Anterior Cord Syndrome (Archived)

Excerpt

Anterior cord syndrome is an incomplete spinal cord syndrome that predominantly affects the anterior two-thirds of the spinal cord, resulting in motor deficits and loss of sensory function in pain and temperature. The patient presentation varies depending on the portion of the spinal cord affected and the time to treatment. Other findings include back pain or autonomic dysfunction, such as hypotension, neurogenic bowel or bladder, and sexual dysfunction. The severity of motor dysfunction can vary, typically resulting in paraplegia or quadriplegia depending on how rostral the level of the spinal cord involved is.

The syndrome is caused by ischemia within the anterior spinal artery (ASA), which supplies blood to the anterior two-thirds of the spinal cord. The ASA forms from the bilateral vertebral arteries at the foramen magnum. The ASA runs as an uninterrupted artery within the anterior median sulcus of the spinal cord to the conus medullaris. Radicular arteries enter the spinal canal through the intervertebral foramen and primarily supply the nerve roots; however, some anastomoses contribute to the ASA. The largest of these radicular arteries is the artery of Adamkiewicz, which most commonly arises off of a left intercostal artery between segments T9 to T12 but can vary anatomically. The ASA branches into small sulcal and penetrating arteries that enter the body of the spinal cord.

The ASA supplies blood to the spinal cord's bilateral anterior and lateral horns and the bilateral spinothalamic tracts and corticospinal tracts. The anterior horns and corticospinal tracts control the somatic motor system from the neck to the feet. The lateral horns span levels T1 to L2 of the spinal cord and comprise the neuronal cell bodies of the sympathetic nervous system. The spinothalamic tracts relay pain, temperature, and sensory information. The anterior spinal artery, with a few radicular artery contributions, is the sole source of blood supply to these areas of the spinal cord via its sulcal and penetrating arteries.

Ischemia of the ASA causes symptoms consistent with the dysfunction of these tracts. Since the ASA is formed from the more cephalad vertebral arteries and runs caudally, the more rostral the location of ischemia, the more widespread or severe the symptoms are. Since the lateral horns are located only between T1 to L2 of the spinal cord, autonomic symptoms are not always present if ischemia does not involve this region. Proprioception, vibratory sense, two-point discrimination, and fine touch are not affected in anterior cord syndrome and are carried by the dorsal column of the spinal cord, which is perfused by two posterior spinal arteries running in the posterior lateral sulci.