TY  - CHAP
M1  - Book, Section
TI  - Agenesis of the Corpus Callosum
A1  - Bianchi, Diana W.
A1  - Crombleholme, Timothy M.
A1  - D'Alton, Mary E.
A1  - Malone, Fergal D.
PY  - 2015
T2  - Fetology: Diagnosis and Management of the Fetal Patient, 2e
AB  - Key  PointsThe  corpus  callosum  is  a  major  pathway  connecting  the  two  hemispheres  of  the  brain.  By  the  17th  week  of  gestation,  the  mature  corpus  callosum  is  formed.In  agenesis  of  the  corpus  callosum  (ACC),  the  commissural  fibers  do  not  cross  the  midline  but  rather  form  thick  bundles  of  fibers  called  Probst  bundles,  which  course  in  a  posterior  direction  along  the  medial  walls  of  the  lateral  ventricles.  These  bundles  indent  and  separate  the  anterior  horns  of  the  lateral  ventricles.ACC  may  be  isolated,  but  often  is  associated  with  other  malformations  and  genetic  syndromes.ACC  occurs  in  <1%  of  the  general  population  and  in  2%  to  3%  of  the  developmentally  disabled  population.The  finding  of  mild  ventriculomegaly  during  routine  prenatal  ultrasound  examination  should  prompt  a  targeted  search  to  confirm  the  presence  of  the  corpus  callosum.The  most  consistent  and  easy-to-identify  finding  is  the  teardrop  configuration  of  the  lateral  ventricles.Prenatal  magnetic  resonance  imaging  (MRI)  and  three-dimensional  ultrasound  examination  may  be  helpful  in  confirming  the  diagnosis.  MRI  may  also  be  useful  in  identifying  other  subtle  brain  abnormalities  that  may  not  be  apparent  on  sonogram  but  may  have  an  impact  on  the  long-term  prognosis.The  natural  history  of  antenatally  detected  ACC  is  not  known  due  to  the  fact  that  there  have  been  relatively  few  case  series  reported.Fetal  karyotype  should  be  considered  when  ACC  is  diagnosed  antenatally  due  to  its  association  with  chromosomal  abnormalities.Patients  prenatally  diagnosed  with  ACC  can  be  managed  according  to  routine  prenatal  care  guidelines.The  neonate  with  suspected  ACC  should  be  examined  carefully.  MRI  is  the  radiologic  examination  of  choice.ACC  in  addition  to  other  abnormalities  is  often  associated  with  poor  neurologic  outcomes.  The  long-term  outcome  of  isolated  ACC  has  not  yet  been  elucidated.The  recurrence  risk  of  ACC  depends  on  the  underlying  cause.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/19
UR  - obgyn.mhmedical.com/content.aspx?aid=1106396059
ER  -