Supranuclear ophthalmoplegia with basilar artery aneurysms.

In two patients, large aneurysms of the basilar artery produced a supranuclear gaze paresis, involving horizontal gaze in one case and vertical gaze in the other. In both cases the diagnosis was suggested by computed tomography and confirmed by vertebral angiography. Autopsy findings in one case confirmed the diagnosis. Although supranuclear gaze palsies must reflect damage to structures deep within the brain stem, these cases illustrate that an extrinsic lesion may produce such damage indirectly. Basilar artery aneurysm should be considered in patients presenting with supranuclear gaze paresis and long tract signs.