Otology Korean J Otorhinolaryngol-Head Neck Surg 18;61(1):58-13 / pissn 92-5859 / eissn 92-6529 https://doi.org/1.3342/kjorl-hns.17.1 Caloric Test as a Possible Prognostic Indicator in Sudden Deafness Eun Jung Lim 1, Jung Soo Kim 2, Sung Jae Heo 2, Jin Geol Lee 1, Ki Hwan Kwak 1, Joo Hyeon Shin 1, and SungHee Kim 1 1 Department of Otolaryngology-Head and Neck Surgery, Daegu Fatima Hospital, Daegu; and 2 Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, Kyungpook National University, Daegu, Korea 돌발성난청에서온도안진검사의의의 임은정 1 김정수 2 허성재 2 이진걸 1 곽기환 1 신주현 1 김성희 1 대구파티마병원이비인후과, 1 경북대학교의학전문대학원이비인후-두경부외과학교실 2 Received August 9, 17 Revised October 12, 17 Accepted October 31, 17 Address for correspondence SungHee Kim, MD, PhD Department of Otolaryngology- Head and Neck Surgery, Daegu Fatima Hospital, 99 Ayang-ro, Dong-gu, Daegu 41199, Korea Tel +82-53-9-735 Fax +82-53-9-7352 E-mail sungheekim@fatima.or.kr Background and Objectives Dizziness has been known as a prognostic factor in sudden sensorineural hearing loss (SSHL), but it is difficult to describe and quantify its subjective symptoms. Also, dizziness itself cannot imply vestibular dysfunction in SSHL. Comprehensive evaluation of vestibular function may help us understand the extent of lesions in sudden deafness. The purpose of this study is to determine whether an impaired caloric response is associated with disease severity and hearing outcome. Subjects and Method A retrospective chart review was conducted of 488 patients diagnosed as unilateral SSHL. The patients were divided into two, an abnormal caloric group (canal paresis >%) and normal caloric group (canal paresis %). Initial demographic and audiologic findings and final hearing outcomes were compared between the two groups. Results The initial pure tone averages of SSHL patients of abnormal caloric group and normal caloric group were 75.4±28.4 db HL and 68.2±25.4 db HL (p=.4), respectively. Patients of abnormal caloric test group showed worse hearing outcome across all frequencies compared to those of the normal caloric group. Also, a significant correlation was noted between the magnitude of hearing recovery and canal paresis (r=-.223, p<.1). Conclusion SSHL patients of abnormal caloric test showed worse initial hearing level and poorer hearing outcome. Evaluation of vestibular function in SSHL patients is important because subjective symptoms alone cannot account for vestibular hypofunction patients, and the caloric test can help in the counseling of patients and prediction of hearing outcome in SSHL patients. Korean J Otorhinolaryngol-Head Neck Surg 18;61(1):58-13 Key Words Caloric test ㆍ Sudden deafness. 