title: Fusion of the cerebellar hemispheres ventral to the brainstem: a rare hindbrain-related malformation.
abstract: BACKGROUND
  New variations of cerebellar malformations are being increasingly recognized using modern neuroimaging techniques. Until now only dorsal cerebellar fusion syndromes, such as the rhombencephalosynapsis and its variations have been recognized.
  
  
  METHODS
  We report on a 17-month-old male infant presenting with an exceptional hindbrain related malformation characterized by midline fusion of the cerebellar hemispheres ventral to the brainstem and causing symptoms due to brainstem compression.
  
  
  CONCLUSIONS
  A more detailed understanding of the cerebellar embryogenesis is required to unravel the underlying mechanisms leading to this type of cerebellar malformation, which cannot easily be integrated into the common classification systems. Both the morphological features and the clinical presentation are different from those of other cerebellar structural abnormalities. If this type of congenital malformation is detected more frequently in the future, it seems reasonable that it should be added to the list of cerebellar malformations as a distinct type.
authors.affiliation: Department of Neurosurgery, University of Essen, Hufelandstrasse 55, 45122 Essen, Germany. sandalcioglu@uni-essen.de
authors.forename: Ibrahim Erol
authors.initials: IE
authors.lastname: Sandalcioglu
authors.forename: Thomas
authors.initials: T
authors.lastname: Gasser
authors.forename: Johannes Anthonius Petrus
authors.initials: JA
authors.lastname: van de Nes
authors.forename: Udo
authors.initials: U
authors.lastname: Menken
authors.forename: Dietmar
authors.initials: D
authors.lastname: Stolke
authors.forename: Helmut
authors.initials: H
authors.lastname: Wiedemayer
mesh_terms: D002526:Cerebellar Diseases / Q000150:complications* / Q000473:pathology; D002531:Cerebellum / Q000002:abnormalities* / Q000000981:diagnostic imaging; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D011859:Radiography; D012249:Rhombencephalon / Q000002:abnormalities*