Narrow internal auditory canal syndrome: parasaggital reconstruction

2000 ◽  
Vol 114 (5) ◽  
pp. 392-394 ◽  
Author(s):  
Yang-Sun Cho ◽  
Dong Gyu Na ◽  
Jae Yun Jung ◽  
Sung Hwa Hong

Narrow internal auditory canal (IAC) syndrome is a malformation of the temporal bone, that is defined as an IAC diameter of only 1–2 mm on high-resolution computed tomographic scans (HRCT). This syndrome is known to be caused by the absence (aplasia or hypoplasia) of the vestibulocochlear nerve. We present a case of unilateral narrow IAC syndrome which was diagnosed by HRCT. The aplasia of the vestibulocochlear nerve was confirmed using parasigittal reconstruction magnetic resonance image (MRI). The IAC was composed of two separate canals, one of which contained a facial nerve and the other was empty with aplasia of the vestibulocochlear nerve.

2012 ◽  
Vol 18 (2) ◽  
pp. 179-182
Author(s):  
Sathiya Murali ◽  
Arpana Shekhar ◽  
S Shyam Sudhakar ◽  
Kiran Natarajan ◽  
Mohan Kameswaran

Internal auditory canal (IAC) stenosis is a rare cause of sensorineural hearing loss. Patient may present with symptoms of progressive facial nerve palsy, hearing loss, tinnitus and giddiness. High resolution temporal bone CT-scan and magnetic resonance imaging (MRI) are the important tools for diagnosis. No specific management has been devised. Here is presentation of a case of unilateral (left) IAC stenosis with profound hearing loss and progressive House Brackmann Grade III-IV facial weakness. The diameter of the IAC was less than 2 mm on high resolution temporal bone computed tomography (HRCT) scan. It was managed by facial nerve decompression by translabyrinthine approach in an attempt to prevent further deterioration of facial palsy. DOI: http://dx.doi.org/10.3329/bjo.v18i2.12014 Bangladesh J Otorhinolaryngol 2012; 18(2): 179-182


2003 ◽  
Vol 117 (10) ◽  
pp. 784-787 ◽  
Author(s):  
Seung Kuk Baek ◽  
Sung Won Chae ◽  
Hak Hyun Jung

Congenital internal auditory canal stenosis is a rare cause of sensorineural hearing loss in children. A retrospective analysis including clinical manifestation and radiological findings was made for seven patients who were diagnosed with congenital internal auditory canal stenosis from 1996 to 2002. Chief presenting symptoms were hearing loss, facial nerve palsy, dizziness, and tinnitus. Hearing loss including deafness was found in five cases, vestibular function loss in four cases, and profound functional loss of facial nerve in two cases. In all cases, the diameter of the internal auditory canal was less than 2 mm on high-resolution temporal bone computed tomography (CT) scan. Two cases revealed bilateral internal auditory canal stenosis, and others were unilaterally involved cases. Congenital internal auditory canal stenosis can be an important cause of sensorineural hearing loss, facial nerve palsy, and vestibular dysfunction. High resolution temporal bone CT scan and magnetic resonance (MR) imaging were important tools for diagnosis.


2017 ◽  
Vol 30 (4) ◽  
pp. 385-388
Author(s):  
Charlie Chia-Tsong Hsu ◽  
Dalveer Singh ◽  
Trevor William Watkins ◽  
Gigi Nga Chi Kwan ◽  
Sachintha Hapugoda

