6.6 Headache attributed to cerebral venous thrombosis (CVT)

Headache caused by cerebral venous thrombosis. It has no specific characteristics: it is most often diffuse, progressive and severe, but can be unilateral and sudden (even thunderclap), or mild, and sometimes is migraine-like.

Diagnostic criteria:
A. Any new headache, fulfilling criterion C
B. Cerebral venous thrombosis (CVT) has been diagnosed
C. Evidence of causation demonstrated by both of the following:

    1. headache has developed in close temporal relation to other symptoms and/or clinical signs of CVT, or has led to the discovery of CVT
    2. either or both of the following:

      a) headache has significantly worsened in parallel with clinical or radiological signs of extension of the CVT
      b) headache has significantly improved or resolved after improvement of the CVT

D. Not better accounted for by another ICHD-3 diagnosis.

Headache is by far the most frequent symptom of cerebral venous thrombosis (CVT), present in 80-90% of cases, and also the most frequent inaugural symptom. 6.6 Headache attributed to cerebral venous thrombosis has no specific characteristics, but most often is diffuse, progressive and severe, and associated with other signs of intracranial hypertension. It can also be unilateral and sudden, and sometimes very misleading, mimicking 1. Migraine, 4.4 Primary thunderclap headache, 7.2 Headache attributed to low cerebrospinal fluid pressure or 6.2.2 Headache attributed to non-traumatic subarachnoid haemorrhage (CVT can be a cause of SAH).

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 of 6.6 Headache attributed to cerebral venous thrombosis, any recent persisting headache should raise suspicion, particularly in the presence of an underlying prothrombotic condition. Diagnosis is based on neuroimaging (MRI with T2*-weighted images plus MRA, or CT scan plus CT angiography, and intra-arterial angiography in doubtful cases). Treatment should be started as early as possible and includes symptomatic treatment, heparin followed by at least six months of oral anticoagulation and, whenever indicated, treatment of the underlying cause.