원저 J Korean Neurol Assoc / Volume 23 / June, 2005 기저동맥의신연증과뇌간경색 전남대학교의과대학신경과학교실 박종귀김병채이승한최성민박만석김명규조기현 Brainstem Infarction in Patients with Basilar Artery Dolichosis Jong-Gwi Park, M.D., Byeong C. Kim, M.D., Seung-Han Lee, M.D., Sung-Min Choi, M.D., Man-Seok Park, M.D., Myeong-Kyu Kim, M.D., Ki-Hyun Cho. M.D. Department of Neurology, Chonnam National University Medical School, Gwangju, Korea Background: Basilar arterial dolichosis (BD) has chracteristics of tortuosity and elongation. BD can cause obstructive hydrocephalus, direct compression of brainstem and cranial nerves, and cerebral ischemia or infarction. It has been reported that brainstem infarction is usually located contralateral to the side of lateral displacement. This study was aimed to reveal the relation between the location of the infarction and the some characteristics of BD. Methods: Among the 143 patients who had brainstem infarction from January, 2003 to July, 2004, 40 patients with BD were analyzed retrospectively. Characteristics of BD and infarct site were analysed with special respect via MRI and MRA. We surveyed the relation between the location of the infarction and the lateral displacement of BD. Subjects were divided into two groups by the degree of the lateral displacement of basilar artery (BA). We made a comparison between the two in clinical characteristics and risk factors. Height of the infarct site and the maximal point of lateral displacement from arbitrarily defined standard level (lower pons) were measured. We surveyed the lesional laterality associated with relative height of the infarct site. Results: Infarct lesions located to the contralateral side of the laterally displaced BA were more prevalent (25 cases, 62.5%). There was significant correlation between the lesional laterality and the lateral displacement of the BA in group B (p=0.039) and between the lesion-height and the maximal dolichosis-height (r=0.639, p<0.001). Conclusions: Patients with BD are more likely to have brainstem infarction at the contralateral side of the laterally displaced BA. J Korean Neurol Assoc 23(3):318-323, 2005 Key Words: Basilar artery dolichosis, Brainstem infarction 서론 두개내동맥의신연증 (dolichosis) 은두개기저부동맥혈관의사행 (tortuosity) 및신연 (elongation) 을특징으로하는비교적드문질환이다. 