[Wallenberg's syndrome as the presenting symptom of a cavernous angioma]

Cavernous angiomas account for 5-13% of all vascular malformations. In 75% of cases they are situated in the posterior fossa and up to 30% are associated with abnormal venous drainage. The main complication is haemorrhage; the presence of a neurological focus without radiological evidence of bleeding is very rare.

We report the case of a 54-year-old male with cardiovascular risk factors who presented symptoms that progressively deteriorated over a 72-hour period involving the left lower cranial nerves, sensory impairment and coordination disorder, compatible with Wallenberg's syndrome. Two computerised axial tomography scans of the brain were normal and so a tentative diagnosis of ischemic stroke in progression was proposed. Five days later, magnetic resonance imaging (MR) revealed the presence of a venous angioma and associated abnormal venous drainage.

Cavernous angiomas present a dynamic balance between intracavernous bleeding and thrombosis, with very slow venous blood flow. Upsetting this balance leads to an increase in the intracavernous pressure and involvement of the surrounding tissue, with no radiological expression of bleeding. In these cases MR scanning helps to distinguish between a vascular malformation with reduced blood flow and a clinical picture of ischemic stroke of an arterial origin.