Analysis of the diagnosis maneuver of lateral semicircular canal benign positional paroxysmal vertigo and observation of the otolith movement using physical engine / 解剖学报

Objective To analysis the diagnosis maneuvers of lateral semicircular canal benign positional paroxysmal vertigo (BPPV) and to explore the diagnostic mechanism. Methods The three-dimensional BPPV labyrinth model was established based on the physical engine. The otolith in different positions of the lateral semicircular canal was set up. The otolith movement in different positions during the horizontal roll test was analyzed, and the induced nystagmus could be inferred. Results Horizontal roll test nystagmus manifestations were diverse, including bilateral ageotropic nystagmus, which could be judged as otolith in ampullary and crista, and weak side of nystagmus was the affected side; bilateral geotropic nystagmus could be judged as otolith in the long arm of the lateral semicircular canal, and strong side of nystagmuss was the affected side; Ageotropic nystagmus in one side and geotropic nystagmus in another side, considering otolith in ampullary of long arm. The horizontal roll test may restore otolith to utricle and reduce the sensitivity of the diagnostic tests. The result of 10 repetitions were consistent. Conclusion Sixty degree horizontal roll test effectively corrects the defects of 90 degree horizontal roll test. The analysis of diagnostic tests based on the physical engine is of great significance for us to understand the diagnostic mechanism of BPPV in the lateral semicircular canal and to improve and innovate diagnostic maneuver.

Middle Ear Actinomycosis Involving Facial Nerve and Lateral Semicircular Canal / 대한이비인후과학회지

Actinomycosis is a chronic granulomatous disease caused by the species of Actinomyces. Although it has become a rare disease in the present antibiotics era, it still needs long term antibiotic treatment and often mis- or delayed- diagnosed due to no typical sign and symptoms. Most often, it occurs in the cervicofacial region. Middle ear is not a common site for Actinomycosis, and the inner ear involvement is extremely rare. Here, we report a case of middle ear Actinomycosis involving facial nerve and lateral semicircular canal.

Clinical Characteristics of 7 Patients with Lateral Semicircular Canal Dysplasia / 대한평형의학회지

BACKGROUND AND OBJECTIVES: Dysplasia of lateral semicircular canal (LSCC) is the most common inner ear malformation, because LSCC is the last single structure to be formed during inner ear embryogenesis. There have been several case reports about the LSCC anomaly which showed clinical spectrum ranging from no symptom to severe sensorineural hearing loss. The authors investigated the clinical characteristics of 7 patients with LSCC dysplasia. MATERIALS AND METHODS: The medical records of 7 patients who were diagnosed as LSCC dysplasia from temporal bone computed tomography were retrospectively reviewed. We analysed the findings of history taking, pure tone audiometry, speech audiometry, and caloric tests. RESULTS: The LSCC dysplasia was observed in all of 7 patients in which 5 showed unilaterally confined LSCC dysplasia, 1 showed bilaterally confined LSCC dysplasia, and 1 exhibited bilateral LSCC dysplasia combined with bilateral posterior semicircular canal dysplasia. From 7 patients, hearing loss was chief complaint only in 2 patients. Pure tone audiometry revealed sensorineural hearing loss in one patient, and conductive hearing loss in the other patient. Two patients complained of whirling type vertigo, and 3 complained of nonspecific dizziness. CONCLUSION: The patients with LSCC dysplasia may show variable symptoms such as sensorineural hearing loss, conductive hearing loss, vertigo and nonspecific dizziness.

Influence of Head Position in Rotation Test / 대한평형의학회지

BACKGROUND AND OBJECTIVES: Rotation test is a widely used method to evaluate the function of the vestibular system. Generally, the head position to be tilted forwards 30degrees during rotation is preferred in order to bring the horizontal semicircular canals into the plane of rotation, thus ensuring maximum response. However literatures do not provide a clear reference concerning head position during the rotation test. So, we evaluated the vestibuloocular reflex (VOR) induced by sinusoidal rotation in the horizontal plane in the two different head positions: the head tilted forward 30degrees and with the head upright. MATERIALS AND METHODS: A total of 20 men with no known neuro-otological disorders and 9 guinea pigs were studied. The rotations of slow harmonic acceleration on various frequencies were performed with the subject's head in the upright position and in the 30 pitched down position. Computerized electronystagmography in human and magnetic coil in guinea pigs were used to measure the maximum velocity of slow component of horizontal nystagmus and to calculate gain, phase and symmetry of VOR responses. RESULTS: In both groups, results showed no significant differences in gain, phase and symmetry. CONCLUSION: In the two different head positions, there were no significant differences in gain, phase and symmetry. The posture of head upright is more comfortable for the patient and gives enough response for the evaluation of vestibular function.

