Cavernous Sinus Thrombosis as a Complication of Undiagnosed Protein Losing Enteropathy Secondary to Mixed Connective Tissue Disease: A Case Report

Background: Mixed connective tissue disease is a rare autoimmune disease that can lead to dysfunction in multiple organ systems. It has known prothrombogenic properties that typically spare the vasculature of the central nervous system. Mixed connective tissue disease is also a cause of protein-losing enteropathy, a disorder resulting from gastrointestinal mucosal damage that presents with hypoproteinemia. Cavernous Sinus Thrombosis (CVST) is a rare form of cerebral venous sinus thrombosis, accounting for a small percentage of all CVST cases. Case Report: A middle-aged woman presented with headache, rash and edema. She had a recent history of an unprovoked portal venous thrombosis but has discontinued her anticoagulation. A magnetic resonance venography demonstrated cavernous sinus thrombosis. A heparin drip was started and because of profound hypoproteinemia, a 24-hour stool alpha-1-antitrypsin was obtained, confirming protein-losing enteropathy. She improved and was discharged on enoxaparin, hydroxychloroquine and a prolonged prednisone taper. Conclusion: Mixed connective tissue disease can have an insidious onset. In this case it resulted in two severe, reversible, life-threatening disorders. Both protein-losing enteropathy and cavernous sinus thrombosis were caused by the autoimmune disease and occurred concurrently. An earlier diagnosis and treatment may have prevented both complications.