서 론 돌발성난청은이비인후과적응급질환이기는하나병인을 정확히찾기어렵고치료에대해경험적치료가이루어지고있 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 어돌발성난청에서포괄적인내이기능에대한평가가병의정도와병인을이해하는데도움이될것으로생각된다. 1,2) 현재돌발성난청의예후인자에관한많은연구들이발표되고있으며초기청력소실의정도, 청력도의형태, 치료개시시간, 나이, 어지러움의동반여부등이중요한예후인자로보고되어진다. 3) 이중어지럼증은대표적인돌발성난청의예후인자이나주관적으로환자가느끼는증상으로이를정성적, 정량 58 Copyright 18 Korean Society of Otorhinolaryngology-Head and Neck Surgery
Caloric Test in Sudden Deafness Lim EJ, et al. 적으로평가하기어려우며어지럼증유무가객관적인전정기능검사결과와일치하지않는경우가많아어지럼증상이없다하여전정기능계를침범하지않았다고판단하기는어렵다. 일반적으로돌발성난청에서전정기능이저하된경우좀더광범위한내이의병변을의미하는것으로고려되며나쁜예후가예측된다는연구들이있으나 2,4) 어지럼증이없는환자들을포함하여전정기능검사결과와돌발성난청의예후에대해서는연구가많지않다. 1) 이에저자들은돌발성난청환자의온도안진검사 (caloric test) 를후향적으로분석하여온도안진검사의이상여부, 특히반규관마비가돌발성난청의예후에관계가있는지확인하고자하였다. 대상및방법 본연구는 1년 9월부터 17년 3월까지본원이비인후과에서돌발성난청으로진단되어입원치료를시행받은총 982명 (982귀) 을대상으로후향적연구를시행하였다. 모든환자들은 3일이내에연속된 3개의주파수에서 3 db 이상의갑작스러운청력저하를보이는돌발성난청의기준을만족하였다. 이중발병후 2주가지나병원을방문하였거나치료후경과관찰이 1개월이상되지않은환자는제외하였다. 또한메니에르씨병, 중추성현훈, 재발성또는양측성돌발성난청, 소뇌교각종양등의병력이있거나중이염또는병변귀가유일청인경우, 온도안진검사상양측전정기능소실소견을보이거나반대측귀의반규관마비소견을보이는경우를제외하였다 (Table 1). 환자들은 7일간입원치료를하였으며 Dexamethasone (Dexamethasone sodium phosphate 5 mg/ml; Yuhan Corp., Seoul, Korea) 을하루 2회정맥주사하였으며이후퇴원하여 7일에걸쳐경구스테로이드인 Solondo(Prednisolone Table 1. Reason for excluded ears from total 982 ears Reason for exclusion No. History of otitis media 33 Pre-existing hearing loss, only ear, better ear 76 Meniere s disease 47 Bilateral vestibulopathy (caloric sum <12 degree/sec) 46 Contralateral vestibulopathy (canal paresis >%) 58 Short follow-up period (less than 1 month) Late hospital visit (more than 14 days after disease onset) 55 Recurrent of bilateral sudden deafness 37 Caloric test was not tested 52 Central lesion (acoustic neuroma or etc.) 1 Total 494 5 mg; Yuhan Corp.) 를 3 mg/day 4일, 15 mg/day 3일로감량치료하였다. 입원기간동안통증의학과에서성상신경차단술을하루 1회씩시행하였으며 Carbogen(5% CO 2 와 95% O 2 로구성된혼합가스 ) 을입원기간동안 1일 8회, 1시간간격으로 3분씩흡입하도록하였다. 5) 고실내 Dexamethasone (Dexamethasone sodium phosphate 5 mg/ml) 주입술을 1주일에 2회씩총 4회시행하였으며해당된 488명의환자는모두온도안진검사를시행받았다. 청력검사는치료전초기순음청력도와치료후청력이어느정도안정되었다고판단되는치료후최소 1개월이경과한시점의순음청력도를기준으로청력역치를평가하였다. 평균청력은.5, 1, 2, 3 khz를 4분법으로평균하였다. 치료전후청력회복정도는초기청력의평균값에서치료후청력의평균값을뺀값으로정하였다. 