The relative inaccessibility of the medulla within the spinal column constitutes a major obstacle for both in vivo and postmortem studies. This fact as well as the complex and highly variable blood supply of the spinal cord explain why our knowledge about the physiology and pathophysiology of medullary circulation is still limited. As late as 1958, Gillilan mentions that knowledge of the spinal vascular supply was apparently so deficient among neurologists and neurosurgeons that clinical studies almost always began with a synopsis of the normal medullary blood supply. Clinical syndromes such as the anterior spinal artery syndrome, intermittent spinal claudication (Verbiest, 1954, 1976, Jellinger and Neumayer, 1972) and the vascular myelopathies (Neumayer, 1967) are largely unexplained with regard to their pathogenesis. From our present morphological knowledge we cannot understand the course taken by the repeatedly reported fibrocartilaginous emboli of intervertebral disk tissue into the anterior spinal artery (Peiffer et al. 1976). Until recently, the subacute necrotizing myelitis (Foix-Alajouanine disease), later termed “angiodysgenetic necrotizing myelopathy” (Scholz and Manuelidis, 1950), was considered a distinct clinical entity, and only lately could its underlying vessel anomaly be satisfactorily demonstrated and interpreted. Disorders whose pathogenesis also involves vascular mechanisms, such as the syndromes of the narrow spinal canal or of slowly progressive tumor compression, were usually explained in the past by decreasing arterial supply. Despite the well-known pathoanatomical fact that arteriosclerosis of the medullary vessels is extremely rare, literature on spinal circulatory disorders abounds in explanations analogous to the conditions in ischemic brain disease, where obstructions in the arterial vasculature are often found. This becomes understandable in light of the fact that even today the possible impact of venous disorders cannot be clinically estimated, although circulatory deficiencies in the venous system have occasionally received pathoanatomical and surgical attention (Stoch-dorph, 1961, 1969; Jellinger, 1966; Neumayer, 1966; Wüllenweber, 1969).