大 韓 放 용f 線 ':! 學 會 誌 第 26 卷 第 2 號 pp. 279-285, 1990 Joum al 01 Ko rean Radiolog ical Society‘ 26 (2) 279-285, 1990

CT and MR Findings of

Hyo Keun Lim, M.D., In Wool‘ Choo, M.D., Sang Hoon Bae, M.D., Mun Gyu Lee, M.D.*, Choon Whan Han, M.D.**, In One Kim, M.D.**, Kyung Mo Yeon, M.D. **

Department o[ Radiology, College o[ Medicine, Ha11ym University

〈국문초록〉

Schizencephaly의 전산화단층촬영 및 자기공명영상소견

한림대학교 의과대학 방사선과학교실

임 효 근 • 주 인 욱 • 배 상 훈 • 이 문 규* 한 춘 환* * 김인 원 ** 연경 모**

1 98 8 년 3 월부 터 1989 년 11 월까지 1 년 8 개월동안 경험한 1 2 례 의 특징적인 sc hi ze n cep h a l y 의 전 산화단충촬영 및 자기공명영상소견 들을 임상소견과 함께 역행적으로 분석하였으며 문헌고찰을 통하여 이제까지 밝혀진 병인론에 대 하여 언급하는 바이다 . 엄상적으로 모든례에서 다양한 정도의 운동장애를 보였으며 경련발작 및 발육지연이 각각 8 례 (67 %)에서 관찰되었으며 이러한 임상소견들은 병적인 뇌의 범위와 밀접한 연관성을 갚는 것으 로 생각되었 다. 전산화단층촬영 및 자기공명영상에서 전 12 례중 type 1 이 4 례， type II 가 7 례였으며 두 유형이 공존한 증 례도 한례가 있었 다. 병변의 위치는 전례에서 두정부 에 있었으며 일측성이 7 례로서 5 례 의 양측성보다 많았다 . 뇌실확장은 11 례에서 있었으나 대부분이 경미한 정도 의 확장을 보였으며 동반된 기형으로는 균열주위의 다 소 뇌퇴 증 ( po l y mi c rog y ria ) 이 전례에서 관찰되었으며 그 외 투명 중격막결손 (5 례 ) ， 소뇌 증 (3 례 ) ， 뇌 량체의 기형 (3 례 ) ， 측 두엽기형(1례)， 및 뇌실내 이소성피 질 (1 례 )퉁 이 있었다 . 자기공명영상은 이 질환 의 해부학적 변화와동반된 기형을 관찰하 는 데 있 어서 전산화단충촬영 보다 우월하였 다.

- Abstract-

Retrospective analysis of the CT and MR findings with Clinical findings was perfo rmed in 12 patients with schizencephaly. Clinically, all patients showed a variable range of neurologic disability, which may be related to the amount of tissue involved. In CT and MR. 4 pa tients had type 1 and 7 patients h ad type II . One patient had mixed type (ψpe 1 and type II). All clefts located in the pariental area (parasylvian region). Five patients had bllateral clefts and 7 patients had unilateral clefts. Eleven

• 울 산대 학교 의과 대 학 진단방사선과학교실 • Department o[ Radiology, College o[ Medicine, U1san University • 서울 대 학교 의과대학 진단방사선과학교실 .. Department o[ Radiology, College of Medicine, Seoul NationaJ University Received J anuary 27, accepted Feduany, 17 1990 이 논문은 1 990 년 l 월 27 일 접수하여 19 90 년 2 월 1 7 일에 채택되었 음 -279- - 大韓放射線훌훌學會誌 · 第 26 卷 第 2 號 1990 -

patients showed . mild in 10 patients and moderate in 1. Among the associated anomalies. polymicro밍rria along cleft was the most frequent anomaly (100 %). MR imaging was superior to CT in demonstration of the anatomical changes of this anomaly and associated anomalies.

