Effects of Gaze Positions on Ocular Vestibular Evoked Myogenic Potentials / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Recent works have demonstrated the existence of ocular vestibular evoked myogenic potentials (OVEMPs), which reflects otolith-ocular reflex. The purpose of this study was to identify an appropriate gaze position to detect OVEMPs produced by air-conducted sound stimulation in healthy subjects. SUBJECTS AND METHOD: Twenty four healthy subjects (35 ears) were included in this study. Surface electromyographic activity was recorded from active electrodes placed inferior to each eye. Stimulation with 500 Hz short tone bursts was used to activate the vestibular end-organs. RESULTS: Sound stimulation evoked negative-positive biphasic responses on both ipsilateral and contralateral eyes, while responses were contralateral eye-dominant. Contralateral eye responses had higher response incidence and larger amplitudes. Altering the direction of gaze generally changed the incidence and size of the inter-peak amplitudes. The higher incidence and larger amplitudes were recorded when the eyes are directed to the superior and ipsilateral side to the sound stimulation. In that gaze position, the amplitude was 5.3 micronV, the first negative peak latency was 10.5 ms and the following positive peak latency was 15.4 ms on the average. CONCLUSION: OVEMPs can be evoked using an air-conducted 500 Hz tone burst and are best recorded contralaterally with a upward gaze towards the source of sound stimulation. Further changes of the test parameters are needed for higher and consistent responses.

Effects of Changes of Plateau and Rise/Fall Times on Ocular Vestibular Evoked Myogenic Potentials

BACKGROUND AND OBJECTIVES: The ocular vestibular evoked myogenic potential (OVEMP) is a recently discovered test of labyrinthine function, analogous to the cervical VEMP. Recent works have demonstrated the existence of OVEMPs, which likely reflect otolith-ocular reflex. The purpose of this study was to identify the optimal plateau and rise/fall times of short tone bursts to detect OVEMPs in healthy subjects. MATERIALS AND METHODS: Thirteen healthy subjects (26 ears) were included in this study. Surface electromyographic activity was recorded from active electrodes placed inferior to each eye. Stimulation with 500 Hz short tone bursts was used. We used a variety of plateau and rise/fall times. Three different plateau times (1, 2, and 3 ms) and rise/fall times (0.5, 1, and 2 ms) were used. The incidence, amplitudes and latencies were compared. RESULTS: VEMP responses were clearly observed in all 26 ears at the plateau time of 2 ms and two rise/fall times (0.5 and 1 ms). The amplitudes in the individual ears tested were lower at the rise/fall time of 2 ms than at the other conditions. The amplitudes were lower at the plateau time of 3 ms compared to the other conditions. When the rise/fall time was prolonged from 0.5 to 2 ms, the n1 and p1 latencies were prolonged in parallel. However, there was no such change in latencies according to the plateau times. CONCLUSIONS: Our findings show that the ideal stimulation pattern for evoking OVEMP is at the rise/fall times of 0.5 or 1 ms and the plateau time of 2 ms. The waveform morphology of the VEMP responses observed with this stimulation pattern was simultaneously the most constant and marked.

Otolith Function Tests in Patient with Meniere's Disease

BACKGROUND AND OBJECTIVES: The aims of this study were to measure otolith function using subjective visual vertical (SVV) test and vestibular evoked myogenic potential (VEMP) test in patients with unilateral Meniere's disease, and to see the relationship of the otolithic impairment with caloric and audiologic results. MATERIALS AND METHODS:Twenty two patients with unilateral Meniere's disease who received treatment and also had been tested for pure tone, caloric, SVV and VEMP tests were enrolled. All the tests were done simultaneously. RESULTS: Five of 22 (23%) patients showed abnormal tilt to the lesion side in SVV test, and 13 of 22 (59%) patients showed abnormal VEMP results on the affected side. There was no correlation between SVV tilts and unilateral weakness (UW) in caloric tests or pure-tone average. There was also no difference of UW in patients with or without VEMP abnormalities. Two patients showed abnormal finding in both SVV & VEMP tests. One patient showed UW (47%) and SVV tilt (3.08degrees) to the lesion side, and the other showed normal UW and SVV tilt (3.22degrees) to the lesion side. CONCLUSION: Our results demonstrate that the otolith system was implicated in 16 out of 22 (73%) patients with Meniere's disease. However, there was no correlation between the abnormal results of the three tests and these findings suggest that impairment of the otolithic function is depending on the extent and/or the localization of Meniere's disease, suggesting vestibular rehabilitation for the specific lesion might be helpful.

