3. Discussion:
UC is a type of inflammatory bowel disease that causes inflammation and ulcers in the colon and rectum. It is associated with several extra-intestinal manifestations including arthritis, uveitis, erythema nodosum, pyoderma gangrenosum, primary sclerosing cholangitis among several other conditions(4). Patients with inflammatory bowel disease are at an increased risk for both venous and arterial thromboembolism. This risk appears to be increased in patients with pan-colonic disease and those with ulcerative colitis. Hypercoagulable states associated with UC, are often serious, recurrent, tend to occur at unusual sites (e.g., cerebral vein), are associated with active disease, and occur in younger individuals. CVT is a rare but severe complication of UC. Most commonly, the superior sagittal and lateral sinuses are involved(2). Furthermore, it has been associated with the use of steroids, possibly indicating an active underlying disease. Our patient was a young female (in her 30s), who had ulcerative colitis flare despite steroids and azathioprine therapy.
What increases the chances of hypercoagulation in UC is not known. Data suggests that it is multifactorial and includes elevated levels of factors V, VIII, fibrinogen, total homocysteine, and decreased levels of antithrombin III as well as platelet disorders. Thrombocytosis and leukocytosis are common(5). Assessment of coagulation factors, homocysteine, and antithrombin III could not be done in our patient due to unaffordability and was unlikely to alter our treatment plan.
She was started on early anticoagulation with heparin. The European guidelines recommend treating acute CVT with heparin at a therapeutic dosage even in patients with intracerebral hemorrhage at baseline followed by oral anticoagulants for 3-12 months(6). With bridging anticoagulation, our patient recovered fully or her symptom was improved. She was commenced on oral dabigatran on discharge. This is the standard practice unless there is a contraindication to anticoagulation such as active bleeding. Her risk factors for coagulopathy included her positive family history of stroke in her mother and her diagnosis of UC. Her flare of ulcerative colitis increased the risk of thromboembolism. For patients with acute severe UC who fail to respond to steroids and immunosuppressant, surgery is indicated(7). Total proctocolectomy often cures the patient of Ulcerative colitis. However, case has been reported in a patient who developed CVT 10 years after total proctocolectomy(8). This case also highlights the importance of regular follow-up in such a patient to monitor the disease activity. Our patient had missed several appointments due to COVID pandemic.
Furthermore, thalamic infarction following CVT is rare and is sparsely reported in the literature. It may be either arterial or venous in origin. Occlusion of the artery of Percheron is responsible for arterial ischemia whereas venous infarction may be caused by thrombosis of the straight sinus, where the posterior group of thalamic veins drains. This is due to upstream venous pressure. Our patient had thrombosis of the straight sinus and was responsible for bilateral thalamic infarction. It is important to differentiate between these two as arterial occlusion requires immediate thrombolysis, whereas venous occlusion requires anticoagulation(9).
4. Conclusion:
Cerebral sinus vein thrombosis is a rare but often fatal complication of ulcerative colitis if undiagnosed. Cerebral venous sinus thrombosis may rarely cause bilateral thalamic infarction. Patients with ulcerative colitis should follow up with their regular physician to track activity of the disease.