호발부위는주로후방순환계인원위부척추동맥 (distal vertebral artery) 과기저동맥 (basilar artery) Received January 11, 2005 Accepted March 8, 2005 *Ki-Hyun Cho, M.D. Department of Neurology, Chonnam National University Medical School 8 Hag-dong, Dong-gu, Gwangju, 501-190, Korea Tel: +82-62-220-6171, Fax: +82-62-228-3461 E-mail: kcho@chonnam.ac.kr 이고간혹두개내원위부내경동맥 (intracranial distal internal carotid artery) 과근위부대뇌동맥 (proximal cerebral artery) 도이환되는것으로알려져있다. 1-3 발병기전은내탄성막 (internal elastic lamina) 의결손, 고혈압, 및죽상동맥경화증과밀접한연관이있을것으로추정되고있으나명확하지않다. 신연증환자에서흔히나타나는증상은폐쇄성수두증, 뇌간혹은뇌신경의압박, 뇌허혈및뇌경색등에의해나타나게되며, 컴퓨터단층촬영및자기공명영상소견은뇌허혈및뇌경색병변, 출혈성병변, 압박성병변, 뇌위축등이다. 4,5 국외의몇몇보고에의하면후방순환계에서의경색은주로열공성경색이며기저동맥의사행이보일때사행측의반대편뇌간에경색이잘생기는것으로보고되고있으나, 3,6 신연증과뇌경색병변 318 J Korean Neurol Assoc Volume 23 No. 3, 2005
기저동맥의신연증과뇌간경색 의위치와의연관성에대한연구는아직국내외적으로미흡한실정이다. 이에기저동맥의신연증이동반된뇌간경색환자들의영상소견, 임상적특성, 그리고신연증의특성과병변의위치와의연관성을알아보고자하였다. 대상과방법 2003 년 1월부터 2004 년 7월까지전남대병원신경과에뇌간경색으로입원한 143 명의환자중혈관조영술영상이없어신연증여부의평가가불가능한 5명을제외하고뇌자기공명영상및뇌자기공명혈관조영술로기저동맥의신연증이있는것으로확인된 40명을대상으로후향적연구를하였다. 뇌자기공명영상은 1.5T 초전도체자기공명영상기기 (GE Signa Horizon, U.S.A) 와 3T 초전도체자기공명영상기기 (Siemens Trio, Germany) 와 bird cage 형두부코일을이용하였다. 절편두께 5 mm, matrix 256x192, 촬영시야 (field-of-view) 22 cm의조건에서 T1강조영상 (TR/TE=500 msec/8 msec) 과 T2 강조영상 (TR/TE=3,500 msec/100 msec) 을얻었다. 확산강조영상은 echo planar imaging 기법을이용하여확산경사자기를 x, y, z 세방향으로가한후등방성영상을얻었다. 확산강조영상을얻기위한영상변수로는 TR/TE(msec)=10,000/96, matrix 128 128, b 값 1,000 sec/mm 2, 절편두께 5 mm 로하였다. 뇌자기공명혈관조영술은 3D-TOF 기법을이용하여축상면방향으로얻었으며이때사용된영상변수들은 TR/TE (msec)=33/6.9, flip angle 20, scan thickness 1.4 mm, slice/slab 64를사용하여모두 3분 30 초에걸쳐얻었다. Willis 환주위를중심으로스캔한슬랩 (slab) 은 50 mm 의두께로 3차원용적으로얻었다. 각축상면원천영상 (axial source image) 들은 workstation 으로옮겨최대강도투사 (maximum intensity projection) 기법으로후처리 (postprocessing) 하였다. 이때절편의축방향으로 20도씩회전하여 360 도를회전시킨재투사영상 (reprojection image) 을 18개얻었다. 기저동맥의신연은 Smoker 등 1 의제안처럼혈관의주행중사대 (clivus) 의외측경계부위까지치우치는부위가있거나기저동맥이안장위수조 (suprasellar cistern) 상방에서분기되는것으로정의하였다. 뇌자기공명혈관조영술압축영상 (compressed image) 에서전체적인모양을확인한후기저동맥의사행이의심되는경우원천영상에서기저동맥이분지되는부위의위치, 사행 (tortuosity) 의정도, 동맥의외경을측정하였다. 분지되는위치는안장등 (dorsum sellae) 의하방 (H0), 안장위수조내 (H1), 제3뇌실바닥 (H2), 제3 뇌실바닥상방 (H3) 으로, 사행의정도는 Figure 1. The shape of basilar artery. (A) C shape, (B) J shape, (C) S shape Figure 2. Definition of group A and B. Group A is defined as basilar artery lay on the medial to lateral margin of clivus or dorsum sellae (black arrow). Group B is defined as basilar artery lay on the cerebellopontine angle cistern (white arrow). 