Official reprint from UpToDate®
www.uptodate.com ©2016 UpToDate®

Prenatal diagnosis of CNS anomalies other than neural tube defects and ventriculomegaly

Ana Monteagudo, MD
Ilan E Timor-Tritsch, MD
Section Editors
Louise Wilkins-Haug, MD, PhD
Deborah Levine, MD
Deputy Editor
Vanessa A Barss, MD, FACOG


Malformations of the central nervous system (CNS) are the second most common type of major congenital anomalies, after congenital heart disease. Ultrasound examination is an effective modality for prenatal diagnosis of these anomalies.

Prenatal sonographic diagnosis of midline CNS anomalies will be reviewed here. Prenatal diagnosis of neural tube defects and ventriculomegaly are discussed separately. (See "Ultrasound diagnosis of neural tube defects" and "Fetal cerebral ventriculomegaly".)


CNS structures typically evaluated during a basic fetal ultrasound examination include: lateral ventricles, choroid plexuses, cavum septi pellucidi, thalami, cerebellum, cisterna magna, and spine (image 1 and image 2 and image 3) [1].

A thorough understanding of the normal sonographic appearance of the CNS across gestation is crucial for accurate diagnosis because the presence or absence of a structure may be normal or abnormal depending upon the age of the fetus. Poor timing of the examination, rather than poor sensitivity, can be an important factor in failing to detect a CNS abnormality [2]. As an example, a sonogram of the fetal brain at 14 weeks of gestation cannot detect agenesis of the corpus callosum since this structure does not become sonographically apparent until 18 to 20 weeks of gestation and does not acquire its final form until 28 to 30 weeks (see 'Disorders of the corpus callosum' below).

Ideally, pregnancies at increased risk of fetal CNS anomalies and those with suspicious findings on a basic examination should undergo fetal neurosonography performed by clinicians with expertise in this area. Magnetic resonance imaging (MRI) is an option for further evaluation in cases of diagnostic uncertainty when additional information will influence subsequent management of the pregnancy [3].


Subscribers log in here

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information or to purchase a personal subscription, click below on the option that best describes you:
Literature review current through: Sep 2016. | This topic last updated: Sep 1, 2016.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2016 UpToDate, Inc.
  1. International Society of Ultrasound in Obstetrics & Gynecology Education Committee. Sonographic examination of the fetal central nervous system: guidelines for performing the 'basic examination' and the 'fetal neurosonogram'. Ultrasound Obstet Gynecol 2007; 29:109.
  2. Kohlenberg, C, Lumley, J, Yates, J, Bell, R. A prospective population-based study of CNS abnormality detection at 16 to 20 weeks by ultrasonography. J Ultrasound Med 1996; 15:29.
  3. Rossi AC, Prefumo F. Additional value of fetal magnetic resonance imaging in the prenatal diagnosis of central nervous system anomalies: a systematic review of the literature. Ultrasound Obstet Gynecol 2014; 44:388.
  4. Icenogle DA, Kaplan AM. A review of congenital neurologic malformations. Clin Pediatr (Phila) 1981; 20:565.
  5. Babcock DS. Sonography of congenital malformations of the brain. Neuroradiology 1986; 28:428.
  6. Filly RA, Chinn DH, Callen PW. Alobar holoprosencephaly: ultrasonographic prenatal diagnosis. Radiology 1984; 151:455.
  7. Cohen MM Jr, Sulik KK. Perspectives on holoprosencephaly: Part II. Central nervous system, craniofacial anatomy, syndrome commentary, diagnostic approach, and experimental studies. J Craniofac Genet Dev Biol 1992; 12:196.
  9. Bronshtein M, Wiener Z. Early transvaginal sonographic diagnosis of alobar holoprosencephaly. Prenat Diagn 1991; 11:459.
  10. González-Gómez F, Salamanca A, Padilla MC, et al. Alobar holoprosencephalic embryo detected via transvaginal sonography. Eur J Obstet Gynecol Reprod Biol 1992; 47:266.
