Clinical signs associated with megadolichobasilar artery anomaly.

The elongation and ectatic course of the basilar artery (BA), called megadolichobasilar artery anomaly (MDBAA) is a macroscopic description of a neuroradiologic finding. Clinically ischemic brain stem syndromes and peripheral cranial nerve disturbances especially of the trigeminal and facial nerves, cerebellar dysfunction and CSF circulation disturbances are observed. Seldom a subarachnoid hemorrhage is proven. In CT and MRI often a tumorlike mass with a ringlike contrast enhancement combined with a nonhomogeneous lesion due to partial thrombosis, is detected. Angiography in most cases shows fusiform dilatation of the BA, elongation of the top of the basilar trunk, asymmetric tortuosity or dislocation of the irregular shaped wall of the BA. Fifteen patients within the last 12 years are demonstrated. The role of reticular fiber deficiency in the media and defects of the elastic lamina as the basis of these malformations is reported. We discuss coincidental findings of MDBAA with atherosclerosis, congenital factors causing generalized vasculopathy, metabolic disturbances in form of so called inborn errors of metabolism and endocrine deficiencies. In cases with clinical signs the morbidity is remarkably high.