Comparison of Air Caloric Test and Vibration-Induced Nystagmus Test in Patients with Unilateral Chronic Otitis Media without Vertigo

BACKGROUND AND OBJECTIVES: The aims of the study were to characterize the vibration-induced nystagmus (VIN) and air caloric test in patients with unilateral chronic otitis media, and to clarify the clinical availability of VIN by comparing the results of VIN test with those of air caloric test. MATERIALS AND METHODS: Nineteen patients with unilateral chronic otitis media who had had no vestibular symptoms in past history were investigated. Pure tone audiometry (PTA), air caloric, VIN and subjective visual vertical (SVV) tests were done and the results were analyzed to estimate the utility for investigating vestibular imbalance. RESULTS: If we consider a patient with abnormal results from two or more tests as a patient with latent vestibular imbalance, because they had no previous vestibular symptoms, 3 patients was considered to have latent asymmetric vestibular function. False positive rate were 32% in air caloric test, 5% in VIN test and 0% in SVV test. CONCLUSION: Our findings show that vestibular imbalance in patients with chronic otitis media should be determined through various tests and vibration-induced nystagmus test can be more useful than air caloric test in estimating the vestibular imbalance.

Follow-up Examination of Vibration-Induced Nystagmus in Patients with Unilateral Vestibular Neuritis

BACKGROUND AND OBJECTIVES: The aim of this study was to verify if vibration-induced nystagmus in patients with vestibular neuritis changed over time and to compare the results of vibration-induced nystagmus (VIN) test to those of caloric test. MATERIALS AND METHOD: We compared VIN results with those of caloric testing in 23 patients (M:F = 11:12, 15~67 years old) with unilateral vestibular neuritis seen at onset and in follow-up for around 2 months. The eye movement recordings were made and the maximum slow-phase eye velocities (SPV) were calculated during vibration. If spontaneous nystagmus was present, it was subtracted from the slow-phase eye velocities of VIN. RESULTS: In acute stage, VIN of which SPV was directed towards the lesioned side was observed in 21 (91%). In follow-up, VIN of which SPV was directed towards the lesioned side was observed in 19 (83%). There was a significant decrease of the SPV of VIN over time. Significant correlations were observed in between canal paresis & SPV of VIN in both acute and follow-up stages. CONCLUSION: Our findings show that VIN test can predict the severity of vestibular asymmetry not only in acute stage but also in follow-up stage. Our results suggest that vibration-induced nystagmus might represent the peripheral vestibular asymmetry in patients with vestibular neuritis.

Changes of Vibration-Induced Nystagmus by Age in Normal Subjects

BACKGROUND AND OBJECTIVES: It has been reported that vibration applied either on the mastoid or on the sternocleidomastoid (SCM) muscles induces nystagmus in normal subjects. The aims of the study were to characterize the direction and velocity of slow-phase eye movement which is induced by vibration in normal subjects and to propose the mechanism of vibration-induced nystagmus (VIN) in normal subjects. MATERIALS AND METHOD: We recorded eye movements during unilateral 100-Hz vibration on the mastoid bone and SCM muscles in 56 normal subjects. The subjects were divided into 4 groups in ages (20s, 30s, 40s, 50~60s). The directions of VIN, the degree of maximal slow-phase eye velocities were analyzed according to age. Positive value means slow-phase velocity (SPV) to the right side. RESULTS: In 20s, vibration on right/left mastoids induced SPV of 1.2+/-2.0degrees/sec, 0+/-2.1degrees/sec and on right/left SCM muscles, 1.1+/-1.9degrees/sec, -1.2+/-2.5degrees/sec. In 30s, vibration on right/left mastoids induced SPV of 3.3+/-3.8degrees/sec, -0.3+/-1.4degrees/sec and on right/left SCM muscles, 2.8+/-4.2degrees/sec, -1.0+/-1.5degrees/sec. In 40s, vibration on right/left mastoids induced SPV of 0+/-1.7degrees/sec, -0.2+/-1.2degrees/sec and on right/left SCM muscles, 0+/-1.8degrees/sec, 0+/-1.0degrees/sec. In 50~60s, vibration on the right/left mastoids induced SPV of -1.3+/-1.3degrees/sec, 1.2+/-1.3degrees/sec and on right/left SCM muscles, -0.6+/-0.9degrees/sec, 0.9 +/-1.5degrees/sec. The directional preponderance of the slow-phase eye movement to the vibrated side was statistically significant in 20s and 30s, however, the preponderance of the slow-phase eye movement changed into the non-vibrated side in 50~60s. CONCLUSION: The proprioceptive input, changing major rotator from the inferior oblique muscle to the sternocleidomastoid muscles might explain the change of the directional preponderance of the slow-phase eye movements in normal subjects according to ages. Although this directional preponderance is not consistent in all age groups, it is still important in discriminating normal responses from abnormal responses which can be induced by vibration.

