Intraoperative neurophysiological monitoring of functional changes following durotomy with decompression for acute spinal cord injury
Yang Jiujie1, 2, Li Zhi2, Wang Shujie3, Tian Ye3, Zhao Wei2
1Shenyang Medical College, Shenyang 110034, Liaoning Province, China; 2Department of Orthopedics, Affiliated Central Hospital of Shenyang Medical College, Shenyang 110034, Liaoning Province, China; 3Department of Orthopedics, Peking Union Medical College Hospital, Beijing 100000, China
Abstract: BACKGROUND: Traditional spinal canal expansion and decompression for acute spinal cord injury can only relieve bony compression (i.e., epidural pressure), but cannot obviously reduce intradural pressure. Therefore, durotomy with decompression is proposed; however, the therapeutic effect of this surgery is mixed.
OBJECTIVE: Using intraoperative neurophysiological monitoring (IONM) to estimate the efficacy of durotomy for acute spinal cord injury and to evaluate the significance of IONM of nerve function during surgery for acute spinal cord injury.
METHODS: The clinical data of 51 patients with acute spinal cord injury of American Spinal Injury Association (ASIA) grades A and B undergoing surgical treatment were retrospectively analyzed. According to the surgical procedures, they were divided into durotomy group (n=19, receiving durotomy with posterior spinal decompression) and bone decompression group (n=32, receiving posterior spinal decompression alone). The KEY PONIT multi-function monitor was used to monitor the spinal cord function in combination with somatosensory and motor evoked potentials. Intraoperative neurophysiological data and the spinal cord function scores before and 6 months after surgery were compared and analyzed between two groups.
RESULTS AND CONCLUSION: The ASIA score was 236.47±31.29 in the durotomy group at 6 months postoperatively, which was significantly higher than that of the bone decompression group (205.48±26.28; P < 0.05). The motor evoked potential amplitude of the patients in the duratomy group increased by (82.30±30.01) µV compared with the baseline, which was significantly higher than that after bone decompression alone [(6.1±25.6) µV, P < 0.000 1]. Changes in motor evoked potential amplitudes after decompression were basically consistent with the outcomes of postoperative neurological function in all patients. These findings indicate that durotomy with bony decompression is recommended for patients with acute spinal cord injury of ASIA grades A and B, which can further improve spinal nerve function of such patients. The use of IONM during acute spinal cord injury surgery can promptly reflect the functional changes of the spinal cord, and the change of IONM parameters tend to be consistent with the postoperative neurological outcomes of the patients.
Key words: spinal cord injury, acute spinal cord injury, surgical treatment, intraoperative neurophysiological monitoring, intramedullary decompression, motor evoked potential