. In order to study the characteristics of elderly patients (70 or over at onset) with endolymphatic hydrops disorders, we selected six patients with Meniere's disease (MD), five patients with delayed endolymphatic hydrops (DEH), and two patients with syphilis of the labyrinth (SL) from 7112 patients who had visited the Neurotological Clinic of the Toyama Medical and Pharmaceutical University Hospital during 1979-1998. Clinical features were characterized as follows: (1) Since 1990, the proportion of elderly patients increased as lifespans lengthened. (2) A narrow fluctuation in hearing, low positive rate on glycerol test, high positive rate of dominant-SP in EcochG, and the moderate abnormal rate of the oculomotor system tests were found. (3) The prognosis was relatively good. From these neurotological observations, it could be concluded that elderly patients with endolymphatic hydrops disorders were characterized by the multipathological finding of the endolymphatic hydrops and the complications of CNS disorders. ( info) |