Index Words: Brain. abnormalities 13.14 Brain. CT 13.1211 Brain. MR studies 13. 1214

CT was obtained in 10 patients. MR in 5 Introduction and both CT and MR in 3. Of these patients. only CT was obtained in 7 patients and only Schizencephaly is a developmental anomaly MR in 2. CT scans were obtained with a manifested by full-thickness clefts within the Technicare (Quantum) and GE 9800 scanner cerebral hemispheres. Pathologically. these in the axial plane with 100mm contiguous clefts are characterized by an infolding of cor­ slices before and after administration of in­ tical gray matter along the cleft from the cor­ travenous contrast material. Four patients 1 3 tex into the ventricrles - ). The most widely were imaged on a 2.0-T Goldstar Spectro 2000 accepted pathogenasis of this anomaly is that unit and 1 patient on a 0.5-T Goldstar Super­ a segmental failure occurs in the formation of tec 5000 unit. At each field of strength. Tl­ a portion of the germinal matrix or in the and T2-weighted spin-echo(SE) images were migration of the primitive con­ obained with a TR of 2000 msec and TE of 30 tained therein 1.4.5). Recently. several reports of msec and 80 msec in the axial plane and a TR this anomaly using sonography6). CT4 .5 .7 - 9 ) of 500 msec and TE of 30 msec in the coronal and MR 10-14) have been made. and sagital plane. Slice thickness was 5 mm The purpose of this paper is to describe the with a 2 mm interslice gap. characteristic CT and MR findings with clinic­ Pathologic confirmation was not possible. al findings and compare the efficacy of CT and These patients were diagnosed from the char­ MR in detection of this anomaly. Proposed acteristic gross morphology of the lesion. theories of pathogenesis are also discussed. which has b een established from the patholo­ gic. CT. MR experience. Subjects and Method Results Twelve patients with schizencephaly were scanned with CT and or MR during the past 2 The clinical and radiological findings of 12 years because of motor deficits. or de­ patients are presented in Table 1. The charac­ velopmental delay. The patient ages ranged teristic CT or MR finding is a cortically lined from 1 year to 9 years. with a mean of 4 years. cleft extending through the full-thickness of The patients included in this study were 6 the . The cortex lining the males and 6 females. respectively. AlI patients cleft is thicker than the other normal cortex had motor deficits and 9 patients of them had and a vessle is seen extending between the intractable and developmental de­ cortical surfaces of the cleft (Fig 1). Four pa ­ lay(Table 1). tients had type l(Fig 2-a) and 7 patients h ad

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Table 1. Summary of Clinical and Radiological Findings in 12 Cases of Schizencephaly

CT and MR Findings Case Age Clinical Modality No Sex Findings ηpe Location Symmetry V.Div V.Di1 Associated anomaly

5 / F Quadripl CT 1 & II Parietal Bi1 + Mod. A.S.P. , D.D. Polymlcrogyria 211M Parapl CT II Parietal Bi1 Mild Mlcrocephaly, D.D Polymicrogyria Seizure 3 4 / F Parapl CT II Parietal Bi1 + Mild ’ D.D. A.S.P., Seizure Polymicrogyria 4 6 / 1\‘ Parapl CT II Parietal Bi1 + Mild Microcephaly, D.D. A.S.P. , Seizure Polymicrogyria 5 8 / F Quadripl CT Parietal Bil + Mild Polymicrogyria 6 21M Hemipl CT II Parietal Uni1 + Mild Polymicrogyria Seizure σ 7 21M Hemipl II Parietal Unil + Mild Polymicrogyria mm D. of C.C mm 8 9 / M Hemipl Parietal Unil + Mild A.S .P., Seizure D. of C.C, D. of T.L, Polymicrogyria 9 3 1M Hemipl CT II Parietal Uni1 + Mild A.S.P., D.D MR D. Of C.C Polymicrogyria 10 2 / F Hemipl MR Parietal Uni1 h‘ild H.G.M, Seizure Polymicrogyria 11 3 / F Hemipl CT Parietal Unil Mild Polymicro밍rria Seizure Polymicrogyria 12 3 / F Hemipl CT II Parietal Uni1 + Mild Seizure MR Polymicrogyria