또한 Siegel이제시한판정표를기준으로최종 25 db 역치이내로청력호전이있는경우를완전회복 (grade I), 15 db 이상청력호전이있고최종청력이 25~45 db 범위의청력역치인경우를부분회복 (grade II), 15 db 이상청력호전이있고최종 45 db 초과의청력역치인경우를경도회복 (grade III), 15 db 미만으로청력호전이있거나최종 75 db 이상청력역치인경우를불변 (grade IV) 으로구분하였으며 grade I, II, III을청력회복이있는경우로판정하였으며 grade IV를청력회복이없는경우로분석하였다. 온도안진검사는어두운방에서눈을뜬상태로검사가진행되었으며비디오안구운동검사기를이용하여안구의운동을측정하였다. 냉온교대온도자극은 air caloric stimulator (Air Fix; Interacoustics, Middelfart, Denmark) 를통해 24도와 5도의공기 8L를 초간외이도에지속적으로관류하도록하였다. 병변측의편측마비가 % 를초과하는경우를반규관마비 (canal paresis) 라정의하였으며온자극과냉자극으로발생한안진의느린반응의최고속도의합이양쪽에서모두 12 degree/sec 이하인환자는양측전정기능소실소견으로배제되었으며반대측반규관마비가있는환자도배제되었다. 온도안진검사상반규관마비여부가청력회복에미치는영향을알아보았다. 아울러내원당시어지럼증의유무에의한영향도함께분석하였다. 통계분석은 independent t-test, chi-square test, score test for trend를사용하여반규관마비가있는군과없는군간에비교를하였다. 반규관마비정도 (magnitude) 와초기청력역치와청력회복정도의관련성을알아보기위해 correlation test를시행하였다. 반규관마비정도, 나이, 초기청력정도, 치료개시시간의변수들을포함하여다중회귀분석 (multivariate regression analysis) 을사용하여분석하였다. www.kjorl.org 59
Korean J Otorhinolaryngol-Head Neck Surg 18;61(1):58-13 Table 2. Comparison of initial demographic findings between patients with normal and abnormal caloric response Caloric test CP % (n=34, %) CP >% (n=184, %) p value Sex Male 141 (46.4) 88 (47.8).757 Female 163 (53.6) 96 (52.2) Age (years) 49.8±15.8 51.8±13.8.149 Initial PTA (db HL) Mild ( ) Moderate ( 55) Moderate-severe ( 7) 5 (16.4) 59 (19.4) 65 (21.4) 21 (11.4) 31 (16.8) 36 (19.6).7* Severe ( 9) Profound (>9) 62 (.4) 68 (22.4) 3 (16.3) 66 (35.9) Interval before first visit (days) 3.7±2.8 4.5±3.4.7* Side Right 142 (46.7) 73 (39.7).129 Left 163 (53.3) 112 (.3) Dizziness (-) (+) 2 (66.4) 12 (33.6) 136 (73.9) 48 (26.1).83 PTA of.5, 1, 2, and 3 khz. *statistically significant (p<.5). CP: canal paresis, PTA: pure-tone average, HL: hearing level Table 3. Comparison of pure-tone average of initial and posttreatment and hearing improvement after treatment between patients with normal and abnormal caloric test Caloric test CP % (n=34) CP >% (n=184) p value Initial 68.2±25.4 75.4±28.4.4* Post-treatment 36.6±24.2 51.1±31.8 <.1* Improvement 31.9±23.3 23.9±22.1 <.1* *statistically significant (p<.5). CP: canal paresis 또한어지러움증상의유무에따라군간에비교를같은 통계분석을이용하여비교하였다. 통계적인처리는 SPSS 12.(SPSS software, SPSS Inc., Chicago, IL, USA) 을이용하여분석하였으며, 통계결과는 p value 가.5 미만인결과의경우유의한차이가있는것으 로판단하였다. 본후향적연구는헬싱키선언에따라기관윤 리심의위원회 (Institutional Review Board) 의승인 (IRB No. DFE17ORIO25) 을받았다. 결 과 최종해당된환자는 488 명으로이들중남자는 229 명 (46.9%), 여자는 259 명 (53.1%) 이었으며평균나이는 5.7 세로 7 세부터 85 세까지다양하게분포하였다. 전체환자중온도안진검사상반규관마비가있는환자는 184 명 (37.7%), 온도안진검사가정상인환자는 34 명 (62.2%) 이었다. 환자의성별, 나이, 병변측의방향및어지럼증의유 무는두군간차이를보이지않았다. 