Research in Vestibular Science Vol. 11, Suppl. 1, June 2012 Symposium III pissn 2092-8882, eissn 2093-5501 비전정성어지럼 계명대학교의과대학동산병원신경과학교실 이형 Non-Vestibular Dizziness Hyung Lee, MD Department of Neurology, Keimyung University Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Korea Corresponding Author: Hyung Lee, MD Department of Neurology, Keimyung University Dongsan Medical Center, Keimyung University School of Medicine, 56 Dalseong-ro, Jung-gu, Daegu 700-712, Korea Tel: +82-53-250-7835 Fax: +82-53-250-7840 E-mail: hlee@dsmc.or.k Copyrightc 2012 by The Korean Balance Society. All rights reserved. Non-vestibular dizziness is a common complaint in patient who seeking dizzy clinic. Patients with non-vestibular dizziness presented their dizziness as light-headed, free floating sensation, or dissociated from body whereas patients with vertigo usually complained of an illusion sensation of an environment (i.e., a sensation of spinning). It is known that non-vestibular dizziness is more common than vestibular dizziness with vertigo in dizzy outpatient clinic. Presyncopal light-headedness due to orthostatic hypotension and psychogenic dizziness are two common causes of non-vestibular dizziness. Here the author reviews the clinical features of non-vestibular dizziness and the keys to the differential diagnosis of non-vestibular dizziness from vestibular dizziness. Research in Vestibular Science 2012;11 Suppl 1:S113-S117 Key Words: Non-vestibular dizziness; Diagnosis 서론어지럼은두통과더불어임상에서가장흔히접하게되는증상으로의사를찾는모든환자의 5-10%, 신경과나이비인후과를찾는환자의 10-15% 를차지한다. 1 이렇게흔한증상임에도불구하고대부분의임상의사들은어지럼의원인이되는질환에대해올바로진단하고관리하는데어려움을느끼고있으며, 이는그원인이다양하고, 환자마다느끼는정도및표현이다양하며, 증상이역동적으로변하기때문일것이다. 또한어지럼은증상이기도하면서질환일수도있는데, 별다른징후없이주관적으로만느낄수도있고서로다른질환일지라도유사한징후만을나타내는수도있다. 따라서임상의사는어지럼과관련된해부생리학적인지식과각각의질환에대해잘알고있어야하며, 환자로부터적절한정보를경제적으로얻어낼수있는기술을익혀야한다. 전정성어지럼환자들이주위가돌아가는형태의어지럼을호 소하는데비해비전정성어지럼 (non-vestibular dizziness) 환자들은대개머리속이텅빈느낌, 몸이붕뜨는느낌, 몸과마음이분리된것같은느낌등다소모호하고다양한양상의어지럼을호소한다. 본장에서는비전정성어지럼의임상양상, 흔한원인및전정성어지럼과의감별점등을살펴보고자한다. 본론 1. 어지럼의분류어지럼을분류하는방법은여러가지가있지만, 임상에서유용하게쓸수있는분류법을소개하기로한다. 환자가호소하는모든어지럼은일곱가지아형으로분류될수있다. 2 Type I은위에서언급한현훈을일컫는다. 현훈은양쪽전정계긴장도의균형이깨져서나타나게되며, 말초성전정기관 S113
Res Vestibul Sci Vol. 11, Suppl. 1, Jun. 2012 인미로나전정신경혹은중추신경계의전정회로가침범되었음을시사한다. Type II는실신할것같은느낌, 실신성 (pre-syncope or near-faint) 어지럼으로서, 뇌의당이부족하거나, 뇌의혈류가미만성으로감소될때발생하는데, 과환기증후군 (hyperventilation syndrome), 자율신경의이상이나약물의부작용으로나타나는기립성저혈압, 혈관성미주신경발작 (vasovagal attack), 부정맥등에의한심박출량의감소, 당뇨병, 주정중독등에서관찰된다. Type III는균형이상 (dysequilibrium) 이며, 전정척수반사, 고유수용체감각, 소뇌혹은전두엽이나기저핵같은운동조절을담당하는곳에이상이있을때나타나는데, 서있거나몸을움직일때만발생하는특징이있다. 감별진단의첫단계는현훈이동반되는지아닌지를구분하여야한다. 