A 32-year-old, otherwise healthy man with recurrent metastatic papillary thyroid carcinoma underwent total thyroidectomy with modified radical neck dissection on the right side that included removal of the internal jugular vein. On the second postoperative day, he had ipsilateral conjunctival chemosis. Three weeks later, he was referred for headache, pulse synchronous tinnitus and binocular horizontal diplopia. Examination showed bilateral chemosis (fig 1) and papilloedema (figs 1 and 2) with bilateral sixth cranial nerve palsies. Cranial magnetic resonance imaging was …