초기청력을비교하였을때반규관마비군은경도난청이 11.4%, 중등도난청이 16.8%, 중등고도난청이 19.6%, 고도난청이 16.3%, 농이 35.9% 이며, 반규관마비가없는정상군은경도난청이 16.4%, 중등도난청이 19.4%, 중등고도난청이 21.4%, 고도난청이.4%, 농이 22.4% 로양군간에통계적으로유의하게초기청력정도에차이가있었다 (p=.7). 또한치료개시시간이반규관마비가없는정상군은 3.7±2.8 일로반규관마비군의 4.5±3.4 일에비해유의하게짧았다 (p=.7)(table 2). 반규관마비군과반규관마비가없는정상군간청력의회복정도를비교해보았을때통계적으로유의하게두군간차이를보였으며 (p<.1)(table 3) Siegel의판정표를기준으로평가하였을때에도두군간통계적으로유의한차이를보였다 (p<.1)(fig. 1). 반규관마비의정도 (magnitude) 와청력간의관계를분석하였을때, 반규관마비의정도와초기청력은양의상관관계 (Pearson s; r=.141, p=.2) 를보였으며반규관마비의정도와청력회복의정도는음의상관관계 (Pearson s; r=-.223, p<.1) 를보여반규관마비의정도가심할수록초기청력역치가높고회복정도가낮음을확인할수있었다 (Fig. 2). 청력회복정도에미치는영향을분석하기위해기존에알려진예후인자들과반규관마비정도를함께다중선형회귀분석을시행한결과초기청력정도, 반규관마비정도, 나이, 치료개시시간이모두유의하게청력회복정도에영향을미치는것으로파악되었고, 이모델에의한설명력은 R 2 =.272 51
Caloric Test in Sudden Deafness Lim EJ, et al. 였다 (Table 4). 이에반해예상과달리주관적인어지럼증의여부는통계 적으로유의하게청력회복과상관관계를보이지않았다. 주 관적인어지러움을호소하는환자 ( 총 15 명 ) 중반규관마비 를보이는환자는 48 명 (32%) 였으며반규관마비가없는정 상군은 12 명 (68%), 어지러움이없는환자 ( 총 338 명 ) 중반규 관마비를보이는환자는 136 명 (.2%) 이었으며반규관마비 가없는정상군은 2 명 (59.7%) 이었다. 어지럼증이있는환자 군 (15 명 ) 과없는환자군 (338 명 ) 에서초기청력정도와청력 호전정도를비교해본결과통계적으로유의한차이는없었 으며 (Table 5), Siegel 의판정표를기준으로회복정도를분 Siegel s improvement rate (%) 1 Fig. 1. Comparison of hearing outcome in CP and normal caloric group according to Siegel s criteria. In CP group (CP >%), Siegel grade I, II, III, and IV were 27%, 16%, 12%, and 45%. In normal caloric group, Siegel grade I, II, III, and IV were 44%, 25%, 8%, and 23%, respectively. Considering Siegel I, II, and III as hearing improvement, hearing outcome was significantly worse in CP group (p<.1). *statistical significance (p<.1). CP: canal paresis. * CP % CP >% Caloric test result Siegel IV Siegel III Siegel II Siegel I 석을하였을때주관적인어지럼증은청력개선정도에차이 가없었다 (p=.612)(fig. 3). 고 찰 돌발성난청은 3 일이내의시간동안급작스럽게청력소실 을일으키는응급질환으로아직병인에대한정확한확인이 어렵고경험적인치료들이시행되고있는실정이다. 돌발성난 청의예후와관계되는요소로는초기의청력정도, 치료개시 시간, 나이, 어지러움의유무등이일반적으로통용되는사항 이나 6,7) 이에대해서도이견을제시하는보고들이많다. 8-11) 본연구에서는예상과달리주관적어지러움의여부는청력 Table 4. Multivariate regression analysis for hearing improvement Variable B SE β p value Initial PTA.376.36.433 <.1* CP -.9.34 -.244 <.1* Age -.287.62 -.187 <.1* Interval -1.61.34 -.1.1* *statistically significant (p<.5), hearing improvement calculated by initial PTA minus post-treatment PTA, interval before first visit. SE: standard error, CP: canal paresis, PTA: pure-tone average Table 5. Comparison of pure-tone average of initial, post-treatment and hearing improvement between patients with and without dizziness Non-dizziness (n=338) Dizziness (n=15) p value Initial 71.1±7.3 7.3±26.4.761 Post-treatment 42.1±29. 