급성일측말초성전정신경질환은균형이상이일시적이고, 대개급성현훈이동반되는점으로쉽게감별된다. 급성현훈이동반되지않는경우라면, 어두운곳에서악화되는지를살펴보아야한다. 특히눈에보이는것들이좌우혹은상하로계속해서움직이는동요시 (oscillopsia) 나청각소실과동반되어균형이상이나타나는경우는이독성약제등에의한양측전정기능소실을생각하여야한다. 한편어두운곳에서악화되면서말초신경의이상증상인무감각 (numbness), 근력약화, 내장및방광의기능이상등이동반된다면고유수용체기능의소실을생각하여야한다. 마지막으로소뇌와전두엽및기저핵에이상이있을때에도급성현훈도없고, 어두운곳에서악화되지도않는균형이상이발생할수있는데, 이때사지의운동실조가있으면소뇌병변을, 행동이느리거나, 연합운동 (associated movement) 가소실된경우는전두엽혹은기저핵의이상을생각하여야한다. 3 Type IV는심인성 (psychogenic) 어지럼으로중추신경계로들어온감각을통합 (integrating) 하는데문제가있는경우유발되며, 대개는몸이붕뜬느낌, 넘어질것같은느낌, 머리안이도는느낌등의비특이적인어지럼 으로기술될수있으며, 발작적혹은만성적으로나타날수있고, 공황장애, 광장공포증, 불안장애, 우울증, 신체형장애 (somatoform disorder), 히스테리아, 외상후증후군등에서나타난다. Type V는안성 (ocular) 어지럼으로시각계와전정계의불일치로나타나며, 새로운안경을끼거나, 안구운동신경마비등에서나타나는어지럼이다. Type VI는복합성 (multisensory) 어지럼으로시각계, 전정계, 체성감각계가복합적으로문제가있을때나타나며, 당뇨, 노화등이원인이된다. 마지막으로 Type VII은가성어지럼 (pseudo-dizziness) 으로전정계, 시각계, 체성감각계는정상임에도불구하고환자가어지럽다고호소하는아형으로, 잘파악해보면어지럼으로간주하는범주에포함시킬수없는것들, 예를들면, 머리가아픈것, 기억력이떨어지는것, 피곤한것등어지럼이아닌현상을환자가어지럽다는용어를사용하는경우로, 엄밀한의미의어지럼에속하지않는어지럼이라고말할수있을것이다. 이들은 Table 1에정리되어있다. 상기언급한어지럼분류법의가장큰장점은, 어떠한어지럼이던일곱가지아형으로전부나누어질수있으며, 특정질환은특정한아형의어지럼만을일으키게되므로, 모든어지럼의기저 (underlying) 질환을쉽게감별케하여올바른진단과치료를할수있게하여준다는점이다. 2. 전정성어지럼과비전정성어지럼의감별진단어지럼이전성성인지비전정성인지를파악하는것도중요한데이를위해서환자가호소하는어지럼의표현, 지속시간, 유발요인, 동반증상등이많은도움을주게되며, 자세한내용은참고문헌을참조하기바란다. 3-5 전정성어지럼과비전정성어지럼의감별점은 Table 2와같다. 특히회전성어지럼은시간이흐름에따라원인요소가약화되거나, 중추신경계의보상으로인하여그강도가약해 Table 1. Classification of dizziness Type TypeⅠ TypeⅡ TypeⅢ TypeⅣ TypeⅤ TypeⅥ TypeⅦ Nature and mechanism Vertigo, vestibular tone imbalance Pre-syncope or near-faint, diffuse cerebral ischemia Disequilibrium, loss of vestibulospinal, proprioceptive, cerebellar, or motor function Psychogenic, impaired central integration of sensory signals Ocular, visual-vestibular mismatch due to impaired vision Multisensory, partial loss of multiple sensory system function Pseudo-dizziness S114
이형. 비전정성어지럼 Table 2. Differentiation of vestibular dizziness from non-vestibular dizziness Factor Vestibular Non-vestibular Common descriptive form Spinning (environment moves), merry-go-round, drunkenness tilting, motion sickness, off balance Light-headed, floating, dissociated from body, swimming, giddy, spinning inside (environment stationary) Course Episodic Constant Common precipitating factors Head movements, position change Stress, hyperventilation Commonly associated symptoms Nausea, vomiting, oscillopsia, hearing loss, unsteadiness Paresthesia, syncope, difficulty concentrating, tension headache 지게마련인데일반적으로증상의호전, 악화가없이오랫동안계속해서회전하고있다고느끼는어지럼은전정성어지럼이아니다. 3 또한이학적검사에서설명할머리흔듬안진 (head shaking nystagmus) 은거의모든전정성어지럼에서나타나므로감별진단을위해꼭해야할쉬우면서도매우유용한검사법이라할수있다. 