Note: a) Quadriplegia, Parapl=Paraplegia, Hemipl=Hemiplegia D.D=Developmental Delay b) Bil= Bilateral, Unil=Unilateral c) Mod. =Moderate d) V.div=Ventricular diverticulum, V.d i1 =Ventricular dilatation e) A. S.P.=Absent Septum Pellucidum, D. of C.C=Dysgesis of Corpus Callosum, D. of T.L= Dysgenesis of Temporal Lobe, H.G.H=Heterotopic Gray Matter type II(Fig 2-b). One patient had mixed type­ and moderate in one. Among the associated (Fig 1). All cleft slocated in the parietal area anomalies, polymicrogyria was the most com­ (parasylvian region). Five patients had bilater­ mon anomaly (Fig. 1) and all patients showed al clefts and 7 patients had unilateral cleft. this anomaly. Other associated anomalies con­ Small triangular diverticulums at the ven­ stited of absent septum pellucidum (5 / 12), tricular margin of the clefts were demons­ microcephaly(4/ 12), dysgenesis of corpus tratcd in 9 patients(Fig. 2-a). Eleven patients calosum(3/ 12), dysgenesis of temporal lobe(l/ showed ventriculomegaly, mild in 10 patients 12) and heterotopic gray matter within the

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Fig. 1. CT and MR images of schizencephaly. a. Axial contrast-enhanced CT scan of patient (bilateral schizencephaly). Thick cortex ex­ tends to lateral wall of right lateral ventricle (arrow heads) without V념 ible true cleft (ηpe 1). Cortical gtay-matter lined wide cleft ex­ tends through full-thickness of left cerebral hemisphere (1γpe n). En­ hanced vascular structures are noted in the heterotopic cortical a b surfaces of cleft (arrows) b. Axial SE 2000/ 80 MR image of patient 10 (unilateral schizencephaly). Irregular thick cortical gray-matter extends down to wall of right lateral ventricle (arrow heads). A true cleft is invisible (1γpe 1). This irre g비 ar thick heterotopic cortical gray matter suggests polymicrogyria.

Fig. 2.1γpe of schizencephaly. a. Axial CT scan of patient 5 show­ ing bilateral schizencephaly with fused lips (Type 1). b. Axial CT scan of patient 2 showing bilateral schizencephaly with open lips (1γpe n)

lateral ventricle( 1112). and separated, with coexistent “ hydrocepha- In the 3 patients (patient 7 , 9 and 12) per- lus" (type II). Pathologically, these clefts are formed toth CT and MR. the MR scan more covered by abnormally thick cortical gray mat- clearly demonstrated the cleft communicating ter with a fusion of the pial g!ial !ining of the with the lateral ventricle and associated ano- brain and the ependyma of the ventricle form- malies (Fig. 3). ing “ pial-ependymal seam"2’ Gray-matter heterotopias and areas of polymicro밍rria are l 31 Discussion frequently found within and near the cleft - . The pathosgensesis of schizencephaly has In 1946. Yakovlev and wadsworth 1.21 intro- not b een clearly estab!ished. Several theories duced the term schizencephaly to describe bi- have been introduced. The most widely lateral. nearly symmetrical. full-thickness accepted theory of these is a segmental failure clefts within the cerebral mantles. They de- in the formation of a portion of the germinal vided schizencephalies into two groupsi those matrix or in the migration of the primitive 4 51 that the walls of the cleft were fused (type 1) n euroblasts contained therein I. . . -282- Hyo Keun Lim ‘ et al.: CT and MR Findings of Schi zence phaly -

Fig. 3. CT and MR images of patient 7. a. Axial CT scan. Cortical gray-matter lined holohemispheric cleft is noted in the left parietal lobe b. Axial SE 300(}80 MR image. MR demonstrates a h이ohemispheric cleft communicating with lateral ventricle (arrow headsl and abnormal thick corical graymatter suggesting polymicrogyria more clearly than CT. c. Sagital SE 50