Lateral Semicircular Canal Dysplasia in Middle Ear Cholesteatoma Patients / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Lateral semicircular canal (LSC) dysplasia is the most common congenital anomaly in the inner ear. The LSC dysplasia usually accompanies other inner ear anomalies, and the concurrent occurrence of the inner ear anomaly and the middle ear anomaly also has been reported. The purpose of this study was to investigate the LSC dysplasia among patients with middle ear cholesteatoma. MATERIALS AND METHOD: Medical record and temporal bone computed tomographic (CT) scan of cholesteatoma patients with the LSC dysplasia were analyzed retrospectively. RESULTS: There were four cases of the LSC dysplasia among 262 cholesteatoma patients (1.5%) during five years. Temporal bone CT scan showed short, dilated LSC and enlarged vestibule. The cochlea and the opposite side of the bony labyrinth were normal. All of the patients showed middle ear cholesteatoma occurring on the affected ear. Three patients showed mixed type of hearing loss, and the other one patient with Down's syndrome showed profound hearing loss on auditory brainstem response. In the velocity step test, two patients were normal, and one patient showed decreased response in the affected side. CONCLUSION: This study showed that the LSC dysplasia might be a relatively common inner ear anomaly encountered on the preoperative CT scan of cholesteatoma patients. The relationship between the LSC dysplasia and the development of middle ear cholesteatoma is not clear, and further studies are needed.

Effectiveness of Cupulolith Repositioning Maneuver in the Treatment of Lateral Semicircular Canal Cupulolithiasis / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: There is still a controversy surrounding lesion side differentiation and treatment of the lateral canal cupulolithiasis. The purpose of this study is to understand side differentiation, and study the treatment of this disease through analyses of clinical features, electronystagmographic (ENG) results, treatment maneuvers and its effectiveness. MATERIALS AND METHODS: Twenty three patients who showed ageotropic direction-changing horizontal positional nystagmus were included in this study. A supine head turning test was performed to induce positional nystagmus. Clinical findings and typical features of the nystagmus were recorded. Neurologic examinations, ENG tests, and MRI (6 cases) were checked to exclude the possibility of any central lesions. Cupulolith Repositioning Maneuver (CuRM) was applied on the patients and these patients were instructed to keep the healthy side at the lateral decubitus position while sleeping. RESULTS: The nystagmus had a short latency, no fatigability, and persistency in character. In one patient, nystagmus was resolved spontaneously, so we could not decide the lesion side. However, seventeen out of 22 patients showed significant differences between the intensity of each side nystagmus, and all of them showed stronger nystagmus when the head was rotated to the unaffected side. In five patients who showed no significant difference between the intensity of each side nystagmus, two cases showed same results and three cases showed opposite results. Typical nystagmus and spinning sensation in the supine head-turning test had completely subsided after physical therapy. CONCLUSION: In the cupulolithiasis of lateral semicircular canal, ageotropic nystagmus was stronger when the pathological ear was at the uppermost position, and this excitatory nystagmus beat to the lesion side. But, if there was no significant difference between the intensity of each side nystagmus, associated canal paresis, other types of BPPV, past history of acute vestibuloneuritis, and Meniere's disease, etc. might be helpful to localize the lesion side. CuRM and post- treatment lateral decubitus position kept during the night (while sleeping on the day of treatment) were effective in treating the cupulolithiasis of lateral semicircular canal.

A Case of Lateral Semicircular Canal Dysplasia with Normal Cochlea / 대한이비인후과학회지

Congenital anomalies of the inner ear in comparison with anomalies of the external and middle ear present a clinical problem for diagnosis, because the inner ear structures can not be observed directly. Ontolaryngologists can diagnose these anomalies by radiological study alone. In recent years, high-resolution computed tomographs permits more reliable and definitive diagnosis of these anomalies. Although the incidence of anomalies of the vestibular canals have been less well studied than those of cochlear anomalies, congenital malformation of the semicircular canals are rare. We present one case with computed tomographic findings of lateral semicircular canal dysplasia with normal cochlea development. Initial air and bone conductions were within normal limits, although he mainly complained dizziness. Bithermal caloric responses were absent on the involved side. Computed tomogram showed isolated lateral semicircular canal dysplasia. To our knowledge, this case is the first report of labyrinthine dysplasia with normal cochlear development in Korea.

Direction Changing Positional Nystagmus from Canalolithiasis and Cupulolithiasis of Lateral Semicircular Canal / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Clinical features of positional nystagmus may be different according to the etiology. Thus, efforts have been made to find out etiologies of various positional nystagmus. Until recently, positional vertigo was thought to arise from lesions of central nervous system. However, more recent investigations suggest that the peripheral lesion may be the main cause. Moreover, there have been some reports suggesting that directional changing positional nystagmus occurs due to canalolithiasis and cupulolithiasis of the lateral semicircular canal. The objectives of the study were to investigate the etiologies and clinical aspects of DCPN (direction changing positional nystagmus) from canalolithiasis and cupulolithiasis of the lateral semicircular canal, and to assess the effectiveness of the treatment. MATERIALS AND METHODS: Among 15 patients with DCPN, 9 patients showed nystagmus compatible with canalolithiasis of lateral semicircular canal and 6 patients with cupulolithiasis of lateral semicircular canal. Patients with cupulolithiasis and canalithiasis of the lateral semicircular canal did not respond to physical therapy for posterior semicircular canal. However, they were completely recovered by reposition maneuver for the lateral semicircular canal with or without using vibrator although 3 of them had recurred symptom. Four patients had BPPV of the posterior semicircular canal prior to the development of DCPN and 3 patients underwent the treatment of previous Meniere's disease. CONCLUSION: The patients with DCPN were due to canalithiasis and cupulolithiasis of the lateral semicircular canal, and physical therapy for lateral semicircular canal was rewarding.