Background We report a case of hypertensive microbleeds strategically located at the attached segment (AS) and root entry zone (REZ) at the left facial nerve causing facial paralysis. Case Report A 60-year-old woman presented with sudden onset left facial paralysis. Medical history was significant for poorly controlled hypertension secondary to bilateral adrenal hyperplasia (primary hyperaldosteronism). The patient was initially treated for presumptive Bell’s palsy. Subsequent magnetic resonance imaging of the brain and internal auditory canal showed two microbleeds at the left cerebellopontine angle. Dedicated coronal T1 magnetization prepared rapid acquisition gradient echo and T2 sampling perfection with application optimized contrasts using different flip angle evolution sequences revealed two acute microbleeds located at the attached AS and REZ of the left facial nerve. The patient experienced only partial recovery from House–Brackmann grade IV facial paralysis at presentation to a House–Brackmann grade III facial paralysis at 1 year of follow up. Conclusions To the best of the authors’ knowledge, this is the first reported case of facial paralysis caused by microbleeds directly affecting the vulnerable AS and REZ facial nerve segments. We discuss the zonal microanatomy of the facial nerve and the crucial role of high resolution MRI for diagnosis.


1981 ◽  
Vol 90 (6) ◽  
pp. 643-649 ◽  
Author(s):  
Charles W. Beatty ◽  
Lowell D. Harris ◽  
Ku Won Suh ◽  
David F. Reese

Thin-section (1.5 mm) high-spatial-resolution computed tomography (CT) in combination with computerized high-resolution image reconstruction is an effective, noninvasive means of studying patients with a variety of temporal bone abnormalities. To determine what degree of definition and anatomic accuracy could currently be obtained by using these techniques, we performed thin-section CT and high-resolution image reconstruction with use of two fresh-frozen cadaver head specimens. We then compared these images with the actual anatomic macrosections subsequently obtained from the specimens. We concluded that high-resolution CT scans of the temporal bone can produce accurate, highly detailed, diagnostic images of the internal auditory canal, vestibule, cochlea, vestibular aqueduct, semicircular canals, ossicles, and middle ear space.


2011 ◽  
Vol 126 (1) ◽  
pp. 66-71 ◽  
Author(s):  
T Y Kew ◽  
A Abdullah

AbstractObjective:We report an extremely rare case of duplication of the internal auditory canal associated with dysfunction of both the facial and vestibulocochlear nerves. We also review the literature regarding the integrity of the facial and vestibulocochlear nerves in such cases.Case report:A 34-year-old man presented with unilateral, right-sided, sensorineural hearing loss and facial nerve palsy since childhood. Facial nerve function was observed to be House–Brackmann grade III. Computed tomography and magnetic resonance imaging demonstrated ipsilateral duplicate, vacant internal auditory canals. Based on the clinical presentation, we interpreted these radiological findings as aplasia of the vestibulocochlear nerve and severe hypoplasia of the facial nerve.Conclusion:To our best knowledge, this is the first report of vestibulocochlear nerve aplasia and severe facial nerve hypoplasia in a case of ipsilateral duplication of the internal auditory canal. High resolution gradient echo magnetic resonance imaging sequences are advocated for assessment of neural integrity in patients with an abnormal internal auditory canal and facial and/or vestibulocochlear nerve dysfunction.


2016 ◽  
Vol 69 (1) ◽  
Author(s):  
R. Agarwal ◽  
N. Singh ◽  
A.N. Aggarwal

Allergic bronchopulmonary aspergillosis (ABPA) is rarely described outside the setting of asthma or cystic fibrosis. The occurrence of ABPA in other structural lung diseases included scars of old healed pulmonary tuberculosis (PTB) is also unknown. In this case, we report a 62- year old lady treated for PTB 40 years ago who presented with increasing dyspnea on exertion, cough with expectoration of blackish brown mucus plugs and wheezing. High-resolution computed tomographic scan of the thorax showed parenchymal fibrosis and volume loss in left upper lobe while central bronchiectasis, mosaic attenuation, centrilobular nodules with a tree-in-bud pattern were observed in the other lobes. Investigations revealed a diagnosis of ABPA. The patient was treated with prednisolone and showed a significant response. We review the current literature on this unusual association of previous and cured TB with ABPA, and also discuss the hypothesis of this possible relationship.