정중앙 (L0), 사대외벽의내측경계 (L1), 외측경계 (L2), 소뇌교뇌수조 (cerebellopontine angle cistern)(l3) 로분류하였다. 외경은기저동맥의주행중가장넓은부위에서측정프로그램을이용하여 3회측정하여평균치를구하였다. 신연증을보이는기저동맥은 C자, J자, S자모양으로구분하였다 (Fig. 1). 기저동맥의사행이심한정도에따라사대외벽의내측경계 (L1) 에있는경우를 A군으로, A군보다더심한사행을보이는경우를 B군 (L2, L3) 으로나눈후 (Fig. 2) 두군간에임상적특성및위험인자를비교하였다. 병변의높이 ( 임의로설정한기준으로부터수직높이 ) 와사행이가장심한곳의높이의상대적인차이에따라병변의편재성에의미가있는지알아보았다. 기준 (0 mm) 은통계적처리를위 J Korean Neurol Assoc Volume 23 No. 3, 2005 319
박종귀김병채이승한최성민박만석김명규조기현 석하였고, 나이, 혈중지질치, 지단백, ESR, CRP, 호모시스테인, 요산등과같은연속형변수들은 Student t-test 를이용하였다. Pearson correlation 을사용하여병변의위치와사행이가장심한곳의위치의연관성을살펴보았다. 통계분석은 Statistical Package for Social Science (SPSS) 10.0을이용하여 p 값이 0.05 이하일때통계적으로유의한것으로평가하였다. Figure 3. The measurement of relative lesional height. Height of the infarct site (A, white arrow) and the maximal lateral displacement of the basilar artery (B, black arrow) are measured from the standard level (C). Standard level (C) is arbitrarily defined at the site of basal surface showing the inferior cerebellar peduncle. 하여하부소뇌다리 (inferior cerebellar peduncle) 가보이는하부뇌교를임의로설정하였다. 병변의위치는뇌자기공명영상축상면에서병변이가장큰부위로설정하고, 사행이가장심한위치는기저동맥의주행중중심선에서가장먼곳을설정한후이들을시상면영상에서확인하여기준과의높이차이를 2명의신경과의사가측정하여그평균값을구하였다 (Fig. 3). 축상면영상과시상면영상을함께비교하기위해서의료영상저장전송시스템 (picture archiving communication system, PACS) 을사용하였다. 뇌혈관질환의위험인자로서고혈압 ( 이미진단받은경우와입원중수축기혈압이 140 mmhg 혹은이완기혈압이 90 mmhg 이상인경우 ), 7 당뇨병 ( 이미진단받고혈당강하제또는인슐린을투여하고있는경우, 공복시혈당이 126 mg/dl 이상, 혈당이 200 mg/dl 이상인경우 ), 8 고지혈증 (total cholesterol >240 mg/dl 또는 triglyceride > 180mg/dl) 9 과, 흡연여부, 적혈구침강속도 (erythrocyte sedimentation rate, ESR), C-반응성단백질 (C-reactive protein, CRP), 호모시스테인, 지단백, 요산등을조사하였다. 통계적으로는성별, 고혈압, 당뇨, 고지혈증유무, 흡연여부등과같은이산형변수들은 chi-square(χ 2 ) test 를이용하여분 결과 1. 대상군의임상적특성및신연증의영상소견 대상은총 40명으로연령은 34-96 세 ( 평균 64.6±9.9 세 ) 였고남자가 27 명 (67.5%), 여자는 13 명 (32.5%) 이었다. 동반된뇌혈관질환의위험인자는고혈압 37 명 (92.5%), 당뇨 17명 (42.5%), 고지혈증 15명 (37.5%), 흡연 9명 (22.5%), 일과성허혈발작 2명 (5.0%), 뇌졸중기왕력 8명 (20%) 이었다. 뇌간경색의위치는뇌교 (34예 ), 연수 (5예 ), 중뇌 (4예 ), 소뇌 (2예 ), 시상 (1예 ) 에중복된병변이있었고, 뇌교중간 (17 예 ) 부위에병변이가장많았다. 환자에서나타난임상증상은부전마비 (24 예 ), 구음장애 (16 예 ), 현훈 (8예 ), 실조증 (4예 ), 복시 (4예 ), 저림 (1예), Horner 증후군 (1예) 순으로중복된경우가많았다. 기저동맥이분지되는높이에따른분류는 H0에해당하는환자가 6명 (15.0%), H1은 25명 (62.5%), H2는 8명 (20.0%), H3은 1명 (2.5%) 이었으며, 사행의정도에따른분류는 L1에해당하는환자는 24명 (60.0%), L2는 9명 (22.5%), L3은 7명 (17.5%) 이었고, 직경은평균 3.42±1.35 mm (1.20-7.33 mm) 였다. 