How are you? Vasculitis refers to a large group of diseases involving inflammation of the blood vessels. It can include central nervous system vasculitis, a type of vasculitis that also involves the brain and spinal cord as well as Giant Cell Arteritis or inflammation of the walls of the arteries. Both of these may present with headache. The cause may be idiopathic or due to secondary causes such as infection, allergy or immune system disorders. Diagnostic tests such as blood and imaging studies are important considerations in the diagnosis. It is best that you discuss this with your doctor for proper evaluation. Your medical history and symptoms present are important factors also. Take care and do keep us posted.