6,7 3. 심인성어지럼심인성어지럼은정신과적문제로인해어지럼이일어나는경우로모든신경이학적검사소견은정상이며, 대개진성어지럼이아닌멍하거나어찔하다는느낌의어지럼을호소하고, 스트레스를받는상황에서악화되는것으로알려져있다. 어지럼을호소하는환자들중이러한심인성어지럼의빈도는국내의연구에서는 22.6% 로보고된바있으며, 8 외국에서는전체어지럼환자의 20-50% 로매우높게보고되고있다. 9 모두가일치하는심인성어지럼의진단기준은아직없지만 Furman과 Jacob 9 은정신과적어지럼이란용어의사용을엄격하게적용하는새로운정의를제시하였는데이는다음과같다. 첫째, 어지럼이정신과적증상군 (psychiatric symptom cluster) 의다른증상들과같이나타나고전정기능이상과관련이없어야한다. 둘째, psychogenic overlay의현상과혼동하지말아야하고, 신경이과적어지럼의경우엔어지럼의핵심증상이있으며정신과적요인들은단지이와관련된병적행동을증폭시킨다. 그리고 psychogenic overlay가어지럼을유의하게증가시키는경우와어지럼보다는정신과적증상이현저한경우에는정신과자문이나전과가도움이된다. 심인성어지럼의진단적접근은주로환자의증상의기술에의존한다. 객관적으로증상을동반할만한신경이학적소견이없거나미약한경우에는환자의대인관계양상과질및증상이나타날당시의생활상태를알아보아야한다. 정신과환자가기질성어지럼증후군 (organic vertigo syndrome) 을보일수있고, 역으로기질성어지럼증후군을앓고있는환자가이차적으로정신과적문제가나타날수도있으므로신경이과와정신과두영역모두에대한상당한이해가필요하다. 10 어지럼을일으키는정신과적질환으로는공황장애, 광장공포증, 불안장애, 우울증, 신체형장애, 체위공포성어지럼등이있다. 10 이중대표적인질환인공황장애의특징은다음과같다. 공황장애는불안장애의일종으로, 이유없이삽화적으로갑자기불안이극도로심해지며숨이막히거나심장이두근대고죽을것만같은극단적인공포증세를보이는상태이다. 이런불안상태가대개 1시간이내의기간동안지속되며대개주 2회정도나타난다. 주증상은강한공포, 곧죽지않을까하는불안이다. 이와동반하여호흡곤란, 심계항진, 흉부통증, 흉부불쾌감, 질식감, 혹은숨이답답한느낌, 현기증, 어지럼내지휘청거리는느낌, 자기나주위가달라진것같은비현실감, 손발이저리는감각이상이나몸의떨림과진전, 때로는돌발적인열감이나냉감, 땀흘림등이나타난다. 동시에실신하거나죽거나또는미치거나어떤사고를저지르지않을까하는공포등이엄습한다. 과호흡으로인해호흡성 alkalosis가오고, 그로인한신체증상도나타난다. 발작이없는시기에는그런일이또생기지않을까하는예기불안 (anticipatory anxiety) 이있다. 이어서 죽을병이아닌가 하는등의건강염려증 (hypochondriasis) 이생기고발작이일어났던장소나상황과유사한장소와상황을피하려는회피행동 (avoidance behavior) 을나타낸다. 그리고자신이쓰러져도도와줄사람이없는것이두려워서외출이나혼자있는것을피하거나, 외출할때는누구와꼭동행하려하는등의광장공포증 (agoraphobia) 도생긴다. 이질환에서나타나는어지럼은 giddy, unsteady sensation, progressive presyncopal lightheadedness로나타난다. 11 그러나이러한어지럼은대개주된증상인심장이멎거나숨이막혀죽을것같다는느낌및이와관련된자율신경계의항진증상에동반되어나타나므로이에대해자 S115
Res Vestibul Sci Vol. 11, Suppl. 1, Jun. 2012 Table 3. Common symptoms during panic attacks Shortness of breath, smothering, choking Palpitations, accelerated heart rate Chest pain or discomfort Sweating Dizziness, unsteady feeling, sensory illusions Nausea or abdominal distress Depersonalization or derealization Numbness or tingling sensations (paresthesias) Flushes (hot flashes) or chills Trembling or shaking Fear of dying Fear of going crazy or doing something uncontrolled 세한문진을해보면쉽게감별진단할수있다 (Table 3). 4. 기립성어지럼기립성어지럼은흔히기립성저혈압 (orthostatic hypotension) 에의해유발된다고생각되는데, 기립성저혈압의정의는누워있다가일어서서 3분이내에수축기혈압이 20 mm Hg 이상또는이완기혈압이 10 mm Hg 이상떨어지는경우로서혈압을측정하여진단한다. 12 기립성저혈압의경우어지러운증상이없이혈압강하만나타나는경우도있는반면에실신성어지럼이없다면기립성어지럼이라고는말할수없다. 기립성저혈압의혈압이떨어지는정도와기립성어지럼의증상의정도는서로잘들어맞지않고, 어느경우에낙상, 외상또는사망률의증가와더깊은상관관계가분명한지는논란의여지가많다. 13,14 다시말해기립성어지럼과기립성저혈압은서로공유하는부분도있지만엄밀히말해다른개념이라말할수있는데, 기립성어지럼은특정질환을일컫는것이아니라환자의일어설때어지럽다라는증상을일반적으로일컫는것이며, 기립성저혈압은기립혈압측정을통한검사결과에따른현상을부르는용어이다. 