Case Presentation: A 62 year-old Caucasian male, with a 10-year history of ulcerative colitis (UC), presented to ER with acute onset of throbbing frontal headache for 1 day with associated photophobia and severe right eye pain. He reported having nausea and several episodes of vomiting. He denied any vision changes, speech difficulty, focal weakness, rash, joint pains, neck pain or rigidity. About 1 month prior to this presentation, he had had diffuse abdominal pain and bloody diarrhea and was diagnosed with UC flare, was started on mesalamin as his only medication. He had no personal or family history of blood disorders or any malignancy. He never smoked and denied alcohol use. His physical exam was completely normal including vital signs and detailed unremarkable neurological exam. Blood work including CBC and CMP was normal. He was given IV morphine for pain that but failed to relieve his headache. Computerized tomography (CT) scan of the head without contrast showed right-sided transverse and straight sinus thrombosis (image). Magnetic resonance imaging (MRI) of brain was done for confirmation. It confirmed the same findings and showed extension of the thrombus into the upper jugular vein (image). The patient was started on anticoagulation with therapeutic low molecular weight heparin that was switched to warfarin which he received for 3 months with an INR target of 2 to 3. Three weeks after completion of anticoagulation, the patient underwent testing for prothrombotic conditions, including protein S, protein C, and antithrombin deficiency, antiphospholipid syndrome, prothrombin G20210A mutation, and factor V Leiden; all were negative. 

Discussion: Cerebral venous thrombosis (CVT) is a rare disorder; the annual incidence is about 3 to 4 cases per million. It is more common in women than men, with a ratio of 3:1.  CVT has been reported as an uncommon and serious complication of UC, with an annual incidence varying between 0.5 to 6.7%. It is suspected to be a consequence of the hypercoagulable state occurring during disease relapse. Thrombophilia is the most common risk factor of CVT. Others include pregnancy, hormonal contraceptive therapy, head trauma and localized infections as sinusitis as well as systemic infections. The clinical presentation is highly variable. Although headache is the main presenting complaint in almost 90% of patients, it remains to be a challenging diagnosis due to its wide range of clinical pictures and different risk factors. Head CT is the most frequently performed study but it has poor sensitivity. Head MRI combined with MR venography is the most sensitive study. Our case raises the awareness among health professionals about the inflammatory bowel diseases (IBD) as a rare etiology of CVT, and signifies the importance of considering antithrombotic prophylaxis in all hospitalized IBD patients, especially those with active disease.

Conclusions: CVT is a very serious condition that should never be missed in patients who present with acute or subacute headache with unusual features. This unusual case report emphasizes the significance of timely diagnosis of CVT through neuroimaging and the necessity of immediate anticoagulation as the most crucial step in patient management. Such case is unique in how a fatal condition may masquerade in a common migraine picture and be easily missed if high degree of vigilance is lacking.