  11. Turner CD, Silva S, Jeanty P. Prenatal diagnosis of alobar holoprosencephaly at 10 weeks of gestation. Ultrasound Obstet Gynecol 1999; 13:360.
  12. Wong HS, Lam YH, Tang MH, et al. First-trimester ultrasound diagnosis of holoprosencephaly: three case reports. Ultrasound Obstet Gynecol 1999; 13:356.
  13. Nelson LH, King M. Early diagnosis of holoprosencephaly. J Ultrasound Med 1992; 11:57.
  14. Tóth Z, Csécsei K, Szeifert G, et al. Early prenatal diagnosis of cyclopia associated with holoprosencephaly. J Clin Ultrasound 1986; 14:550.
  15. Chervenak FA, Jeanty P, Cantraine F, et al. The diagnosis of fetal microcephaly. Am J Obstet Gynecol 1984; 149:512.
  16. Chervenak FA, Rosenberg J, Brightman RC, et al. A prospective study of the accuracy of ultrasound in predicting fetal microcephaly. Obstet Gynecol 1987; 69:908.
  17. Kurtz AB, Wapner RJ, Rubin CS, et al. Ultrasound criteria for in utero diagnosis of microcephaly. J Clin Ultrasound 1980; 8:11.
  18. Wallis D, Muenke M. Mutations in holoprosencephaly. Hum Mutat 2000; 16:99.
  19. Kagan KO, Staboulidou I, Syngelaki A, et al. The 11-13-week scan: diagnosis and outcome of holoprosencephaly, exomphalos and megacystis. Ultrasound Obstet Gynecol 2010; 36:10.
  20. Edwards TJ, Sherr EH, Barkovich AJ, Richards LJ. Clinical, genetic and imaging findings identify new causes for corpus callosum development syndromes. Brain 2014; 137:1579.
  21. Palmer EE, Mowat D. Agenesis of the corpus callosum: a clinical approach to diagnosis. Am J Med Genet C Semin Med Genet 2014; 166C:184.
  22. Alby C, Malan V, Boutaud L, et al. Clinical, genetic and neuropathological findings in a series of 138 fetuses with a corpus callosum malformation. Birth Defects Res A Clin Mol Teratol 2016; 106:36.
  23. Paul LK, Brown WS, Adolphs R, et al. Agenesis of the corpus callosum: genetic, developmental and functional aspects of connectivity. Nat Rev Neurosci 2007; 8:287.
  24. Sotiriadis A, Makrydimas G. Neurodevelopment after prenatal diagnosis of isolated agenesis of the corpus callosum: an integrative review. Am J Obstet Gynecol 2012; 206:337.e1.
  25. Atlas SW, Shkolnik A, Naidich TP. Sonographic recognition of agenesis of the corpus callosum. AJR Am J Roentgenol 1985; 145:167.
  26. Hilpert PL, Kurtz AB. Prenatal diagnosis of agenesis of the corpus callosum using endovaginal ultrasound. J Ultrasound Med 1990; 9:363.
  27. Gebarski SS, Gebarski KS, Bowerman RA, Silver TM. Agenesis of the corpus callosum: sonographic features. Radiology 1984; 151:443.
  28. Lockwood CJ, Ghidini A, Aggarwal R, Hobbins JC. Antenatal diagnosis of partial agenesis of the corpus callosum: a benign cause of ventriculomegaly. Am J Obstet Gynecol 1988; 159:184.
  29. Vergani P, Ghidini A, Mariani S, et al. Antenatal sonographic findings of agenesis of corpus callosum. Am J Perinatol 1988; 5:105.
  30. Meizner I, Barki Y, Hertzanu Y. Prenatal sonographic diagnosis of agenesis of corpus callosum. J Clin Ultrasound 1987; 15:262.
  31. Li Y, Estroff JA, Khwaja O, et al. Callosal dysgenesis in fetuses with ventriculomegaly: levels of agreement between imaging modalities and postnatal outcome. Ultrasound Obstet Gynecol 2012; 40:522.
