RESUMEN
Lasjaunias differentiated true vein of Galen aneurysmal malformations (MAVG), which drain to the median prosencephalic vein of Markowski, the embryonic precursor of the vein of Galen, from the aneurysmal dilatations of vein of Galen (VGDA), which reveal venous drainage into a dilated vein of Galen, but already formed. In angioarchitectural terms, MAVG can still be divided in two subtypes: the mural form and the choroidal form, the most common. The authors describe the clinical case of a 18 years-old female, without symptoms until July 2001, who presented an episode of impaired equilibrium associated with vomits and non-specific vision disturbances. This episode had an approximate duration of 6-8 hours with complete recovery. Neuroimaging studies were performed including CT, MRI and digital angiography, disclosed an aneurysmal vein of Galen malformation of choroidal type and Dandy-Walker malformation, association that the authors couldn't found so far described in the literature.