ABSTRACT
BACKGROUND AND OBJECTIVES: The facial nerve schwannoma, hard to diagnose due to its rareness and relatively slow growth rate, is best managed by surgical procedures. We have tried to find the most useful management strategy for the facial nerve schwannoma. MATERIALS AND METHODS: We reviewed 11 cases of facial nerve schwannoma which were surgically treated. We analyzed the treatment results according to the age of the patient, the size and site of the tumor and accompanying symptoms. RESULTS: The clinical manifestations were various and surgical approaches were determined according to the age, site and size of the tumor, preoperative facial nerve function and hearing. When the preoperative facial nerve functions were better than House-Brackmann grade III, the results of the surgical treatments were favorable, but when worse than House-Brackmann grade IV, the results were unfavorable. CONCLUSION: For the treatment of the facial nerve schwannoma, the site and size of the tumor, age of the patient, preoperative hearing level and facial nerve function are considered as the decisionmaking factors. We proposed the flow-sheet of the management of the facial nerve schwannoma. Patients with no or mild facial palsy preoperatively can be managed by enucleation only. Patients with more than moderate degree facial palsy or large tumor can be managed by total resection with reconstruction of the facial nerve, which results in somewhat unfavorable results in respect to the facial nerve function.
Subject(s)
Humans , Facial Nerve , Facial Paralysis , Hearing , NeurilemmomaABSTRACT
BACKGROUND AND OBJECTIVE: It is well known that compensation begins after acute unilateral peripheral vestibular function loss. The change of vestibulo-ocular reflex (VOR) is variable and affected by many factors. But there is no studies reported on the changes of individuals with the lapse of time. Using the rotation chair test and caloric test, we wanted to know the individual compensatory process of VOR as time progresses following an acute unilateral peripheral vestibular loss. MATERIALS AND METHODS: Subjects were patients of acute peripheral vestibular neuritis (n=19) whose nystagmus showed more than 24 hours. The follow up period was 10 weeks until the head shake nystagmus (HSN) disappeared. We measured the duration of each spontaneous nystagmus (SN) and HSN. Sinusoidal harmonic acceleration (SHA) was tested at 0.04 and at 0.08 Hz level, with the step velocity of 100 degrees per second. We also performed caloric test after HSN disappeared. RESULTS: SN and HSN each lasted 25 days and 50 days. VOR changes had an irregular pattern among individuals with gain increasing after decrement and phase lead decreasing after increment. Furthermore, the gain asymmetry was more irregular and lasted longer as well at the step velocity. Even though compensation has been reached, the caloric test revealed continuous abnormal values, which is quite different from the recovery of VOR in the rotatory test. CONCLUSION: During the early compensation period, we could recognize that the individual VOR changes recovered with a irregular pattern. On the other hand, the caloric test was not altered even after compensation.
Subject(s)
Humans , Acceleration , Caloric Tests , Compensation and Redress , Follow-Up Studies , Hand , Head , Reflex, Vestibulo-Ocular , Vestibular NeuronitisABSTRACT
The endolymphatic secretory epithelium are stria vascularis in cochlear and dark cell in vestibule which are regulated by Na+-K+ ATPase. It is important that we study intracytoplasmic Na+-K+ ATPase for the physiologic research of inner ear. Recently cerium-based method for stain of Na+-K+ ATPase was developed. This study was underkaken to investigate the morphologic changes and Na+-K+ ATPase activity in stria vascularis and vestibular dark cell of mongolian gerbil after systemic intramuscular injection(200mg/kg or 300mg/kg) for 7days or local infiltration of streptomycin through round window. The results are as follows. 1) The strong Na+-K+ ATPase activity was seen at basolateral infoldings of marginal cell in stria vascularis but weak Na+-K+ ATPase activity in dark cell near transitional area. 2) There was no change of Na+-K+ ATPase activity in the stria vascularis and dark cell by systemic injection of streptomycin. The decrease of Na+-K+ ATPase activity in stria vascularis was seen at destruction site of infoldings by local infiltration of streptomycin but no changes in dark cell. 3) The ultrastructural changes of marginal cell by local infiltration of streptomycin were intracytoplasmic vacuole, partial loss of cytoplasmic infoldings, edema, and increase of melanin particle. but, there was no change of ultrastructure in dark cell except increase of melanin particle. The changes of ultrastructure of stria vascularis was variable by systemic streptomycin injection and there was no dark cell change except increased melanin particle. From the above results, the changes of ultrastructure and Na+-K+ ATPase were more severe by local infiltration of streptomycin through round window than systemic injection of streptomycin. The local infiltration of streptomycin through round window may be suitable method for the induction of inner ear damage.
Subject(s)
Adenosine Triphosphatases , Cytoplasm , Ear, Inner , Edema , Epithelium , Gerbillinae , Melanins , Streptomycin , Stria Vascularis , VacuolesABSTRACT
We investigated the vestibulo-ocular reflex which is followed by the change of angular acceleration in sinusoidal harmonic acceleration test. 20 normal volunteers with no evidence of previous otoneurologic disease were tested. The maximal slow phase eye velocity, gain and asymmetry were obtained in five different amplitudes of rotation, 30degrees, 60degrees, 90degrees, 120degrees and 150degrees with properly fixed conditions such as darkness and the frequency of rotation fixed at 0.05Hz. During each test, we asked the examinees to be alert and keep the eyes open. At least 5 minute interval was given between the tests and recalibrations were done before each test. The results of this test were as follows. 1) The maximal slow phase eye velocities were gradually increased according to the increment of the amplitudes of rotation with the statistical significances(p0.05). Therefore, from the above results, sinusoidal harmonic acceleration test with the frequency fixed at 0.05Hz, gain is higher when the amplitude of rotation is smaller and the pattern of the nystagmus is more evident when the amplitude of rotation is bigger. But The authors conclude that in order to get the results which are statistically significant, the amplitude of rotation should be lower than 90degrees.