신연증을보이는기저동맥은 C자모양이 25명 (62.5%) 으로가장많았고, J자모양은 9명 (22.5%), S자모양이 6명 (15.0%) 이었다. 뇌간경색병변이사행방향과반대측에있는경우 (25 예, 62.5%) 는동측에있는경우 (15 예 ) 보다더많았으나통계적으로유의하지는않았다 (Table 1). 뇌간경색의위치와사행이가장심한곳의위치는양의상관관계를보이는것으로나타나 (r=0.639, p<0.001) 사행이가장 Table 1. The relation between the lesional laterality and the severity of basilar arterial tortuosity Group A Group B Total Ipsilateral Contralateral Total p value 11 4 15 13 12 25 Group A; Subjects whose basilar artery lay on the medial to lateral margin of clivus or dorsum sellae, Group B; Subjects who have more tortuositic basilar artery than group A, P value was calculated with chi-square test. 24 16 40 0.182 320 J Korean Neurol Assoc Volume 23 No. 3, 2005
기저동맥의신연증과뇌간경색 Table 4. Relation between the lesional laterality and the lateral displacement of the basilar artery in group B (n=16) Lesion site Lateral displacement Left Right Total p value a Left Right Total 1 7 8 5 3 8 6 10 16 0.039 Group B; Subjects who have more tortuositic basilar artery than group A, P value a was calculated with chi-square test. 심한곳과가까운곳에병변이있는것으로관찰되었다 (Fig. 4). 병변의높이와사행이가장심한곳의높이의차에따라나눈후병변의편재성을비교한결과병변의높이가사행이가장심 Figure 4. The correlation between the lesion-height and the maximal dolichosis-height (n=40, r=0.639, p<0.001). 0 mm indicates standard level. Table 2. The relation between the lesional laterality and the relative lesional height on the basis of the maximal lateral displacement site of basilar artery 한곳보다높은경우 (22 명 ) 에서사행의방향과동측인경우는 8 명이었고, 반대측인경우는 14명이었다. 병변의높이가사행이심한위치보다낮은경우 (18 명 ) 에서는사행의방향과동측인경우는 7명이었고, 반대측인경우는 11명으로, 사행최고지점에대한병변의상대적위치 ( 상 / 하 ) 에따른병변의편재성 ( 좌 / 우 ) 을보이지는않았다 (Table 2). Height Lesional site Ipsilateral Contralateral Total p value 2. 군설정후결과 High Low Total 8 7 15 14 11 25 22 18 40 0.870 Height; relative lesional height on the basis of the maximal lateral displacement site of basilar artery, P value was calculated with chi-square test. 기저혈관사행의정도가경미한경우 (A군 ) 에해당하는환자는 24명으로연령은 51-81 세 ( 평균 64.9±7.5 세 ) 이고남자가 17 명, 여자가 7명이었다. 사행의정도가좀더심한경우 (B군 ) 에해당하는환자는 16명으로연령은 34-96 세 ( 평균 64.2±12.9 세 ) 이고남자가 10명, 여자가 6명이었다. 