Secondary objectives are the impact of pretreatment of the AVICH score. Patients outcome is measured using the modified Rankin Scale (mRS) and are grouped in favorable (mRS score, 0-2) and unfavourable (mRS score, 3-6) outcome at last follow-up (LFU). The following parameters, which are part of the AVICH score, will be compared between the 2 groups: ICH score including age, Glasgow Coma Scale (GCS) score, haemorrhage volume, presence of intraventricular hemorrhage (IVH), and localization of the ICH. Spetzler-Martin grade including AVM size, eloquent location, and venous drainage, as well as the Lawton-Young grade, including age, presence of ruptured AVM, and the nidus structure. In addition pre-/postruptured treatment modalities, including embolization, radiotherapy, surgery or no treatment will be analysed. Outcome (mRS) at 3 months, at 1 year, and at LFU will be compared.