신체의평형을유지하기위해필요한시각계, 말초전정감각계, 체성감각계그리고이를통합하는중추신경계중에서어느한곳이라도이상이있다면어지럼은발생할수있다. 기립성저혈압이발생할때통합및조절하는중추신경계중특히대뇌의관류저하가더뚜렷하게일어날것이고이때어지럼을느끼는것은당연한것으로여겨지지만, 기립성저혈압에의해뇌간과내이의혈류부전이발생하고전정계의 Figure 1. Neurogenic orthostatic hypotension in multiple system atrophy. After the tilt, there was a decrease of blood pressure of more than 30 mm Hg and recovery of blood pressure is observed in the supine period. 장애가발생하여어지럼이아닌현훈이나이명이나타날수있는지에대하여는더많은연구가필요하다. 비록척추동맥압박이나협착에의하여뇌간이나내이의혈류감소로인하여안진과현훈이유발되는경우나소뇌동맥협착에서현훈이있는경우는보고되었지만기립경검사 (tilt test) 등을통하여기립성저혈압을재현하여뇌간이나내이의혈류저하와현훈의발생을명확하게증명한보고는없다. 15,16 기립성저혈압은병태생리학적으로두가지로나눌수있는데, 기립시 3분이내에발생하는초기형기립성저혈압 (initial orthostatic hypotension) 과 5분에서 45분사이에발생하는지연형기립성저혈압 (delayed orthostatic hypotension) 으로구분된다고한다. 17,18 발생시기에따라구분할수도있는데원인은서로다르다. 급성으로발생한기립성저혈압은부신위기, 부정맥, 심근경색, 패혈증, 탈수, 화상, 발열, 구토, 설사, 출혈, 약물등에의해서초래될수있고오래전부터지속된만성기립성저혈압은노화에따른압력반사기능의저하, 조절되지않은고혈압, 자율신경계기능부전으로인해일어날수있다. 자율신경계기능부전은뇌간병변, 레비소체치매, 다계통위축증, 척수병증, 다발성뇌경색, 파킨슨병등중추신경계질환과알코올성이나당뇨병성신경병증, 비타민결핍성신경병증, 부종양성신경병증등말초신경계질환에의해나타날수있다. 15 이중약물에의한기립성어지럼및저혈압을문진을통해반드시배제하여야하는데, 흔한약물로는교감신경차단제, 항정신병약제, 항불안제, 수면제, 항고혈압제, 이뇨제, TCA, levodopa 등이대표적이다. Figure 1은다계통위축증 (multiple system atrophy) 에서볼수있는전형 S116
이형. 비전정성어지럼 Figure 2. The arterial baroreceptors are mechanoreceptors located in the carotid sinuses (innervated by the glossopharyngeal nerve, IX) and aortic arch (innervated by the vagus nerve, X) that respond to stretch elicited by increase in arterial pressure. Primary baroreceptor afferents provide monosynaptic excitatory input to the nucleus of the solitary tract. Barosensitive NTS neurons initiate a sympathoinhibitory pathway that involves a projection from the NTS to interneurons in the caudal ventrolateral medulla (CVL) that send an inhibitory projection to sympathoexcitatory neurons located in the rostral ventrolateral medulla. The baroreflex-cardioinhibitory pathway involves a direct input from the NTS to a group of vagal preganglionic neurons located in the ventrolateral portion of the nucleus ambiguus (NA). These neurons project to the cardiac ganglion neurons that elicit bradycardia. The baroreflex, via the NTS, also inhibits secretion of arginine vasopressin by magnocellular neurons of the supraoptic (SON) and paraventricular (PVN) nuclei of the hypothalamus, in part by inhibiting noradrenergic cells of the A1 group. 적인기립성저혈압이다. 기립시혈압을유지시켜주는압력반사회로는대동맥궁과경동맥동의동맥압력수용기에있다 (Figure 2). 19 결 비전정성어지럼은주위가돌아가는전정성어지럼보다외래단위에서더흔히볼수있는어지럼이며많은경우에서정신과적혹은심혈관계질환의증상으로나타난다. 철저한문진및이학적검사를통해어지럼의유형및원인분석이무엇보다도중요하다할수있다. 론 REFERENCES Springer; 1999. 2. Lee TK, Sung KB. Overview and history taking of dizziness. Res Vestibul Sci 2005;4:67-73. 