기저동맥의사행정도 Table 3. Demographic and clinical characteristics Variables Group A (n=24) Group B (n=16) p value Age (y) Male (n,%) Hypertension (n,%) Diabetes mellitus (n,%) Hyperlipidemia (n,%) Smoke (n,%) TIA (n,%) Previous CVA (n,%) Total cholesterol (mg/dl) HDL (mg/dl) Triglyceride (mg/dl) CRP (mg/dl) Homocysteine (u mol/l) Fibrinogen (mg/dl) 64.60±9.87 17 (70.8) 23 (95.8) 11 (45.8) 9 (37.5) 5 (20.8) 1 (4.2) 5 (20.8) 195.67±9.98 38.47±9.85 163.54±32.36 0.51±0.22 12.67±1.74 264.79±8.37 64.19±12.92 10 (62.5) 14 (87.5) 6 (37.5) 6 (37.5) 4 (25.0) 1 (6.3) 3 (18.8) 192.69±9.66 39.64±2.86 137.38±17.06 0.70±0.23 12.10±1.28 262.14±17.47 0.832 0.581 0.327 0.601 1.000 0.757 0.767 0.872 0.839 0.733 0.539 0.565 0.814 0.879 TIA; transient ischemic attack, CVA; cerebrovascular accident, HDL; high-density lipoprotein, CRP; C-reactive protein, Group A; subjects whose basilar artery lay on the medial to lateral margin of clivus or dorsum sellae, Group B; subjects who have more tortuositic basilar artery than group A. J Korean Neurol Assoc Volume 23 No. 3, 2005 321
박종귀김병채이승한최성민박만석김명규조기현 에따른동반된뇌혈관질환의위험인자는고혈압, 당뇨, 고지혈증, 흡연, 일과성허혈발작, 뇌졸중기왕력으로두군간의빈도분석에서통계적유의성은없었다. 그외에혈중지질치, ESR, CRP, 지단백, 호모시스테인, 섬유소원, 요산값에서도두군간의평균치비교에서통계적유의성은없었다 (Table 3). 기저혈관의사행정도가심한 B군에한정하여병변의위치와사행방향과의연관성을살펴보았을때반대측에있는경우는 12명 (72.5%), 동측에있는경우가 4명이었고이는통계적으로유의성을보여 (p=0.039) 병변이사행방향과반대측에호발하는것으로나타났다 (Table 4). 고찰 두개내동맥의신연증은전체인구의약 0.05% 이하의낮은빈도를보이는질환이지만처음뇌졸중이발생한환자의뇌컴퓨터단층촬영혹은뇌자기공명영상에서약 3% 이상의빈도로발견된다고보고되어있다. 10 신연증의위험인자는고혈압, 흡연, 남성등인데특히동맥경화증이나고혈압을보이는장년, 노년층의남자에게흔하다고한다. 신연증이잘생기는위치는척추기저동맥, 두개내내경동맥, 중대뇌동맥, 전대뇌동맥, 후대뇌동맥순으로발생한다고알려져있다. 11 신연증의발병기전은명확하지않지만혈관벽의동맥경화성변성, 선천성기형, 또는전반적인동맥의변성의일부라는주장이있다. 신연증이동맥경화성변성때문이라는것은다음과같다. Pico 등 6 은두개내혈관의신연증이있는 63명과 447 명의신연증이없는대조군과의비교에서고령, 남성, 고혈압, 심근경색의기왕력이신연증과밀접한관계가있다고하였다. Nakayama 등 12 과 Pessin 등 13 은기저동맥신연증환자의부검에서혈전이많이발견되었고, 죽상동맥경화성변화에의한동맥협착이발견되었다고보고하였다. 신연증이선천성기형이라는근거는병리조직학적으로동맥벽내탄성층 (internal elastic laminar) 의결손과평활근위축에따른중막층의이차성위축을보이고, 동맥경화성변성의결여와나이에따른신연증유병률의차이가없다는것 14,15 등이다. 신연증이전반적인동맥의변성이라는근거는기저동맥의신연증이두개내혈관의전반적인확장의일부라는점, 복부대동맥류와다른전신혈관의확장과연관이있다는점등이다. 11,16 본연구에서도고혈압 (37 명, 92.5%), 남성 (27 명, 67.5%), 당뇨 (17 명, 42.5%) 등이일반적으로알려진것보다많아동맥경화와관련되어있을것으로생각되나대상군의숫자가적고, 대조군이없으므로통계적분석을할수는없었다. 신연증이기저동맥에잘발생하는이유는고혈압, 선천성원 인등의요인과함께후순환계에대한교감신경계의지배가상대적으로적기때문이라고생각해볼수있으나명확하지는않다. 2 신연증이뇌경색을일으키는기전은모동맥혹은관통동맥 (penetrating artery) 에서의지방초자질변성 (lipohyalinosis) 및죽종 (astheroma) 으로인한혈관내협착, 혈전형성, 신연과왜곡 (disortion), 동맥간색전증, 동맥박리등으로알려져있다. 