Spinal Cord Injuries

Abstract

A recent article by Dr Robert Heimburger in the Journal was titled, “Is there hope for return of function in lower extremities paralyzed by spinal cord injury?” This question can be answered by showing that innovative attempts are currently being pursued in the hope, as requested by Dr Heimburger, to improve the neurologic results of patients who tragically sustain a spinal cord injury (SCI). Dr Heimburger paid tribute in his article to Dr LW Freeman, who spent the major portion of his laboratory life producing evidence that axons could progress in an experimental animal from the cut end of a divided intercostal nerve when the distal end of the nerve is implanted into the lower segment of an anatomically transected spinal cord. Freeman reported that large numbers of animals who underwent this procedure demonstrated the return of muscular function and walking ability in their paralyzed limbs. Fortunately, only a very few patients sustain an anatomically transected spinal cord as a result of their injury. What does occur in an overwhelming number of SCI patients is not an anatomic transection of the cord, but a physiologic transection of the injured cord, which results in complete lack of neurologic activity below the site of injury. Laboratory efforts today are directed toward development of axonal activation at the site of the SCI. This effort should be strenuously continued. But improvement in the future treatment of an SCI is also of extreme importance and, if successful, elevating the longterm results of spinal cord injuries might well occur. When a spinal cord injury is surgically treated today, efforts are directed to firmly stabilizing the vertebral column, but little, if any, attention is focused precisely on the injured spinal cord, which, after all, is the critical area of any such injury. If treatment could be directed specifically to the injured spinal cord, perhaps longterm improvement in postoperative motor function might follow. Studies have shown little difference if an operation is carried out early or later in the presence of an SCI. Regardless of the timing of the operation, all that apparently may be done to treat an edematous spinal cord is to perform a decompressive laminectomy. This maneuver does little to decrease the high interstitial pressure present in an edematous spinal cord restricted by the firm, enveloping dura mater that surrounds the swollen spinal cord. The reason there is a strong reluctance to open the dura over a swollen edematous spinal cord is that such an opening can lead to instant extrusion of edematous spinal cord material. Even if a traumatized spinal cord is exposed after an opening in the dura mater, nothing is done specifically to the injured spinal cord that might lead to improved clinical results. Dr Heimburger’s article asked whether there might be hope that something could be done in the future for patients with an SCI. This hope is currently addressed in a recent article entitled “Can the standard treatment of acute spinal cord injury be improved: perhaps the time has come.” In this recent article, two considerations are presented that propose a direct surgical approach to a traumatized spinal cord, which should be done as early as possible after SCI. The problem of extrusion of edematous spinal cord tissue after the opening of the dura is first addressed. This problem can be controlled by making two small midline longitudinal incisions in the dura mater 1 to 11⁄2 cm directly above and below the area of spinal cord impaction and edema formation. These two longitudinal incisions are slowly drawn toward each other over a 10-minute period until the longitudinal incisions connect directly over the major spinal cord injury site. This technique prevents edematous material from being extruded at the site of the SCI because the material is slowly squeezed up and down the spinal cord (comparable to squeezing the middle of a toothpaste tube with one’s thumb—a high interstitial tissue pressure forces itself into areas of lower interstitial pressure). After an injured spinal cord is exposed after the widely opened dura mater, an intact omental pedicle can be placed directly on the site of the SCI. The reason for this maneuver is based on the omentum’s enormous ability to absorb edema fluid. The edema fluid that is present at