The Syndromes of the Arteries

The Vertebral Artery Each vertebral artery enters the foramen magnum in front of the roots of the hypoglossal nerve, inclines forwards and medially to the anterior aspect of the medulla oblongata and unites with its fellow at the lower border of the pons to form the basilar artery. The posterior inferior cerebellar and the anterior spinal arteries are its principal branches and it sometimes gives off the posterior spinal artery. A few small branches are supplied directly to the medulla oblongata. These are in line below with similar branches of the anterior spinal artery and above with the paramedian branches of the basilar artery. In some cases of apparently typical thrombosis of the posterior inferior cerebellar artery, post-mortem examination has demonstrated occlusion of the entire vertebral artery (e.g., Diggle and Stcpford, 1935). In some of these the thrombus has extended from the posterior inferior cerebellar artery just before death but in others there is no doubt that it was the primary condition. In these it is usual to find that the basilar artery has commenced early in the region of the inferior olive and supplies the median area of the medulla oblongata normally irrigated by the vertebral and ,anterior spinal arteries. The usual result of vertebral artery thrombosis is simply a combination of those features which result from occlusion of the posterior inferior cerebellar artery and of the medullary portion of the anterior spinal artery with all their variations (q.v.). Several eponyrns have been attached to the syndrome of the vertebral artery. The common picture is sometimes known as the BabinskiNageotte syndrome. The syndrome of CestanChenais is similar but weakness of the tongue and involvement of the descending root of the fifth nerve and of the spinothalamic tract are absent. (See also Cabot, I937; Pines and Gilensky, 1930.)