  32. Hernanz-Schulman M, Dohan FC Jr, Jones T, et al. Sonographic appearance of callosal agenesis: correlation with radiologic and pathologic findings. AJNR Am J Neuroradiol 1985; 6:361.
  33. Pilu G, Sandri F, Perolo A, et al. Sonography of fetal agenesis of the corpus callosum: a survey of 35 cases. Ultrasound Obstet Gynecol 1993; 3:318.
  34. Poe LB, Coleman LL, Mahmud F. Congenital central nervous system anomalies. Radiographics 1989; 9:801.
  35. Leech RW, Shuman RM. Holoprosencephaly and related midline cerebral anomalies: a review. J Child Neurol 1986; 1:3.
  36. Malinger G, Zakut H. The corpus callosum: normal fetal development as shown by transvaginal sonography. AJR Am J Roentgenol 1993; 161:1041.
  37. Rizzo G, Pietrolucci ME, Capponi A, Arduini D. Assessment of corpus callosum biometric measurements at 18 to 32 weeks' gestation by 3-dimensional sonography. J Ultrasound Med 2011; 30:47.
  38. Pashaj S, Merz E, Wellek S. Biometry of the fetal corpus callosum by three-dimensional ultrasound. Ultrasound Obstet Gynecol 2013; 42:691.
  39. Shen O, Gelot AB, Moutard ML, et al. Abnormal shape of the cavum septi pellucidi: an indirect sign of partial agenesis of the corpus callosum. Ultrasound Obstet Gynecol 2015; 46:595.
  40. Shinar S, Har-Toov J, Lerman-Sagie T, Malinger G. Thick corpus callosum in the second trimester can be transient and is of uncertain significance. Ultrasound Obstet Gynecol 2016; 48:452.
  41. Santo S, D'Antonio F, Homfray T, et al. Counseling in fetal medicine: agenesis of the corpus callosum. Ultrasound Obstet Gynecol 2012; 40:513.
  42. Tang PH, Bartha AI, Norton ME, et al. Agenesis of the corpus callosum: an MR imaging analysis of associated abnormalities in the fetus. AJNR Am J Neuroradiol 2009; 30:257.
  43. Bedeschi MF, Bonaglia MC, Grasso R, et al. Agenesis of the corpus callosum: clinical and genetic study in 63 young patients. Pediatr Neurol 2006; 34:186.
  44. Kasprian G, Brugger PC, Schöpf V, et al. Assessing prenatal white matter connectivity in commissural agenesis. Brain 2013; 136:168.
  45. D'Antonio F, Pagani G, Familiari A, et al. Outcomes Associated With Isolated Agenesis of the Corpus Callosum: A Meta-analysis. Pediatrics 2016; 138.
  46. Jou HJ, Shyu MK, Wu SC, et al. Ultrasound measurement of the fetal cavum septi pellucidi. Ultrasound Obstet Gynecol 1998; 12:419.
  47. Kuhn MJ, Swenson LC, Youssef HT. Absence of the septum pellucidum and related disorders. Comput Med Imaging Graph 1993; 17:137.
  48. Barkovich AJ, Norman D. Absence of the septum pellucidum: a useful sign in the diagnosis of congenital brain malformations. AJR Am J Roentgenol 1989; 152:353.
  49. Malinger G, Lev D, Kidron D, et al. Differential diagnosis in fetuses with absent septum pellucidum. Ultrasound Obstet Gynecol 2005; 25:42.
  50. Falco P, Gabrielli S, Visentin A, et al. Transabdominal sonography of the cavum septum pellucidum in normal fetuses in the second and third trimesters of pregnancy. Ultrasound Obstet Gynecol 2000; 16:549.
  51. Sahinoglu Z, Uludogan M, Delikara MN. Prenatal sonographic diagnosis of dilated cavum vergae. J Clin Ultrasound 2002; 30:378.
  52. Sherer DM, Sokolovski M, Dalloul M, et al. Prenatal diagnosis of dilated cavum septum pellucidum et vergae. Am J Perinatol 2004; 21:247.
