메니에르병에서 내림프낭감압술 후 장기 추적관찰에 따른 치료 결과

서명환,김봉직,김종선 대한이비인후과학회 2008 대한이비인후과학회지 두경부외과학 Vol.51 No.4

The treatment result of endolymphatic sac decompression (ELSD) is controversial especially after a long term follow-up period. The aims of this study are to review the long term treatment outcome of ELSD and to analyze the factors associated with the long term prognosis. Subjects and Method:A retrospective review of medical records was performed. Sixteen patients (18 ears) who had been diagnosed with definite Ménière’s disease, had undergone ELSD and been followed up for more than 2 years were included in this study. The average follow up period was 88.6 months, with the range spanning from 25.7 to 243.4 months. All results were described according to the 1995 AAO-HNS criteria. Results:After a long term follow-up, vertigo was successfully controlled in 66.6% and hearing was preserved or improved in 58.8%. Tinnitus and aural fullness were relieved in 27.3% and 60.0% respectively. The preoperative hearing threshold (p=0.03) and caloric test (p=0.05) showed a close relationship with the long term vertigo control after ELSD. Conclusion:Although vertigo and hearing may deteriorate again after 2 years, ELSD generally seems to be able to control vertigo even after a long term follow up. Preoperative hearing threshold and caloric test may be able to serve as prognostic factors. (Korean J Otorhinolaryngol-Head Neck Surg 2008;51:319-25)

국내 동위원소(RI) 방사성폐기물의 육상운반 방사선영향평가

서명환,홍성욱,박진백 한국방사성폐기물학회 2015 한국방사성폐기물학회 학술논문요약집 Vol.2015 No.10

Decreased Immunoreactivities of the Chloride Transporters, KCC2 and NKCC1, in the Lateral Superior Olive Neurons of Kanamycin-treated Rats

서명환,안승철 대한이비인후과학회 2012 Clinical and Experimental Otorhinolaryngology Vol.5 No.3

Objectives. From our previous study about the weak expressions of potassium-chloride (KCC2) and sodium-potassium-2chloride (NKCC1) co-transporters in the lateral superior olive (LSO) in circling mice, we hypothesized that partially damaged cochlea of circling mice might be a cause of the weak expressions of KCC2 or NKCC1. To test this possibility,we reproduced the altered expressions of KCC2 and NKCC1 in the LSO of rats, whose cochleae were partially destroyed with kanamycin. Methods. Rat pups were treated with kanamycin from postnatal (P)3 to P8 (700 mg/kg, subcutaneous injection, twice a day) and sacrificed for immunohistochemical analysis, scanning electron microscope (SEM) and auditory brain stem response. Results. The SEM study revealed partially missing hair cells in P9 rats treated with kanamycin, and the hearing threshold was elevated to 63.8±2.5 dB SPL (4 ears) at P16. Both KCC2 and NKCC1 immunoreactivities were more prominent in control rats on P16. On 9 paired slices, the mean densities of NKCC1 immunoreactivities were 118.0±1.0(control) and 112.2±1.2 (kanamycin treated), whereas those of KCC2 were 115.7±1.5 (control) and 112.0±0.8(kanamycin treated). Conclusion. We concluded that weak expressions of KCC2 and NKCC1 in circling mice were due to partial destruction of cochleae. Objectives. From our previous study about the weak expressions of potassium-chloride (KCC2) and sodium-potassium-2chloride (NKCC1) co-transporters in the lateral superior olive (LSO) in circling mice, we hypothesized that partially damaged cochlea of circling mice might be a cause of the weak expressions of KCC2 or NKCC1. To test this possibility,we reproduced the altered expressions of KCC2 and NKCC1 in the LSO of rats, whose cochleae were partially destroyed with kanamycin. Methods. Rat pups were treated with kanamycin from postnatal (P)3 to P8 (700 mg/kg, subcutaneous injection, twice a day) and sacrificed for immunohistochemical analysis, scanning electron microscope (SEM) and auditory brain stem response. Results. The SEM study revealed partially missing hair cells in P9 rats treated with kanamycin, and the hearing threshold was elevated to 63.8±2.5 dB SPL (4 ears) at P16. Both KCC2 and NKCC1 immunoreactivities were more prominent in control rats on P16. On 9 paired slices, the mean densities of NKCC1 immunoreactivities were 118.0±1.0(control) and 112.2±1.2 (kanamycin treated), whereas those of KCC2 were 115.7±1.5 (control) and 112.0±0.8(kanamycin treated). Conclusion. We concluded that weak expressions of KCC2 and NKCC1 in circling mice were due to partial destruction of cochleae.

전정유발근전위: 측정방법과 임상적용

서명환,정성해,김지수 대한신경과학회 2010 대한신경과학회지 Vol.28 No.1

Only a few tests can evaluate the function of the saccule and inferior vestibular nerve. Vestibular-evoked myogenic potentials (VEMP) are inhibitory potentials recorded in the contracting muscles, usually in the sternocleidomastoids (SCM), when sound stimuli are applied. A disynaptic pathway originating in the saccule is known to mediate VEMP. The main pathway of saccule-induced inhibitory postsynaptic potentials to ipsilateral SCM motoneurons seems to be the medial vestibulospinal tract which descends within the medial longitudinal fasciculus. VEMP have been applied to determine saccular function in many disorders involving the peripheral vestibular apparatus. However, the characteristics and the diagnostic values of VEMP require further exploration in central vestibulopathies. In this review, the basic principles and recording methods of VEMP are overviewed. We will also review VEMP responses found in central as well as peripheral vestibular disorders. Despite several issues that need further elucidation, such as the exact neural pathway mediating VEMP, aging effects on VEMP, and normalization of the muscle contraction during the recording, VEMP allows us exclusive information on the function of saccule and its neural pathway, which cannot be provided by other vestibular function tests.

