ABSTRACT
BACKGROUND AND OBJECTIVES: Sensorineural hearing loss (SNHL) could be caused by dysfunction of the cochlea, abnormality of vestibulocochlear nerve (VCN), or disorder of central auditory pathway. Among these causes, VCN deficiency is one of the causes of profound sensorineural hearing loss. The aim for this study was to evaluate radiologic characteristics of VCN deficiency by reviewing temporal bone computed tomography (TBCT) and magnetic resonance image (MRI) findings of patients with profound unilateral SNHL, diagnosed as VCN deficiency and also, we compared the width of the bony canal of the cochlear nerve (BCCN) between the normal and affected side on TBCT and tried to clarify the diagnositc value of BCCN. MATERIALS AND METHOD: We reviewed TBCT and temporal submillimetric axial and parasagittal 3D turbo spin echo (3D-TSE) T2-weighted MRI of 9 patients who were diagnosed as unilateral VCN deficiency. We evaluated MRI findings in terms of the presence and comparative size of the component nerves (facial, cochlear, superior vestibular, inferior vestibular nerve) then we classified the type of VCN deficiency, according to the Casselman's proposal. We compared the difference of width of IAC and BCCN between normal and affected side on TBCT. RESULTS: We could find the detail anatomic feature of VCN in IAC by parasagittal MRI and could classify the type of VCN deficiency of patients, based on the Casselman's classification. According to the result of the classification, 8 patients were type 2A and the other one was type 1. In the TBCT study, the size of IAC and BCCN of the affected 8 ears were smaller than that of side and one patient had normal IAC but narrow BCCN of the affected ear. CONCLUSION: In this study, we conclude that TBCT and MRI could be useful methods for diagnosis of VCN deficiency. Also, the hypoplastic bony canal of the cochlear nerve on TBCT is finding to overlook easily and may be another important indicator for evaluating VCN deficiency.
Subject(s)
Humans , Auditory Pathways , Classification , Cochlea , Cochlear Nerve , Diagnosis , Ear , Hearing Loss, Sensorineural , Magnetic Resonance Imaging , Temporal Bone , Vestibulocochlear NerveABSTRACT
When a surgeon fails to save intracranial segement of the facial nerve and can not identify the proximal segment of the facial nerve due to severe adhesion or severe brain stem compression by the tumor, the interpositional graft has no place in helping this patient. Hypoglossal-facial nerve (XII-VII) direct side to end anastomosis is the effective facial reanimation technique used in such a case. This technique compensates for the drawbacks of classical XII-VII anastomosis, and the bothersome strong mass movement and hemiparalysis of the tongue. We recently experienced a case where XII-VII direct side-to-end anastomosis was applied. We report our case with literature review.
Subject(s)
Humans , Brain Stem , Facial Nerve , Facial Paralysis , Hypoglossal Nerve , Tongue , TransplantsABSTRACT
A number of methods have been introduced for support the orbital floor following a maxillectomy without orbital exenteration or severe facial trauma. These methods including skin graft and muscular sling provided the unsatisfactory results, like as diplopia, orbital ptosis, enophthalmos and severe facial deformity. Therefore the bone and soft tissue reconstructions using microvascular free flaps were performed recently by many surgeons, but long time operation, donor site morbidity, postoperative large scar, and ptosis of the flap were pointed out as disadvantages of free flap reconstruction. Vascularized calvarial bone flap, a modified method of free calvarial bone graft, was adequate for reconstruction of the orbital floor and the infraorbital rim as a horizontal buttress, especially in case of poor vascular bed and postradiated state. The authors introduced the vascularized calvarial bone flap for the orbital floor and the infraorbital rim reconstruction in 3 cases of maxillectomy, and could be obtained satisfactory results aesthetically and functionally.