42.3±28.1.963 Improvement 29.1±23.2 28.2±23.3.928 1 Initial pure-tone average (db HL) 1 Hearing improvement (db) - Non-dizziness Dizziness r=.1, p<.1 - Non-dizziness Dizziness r=-.223, p<.1 A - 1 CP (%) Fig. 2. Correlation of the magnitude of CP and HL. The magnitude of CP and initial HL was positively correlated (pearson s r=.141, p=.2). As the amount of CP increases, initial hearing threshold was higher (A). The magnitude of CP and hearing improvement was negatively correlated (pearson s r=-.223, p<.1) (B). As the amount of CP increases, the magnitude of hearing improvement was lowered. CP: canal paresis, HL: hearing level. B - 1 CP (%) www.kjorl.org 511
Korean J Otorhinolaryngol-Head Neck Surg 18;61(1):58-13 Siegel s improvement rate (%) 1 의회복정도에영향을미치지않는것으로분석되었다. 기존 의대다수의연구들에서는어지러움동반시나쁜예후를 보고하고있으나구조적으로와우의기저부와전정기관이 인접하므로기저부의손상을의미하는고음역의난청과고 도난청에서더많은어지러움을호소하고있으며이러한청 력형의경우일반적으로회복률이저조한경향을보이므로 이로인한영향을고려해야한다고보고하였다. 6,8,12,13) 또한 Berg 와 Pallasch 14) 도불량한초기청력도를고려하였을경우 어지러움이최종적인청력회복정도에는영향을미치지못 할것이라고보고하였다. 그외에도본연구결과와마찬가지 로어지러움증상자체가청력회복의정도와관계가없었다 는연구들도발표되었다. 9,11,12) 기존의연구에서도어지러움의 정도와전정기관의마비정도는관계가없다는보고가있었 으며 15-17) Inagaki 등 18) 은어지러움이있는환자와없는환자 간에전정유모세포의밀도및조직학적검사에차이가없음 을보고하였다. Non-dizziness Fig. 3. Comparison of hearing outcome in dizziness and non-dizziness group according to Siegel s criteria. The hearing outcome was not different among two groups (p=.612). Wilson 등 12) 과 Liu 등 15) 은주관적인어지럼증보다는객관 적인전정기능검사결과가돌발성난청의좀더예민한예후 의척도가될수있음을보고하였다. 일반적으로와우의손 상정도가심할수록내이의병변이광범위할것으로생각이 되며어지러움여부에관계없이전정기관도침범이될것이 라추정된다. 11,15,18) 이러한전정기관마비군들은상대적으로 내이의병변이심하여기존청력저하정도가심하며청력의 회복도가낮은것으로보고된다. 1,4) Dizziness Siegel IV Siegel III Siegel II Siegel I 본연구결과에서도어지럼증이있는환자는총 15 명으 로전체돌발성난청환자중 3.7% 로기존의보고결과와 비교적일치하는소견을보였다. 6,7) 하지만실제어지러움을 호소하지않는상당수의환자에서온도안진검사상반규관 마비소견을보였으며반규관마비환자의비율로만보았을 때주관적인어지럼증과온도안진검사결과가일치하지않는소견을보였다. 어지러움이있는환자에서도전정기능검사가정상인환자가많았으며 6,8,12) 어지러움을호소하지않는환자를대상으로시행한기존의연구들에서확인해보면평균적으로약 % 정도의돌발성난청환자가전정기능저하소견을보이는것으로보고되어증상은없지만잠재적으로전정기능의저하를보이는환자들이있음을알수있다. 15,19) 돌발성난청환자에있어다양한전정기능검사들과예후의상관관계에대한보고가있었으나다수의연구가돌발성난청환자중어지러움증상이있는환자만을대상으로전정기능검사를시행하여전체돌발성난청환자의예후에대한정보를제공하기는어려웠다. 4,15,17,) 어지러움이없는돌발성난청환자를포함한연구들에서는전정기능검사결과가예후를예측하는데도움이됨을보고하였지만좀더예민하게전정기능의저하및예후를예측하는검사의종류에대해서는이견을제시하였다. 1,11,19,) Jung 등 19) 의연구에따르면전정유발근전위검사 (vestibularevoked myogenic potential, VEMP) 와온도안진검사를시행한연구에서 VEMP 검사결과가온도안진검사보다민감하게청력회복정도를예측하는측도가됨을보고하였으며어지러움증상이없는잠재적전정기능장애군에서도청력회복정도가낮음을보고하였다. VEMP 결과가온도안진검사보다돌발성난청에서전정기관의손상정도를잘반영한다는보고들은해부학적으로구형낭이와우와가까운위치에존재하기때문에동시에손상가능성이크고구형낭과와우안에존재하는유모세포의구조의유사성및공통된혈액공급을받는다는사실을기반으로 VEMP 검사가예후를가늠해볼수있는좋은진단수단이됨을설명하였다. 