Macro-aneurysm in the basal ganglia region

A 59-year-old female patient suddenly developed vomiting and gait disturbances followed by decreasing consciousness. CT scans revealed a hemorrhage within the left basal ganglia region with rupture into the ventricles and consecutive hydrocephalus. On angiography an aneurysm in the region of the caput nuclei caudati was shown to be the source of the bleeding. On repeat-angiography 4 months later the aneurysm was no longer visualized, probably due to thrombosis. This is an extraordinary case of a basal ganglia aneurysm comparable with the aneurysms of Willis' circle, but located in a region where generally microaneurysms--mostly combined with hypertension or moyamoya disease--can be found.