Oculomotor palsy with pupillary sparing, coincidental aneurysm, and chronic lymphocytic leukemic meningeal infiltration.

A patient with oculomotor palsy with pupillary sparing was shown angiographically to have an aneurysm of the internal carotid artery, which proved at operation to arise distal to the origin of the ophthalmic artery. It did not impinge on the oculomotor nerve at any point. The oculomotor palsy persisted postoperatively, and complete intrinsic and extrinsic ophthalmoplegia developed. Cytological studies of cerebrospinal fluid were then made and were positive for malignant lymphocytic leukemic cells. Despite the fact that an aneurysm causing oculomotor palsy with pupillary sparing has been reported, we recommend that nonaneurysmal causes be considered first in patients presenting with that neurological sign.