RT Book, Section
A1 Bianchi, Diana W.
A1 Crombleholme, Timothy M.
A1 D'Alton, Mary E.
A1 Malone, Fergal D.
SR Print(0)
ID 1106396532
T1 Hydrocephalus
T2 Fetology: Diagnosis and Management of the Fetal Patient, 2e
YR 2015
FD 2015
PB McGraw-Hill Education
PP New York, NY
SN 978-0-07-144201-5
LK obgyn.mhmedical.com/content.aspx?aid=1106396532
RD 2024/04/18
AB Key  PointsHydrocephalus  is  usually  due  to  obstruction  of  CSF  flow,  either  within  (noncommunicating  hydrocephalus)  or  outside  (communicating  hydrocephalus)  the  ventricles.Ventriculomegaly  simply  refers  to  enlargement  of  intracranial  ventricles.  It  can  be  associated  with  hydrocephalus  or  abnormal  brain  development.Ventriculomegaly  is  commonly  defined  as  a  measurement  of  10  mm  or  greater  in  the  posterior  horns  of  the  lateral  ventricles  noted  on  an  axial  brain  scan,  irrespective  of  gestational  age.Approximately  40%  of  cases  of  ventriculomegaly  have  associated  CNS  or  extra-CNS  abnormalities,  and  12%  have  an  abnormal  karyotype.Underlying  causes  include  aqueductal  stenosis,  meningomyelocele,  intrauterine  infection  (CMV,  toxoplasmosis,  syphilis),  agenesis  of  corpus  callosum,  X-linked  hydrocephalus  syndromes,  intracranial  hemorrhage,  Dandy–Walker  malformation,  and  intracranial  tumors.L1CAM  gene  mutations  account  for  up  to  25%  of  male  cases  of  isolated  congenital  hydrocephalus.Recurrence  risk,  in  the  absence  of  a  positive  family  history,  or  a  known  L1CAM  mutation,  is  approximately  4%.