title: Dandy-Walker malformation masking the molar tooth sign: an illustrative case with magnetic resonance imaging follow-up.
abstract: Joubert syndrome is a disorder characterized by ataxia, developmental delay, oculomotor anomalies, and breathing irregularities, with cerebellar vermian and midbrain dysgenesis. The molar tooth sign, reflecting the midbrain dysgenesis of Joubert syndrome, is the neuroradiological hallmark and is an essential sign in the identification of this condition. Variable vermian agenesis, an expanded fourth ventricle, and a large posterior cranial fossa with a normal brainstem are typical of Dandy-Walker malformation. The authors report a case in which a Dandy-Walker malformation coexisted with Joubert syndrome, but initially prevented the ''molar tooth sign'' from being recognized because of an important cystic dilatation of the fourth ventricle. In this article, they discuss the importance of the re-examination of brain magnetic resonance features after decompression of the posterior cranial fossa in a patient with Dandy-Walker malformation and additional clinical neurological or systemic abnormalities typical of Joubert syndrome, to not miss the correct diagnosis.
authors.affiliation: Paediatric Neurology Unit, Department of Paediatrics Salus Pueri, University of Padua, Padua, Italy. ste.sartori@tin.it
authors.forename: Stefano
authors.initials: S
authors.lastname: Sartori
authors.forename: Kathrin
authors.initials: K
authors.lastname: Ludwig
authors.forename: Manuela
authors.initials: M
authors.lastname: Fortuna
authors.forename: Cinzia
authors.initials: C
authors.lastname: Marzocchi
authors.forename: Milena
authors.initials: M
authors.lastname: Calderone
authors.forename: Irene
authors.initials: I
authors.lastname: Toldo
authors.forename: Leonardo
authors.initials: L
authors.lastname: Salviati
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Laverda
authors.forename: Romano
authors.initials: R
authors.lastname: Tenconi
mesh_terms: D000015:Abnormalities, Multiple; D002526:Cerebellar Diseases / Q000150:complications / Q000175:diagnosis; D002531:Cerebellum / Q000002:abnormalities; D003616:Dandy-Walker Syndrome / Q000150:complications*; D005124:Eye Abnormalities / Q000150:complications / Q000175:diagnosis; D006801:Humans; D052177:Kidney Diseases, Cystic / Q000150:complications / Q000175:diagnosis; D008279:Magnetic Resonance Imaging; D008297:Male; D012160:Retina / Q000002:abnormalities