Cranial Nerve III, IV, and VI Palsies in the Cancer Patient

Abstract

Cranial nerve III, IV, and VI palsies in cancer patients can be caused by primary cranial nerve neoplasms, direct extension from brain, brain stem and skull base tumors, direct extension or perineural spread from head and neck tumors, metastases from tumors at distant sites, leptomeningeal disease, and other conditions, including raised intracranial pressure, radiation effect, infection, paraneoplastic syndromes, and certain medications. Ophthalmologic findings in patients with cranial neuropathies depend on the cranial nerve III, IV and VI involved and the location of involvement. Primary cranial nerve neoplasms are most commonly schwannomas. Skull base tumors often result in cranial nerve involvement as well as primary tumors of the breast, lung, and prostate that metastasize to the skull base. Head and neck cancers travel through the skull base and result in cranial nerve involvement. Leptomeningeal disease is a common cause of deficits of cranial nerves II–VII. Other conditions–from treatment of the primary tumor to complications of chemotherapy and immunosuppression–can result in cranial neuropathies.