19,21) 하지만 Shih 등 1) 과 Narozny 등 9) 이돌발성난청의예후인자로서온도안진검사의유용성을보고하였으며특히 Shih 등 1) 의연구에서는온도안진검사상반규관마비가청력회복정도에통계적으로유의하게상관관계가있으며특히반규관마비가 % 이상되는환자에서통계적으로유의하게병의호전이없음을확인하여보고하였다. 반규관마비군들은상대적으로내이의병변이심하여초기청력저하정도가심한것으로보고되며 1,4) 본연구에서도같은결과를보였다 (Table 3). 어지러움증상이없는잠재적인전정기능장애군의경우에도마찬가지원리로청력회복에있어나쁜예후를보임이확인되어이들에대한관심이요구된다. 온도안진검사는돌발성난청의예후에있어서대다수의연구에서일관되게병의예후와관계있는것으로보고된다. 1,8-1,12,22) 본연구결과에서도주관적인어지러움증상여부보다는온 512
Caloric Test in Sudden Deafness Lim EJ, et al. 도안진검사결과가좀더병의예후를판정하는데도움이되 는것으로확인되었으며반규관마비정도와청력호전정도 가통계적으로유의하게음의상관관계를보임을확인할수 있었다 (Fig. 2B). 다만초기청력저하정도가반규관마비군 의경우정상군에비해더심하여이러한인자를보정한추가 적인연구가필요할것으로생각된다. 상기의검사는어지러움을후향적진료기록으로확인하여 이로인한한계가있을것으로생각되며대상환자들이 2 주 일이내에치료를시작하여입원기간동안온도안진검사를 받았는데일시적인전정기능장애의경우이미검사시병변 이정상화되었을가능성을고려해야할것이다. 17) 또한온도 안진검사의경우반고리관의기능만을반영하여총체적인전 정기관의기능을반영하기는어려우며온도안진검사결과의 척도중반규관마비 (canal paresis) 만을대상으로하여방향 우위성 (directional preponderance) 등에대한추가적인연구 가있어야할것이다. 그러나상기연구는동일한치료를시행받은비교적많은 수의환자를대상으로하였으며어지러움증상이없는환자 를포함하여잠재적인말초전정기능저하를가진환자군을 확인하였으며전체환자들의병의경과를온도안진검사에대 비해비교하였다. 특히정성적, 정량적으로평가하기어려운 어지러움증상의여부보다객관적인온도안진검사결과가돌 발성난청환자의예후를가늠하는지표가될수있음을뒷 받침하는연구라생각된다. REFERENCES 1) Shih CP, Chou YC, Chen HC, Lee JC, Chu YH, Wang CH. Analysis of caloric testresponses in sudden hearing loss. Ear Nose Throat J 17;96(2):59-64. 2) Wang CT, Huang TW, Kuo SW, Cheng PW. Correlation between audiovestibular function tests and hearing outcomes in severe to profound sudden sensorineural hearing loss. Ear Hear 9;3(1): 11-4. 3) Laird N, Wilson WR. Predicting recovery from idiopathic sudden hearing loss. Am J Otolaryngol 1983;4(3):161-4. 4) Iwasaki S, Takai Y, Ozeki H, Ito K, Karino S, Murofushi T. Extent of lesions in idiopathic sudden hearing loss with vertigo: study using click and galvanic vestibular evoked myogenic potentials. Arch Otolaryngol Head Neck Surg 5;131(1):857-62. 5) Fisch U. Management of sudden deafness. Otolaryngol Head Neck Surg 1983;91(1):3-8. 6) Shaia FT, Sheehy JL. Sudden sensori-neural hearing impairment: a report of 12 cases. Laryngoscope 1976;86(3):389-98. 7) Nakashima T, Yanagita N. Outcome of sudden deafness with and without vertigo. Laryngoscope 1993;13(1):1145-9. 8) Mattox DE, Simmons FB. Natural history of sudden sensorineural hearing loss. Ann Otol Rhinol Laryngol 1977;86(4 Pt 1):463-. 