7 - Spinal Cord Compression

Abstract

Spinal cord compression can result from a myriad of both atraumatic and traumatic causes. The spinal column, comprised of numerous soft tissue and bony structures, is built to provide the body’s structural support and protect the spinal cord and exiting nerve roots. The encased spinal cord depends upon this stability. However, it is simultaneously vulnerable to a variety of compressive phenomena, such as the expansion of blood products, neoplastic disease, infectious collections, or protrusion of bone or intervertebral disc within the limited area of the fat-filled spinal epidural space and meninges. A simplified overview of spinal anatomy is discussed below: The spine is comprised of 33 vertebrae: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused), and 4 coccygeal (fused). The 26 non-fused portions of the spine are separated by cartilaginous intervertebral disks and supported by ligaments, including the anterior longitudinal ligament and posterior longitudinal ligament. Each neural foramen (nerve root exit site) is bounded superiorly by a pedicle, immediately inferiorly by a disc space, posteriorly by facet joints, and anteriorly by the vertebral body.The spinal cord is approximately 40 cm in length, extending from the foramen magnum to the L1-L2 vertebrae. The cervical and lumbar enlargements of the spinal cord, responsible for innervation to the upper and lower extremities, span from C5-T1 and L2-S3, respectively. The spinal cord tapers down to its caudal tip, the conus medullaris, between T10-L1, where the non-neural filum terminale then extends downward to the S2 vertebra. Paired lumbosacral nerves extend caudally, comprising the cauda equina until exiting the spinal column at their corresponding foramina.Vascular supply to the spinal cord includes the anterior spinal artery, supplied superiorly by the vertebral arteries, and paired posterior spinal arteries. The anterior spinal artery provides approximately two-thirds of the blood supply to the spinal cord, and the paired posterior spinal arteries provide the remaining one-third. The anterior and posterior spinal arteries receive additional blood flow from radicular arteries, the largest of which is the artery of Adamkiewicz originating from the aorta. The artery of Adamkiewicz is most commonly located between the T8-L4 levels on the left side.The spinal epidural space is bordered anteriorly by the vertebral body and posteriorly by the dura mater. It contains fat, arteries, and venous plexus. The epidural space is larger along the thoracolumbar spine, corresponding to a higher likelihood of spinal epidural abscess in this region.