  53. Blasi I, Henrich W, Argento C, Chaoui R. Prenatal diagnosis of a cavum veli interpositi. J Ultrasound Med 2009; 28:683.
  54. . The evolutionary and embryologic basis for the development and anatomy of the cavum veli interpositi. AJNR Am J Neuroradiol 1999; 20:1383.
  55. Eisenberg VH, Zalel Y, Hoffmann C, et al. Prenatal diagnosis of cavum velum interpositum cysts: significance and outcome. Prenat Diagn 2003; 23:779.
  56. D'Addario V, Pinto V, Rossi AC, et al. Cavum veli interpositi cyst: prenatal diagnosis and postnatal outcome. Ultrasound Obstet Gynecol 2009; 34:52.
  57. Hertzberg BS, Kliewer MA, Provenzale JM. Cyst of the velum interpositum: antenatal ultrasonographic features and differential diagnosis. J Ultrasound Med 1997; 16:767.
  58. Chen CY, Chen FH, Lee CC, et al. Sonographic characteristics of the cavum velum interpositum. AJNR Am J Neuroradiol 1998; 19:1631.
  59. Tubbs RS, Krishnamurthy S, Verma K, et al. Cavum velum interpositum, cavum septum pellucidum, and cavum vergae: a review. Childs Nerv Syst 2011; 27:1927.
  60. Vergani P, Locatelli A, Piccoli MG, et al. Ultrasonographic differential diagnosis of fetal intracranial interhemispheric cysts. Am J Obstet Gynecol 1999; 180:423.
  61. Russ PD, Pretorius DH, Johnson MJ. Dandy-Walker syndrome: a review of fifteen cases evaluated by prenatal sonography. Am J Obstet Gynecol 1989; 161:401.
  62. Hirsch JF, Pierre-Kahn A, Renier D, et al. The Dandy-Walker malformation. A review of 40 cases. J Neurosurg 1984; 61:515.
  63. Osenbach RK, Menezes AH. Diagnosis and management of the Dandy-Walker malformation: 30 years of experience. Pediatr Neurosurg 1992; 18:179.
  64. Guibaud L, Larroque A, Ville D, et al. Prenatal diagnosis of 'isolated' Dandy-Walker malformation: imaging findings and prenatal counselling. Prenat Diagn 2012; 32:185.
  65. Nyberg DA, Cyr DR, Mack LA, et al. The Dandy-Walker malformation prenatal sonographic diagnosis and its clinical significance. J Ultrasound Med 1988; 7:65.
  66. Taylor GA, Sanders RC. Dandy-Walker syndrome: recognition by sonography. AJNR Am J Neuroradiol 1983; 4:1203.
  67. Fileni A, Colosimo C Jr, Mirk P, et al. Dandy-Walker syndrome: diagnosis in utero by means of ultrasound and CT correlations. Neuroradiology 1983; 24:233.
  68. Kirkinen P, Jouppila P, Valkeakari T, Saukkonen AL. Ultrasonic evaluation of the Dandy-Walker syndrome. Obstet Gynecol 1982; 59:18S.
  69. Burton BK. Recurrence risks for congenital hydrocephalus. Clin Genet 1979; 16:47.
  70. Barkovich AJ, Kjos BO, Norman D, Edwards MS. Revised classification of posterior fossa cysts and cystlike malformations based on the results of multiplanar MR imaging. AJR Am J Roentgenol 1989; 153:1289.
  71. Pilu, G, Perolo, A, David, C. Midline anomalies of the brain. In: Timor-Tritsch, I, Monteagudo, A, and Cohen, H, eds. Ultrasonography of the prenatal and neonatal brain. Stamford: Appleton & Lange, 1996:241.
  72. Bromley B, Nadel AS, Pauker S, et al. Closure of the cerebellar vermis: evaluation with second trimester US. Radiology 1994; 193:761.
  73. Phillips JJ, Mahony BS, Siebert JR, et al. Dandy-Walker malformation complex: correlation between ultrasonographic diagnosis and postmortem neuropathology. Obstet Gynecol 2006; 107:685.
