Treatments and Outcomes of Untreated Cerebral Cavernous Malformations in CHina.

Inclusion Criteria: * Definite diagnosis of cerebral CM on the basis of brain MRI or pathologic examination; * Patients without any surgical intervention (microsurgery, radiosurgery, or multimodality treatment) before enrolment; * Informed consent, and willing to accept long-term follow-up. Exclusion Criteria: * Patients receiving emergency surgery due to acute intracranial hematoma and resultant brain hernia; * Patients with other never system diseases, such as aneurysms, tumors or other vascular malformations except venous development anomaly; * Patients with severe underlying disease, which affects the patient's functional status and life expectancy; * Patients with severe mental or psychologic disease.