2017 ◽  
Vol 131 (8) ◽  
pp. 676-683 ◽  
Author(s):  
E Tahir ◽  
M D Bajin ◽  
G Atay ◽  
B Ö Mocan ◽  
L Sennaroğlu

AbstractObjectives:The bony cochlear nerve canal is the space between the fundus of the internal auditory canal and the base of the cochlear modiolus that carries cochlear nerve fibres. This study aimed to determine the distribution of bony labyrinth anomalies and cochlear nerve anomalies in patients with bony cochlear nerve canal and internal auditory canal atresia and stenosis, and then to compare the diameter of the bony cochlear nerve canal and internal auditory canal with cochlear nerve status.Methods:The study included 38 sensorineural hearing loss patients (59 ears) in whom the bony cochlear nerve canal diameter at the mid-modiolus was 1.5 mm or less. Atretic and stenotic bony cochlear nerve canals were examined separately, and internal auditory canals with a mid-point diameter of less than 2 mm were considered stenotic. Temporal bone computed tomography and magnetic resonance imaging scans were reviewed to determine cochlear nerve status.Results:Cochlear hypoplasia was noted in 44 out of 59 ears (75 per cent) with a bony cochlear nerve canal diameter at the mid-modiolus of 1.5 mm or less. Approximately 33 per cent of ears with bony cochlear nerve canal stenosis also had a stenotic internal auditory canal and 84 per cent had a hypoplastic or aplastic cochlear nerve. All patients with bony cochlear nerve canal atresia had cochlear nerve deficiency. The cochlear nerve was hypoplastic or aplastic when the diameter of the bony cochlear nerve canal was less than 1.5 mm and the diameter of the internal auditory canal was less than 2 mm.Conclusion:The cochlear nerve may be aplastic or hypoplastic even if temporal bone computed tomography findings indicate a normal cochlea. If possible, patients scheduled to receive a cochlear implant should undergo both computed tomography and magnetic resonance imaging of the temporal bone. The bony cochlear nerve canal and internal auditory canal are complementary structures, and both should be assessed to determine cochlear nerve status.


2016 ◽  
Vol 131 (1) ◽  
pp. 26-31 ◽  
Author(s):  
F B Palabiyik ◽  
K Hacikurt ◽  
Z Yazici

AbstractBackground:Pre-operative radiological identification of facial nerve anomalies can help prevent intra-operative facial nerve injury during cochlear implantation. This study aimed to evaluate the incidence and configuration of facial nerve anomalies and their concurrence with inner-ear anomalies in cochlear implant candidates.Methods:Inner-ear and concomitant facial nerve anomalies were evaluated by magnetic resonance imaging and temporal high-resolution computed tomography in 48 children with congenital sensorineural hearing loss who were cochlear implant candidates.Results:Inner-ear anomalies were present in 11 out of 48 patients (23 per cent) and concomitant facial nerve anomalies were present on 7 sides in 4 patients (7 per cent of the total). Facial nerve anomalies were accompanied by cochlear or vestibular malformation.Conclusion:Potential facial nerve abnormalities should always be considered in patients with inner-ear anomalies. Pre-operative facial nerve imaging can increase the surgeon's confidence to plan and perform cochlear implantation. Magnetic resonance imaging should be used to detect inner-ear anomalies; if these are identified, temporal high-resolution computed tomography should be used to evaluate the facial nerve.


1989 ◽  
Vol 100 (3) ◽  
pp. 227-231 ◽  
Author(s):  
Clough Shelton ◽  
William M. Luxford ◽  
Lisa L. Tonokawa ◽  
William W. M. Lo ◽  
William F. House

We suggest a new explanation for the lack of auditory response to electric stimulation in children with cochlear implants: The very narrow internal auditory canal, 1 to 2 mm in diameter, and the probable absence of the cochlear nerve. This defect can be seen on high-resolution computed tomographic x-ray studies and may represent aplasia of the auditory-vestibular nerve. We report on eight children with this anomaly, three of whom have received implants and failed to respond with a sensation of sound. Identification of this problem on screening x-ray films is a contraindication to cochlear Implantation for auditory stimulation.


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