3. Baloh RW, Halmagyi GM. Disorders of the vestibular system. New York: Oxford University Press; 1996. 4. Furman JM, Cass SP. Vestibular disorders; a case-study approach. 2nd ed. New York: Oxford University Press; 2003. 5. Baloh RW, Honrubia V. Bedside examination of the vestbualr system. In: Baloh RW, Honrubia V, editors. Clinical neurophysiology of the vestibular system. 3rd ed. Philadelphia: F.A. Davis Co.; 2001. p.132-51. 6. Hain TC, Spinder J. Head-shaking nystagmus. In: Sharpe JA, Barber HO, editors. The vestibulo-ocular reflex and vertigo. New York: Raven Press; 1993. 7. Takahashi S, Fetter M, Koenig E, Dichgans J. The clinical significance of head-shaking nystagmus in the dizzy patient. Acta Otolaryngol 1990;109:8-14. 8. Lee KK, Lee JY, Kim HW, Lee JY, Paik KC, Lee JI, et al. Psychiatric symptoms manifested in patients with psychogenic dizziness. J Korean Neuropsychiatr Assoc 1999;38:956-65. 9. Furman JM, Jacob RG. Psychiatric dizziness. Neurology 1997; 48:1161-6. 10. Lee KK. Psychogenic vertigo. Res Vestibul Sci 2006;5:185-93. 11. Ballenger JC. Biological aspects of panic disorder. Am J Psychiatry 1986;143:516-8. 12. Consensus statement on the definition of orthostatic hypotension, pure autonomic failure, and multiple system atrophy. The Consensus Committee of the American Autonomic Society and the American Academy of Neurology. Neurology 1996;46: 1470. 13. Ward C, Kenny RA. Reproducibility of orthostatic hypotension in symptomatic elderly. Am J Med 1996;100:418-22. 14. Wu JS, Yang YC, Lu FH, Wu CH, Chang CJ. Population-based study on the prevalence and correlates of orthostatic hypotension/ hypertension and orthostatic dizziness. Hypertens Res 2008; 31:897-904. 15. Kim DU, Han MK, Kim JS. Isolated recurrent vertigo from stenotic posterior inferior cerebellar artery. Otol Neurotol 2011; 32:180-2. 16. Marti S, Hegemann S, von Budingen HC, Baumgartner RW, Straumann D. Rotational vertebral artery syndrome: 3D kinematics of nystagmus suggest bilateral labyrinthine dysfunction. J Neurol 2008;255:663-7. 17. Wieling W, Krediet CT, van Dijk N, Linzer M, Tschakovsky ME. Initial orthostatic hypotension: review of a forgotten condition. Clin Sci (Lond) 2007;112:157-65. 18. Gibbons CH, Freeman R. Delayed orthostatic hypotension: a frequent cause of orthostatic intolerance. Neurology 2006;67: 28-32. 19. Benarroch EE. The arterial baroreflex: functional organization and involvement in neurologic disease. Neurology 2008;71: 1733-8. 1. Brandt T. Vertigo: Its multisensory syndromes, 2nd ed. Berlin: S117