Damage to the spinal cord and subsequent neurological deficit may occur during surgery of the spinal cord. Stagnara wake up test aims at recognizing early intraoperative warning of potential damage.
If the injury is recognized, steps can be taken to undo the process that might have caused it. For example, if spinal injury signs are found following correction of the curves by the distraction of instrumentation rods, the distraction can be reduced.
The neurological deficit may be produced by a number of causes like occlusion or spasm of the artery of Adamkievicz, haemodilution, or excessive stretching when surgical instrumentation is positioned.
Therefore, that early intraoperative warning of potential damage is highly desirable.
Symptoms vary from transient postoperative sensory changes to paraplegia, BrownSequard syndrome and various degrees of
motor-sensory impairment.
Stagnara Wake up test is a simple, safe and reliable method of recognition of such a complication, allowing rapid neurological recovery by reduction of spinal distraction.
Electrophysiological monitoring techniques are more sophisticated and equipment is not always available.
Stagnara wake-up test must be performed by a skilled anesthesiologist, but it does not require any special apparatus. It is routinely used by many surgeons in patients undergoing surgery involving distraction and/or instrumentation.
The Test
Stagnara Wake Up test involves waking the patient during the surgery and asking them to move their feet.
The performance of wake-up tests requires an anesthetic regimen that provides for fast recovery and fast return of cognition to allow immediate examination. The drugs like desflurane and remifentanil are used for these regimens.
Stagnara Wake Up test monitors voluntary motor function. It is simple to perform and does not require sophisticated equipment
The wake-up test has been considered the gold standard of spinal monitoring.
It, however, can miss onset of injury or ischemia. Moreover, it does not identify isolated nerve injury or subtle changes.
Therefore, it is prudent to use the test in conjunction with electrophysiological methods.