Cerebral sinus thrombosis in a young adult with activated protein C resistance and homocysteinaemia

Abstract

A man of 28 years of age with no past history of note was admitted with a history of progressive severe diffuse headache, nausea, vomiting, blurring of vision and diplopia of 3 weeks' duration. He denied any fever or recent head trauma and had no preceding ear, nose or throat symptoms. He occasionally experienced oral ulcers, usually when he missed his routine daily brushing of his teeth. He denied having any genital ulcers. He never smoked and did not drink alcohol. He had a brother who died at a young age from possible thrombosis. His mother developed leg deep venous thrombosis after her first child was born. His father was diabetic. He worked as an interpreter. On examination, he looked ill and was slightly drowsy. He was afebrile, in sinus rhythm and normotensive. The major findings were confined to the nervous system. He had bilateral sixth nerve palsy and bilateral papilloedema, more pronounced on the right side. There were no other neurological signs. Ear, nose and throat examinations were normal. Magnetic resonance imaging of the brain showed a right sigmoid and superior sagittal sinus thrombosis with no cerebral infarction (Figures 1, 2 and 3). Full blood count, erythrocyte sedimentation rate, liver, renal and thyroid function and glucose levels were all normal. His vitamin B12 level was 694 pg/ml (normal 180–710 pg/ml). Autoantibodies including antinuclear antibodies, double-stranded DNA and antineutrophil cytoplasmic antibodies were negative. Cryoglobulins, anticardiolipin antibody, haemoglobin electrophoresis, immunoglobulin levels, antithrombin III, protein C and protein S were all normal or negative. Homocysteine level was markedly raised (confirmed on repetition) at 48.5 μmol/litre (normal <10.3 μmol/litre). Activated protein C ratio was low (less than 2) suggesting resistance. Genotypic confirmation for factor V Leiden mutation was not possible. He was fully anticoagulated with intravenous heparin and later warfarin was started. The international normalized ratio was kept between two and three. Dexamethasone at a dose of 4 mg intravenously 6-hourly was added initially and slowly tapered over a 3-week period. He gradually improved with complete resolution of his headaches, ocular palsies and papilloedema.