The other probable theories consisted of the bilateral clefts showed normal development. destruction of the previously formed hemis­ Also all patients who had type 1 defect exhi­ phere sometime before the sixth gestational bited normal development and fjve among month and a spectrum of encephaloclastic eight patients who had type II defect exhibited disorder. Several pathologiC findings support various developmental delay. All the patients that schizencephaly is a developmental had motor deficits, mild to severe and 8 pa­ anomaly rather than a postdevelopmental des­ tients had seizure that were refractory to tructive process9J . First, the clefts are covered medical terapy. by abnormally thick cortical gray matter sug­ The in vivo evaluation of this anomaly has gesting polymicro잃rria ， which is not a finding been improved with advances of CT and MR, of destructive lesions, secondly, the triangular Using CT ad MR, several reports have been configuration of the ventricle adjacent to the published4.5.7-9. 1O- 14J. In the early reports of cleft (ventricular diverticulum) is not associ­ schizencephaly, they dealt with bilateral open ated with ex vacuo ventricular dilatation. clefts (type II) and a small number of cases Thirdly, a vessle in the subarachinoid space is with unilateral fused clefts (type l) heave been often seen extending between the cortical sur­ reported4.5.SJ . Bird9J et al and Barkovich 13J et faces of the cleft which would not be present al reported many unilateral fused clefts. In our in an area of infarcted brain. patients, four patients had type 1 and seven Clinically, these patients show a broad patients had type II. Interestingly one patient range of neurologic disability, which is pre­ had both type 1 and type II . This variation sumably related to the amount of brain tissue may be more common than previously involved 5 . 1O . 1 이 ， Our data support this concept. thought. Bird9J et al explained reasons for this Six among seven patients showed unilateral variation that CT findings of type 1 defects are cleft exhibited normal development. On the different from the type II and there may be contrary, only one among 5 patients showed 폈 confusion with other lesions, such as prior - 大韓放射線훌훌學會誌 第 26 卷 第 2 號 1990 -

Fig. 4. Axial SE 2000/ 80 MR image of patient 10. Nodular heterotopic gray matter is well seen within lateral ventricle (arrow). Also septum p비 lucidum is absent. Image of schizencephaly in this patient is demomnstrated in Fig. 2-b

infarction. Another interesting finding is that ferentiation of gray andwhite matter. its high- all clefts located in the parietal area. The resolution and multiplanar imaging of ana- answer to this finding is not clear. though tomy. Bird9l et al suggested that if a circulatory dis- turbance is responsible. it may ref1ect the fact Summary that the largest vascular territory(middle cere- bral arteη) is the most likely one to be affected. Schizencephaly is more common and more Among the associated anomalies. the most frequently unilateral anomaly than has been common one was polymicrogyria. They were previously thought. This anomaly shows a demonstrated in all patients. The polymicrogy­ broad range of neurologic disability. which is ria is also a disorder of neuronal migration probably related to the amount of brain tissue occuring in the first trimester. In the CT and involved. This anomaly shows characteristic MR scan. this anomaly shows a thickening of findings in CT and MR. which can differenti­ the cortex with absence of detectable gyri ate this anomaly from other similar conitions. withing the region and the underlying white MR demonstrates more excellently anatomical matter appears somewhat diminishedlOl. It is changes of schizencephaly than CT because of known that schizencephaly and septooptic its superior differentiation of gray and white dysplasia frequently coexist and that both matter. it high-resolution and multiplanar im­ anomalies are associated with absence of the agmg. septum pellucidum in 75-100 % of The results from our study support that MR 4 patients .5l. Out of our patients. five should be the imaging method of choice in patients(42 % ) showed absence of the septum the evaluation of patients who have nerologic pellucidum. Nodular heterotopic gray matter disability. seizure or developmental delay. is also often associated with this anomaly. One of our twelve patients showed nodular REFERENCES heterotopic gray matter within the lateral ven-

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