Central nervous system cavernous malformations: cross-sectional study assessing rebleeding risk after a second haemorrhage.

During an untreated 5-year follow-up after a second haemorrhage, a significantly increased risk of a third haemorrhage compared to the known risk of a first and second bleeding event was identified. The third bleeding was significantly associated with neurological deterioration. These findings may justify a surgical treatment after a second bleeding event.