10,13,17 신연증에서가장흔한증상은일과성허혈발작과뇌경색인데주로기저동맥의순환부전에의한것 18 으로이환된동맥의사행및왜곡으로혈류속도가감소하는혈류역학적요인이주된기전으로생각되며, 3,13 Rautenberg 등 19 은신연증을보인기저동맥의혈류속도를경두개초음파검사 (transcranial doppler; TCD) 로측정한결과정상대조군에비해유의하게떨어져있다고보고하였다. 이러한이유로신연증이있는경우에는방사선학적, 임상적소견상열공성뇌경색이많이관찰된다고보고되고있다. 6 본연구대상의 62.5% 가사행방향과반대측에뇌경색이있었고, 이러한경향은사행의정도가심한경우에뚜렷하였다. 신연증과뇌경색병변부위에대한다른연구에서도본연구와같은결과를보였다. 6 이를근거로신연증이심할수록사행방향과반대측에병변이호발한다고생각된다. 또한, 병변의위치와사행이가장심한곳은양의상관관계를가지고있어 (r=0.639, p<0.001) 사행이심한부위가까운곳에병변이호발함을알수있었다. 이원인은다른보고와같이혈류속도의감소와관통혈관의신장혹은왜곡에의한협착이주된원인으로생각되나, 3 사행이심할수록전단력 (shearing force) 이크고혈관벽반대편에쌓인혈전에의한협착이또하나의원인이라고생각된다. 따라서사행이가장심한곳하방에서는사행방향과반대측에병변이있을것으로기대되고, 반대로사행이가장심한곳상방에는사행방향과동측에병변이있을것으로예상하였으나본연구의결과와는일치하지않았다 (p=0.515). 이는대상군의수가적었다는점과병변의높이와사행이가장심한곳의높이를뇌자기공명영상축상면에서측정하여정확하지않았다는점을고려해야할것으로생각한다. 신연증의치료에대해선아직논란이많은상태로, 혈전증을동반한기저동맥의신연증환자에서유로키나제, 저분자헤파린을사용했다는보고가있고, 20,21 Ince 등 10 은신연증이있는경우아스피린이나와파린으로치료를하여도높은재발률을보인다고보고하였다. Passero 등 3 은후방순환계에동반된죽상동맥경화성변화가있을때뇌경색의발생에신연증이보다중요한역할을할것이라고보았다. 또 Ubogu 등 22 은 cohort 연구에서기저동맥의신연증이뇌경색의독립적인위험인자이며 322 J Korean Neurol Assoc Volume 23 No. 3, 2005
기저동맥의신연증과뇌간경색 사망률을높인다고하였다. 그러나신연증이죽상동맥경화의표지자혹은뇌경색의독립적인위험인자로볼수있는지에대한확실한증거가없어아직까지기저동맥의신연증에대한치료방법이명확하지는않으나신연증과관련된위험요소들을미리예방하는것이중요할것으로생각한다. 결론적으로기저동맥신연증의사행방향과뇌간경색병변위치는사행이심할수록사행방향의반대측에발생되고, 사행이가장심한곳과가까운곳에발생됨을알수있었다. REFERENCES 1. Smoker WR, Price MJ, Keyes WD, Corbett JJ, Gentry LR. High-resolution computed tomography of the basilar artery: 1. Normal size and position. AJNR Am J Neuroradiol 1986;7:55-71. 2. Yu YL, Moseley IF, Pullicino P, McDonald MI. The clinical picture of ectasia of the intracerebral arteries. J Neurol Neurosurg Psychiatry 1982;45:29-36. 3. Passero S, Filosomi G. Posterior circulation infarcts in patients with vertebrobasilar dolichoectasia. Stroke 1998;29:653-659. 4. Vieco PT, Maurin EE 3rd, Gross CE. Vertebrobasilar dolichoectasia: evaluation with CT angiography. AJNR Am J Neuroradiol 1997;18:1385-1388. 5. Tien KL, Yu IK, Yoon SJ, Yoon YK. CT and MR Imaging Features in Patients with Intracranial Dolichoectasia. J Korean Radiol Soc 2000;42:205-214. 6. Pico F, Labreuche J, Touboul PJ, Amarenco P; GENIC Investigators. Intracranial arterial dolichoectasia and its relation with atherosclerosis and stroke subtype. Neurology 2003;61:1736-1742. 7. Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo Jr JL, et al. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. JAMA 2003;289: 2560-2572. 