[Type I neurofibromatosis and megadolichobasilar artery].

Intracranial vascular malformations are rare but tend to appear more frequently than usual in patients with type I neurofibromatosis (NFI). Aneurysms of the basilar artery have been described four times so far. We report two cases of 51- and 62-year-old patients with type I neurofibromatosis who showed long fusiform dilation of the basilar artery. Clinically both patients presented with locked-in syndrome and died 15 and 11 days after admission. The diagnosis was confirmed by autopsy. These are the first published cases of locked-in syndrome following thrombosis of a megadolichobasilar artery in association with neurofibromatosis I. Our results show that cerebral vascular malformations are found more frequently than random chance would predict in patients with NF I.