Headache as the only neurological sign of cerebral venous thrombosis: a series of 17 cases

Background: Headache is the most frequent symptom in cerebral venous thrombosis (CVT), and usually the first. However, it has rarely been reported as the only symptom of CVT. Objectives: To study the characteristics of patients in whom headache was the only presentation of CVT in the absence of intracranial hypertension, subarachnoid haemorrhage (SAH), meningitis, or other intracranial lesion. Methods: From a prospective study of 123 consecutive patients with CVT only those with isolated headache and normal brain computed tomography (CT) scan and cerebrospinal fluid (CSF) examination were included in the present study. All patients underwent an extensive systematic aetiological work-up and were given intravenous heparin followed by oral anticoagulants. A detailed description of the headache was obtained. Results: Headache was only sign of CVT in 17 patients. The lateral sinus was the most frequently involved sinus (n=15). Onset of headache was progressive in 11, acute in 3, and thunderclap in 3 patients. Once established, the headache was continuous in 15, diffuse in four and unilateral in 13, usually ipsilateral to the occluded lateral sinus. No specific risk factor or cause was found. All had a favourable evolution. Conclusion: The pathogenesis of isolated headache in CVT in the absence of intracranial hypertension, SAH, meningitis or intracerebral lesion is unknown but may involve changes in the walls of the occluded sinus. Hence MRI/MRV should be used to look for signs of CVT in all patients with recent headache (progressive or thunderclap) even when the CT scan and CSF examination are normal.