8. American Diabetes Association. Diagnosis and classification of diabetes mellitus. Diabetes Care 2004;27(Suppl 1):5-10. 9. Executive Summary of the Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol In Adults (Adult Treatment Panel III). JAMA 2001;285:2486. 10. Ince B, Petty GW, Brown RD Jr, Chu CP, Sicks JD, Whisnant, JP. Dolichoectasia of the intracranial arteries in patients with first ischemic stroke. Neurology 1998;50:1694-1698. 11. Milandre L, Bonnefoi B, Pestre P, Pellissier JF, Grisoli F, khalil R. Vertebrobasilar aterial dolichoectasia. Complications and prognosis. Rev Neurol 1991;147:714-722. 12. Nakayama Y, Tanaka A, Kumate S, Tomonaga M, Takebayashi S. Giant fusiform aneurysm of the basilar artery: consideration of its pathogenesis. Surg Neurol 1999;51:140-145. 13. Pessin MS, Chimowitz MI, Levine SR, Kwan ES, Adelman LS, Earnest MP, et al. Stroke in patients with fusiform vertebrobasilar aneurysms. Neurology 1989;39:16-21. 14. Besson G, Bogousslavsky J, Moulin T, Hommel M. Vertebrobasilar infarcts in patients with dolichoectatic basilar artery. Acta Neurol Scand 1995;91:37-42. 15. Gautier JC, Hauw JJ, Awada A, Loron P, Gray F, Juillard JB. Dolichoectatic intracranial arteries. Association with aneurysms of the abdominal aorta. Rev Neurol 1988;144:437-446. 16. Nijensohn DE, Saez RJ, Reagan TJ. Clinical significance of basilar artery aneurysms. Neurology 1974;24:301-305. 17. Steel JG, Thomas HA, Strollo PJ. Fusiform basilar aneurysm as a cause of embolic stroke. Stroke 1982;13:712-716. 18. Nishizaki T, Tamiki N, Takeda N, Shirakuni T, Kondoh T, Matsumoto S. Dolichoectatic basilar artery: a review of 23 cases. Stroke 1986;17:1277-1281. 19. Rautenberg W, Aulich A, Rother J, Wentz KU, Hennerici M. Stroke and dolichoectatic intracranial arteries. Neurol Res 1992;14 Suppl 2:201-203. 20. De Georgia M, Belden J, Pao L, Pessin M, Kwan E, Caplan L. Thrombus in vertebrobasilar dolichoectatic artery treated with intravenous urokinase. Cerebrovasc Dis 1999;9:28-33. 21. Cheung RT, Mak W. Two chinese patients with vertebrobasilar dolichoectasia. Stroke 1998;29:2213-2215. 22. Ubogu EE, Zaidat OO. Verterbrobasilar dolichoectasia diagnosed by magnetic resonance angiography and risk of stroke and death: a cohort study. J Neurol Neurosurg Psychiatry 2004;75:22-26. J Korean Neurol Assoc Volume 23 No. 3, 2005 323