  74. Grinberg I, Northrup H, Ardinger H, et al. Heterozygous deletion of the linked genes ZIC1 and ZIC4 is involved in Dandy-Walker malformation. Nat Genet 2004; 36:1053.
  75. Chitkara U, Cogswell C, Norton K, et al. Choroid plexus cysts in the fetus: a benign anatomic variant or pathologic entity? Report of 41 cases and review of the literature. Obstet Gynecol 1988; 72:185.
  76. Chan L, Hixson JL, Laifer SA, et al. A sonographic and karyotypic study of second-trimester fetal choroid plexus cysts. Obstet Gynecol 1989; 73:703.
  77. Shuangshoti, S, Netsky, M. Neuroepithelial (colloid) cysts of the nervous system. Further observations on pathogenesis, incidence, and histochemistry. Neurology 1966; 16:887.
  78. Benacerraf BR, Harlow B, Frigoletto FD Jr. Are choroid plexus cysts an indication for second-trimester amniocentesis? Am J Obstet Gynecol 1990; 162:1001.
  79. Benacerraf BR, Laboda LA. Cyst of the fetal choroid plexus: a normal variant? Am J Obstet Gynecol 1989; 160:319.
  80. Hertzberg BS, Kay HH, Bowie JD. Fetal choroid plexus lesions. Relationship of antenatal sonographic appearance to clinical outcome. J Ultrasound Med 1989; 8:77.
  81. DeRoo TR, Harris RD, Sargent SK, et al. Fetal choroid plexus cysts: prevalence, clinical significance, and sonographic appearance. AJR Am J Roentgenol 1988; 151:1179.
  82. Benacerraf BR. Asymptomatic cysts of the fetal choroid plexus in the second trimester. J Ultrasound Med 1987; 6:475.
  83. Chudleigh P, Pearce JM, Campbell S. The prenatal diagnosis of transient cysts of the fetal choroid plexus. Prenat Diagn 1984; 4:135.
  84. Chuang S, Harwood-Nash D. Tumors and cysts. Neuroradiology 1986; 28:463.
  85. Banna M. Arachnoid cysts on computed tomography. AJR Am J Roentgenol 1976; 127:979.
  86. Menezes AH, Bell WE, Perret GE. Arachnoid cysts in children. Arch Neurol 1980; 37:168.
  87. Robinson, R. Congenital cysts of the brain: Arachnoid malformations. Progr Neurol Surg 1971; 4:133.
  88. Langer B, Haddad J, Favre R, et al. Fetal arachnoid cyst: report of two cases. Ultrasound Obstet Gynecol 1994; 4:68.
  89. Galassi E, Tognetti F, Frank F, et al. Infratentorial arachnoid cysts. J Neurosurg 1985; 63:210.
  90. Pascual-Castroviejo I, Roche MC, Martínez Bermejo A, et al. Primary intracranial arachnoidal cysts. A study of 67 childhood cases. Childs Nerv Syst 1991; 7:257.
  91. Pretorius DH, Russ PD, Rumack CM, Manco-Johnson ML. Diagnosis of brain neuropathology in utero. Neuroradiology 1986; 28:386.
  92. Monteagudo, A, Timor-Tritsch, I. Fetal Neurosonography of congenital brain anomalies. In: Timor-Tritsch 1, Monteagudo A, and Cohen H, Eds. Ultrasonography of the prenatal and neonatal brain. New York: McGraw Hill, 2001.
  93. Bannister CM, Russell SA, Rimmer S, Mowle DH. Fetal arachnoid cysts: their site, progress, prognosis and differential diagnosis. Eur J Pediatr Surg 1999; 9 Suppl 1:27.
  94. Vintzileos AM, Eisenfeld LI, Campbell WA, et al. Prenatal ultrasonic diagnosis of arteriovenous malformation of the vein of Galen. Am J Perinatol 1986; 3:209.
  95. Ordorica SA, Marks F, Frieden FJ, et al. Aneurysm of the vein of Galen: a new cause for Ballantyne syndrome. Am J Obstet Gynecol 1990; 162:1166.
