IV. SPINAL CORD LESIONS A. General comments The complex of anatomy of the vertebral column and the great concentration of important tracts in a structure of small cross-sectional area are unique features related to spinal cord injury. A number of factors influence the severity of pathological changes and functional deficits after spinal cord trauma, including age and the flexibility of the body, the size of the bony canal as influenced by heredity, degenerative changes of joints and intravertebral discs and variations in blood supply. The spinal levels most commonly involved with injury are the lower cervical spine (C4, C5, C6, C7, T1) and the thoracolumbar juncture (T12, L1, L2), the areas of greater mobility. B. Pathophysiology 1. The spinal cord and nerve roots may be injured by: a. Compression from bone, ligaments, extruded disc material and tumors. b. Disruption or overstretching of neural tissues c. Edema following compression or concussion d. Disturbance of circulation 2. Mechanisms of injury a. Direct injury results from force applied directly to the back of the neck or trunk and may cause fractures of spinous processes of laminal arches, concussion of the spinal cord, or direct compression of neural tissue by depressed bone fragments. Lacerations can result from knife or bullet wounds. b. Indirect injury is a more common mechanism resulting from forces applied to the head and trunk or from movements that exceed the normal range, e.g. when the head is suddenly accelerated or decelerated in relation to the trunk.
Posted on: Thu, 04 Jul 2013 14:37:28 +0000
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