Vibration-Induced Nystagmus in Patients with Vestibular Disorders

BACKGROUND AND OBJECTIVES: It has been reported that vibration applied either on the mastoid or the sternocleidomastoid (SCM) muscles induces nystagmus in patients after unilateral vestibular neuritis. The aims of the study were to characterize the vibration-induced nystagmus (VIN) in patients with various vestibular disorders and to compare the results of VIN to unilateral weakness in caloric test. MATERIALS AND METHODS:Fifthy-four patients with Meniere's disease, 58 patients with unilateral vestibular neuritis, 170 patients with migraine-associated dizziness, and 78 patients with chronic recurrent vestibulopathy were included. We recorded eye movements during unilateral 100-Hz vibration on the mastoids and SCM muscles. The bithermal caloric test was also performed. Abnormal criteria of VIN were slow-phase slow-phase velocity (SPV) at 4 all different conditions > or = 2degrees/s with the same directions or mean of SPV at vibration on both mastoids or both SCM muscles > or = 5degrees/s with the same directions. RESULTS: In Meniere's disease, 28 of 57 (49.1%) of patients show pathologic VIN, 21 of 57 (36.8%) show pathologic canal paresis. 14 of 57 (24.6%) show abnormalities in both tests, and 35 of 57 (61.4%) show any abnormalities in either test. In unilateral vestibular neuritis, 43 of 58 (77.6%) showed pathologic VIN, 58 of 58 (100%) show canal paresis. In migraine-associated dizziness, 48 of 170 (28.2%) showed pathologic VIN, 58 of 170 (18.8%) show canal paresis. 15 of 170 (8.8%) showed abnormalities in both tests, and 65 of 170 (38.2%) show any abnormalities in either test. In chronic recurrent vestibulopathy, 23 of 78 (29.5%) of patients show pathologic VIN and 17 of 78 (21.8%) show pathologic canal paresis. Seven of 78 (9.0%) showed abnormalities in both tests, and 33 of 78 (42.3%) show any abnormalities in either test. CONCLUSION: VIN test can increase the sensitivity in detecting vestibular imbalance in vestibular disorders when combined with caloric test.

Otolith Function Tests in Patient with Vestibular Neuritis

BACKGROUND AND OBJECTIVES: Vestibular evoked myogenic potentials (VEMP) test provides a useful method for assessment of saccule function and the functional integrity of the inferior vestibular nerve, and subjective visual vertical (SVV) abnormalities are presumably related to a lesion of the utricle. The aim(s) of this study were to measure otolith function using SVV and VEMP tests, and to define the influence of the otolithic organs in patients suffering from vestibular neuritis. MATERIALS AND METHOD: From September 2005 to January 2006, twelve patients who received treatment in hospital and also had been tested for caloric test, subjective visual vertical (SVV) and vestibular evoked myogenic potential (VEMP) tests with unilateral vestibular neuritis were enrolled. All the tests were done within 8 days after the onset of their symptoms, simultaneously. The SVV was measured in 34 normal subjects as well as in patients. RESULTS: Eight of 12 patients showed abnormal tilt to the lesion side in SVV test, and five of 8 patients showed no VEMP on the affected side. There was no correlation between SVV tilts and unilateral weakness (UW) in caloric tests. Two patients with abnormal UW (54, 82%) showed normal finding in SVV & VEMP tests. One patient with abnormal UW (83%) and SVV tilts (18.04Degree) to the lesion side was normal in VEMP test. Two patients with abnormal UW (28, 37%) and no response in VEMP test were normal in SVV test. CONCLUSION: Our results demonstrate that the incidence of abnormal results were 62.5, 66.7% in VEMP and SVV tests in acute stage of vestibular neuritis, respectively. There was no correlation between the abnormal results of the tests and these findings suggest that impairment of the otolithic function is depending on the extent and/or the localization of vestibular neuritis.

