Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Intracranial arteriovenous malformation ?
    ### Response:
    Intracranial arteriovenous malformations (AVMs) are abnormal connections between the arteries and veins in the brain.  Most people with brain or spinal AVMs experience few, if any, major symptoms. About 12 percent of people with this condition experience symptoms that vary greatly in severity.
    