Non-Atherosclerotic Intracranial Arterial Diseases.

Atherosclerosis is not the only cause of intracranial arterial disease. Arterial dissection, moyamoya disease, vascular inflammatory disease, vasospasm and immunologic disorders are important non-atherosclerotic intracranial arterial diseases. Identification of the correct etiology is important in establishing treatment strategies and assessing prognosis. Careful history taking and appropriate laboratory testing are essential. Although catheter angiography is the most important diagnostic tool to examine various intracranial arterial diseases, other diagnostic modalities such as CT angiography and MR angiography are nowadays widely used. High resolution vessel wall MRI also can assist in making the correct diagnosis as this can yield information regarding vessel wall pathology. Certain diseases such as infectious vasculopathies and moyamoya disease are more prevalent in certain parts of the world, and physicians practicing in these regions should be mindful of these disorders. In this chapter, these non-atherosclerotic intracranial arterial diseases are discussed. Moyamoya disease will be described in another chapter.