A 30-year-old man had protracted severe headaches that he attributed to migraines. He also had binocular horizontal diplopia, worse when looking to the right, and numbness below the right eyelid that progressed to involve the right side of his skull.

He had numerous investigations including magnetic resonance imaging (MRIs), magnetic resonance angiography (MRAs), magnetic resonance venography (MRVs), and a catheter cerebral angiogram. MRI showed T2 signal hyperintensities involving the right cerebellar hemisphere. He was initially thought to have a brain tumor and was seen by a neurosurgeon who disagreed with the diagnosis.

Subsequent investigations suggested the possibility of a cerebellar venous thrombosis with compromised right cerebellar hemispheric venous drainage on a cerebral arteriogram done on June 2001. There was also a partial thrombosis of one of the right occipital veins draining into the right transverse sinus. Cerebrospinal fluid (CSF) analysis showed 18 white blood cells, a protein content of 46, and a glucose content of 62. There was some elevation of the immunoglobulin G (IgG) index and albumin index. The patient was treated with warfarin. Seemingly, attempts to discontinue warfarin were associated with reappearance of his headaches.

His symptoms waxed and waned and he had another hospitalization because of frequent vomiting and numbness on the right side of his forehead and right lower lid. He also had some dizziness and ringing in both ears. On November 2, 2001, he was hospitalized due to severe right occipital headaches. International Normalized Ratio (INR) on admission was 1.65. Neuroimaging studies obtained during that hospitalization are shown. One day after admission, he was taken to the operating room and had a left suboccipital craniotomy.