  96. Rodemyer CR, Smith WL. Diagnosis of a vein of Galen aneurysm by ultrasound. J Clin Ultrasound 1982; 10:297.
  97. Diebler C, Dulac O, Renier D, et al. Aneurysms of the vein of Galen in infants aged 2 to 15 months. Diagnosis and natural evolution. Neuroradiology 1981; 21:185.
  98. Reiter AA, Huhta JC, Carpenter RJ Jr, et al. Prenatal diagnosis of arteriovenous malformation of the vein of Galen. J Clin Ultrasound 1986; 14:623.
  99. Mendelsohn DB, Hertzanu Y, Butterworth A. In utero diagnosis of a vein of Galen aneurysm by ultrasound. Neuroradiology 1984; 26:417.
  100. Watson DG, Smith RR, Brann AW Jr. Arteriovenous malformation of the vein of Galen: treatment in a neonate. Am J Dis Child 1976; 130:520.
  101. Heuer GG, Gabel B, Beslow LA, et al. Diagnosis and treatment of vein of Galen aneurysmal malformations. Childs Nerv Syst 2010; 26:879.
  102. Tolmie JL, McNay M, Stephenson JB, et al. Microcephaly: genetic counselling and antenatal diagnosis after the birth of an affected child. Am J Med Genet 1987; 27:583.
  103. Page LK, Brown SB, Gargano FP, Shortz RW. Schizencephaly: a clinical study and review. Childs Brain 1975; 1:348.
  104. Komarniski CA, Cyr DR, Mack LA, Weinberger E. Prenatal diagnosis of schizencephaly. J Ultrasound Med 1990; 9:305.
  105. Pilu G, Ambrosetto P, Sandri F, et al. Intraventricular fused fornices: a specific sign of fetal lobar holoprosencephaly. Ultrasound Obstet Gynecol 1994; 4:65.
  106. Kutuk MS, Gorkem SB, Bayram A, et al. Prenatal Diagnosis and Postnatal Outcome of Schizencephaly. J Child Neurol 2015; 30:1388.
  107. Greene MF, Benacerraf B, Crawford JM. Hydranencephaly: US appearance during in utero evolution. Radiology 1985; 156:779.
  108. Sepulveda W, Cortes-Yepes H, Wong AE, et al. Prenatal sonography in hydranencephaly: findings during the early stages of disease. J Ultrasound Med 2012; 31:799.
  109. Bauman ML. Neuroembryology--clinical aspects. Semin Perinatol 1987; 11:74.
  110. Dobyns WB, Kirkpatrick JB, Hittner HM, et al. Syndromes with lissencephaly. II: Walker-Warburg and cerebro-oculo-muscular syndromes and a new syndrome with type II lissencephaly. Am J Med Genet 1985; 22:157.
  111. Dobyns WB. Developmental aspects of lissencephaly and the lissencephaly syndromes. Birth Defects Orig Artic Ser 1987; 23:225.
  112. de Rijk-van Andel JF, Arts WF, Hofman A, et al. Epidemiology of lissencephaly type I. Neuroepidemiology 1991; 10:200.
  113. Batanian JR, Ledbetter SA, Wolff RK, et al. Rapid diagnosis of Miller-Dieker syndrome and isolated lissencephaly sequence by the polymerase chain reaction. Hum Genet 1990; 85:555.
  114. Chi JG, Dooling EC, Gilles FH. Gyral development of the human brain. Ann Neurol 1977; 1:86.
  115. Dorovini-Zis K, Dolman CL. Gestational development of brain. Arch Pathol Lab Med 1977; 101:192.
  116. Isaacs H Jr. I. Perinatal brain tumors: a review of 250 cases. Pediatr Neurol 2002; 27:249.
  117. Isaacs H Jr. II. Perinatal brain tumors: a review of 250 cases. Pediatr Neurol 2002; 27:333.
  118. Isaacs H. Fetal brain tumors: a review of 154 cases. Am J Perinatol 2009; 26:453.