• Behçet's disease
• occlusive vasculitis

I enjoyed reading the self assessment question by Abbas et al published recently.¹ It would be of great interest to know the ethnic background of this 33 year old man. In a study by Daif et al, from Saudi Arabia, Behçet's disease accounted for almost one fourth of their cases of cerebral venous thrombosis (CVT),² likely to be explained by the higher prevalence of Behçet's disease in the Middle East.³

It is imperative that all patients with CVT, even in the presence of a known aetiological factor, have a thorough diagnostic work-up, as multiple factors can be encountered in an individual patient.⁴ Also, the factor V gene mutation has been shown to be associated with a sixfold increase in venous thrombosis risk in Behçet's disease.⁵

Recombinant tissue plasminogen activator, rather than urokinase, can be used as a local thrombolytic agent, but must be restricted to patients without haemorrhage. It should be used after anticoagulation therapy alone has not provided sufficient clinical improvement, and after ruling out other causes of a patient's worsening condition.^4,6