Natural history When a cavernous malformation bleeds, this may occur as a minimal clinical event, a significant clinical event, or merely be observed as an increase in size of the lesion on MRI studies without any clinical sequelae. The exact incidence of these events remains uncertain. Regardless of this apparently small hemorrhage rate, certain patients present with hemorrhages which occur very close together in time. Stepwise neurologic deterioration can occur over several months with each deterioration representing a small hemorrhage. While it has been stated by some that cavernous malformations in eloquent areas such as speech cortex, motor cortex, or the brainstem may hemorrhage with higher frequency, it may well be that this merely reflects the fact that each hemorrhage is a clinically significant event.
Little information is available on the natural history of risk for patients who are asymptomatic.
When patients present with recurrent hemorrhage, progressive neurologic deterioration, or intractable epilepsy, then treatment in the form of surgery should be considered. The decision to operate on a patient with a cavernous malformation must be made based on the exact location of the lesion and its surgical accessibility. By and large surgery offers an excellent option in terms of complete excision of lesion with stabilization of symptoms. Even seemingly deep- seated lesions can be reached using currently available stereotactic techniques. Another alternative is that of stereotactic radiosurgery.