Otolith Function Tests in Patient with Vestibular Neuritis

BACKGROUND AND OBJECTIVES: Vestibular evoked myogenic potentials (VEMP) test provides a useful method for assessment of saccule function and the functional integrity of the inferior vestibular nerve, and subjective visual vertical (SVV) abnormalities are presumably related to a lesion of the utricle. The aim(s) of this study were to measure otolith function using SVV and VEMP tests, and to define the influence of the otolithic organs in patients suffering from vestibular neuritis. MATERIALS AND METHOD: From September 2005 to January 2006, twelve patients who received treatment in hospital and also had been tested for caloric test, subjective visual vertical (SVV) and vestibular evoked myogenic potential (VEMP) tests with unilateral vestibular neuritis were enrolled. All the tests were done within 8 days after the onset of their symptoms, simultaneously. The SVV was measured in 34 normal subjects as well as in patients. RESULTS: Eight of 12 patients showed abnormal tilt to the lesion side in SVV test, and five of 8 patients showed no VEMP on the affected side. There was no correlation between SVV tilts and unilateral weakness (UW) in caloric tests. Two patients with abnormal UW (54, 82%) showed normal finding in SVV & VEMP tests. One patient with abnormal UW (83%) and SVV tilts (18.04Degree) to the lesion side was normal in VEMP test. Two patients with abnormal UW (28, 37%) and no response in VEMP test were normal in SVV test. CONCLUSION: Our results demonstrate that the incidence of abnormal results were 62.5, 66.7% in VEMP and SVV tests in acute stage of vestibular neuritis, respectively. There was no correlation between the abnormal results of the tests and these findings suggest that impairment of the otolithic function is depending on the extent and/or the localization of vestibular neuritis.

Characteristics of waveforms of facial electroneurography (ENoG) according to different electrode placement in normal persons / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Electroneurography (ENoG) is regarded as a useful test for evaluating the degree of facial nerve degeneration and predicting the prognosis of the patients with facial nerve palsy. The test results could be changed by many factors, such as electrode position, skin resistance and stimulus magnitude, etc. In this study, the waveforms of ENoG in normal persons were evaluated according to different electrode placement in the nasal alae and in the nasolabial fold, respectively. MATERIALS AND METHODS: Twenty volunteers with normal facial function were included in this study. ENoG was recorded with the recording electrode placed in two different locations, one in the nasolabial fold and the other in the nasal alae, in each person. The recording waves were compared according to their amplitude, sharpness and types of waveform. Interside variability was compared. RESULTS: The amplitude was not significantly different at two locations, but the sharpness was significantly increased when recorded at the nasal alae. Biphasic waveform was more common when recorded at the nasal alae than at the nasolabial fold. This meant that the masseter artifacts were present more commonly at the nasolabial fold. The average of interside variability was 22.77% (17.62) at the nasolabial fold and 23.71% (15.35) at the nasal alae (p>0.05). CONCLUSION: Different electrode placement resulted in different waveforms. By placing the recording electrode at the nasal alae, more biphasic and sharpened waveforms were recorded and less masseter artifacts were observed.

Glomus Tumor of the Trachea / 대한이비인후과학회지

Tracheal glomus tumors are extremely rare. We present clinicopathologic findings of a resected glomus tumor of the trachea in a 43-year-old man with a review of literature, The tumor was an intraluminal polypoid mass, which arose from the posterior wall of the first to third tracheal rings. Tracheal resection with end to end anastomosis was done. Histologically, the tumor exhibited typical features of glomus tumor with areas of glomangiomyoma.

Fibromyxoma Arising from the Maxilla: A Case Report / 대한이비인후과학회지

Fibromyxomatous lesions of the maxilla are rare. Although other locations are also uncommon, this tumor can occasionally be found in jawbone. They are slow-growing, which result in expansion of the surrounding bony cortices. Maxillary and man-dibular myxomas are locally aggressive neoplasms that are thought to arise from fibroblasts of the dental papilla or sinonasal mucosa. The precise origin of these tumors, however, remains controversial. When present in the maxilla, they can extend into the maxillary sinus, the nose, or the orbit. The differential diagnosis should be made from neoplasms in which myxomatous change can be a prominent secondary feature such as liposarcomas, chondrosarcomas, and neurofibromas. We report a case with a large maxillary mass occluding the nasal cavity and expanding hard palate and gingivobuccal area. The histopathologic diagnosis was odontogenic fibromyxoma originating from canine tooth. The treatment was medial maxillectomy.