Spontaneous intracranial hypotension with isolated cortical vein thrombosis and subarachnoid haemorrhage.

Spontaneous intracranial hypotension (SIH) associated with subarachnoid haemorrhage (SAH) has never been reported. Here, we report on a case of a 33-year-old woman with SIH, who developed simple partial sensory seizures 3 weeks later. Neuroimaging studies, including brain computed tomography and angiography, were initially normal, but revealed an isolated cortical venous thrombosis at 3 weeks. One week later, brain magnetic resonance imaging showed SAH around the thrombosed cortical vein. We postulate that the decline in the venous blood flow velocity due to SIH may have resulted in cortical venous thrombosis, which in turn led to rupture of the vessel wall and SAH in this patient.