Clival Mass: An Under Recognized Cause of Sixth Cranial Nerve Palsy

Imaging is routinely ordered in patients with acute sixth cranial nerve palsies, yet replacement of the clival marrow by malignant; tumor is an often under-recognized and potentially life-threatening cause. Neoplastic disease causes loss of the hyperintense clival; marrow signal on precontrast T1-weighted MRI sequences, a sign that may be overlooked by radiologists (1-2). While there have; been individual cases and small case series reported in the literature (3), we herein report the largest series of patients presenting; with a sixth cranial nerve palsy and found to have clivus pathology on imaging.