"Acquired" Dandy-Walker malformation and cerebellar hemorrhage: Usefulness of serial MRI.
OBJECTIVE
Neuroimaging plays a fundamental role in the diagnosis of Dandy Walker malformation (DWM), a posterior fossa anomaly that is usually associated with genetic abnormalities, but may rarely be ascribed to acquired causes. Here, we report the clinical history and neuroimaging studies of a child with a complex cardiac malformation, developmental delay, and oculomotor anomalies whose neuroimaging findings were consistent with an acquired form of DWM.


RESULTS
Fetal MRI at gestational weeks 27 and 31 showed cerebellar and vermis hypoplasia and fourth ventricle enlargement, together with hemosiderin deposits on the cerebellar hemispheric surface, but without significant vermian rotation. Postnatal MRIs at 5 days and 13 months revealed progressive counter-clockwise rotation of the hypoplastic cerebellar vermis with cystic dilation of the fourth ventricle, eventually leading to a full-blown DWM.


CONCLUSIONS
This case strengthens the opinion that DWM is a heterogeneous condition, and may support the hypothesis that acquired meningeal abnormalities in the form of cortico-pial hemosiderosis may play a role in the development of DWM. This case also demonstrates that serial neuroimaging plays a key role in the correct diagnosis of posterior fossa malformations, whose prognosis is difficult to establish on second trimester fetal MRI and requires longer clinical follow-up.
Neuroradiology Department, C.Mondino National Neurological Institute, Pavia, Italy. Electronic address: anna.pichiecchio@mondino.it.
Anna
A
Pichiecchio
Child Neurology and Psychiatry Unit, Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy.
Alice
A
Decio
Neuroradiology Department, C.Mondino National Neurological Institute, Pavia, Italy.
Carol
C
Di Perri
Pediatric Radiology and Neuroradiology Unit, ICP Children Hospital V. Buzzi, Milano, Italy.
Cecilia
C
Parazzini
Neuroradiology Unit, Istituto Giannina Gaslini, Genoa, Italy.
Andrea
A
Rossi
Child Neurology and Psychiatry Unit, C. Mondino National Neurological Institute, Pavia, Italy.
Sabrina
S
Signorini
D002531:Cerebellum / Q000002:abnormalities; D003616:Dandy-Walker Syndrome / Q000150:complications / Q000473:pathology*; D005260:Female; D005333:Fetus / Q000002:abnormalities; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D020300:Intracranial Hemorrhages / Q000209:etiology / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D059906:Neuroimaging / Q000379:methods*; D011247:Pregnancy; D011379:Prognosis
Cerebellar hemorrhage; Dandy–Walker malformation; Fetal MRI; MRI; Pediatric