British Journal of Neurosurgery, February 2013; 27(1): 139–140 © 2013 The Neurosurgical Foundation ISSN: 0268-8697 print / ISSN 1360-046X online DOI: 10.3109/02688697.2012.709552 NEUROSURGICAL IMAGE Cord sign: cortical venous thrombosis evolving to a ring enhancing lesion Maryam Khosravi, Ciaran S. Hill & Neil Kitchen Br J Neurosurg Downloaded from informahealthcare.com by Universitat Autonoma Barcelona on 10/27/14 For personal use only. The National Hospital for Neurology and Neurosurgery, University College Hospital NHS Trust, Queen Square, London Abstract Cortical venous thrombosis can present with non-specific findings including headaches and seizures. Subsequent cortical infarction has a variety of radiological appearances. The authors describe the diagnostic challenge of a case of cortical venous thrombosis presenting with focal motor seizures where imaging showed a ring enhancing lesion and the ‘cord sign’ and underwent a stereotactic brain biopsy. Keywords: cortical thrombosis; venous infarct; ring enhancing lesion; prothrombotic; stereotactic biopsy Case presentation A 47-year-old lady presented with a 3-day history of intermittent involuntary rhythmic oscillation of her left thumb. This progressed over a 6-hour period to weakness of the left upper limb. Initial non-contrast computerised tomography (CT) imaging was unremarkable so she underwent magnetic resonance (MR) imaging of her brain that demonstrated an area of diffuse white-matter hyper-intensity surrounded by vasogenic oedema enveloping the right primary motor cortex on T2 sequencing. There was no sign of a focal lesion. In both axial and sagittal (Figs. 1 & 2) images there are prominent dilated cortical veins that are visible as hypo-intense superficial filling defects (arrowed) otherwise known as the ‘cord sign’.1 These findings are pathognomic of cortical venous thrombosis, often associated with dural sinus thrombosis and retrograde clot propagation, but in this case it was isolated.2 The ‘cord sign’ is the cortical vein equivalent of the ‘delta sign’ seen in a more complete sagittal sinus thrombosis.3 A follow-up CT scan with contrast and MRI T1 contrast and T2 BLADE were performed when the patient suffered a 4 minute tonic-clonic seizure 2 weeks after initial presentation. The scans demonstrated an isolated ring-enhancing lesion (Fig. 3). After discussion at a neurooncology multidisciplinary meeting, it was felt that it was Fig. 1. T2 Blade MRI in axial (left) and sagittal (right) sections demonstrating flow voids – the ‘cord sign’ (arrows) and vasogenic oedema of a cortical venous thrombosis. not possible to exclude a neoplastic or infective cause. Therefore, a stereotactic biopsy targeting the centre of the lesion was performed. This showed fragments of necrotic neuropil accompanied by a macrophage-rich mixed inflammatory reaction and reactive gliosis confirming a diagnosis of a sub-acute infarct secondary to cortical venous thrombosis. Discussion Seizures and headaches are the commonest presenting features of a venous infarct and the clinical and imaging Correspondence: Ciaran Scott Hill, BSc (Hons), MSc, MBBS, MCSP, MRCP, MRCS, DOHNS, DMCC, Specialist Trainee in Neurosurgery, Department of Neurosurgery, Queen Square, London, WC1N 3BG, UK. Tel: ⫹447812714391. E-mail: ciaran.hill@ucl.ac.uk Received for publication 20 January 2012; accepted 1 July 2012 139 Br J Neurosurg Downloaded from informahealthcare.com by Universitat Autonoma Barcelona on 10/27/14 For personal use only. 140 M. Khosravi et al. Fig. 2. T2 Blade MRI in axial (left) and sagittal (right) sections demonstrating flow voids – the ‘cord sign’ (arrows) and vasogenic oedema of a cortical venous thrombosis. findings often mimic neoplasia or infection and can include ring-enhancing lesions with variable degrees of oedema.4,5,6 In this case, the rhythmic movements on presentation were consistent with simple focal seizures. Although Todd’s paresis may have initially contributed to the monoplegia, the localization of the cortical venous infarction adjacent to the primary motor cortex would explain the persistence of a motor deficit. It is important to exclude underlying prothrombotic coagulation abnormalities including factor V leiden, protein C and antithrombin III deficiency. In this case, haematological investigation was normal and the patient’s only risk factor was a 20-year history of oestrogen containing oral contraceptive pill (OCP). The patient stopped the OCP and was treated with 6 months of anticoagulation and anticonvulsant therapy. The monoplegia recovered over a 2-week period and after 6 months she remained symptom free. Fig. 3. CT with contrast showing an isolated ring-enhancing lesion and associated vasogenic oedema. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. References 1. 2. 3. 4. 5. 6. Stam J. Thrombosis of the cerebral veins and sinuses. New Engl J Med 2005;352:1791–98. Virapongse C, Cazenave C, Quisling R, Sarwar M, Hunter S. The empty delta sign: frequency and significance in 76 cases of dural sinus thrombosis. Radiology 1987;162:779. Perkin G. Cerebral venous thrombosis: developments in imaging and treatment. J Neurol, Neurosurg Psychiatr 1995;59:1. Niclot P, Bousser M. Cerebral venous thrombosis. Curr Treat Options Neurol 2000;2:343–52. Lindsay BD, Bates VE, Kinkel PR, Mechtler LL, Kinkel WR. Cerebral venous infarction presenting as enhancing space-occupying lesions: MRI findings. J Neuroimaging 1998;8:210–5. Niclot P, Bousser M. Cerebral venous thrombosis. Curr Treat Options Neurol 2000;2:343–52.