title: Rhombencephalosynapsis: prenatal imaging and autopsy findings.
abstract: OBJECTIVE
  Rhombencephalosynapsis is a rare, but increasingly recognized, brain malformation characterized by congenital fusion of the cerebellar hemispheres and absence of the vermis. Rhombencephalosynapsis is associated with significant developmental delay, seizures and involuntary head movements. We report four cases, with correlation of prenatal and postnatal imaging and autopsy findings.
  
  
  METHODS
  Over a 2-year period, four cases of rhombencephalosynapsis were diagnosed in the perinatal period, three in one center and one in another center. The clinical cases were reviewed, and correlation was made between the prenatal and postnatal imaging and autopsy findings where available.
  
  
  RESULTS
  All cases presented initially with ventriculomegaly on prenatal ultrasound examination. Subsequent magnetic resonance imaging (MRI) established the diagnosis in two cases and postnatal MRI established the diagnosis in a further two cases. Autopsy was available and confirmed the diagnosis in two cases. In one case the pregnancy was terminated, two infants died in the neonatal period and one died in infancy.
  
  
  CONCLUSIONS
  The cases in this perinatal series of rhombencephalosynapsis showed a very poor prognosis. The presence of ventriculomegaly on prenatal ultrasound imaging should alert the physician to consider rhombencephalosynapsis in the differential diagnosis. MRI appears to be the imaging modality of choice in establishing the diagnosis.
authors.affiliation: University College Dublin School of Medicine and Medical Science, Obstetrics and Gynaecology, National Maternity Hospital, Dublin, Ireland. fionnuala.mcauliffe@ucd.ie
authors.forename: F
authors.initials: F
authors.lastname: McAuliffe
authors.forename: D
authors.initials: D
authors.lastname: Chitayat
authors.forename: W
authors.initials: W
authors.lastname: Halliday
authors.forename: S
authors.initials: S
authors.lastname: Keating
authors.forename: V
authors.initials: V
authors.lastname: Shah
authors.forename: M
authors.initials: M
authors.lastname: Fink
authors.forename: O
authors.initials: O
authors.lastname: Nevo
authors.forename: G
authors.initials: G
authors.lastname: Ryan
authors.forename: P
authors.initials: P
authors.lastname: Shannon
authors.forename: S
authors.initials: S
authors.lastname: Blaser
mesh_terms: D000015:Abnormalities, Multiple / Q000000981:diagnostic imaging*; D000328:Adult; D001344:Autopsy; D002531:Cerebellum / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000473:pathology; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D011247:Pregnancy; D011296:Prenatal Diagnosis; D011379:Prognosis; D012249:Rhombencephalon / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000473:pathology; D016216:Ultrasonography, Prenatal / Q000379:methods