IHS	Diagnosis	ICD-10
6.6	Headache attributed to cerebral venous thrombosis (CVT) [I63.6]	G44.810

Diagnostic criteria:

Comments:

Headache is by far the most frequent symptom of CVT (present in 80-90% of cases) and it is also the most frequent inaugural symptom. It has no specific characteristics. Most often it is diffuse, progressive, severe and associated with other signs of intracranial hypertension. It can also be unilateral and sudden, and sometimes very misleading, mimicking migraine, primary thunderclap headache, CSF hypotension or SAH (of which it can be a cause). Headache can be the only manifestation of CVT but in over 90% of cases it is associated with focal signs (neurological deficits or seizures) and/or signs of intracranial hypertension, subacute encephalopathy or cavernous sinus syndrome.

Given the absence of specific characteristics, any recent persisting headache should raise suspicion, particularly in the presence of an underlying prothrombotic condition. Diagnosis is based on neuroimaging (MRI plus MRA or CT scan plus CT angiography or intra-arterial angiography in doubtful cases). Treatment should be started as early as possible and includes symptomatic treatment, heparin followed by at least 6 months of oral anticoagulation and, whenever indicated, treatment of the underlying cause.