9) Narozny W, Kuczkowski J, Kot J, Stankiewicz C, Sicko Z, Mikaszewski B. Prognostic factors in sudden sensorineural hearing loss: our experience and a review of the literature. Ann Otol Rhinol Laryngol 6;115(7):553-8. 1) Weiss D, Böcker AJ, Koopmann M, Savvas E, Borowski M, Rudack C. Predictors of hearing recovery in patients with severe sudden sensorineural hearing loss. J Otolaryngol Head Neck Surg 17; 46(1):27. 11) Korres S, Stamatiou GA, Gkoritsa E, Riga M, Xenelis J. Prognosis of patients with idiopathic sudden hearing loss: role of vestibular assessment. J Laryngol Otol 11;125(3):251-7. 12) Wilson WR, Laird N, Kavesh DA. Electronystagmographic findings in idiopathic sudden hearing loss. Am J Otolaryngol 1982;3(4):279-85. 13) Ahn JH, Yoon TH, Chung JW. Analysis of prognosis in patients with sudden sensorineural hearing loss and dizziness. Korean J Otolaryngol-Head Neck Surg 1;44(1):132-7. 14) Berg M, Pallasch H. Sudden deafness and vertigo in children and juveniles. Adv Otorhinolaryngol 1981;27:7-82. 15) Liu J, Zhou RH, Liu B, Leng YM, Liu JJ, Liu DD, et al. Assessment of balance and vestibular functions in patients with idiopathic sudden sensorineural hearing loss. J Huazhong Univ Sci Technolog Med Sci 17;37(2):264-7. 16) Khetarpal U. Investigations into the cause of vertigo in sudden sensorineural hearing loss. Otolaryngol Head Neck Surg 1991;15(3): 3-71. 17) Park HM, Jung SW, Rhee CK. Vestibular diagnosis as prognostic indicator in sudden hearing loss with vertigo. Acta Otolaryngol Suppl 1;545:-3. 18) Inagaki T, Cureoglu S, Morita N, Terao K, Sato T, Suzuki M, et al. Vestibular system changes in sudden deafness with and without vertigo: a human temporal bone study. Otol Neurotol 12;33(7): 1151-5. 19) Jung SG, Park JW, Han SY, Park SH, Nam SI. The role of vestibular function tests in patients with sudden sensorineural hearing loss who have subclinical vestibular dysfunction. Korean J Otorhinolaryngol- Head Neck Surg 13;56(11):7-5. ) Niu X, Zhang Y, Zhang Q, Xu X, Han P, Cheng Y, et al. The relationship between hearing loss and vestibular dysfunction in patients with sudden sensorineural hearing loss. Acta Otolaryngol 16;136(3): 225-31. 21) Fujimoto C, Egami N, Kinoshita M, Sugasawa K, Yamasoba T, Iwasaki S. Involvement of vestibular organs in idiopathic sudden hearing loss with vertigo: an analysis using ovemp and cvemp testing. Clin Neurophysiol 15;126(5):133-8. 22) Saeki N, Kitahara M. Assessment of prognosis in sudden deafness. Acta Otolaryngol Suppl 1994;51:56-61. www.kjorl.org 513