확산형 흡수식 냉동기의 성능에 영향을 미치는 인자에 대한 연구

서명환,Seo, Myeong-Hwan 한국설비기술협회 1985 설비 : 공조ㆍ냉동ㆍ위생 Vol.2 No.8

THIS PAPER IS A FUNDAMENTAL STUDY ON THE FACTORS AFFECT THE PERFORMANCE OF DIFFUSIVE ABSORPTION COOLING UNIT FOR DOMESTIC ABSORPTIOU REFRIGEATOR THE PURPOSE OF THIS STUDY IS TO ESTABLISH APPROPRIATE VALUES OF THE FACTORS AFFECT THE PERFORMANCE IN THE DESIGN OF DIFFUSIVE ABSORPTION COOUNG UNIT. THAT IS, MOST APPROPRIAT AMMONIA CONCENTRATION, CHARGING PRESSURE AND HEATING POWER WILL BE DERIVED.

구매 및 계약을 위한 EDI

서명환 한국경영정보학회 1993 한국경영정보학회 학술대회논문집 Vol.1993 No.-

수평반고리관과 후반고리관의 양측성 양성돌발성두위현훈

서명환,배승현,정재윤,이정구 대한이비인후과학회 2008 대한이비인후과학회지 두경부외과학 Vol.51 No.12

Bowing nystagmus, lying down nystagmus, null pointand comparing the slow phase velocity during right and left head roll test may be used to distinguish the side of lesion in lateral canal benign paroxysmal positional vertigo (BPPV). Nonetheless, it is sometimes difficult to distinguish the side of lesion. In particular, when multiple canal BPPV such as lateral and posterior canal BPPV is suspected, the problemis even more complicated. From this reason, usually the side of lesion is first identified for the posterior canal, and the lateral canal BPPV is presumed to be present on the identical side. But is this approachalways correct and justifiable? As there are reports on bilateral posterior canal BPPV and bilateral lateral canal BPPV, there should also be bilateral posterior and lateral canal BPPV cases. We report two cases of bilateral posterior and lateralcanal BPPV, and discuss the grounds for diagnosing these cases as bilateral. The first case is a mixed left posterior canalolithiasis plus right lateral canalolithiasis and the second case is a mixed right posterior canalolithiasis plus left lateral cupulolitiasis. In such cases, mixed nystagmus can make it difficult to directly compare the slow phase velocity during the right and left head roll test. New methods are necessary to distinguish the side of the lesion for the lateral canal. We introduce the concept of AHC (attenuated horizontal component) which seems to be important in deciding the side of lesion in multiple canal BPPV. We also introduce head center nystagmus (HCN) to aid the decision on the side of lesion. (Korean J Otorhinolaryngol-Head Neck Surg 2008;51:1155-62)

Parameter Optimization for Applying the Prepulse Gap Paradigm to Humans

서명환,김건우,박일용,오승하 대한청각학회 2013 Journal of Audiology & Otology Vol.17 No.3

Background and Objectives: Turner and colleagues introduced a new method that can detect tinnitus in animals. The stimulus is composed of a small background noise that is identical to the pitch of the tinnitus and a large pulse noise that can evoke a startle response. In normal rats, the gap decreases the startle reflex. However, in tinnitus rats, the gap does not decrease the startle reflex. The goal of this study was to optimize the stimulation paradigm so that the prepulse inhibition of N1-P2 amplitude would be maximized in the normal human subjects. Subjects and Methods: Seven normal control subjects without tinnitus were recruited. The stimulus was composed of two different sounds: the softer background noise and the louder pulse noise. A 50 msec silent gap was inserted before the pulse noise as the gap condition (G condition) but not in the no-gap condition (N condition). The averaged amplitude of the N1-P2 cortical response was recorded for the G and N conditions. Results: The G/N ratio was the smallest when the gap was 20 msec prior to the pulse noise. The G/N ratio was 84.8±16.8% with the Hanning window and 78.5±5.9% without the window. The G/N ratio was 91.1±24.9%, 78.0±5.4%, and 79.0±18.1% when the intensity of the background noise was 10, 20, and 32 dB SL, respectively. When the intensity of the background noise was 20 and 32 dB SL, the N1-P2 amplitude of the G condition was significantly smaller than that of the N condition. Conclusions: The optimal stimulus should be composed of the 1 kHz pulse noise without Hanning window. The intensity of the background noise should be 20 dB HL and the location of the gap should be 20 msec prior to the pulse noise. It seems that with these optimized parameters we could expect a 78.0% inhibition of N1-P2 amplitude in normal subjects without tinnitus.

사용후핵연료 금속 겸용용기를 활용한 저장시설 개념모델에 대한 방사선환경영향평가

서명환,김태만,백창열,차길용 대한방사선방어학회 2012 대한방사선방어학회 학술발표회 논문요약집 Vol.2012 No.11

추골기저동맥 순환부전 발작기에 나타난 안진의 양상

서명환,김건우,이창민,정재윤 대한평형의학회 2010 Research in Vestibular Science Vol.9 No.3

The nystagmus of vertebrobasilar insufficiency (VBI) patients is not clearly understood. In this article we report a videonystagmography (VNG) result which had been recorded in a VBI patient during his ictal period. The spontaneous nystagmus was purely torsional toward the left side. During the various positional tests, up beating left torsional and right horizontal nystagmus was found. Right beating horizontal nystagmus was stronger when the head was turned to the left side. But we were not able to explain the exact mechanism of this nystagmus. Although the mechanism is not fully understood the pattern of nystagmus reported in this article may be helpful in distinguishing VBI from other diseases by means of VNG recording.