A case of isolated oculomotor nerve paralysis due to sphenoid sinus cyst

Abstract

Herein, we report a case of isolated oculomotor nerve paralysis caused by a sphenoid sinus cyst. An 80-year-old man presented with right-sided ptosis, diplopia and occipital headache. He had unilateral ptosis and disturbance of the upward, downward and inward ocular movements, however, ophthalmologic examination showed neither visual impairment, nor pupillary dilatation. The symptoms were clearly caused by isolated right oculomotor nerve paralysis. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a lateral sphenoid sinus lesion with a smooth margin compressing the right cavernous sinus and shaving down the surface of the clivus. Based on a diagnosis of sphenoid sinus cyst, we performed endoscopic surgery under general anesthesia. The ocular movements became normal approximately 2 months after the operation and the right-sided ptosis disappeared within 6 months of the sugery. Since oculomotor nerve paralysis due to sphenoid sinus cyst is highly amenable to cure by endoscopic surgery, operation should be aggressively pursued for its treatment.