[Bilateral abducens nerve palsies in treated cases of subarachnoid hemorrhage].

Isolated abducens nerve palsies associated with the rupture of intracranial aneurysms have rarely been reported. We report two cases of isolated bilateral abducens nerve palsies occurring after subarachnoid hemorrhage due to the rupture of an intracranial aneurysm. Case 1: A 49-year-old woman had bilateral abducens nerve palsies following subarachnoid hemorrhage due to the rupture of the left vertebral artery-posterior inferior cerebellar artery aneurysm. Case 2: A 55-year-old man had bilateral abducens nerve palsies following subarachnoid hemorrhage due to dissecting aneurysm of the right vertebral artery. Case 1 and 2 were treated with surgical clipping of the aneurysm and internal occlusion of the parent artery. In both cases, bilateral abducens nerve palsies achieved almost full recovery several months after treatment. It is speculated that the main causes of palsies are compression and stretching of the bilateral abducens nerves by a thick clot in the prepontine cistern. Although most of the abducens palsies may be reversible and have good prognosis, it is important that they are kept in mind as isolated symptoms of subarachnoid hemorrhage.