[Pathological study of age-related vascular changes in the spinal cord]

To study vascular lesions of the spinal cord in aged persons, we examined the number and distribution of radicular arteries and macroscopic arteriosclerosis of the spinal vascular system in 91 autopsied spinal cords. The average number of anterior radicular arteries per spinal cord was five. The anterior radicular artery appeared most frequently at the level of the 6th and 7th cervical segment, the 4th and 9th thoracic segment, and the 1st lumbar segment. Adamkiewicz's artery appeared most frequently at the 9th thoracic segment. Adamkiewicz's artery usually entered the spinal cord from the left side. Arteriosclerotic changes in the spinal arteries were less severe than those in other arteries. Only one spinal cord had atheromatous plaques in the anterior spinal artery. Transverse sections at each segmental level of 603 autopsied spinal cords were examined histopathologically and medial thickening of the anterior spinal artery was found in 16 cords (2.7%). The thickening of the arterial wall was much more pronounced in cords from patients with severe hypertension, myocardial infarction, and cerebral vascular lesions than in other specimens. Endothelial thickening appeared most frequently in lower cervical, lower thoracic, and upper lumbar segments. The endothelial thickening was mainly caused by fibroelastosis and proliferation of smooth muscle cells. We found no spinal cord infarctions. Arteriosclerotic changes in the spinal arteries were very rare, which may explain the low incidence of vascular lesions in the spinal cord. The number of anterior radicular arteries and the level at which they enter the spinal cord varied greatly. These observations indicate that the number and level of entrance of radicular arteries should be considered in patients with spinal vascular disorders.