and necessary considering the vast number of descriptions of cerebro­ vascular anatomy and pathology. The clinical challenge posed by patients suffering from partial or complete transverse spinal lesions has grown due to new diagnostic and therapeutic approaches. Myelography using water-soluble contrast media, X-ray computed tomography, magnetic resonance imaging and spinal angiography today allow and require both earlier and topographically and pathogenetically more exact classification of diseases of the spinal cord and its surrounding structures. Due to progress in microneurosurgery and interventional neuroradiology, even intramedullary lesions have become more and more accessible and treatable. Therefore this monograph mainly addresses those concerned with invasive therapeutic techniques and who are familiar with the interpretation of radio anatomic findings. A comprehensive description of medullary vascular syndromes would be beyond the scope of this treatise.