[A case study of galen aneurysmal malformation in Bamako]. / Malformation anévrismale de la veine de galien à Bamako à propos d'un cas.

ABSTRACT

Galen aneurysmal malformation is a rare complex congenital vascular malformation of the brain, (less than 1% of intracranial arteriovenous malformations) characterized by pseudoaneurismal dilation of Galen's ampulla associated with one or several arteriovenous fistulas. In most cases, diagnosis is made in the neonatal or postnatal period, exceptionally in adulthood. We report the case of an 18-year male patient hospitalized for psychomotor retardation. Brain computed tomography (CT) scan using spontaneous contrast (A,B,C) showed voluminous isodense mass in the pineal region behind the third ventricle with peripheral calcifications, compatible with large vein of galen aneurysm. Its anteroposterior diameter was 8.5cm, its transverse diameter was 3cm in the axial plane (C) and its height was 3cm in the sagittal plane (G). Imaging objectified homogeneous contrast enhancement (D,E,F,G,H,I). The mass was associated with dilation of the superior sagittal sinus measured at 2.7cm (A,D), of transverse sinuses measured at 1.5cm to the right and at 1,1cm to the left (B,E). Multiple venous perianeurysmal derivations (I), hydrocephaly and small parenchymal cortical-subcortical calcifications were detected. Embolization can't be performed in Bamako, so the patient is waiting for transfer.