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Spinal Injuries
Published in Ian Greaves, Keith Porter, Jeff Garner, Trauma Care Manual, 2021
Ian Greaves, Keith Porter, Jeff Garner
The spinal cord is supplied with blood by three longitudinal vessels: one anterior spinal artery and two posterior spinal arteries. These vessels are fed by radicular branches from the aorta. The anterior spinal artery runs down the midline in the anterior median fissure of the cord. It supplies the anterior two-thirds of the cord along its whole length. The two posterior spinal arteries primarily supply the posterior third of the cord and frequently anastomose with each other and the anterior spinal artery. Ischaemic injury to the cord may be caused by arterial occlusion secondary to trauma or a period of profound hypotension. The most sensitive area of the spinal cord to blood supply (watershed area) is the mid-thoracic region, however, at any given level of the spinal cord, the central cord is also a watershed area. Thus, ischaemic injury can produce a variety of clinical syndromes depending on the vessels involved, the segmental level and the degree of damage in watershed areas. A vascular injury may also cause ischaemia which extends to several segments higher than the initial injury.
Spinal CordAnatomical and Physiological Features
Published in Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal, Principles of Physiology for the Anaesthetist, 2020
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal
The spinal cord is supplied by a single anterior spinal artery and two posterior spinal arteries supplemented by smaller feeder radicular arteries. The anterior spinal artery, which supplies up to anterior two-thirds of the cord, is formed from the terminal branches of the vertebral arteries. It runs in the anterior median fissure. The two posterior spinal arteries, which arise from the posterior inferior cerebellar arteries, descend medial to medial to the posterior nerve roots and supply the posterior one-third of the spinal cord. The anterior spinal artery receives feeders from the subclavian, thyrocostal and costocervical arteries. Three main arteries are also supplemented by branches from the vertebral, deep cervical, ascending cervical, posterior intercostal, lumbar and lateral sacral arteries. The largest feeder artery is the anterior radicular artery of Adamkiewicz (radicularis magna), which supplies the low thoracic and lumbar regions of the spinal cord. It arises from the left posterior intercostal artery, a branch of the aorta, between T8 and L3 in 80% of the population. In about 15% of people, it originates at the level of T5. In these people, there is a watershed zone, especially at T4/T5, as a result of a poorer anastomosis between the cervical, thoracic and lumbar regions. Hence the spinal cord is more vulnerable to ischaemia, especially during aortic cross clamping during thoracic aortic aneurysm repair surgery.
Central nervous system
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
Thirty-one pairs of spinal nerves arise from the spinal cord and derive their name from the area from which they originate (Figs 11.3b,c). The lumbar, sacral and coccygeal nerves leave the cord before its termination and extend inferiorly through the subarachnoid space to form the cauda equina. The spinal cord is incompletely divided by the anterior median fissure and the posterior median septum. The grey matter lies deep in an ‘H’ pattern and the white matter lies superficially. The central canal contains CSF and is continuous with the fourth ventricle. The posterior horns are stimulated by sensory impulses and the anterior horns originate motor impulses. The white matter comprises three tracts, one ascending carrying sensory information, one descending carrying motor information and one intersegmental carrying information from one level to another.
Effects of a contusion load on spinal cord with different curvatures
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Qian-qian Yu, Si-qing Liu, Jian-jie Wang, Meng-lei Xu, Wen-xuan Zhang, Li-ming Cheng, Rui Zhu
As the contusion loads impacted directly on the spinal cord, the rigid cylinder produced both cutting and compressing effects. The maximum von Mises stress in the model located in the contact area between the edge of the cylinder and the spinal cord. This reflected the cutting effect of the inducer. No matter for the pia matter or for the gray and white matter, the maximum von Mises stress under the front-to-back load was larger than the one under the back-to-front load in most cases (Figure 4). The pathological factors in front of the spinal cord such including disc prolapses, osteophyte formation or ligament hypertrophy are estimated to be the most common causes of the spinal cord dysfunction (Davies et al. 2018a, 2018b). The impact on the front spinal cord may cause larger risk from our results possibly due to irregular anterior median fissure. These factors need further study and should be taken more care.