Clinical applications of intraoperative cortex somatosensory evoked potential in the surgery of old at?鄄lantoaxial dislocation

English Keywords:Somatosensory cortical evoked potential  Intraoperative monitoring  Old atlantoaxial dislocation

English Abstract:

  【Abstract】 Objectives: To investigate the effect of the cortex somatosensory evoked potential(CSEP) on spinal cord function under C1-2 dislocation surgery. Methods: In this study, 42 cases with old atlantoaxial dislocation received intraoperative CSEP monitoring. Latency and amplitude of cortical potentials were observed with the value of the latency extension more than 10% and peak amplitude reduction more than 50% defined as abnormality. Preoperative and postoperative JOA score were used to evaluate the neurofunction. Results: True negative rate was 88.1%(37/42), increased amplitude and (or) latency were noted in 35 cases after operation, and neurological function improved. No new neurological deficit was noted, and the other 2 cases showed no change compared with preoperation. True positive was 4.8%(2/42), and decompression ceased in 1 case when suffering from abnormality, and the waveform returned to normal after administration of MEP 40mg, neurological function improved postoperatively. Wave amplitude decreasing 60% was noted in 1 case, and waveform returned to normal after ceasing screw placement, right upper limb was noted numbness after operation. False negative was 2.4%(1/42), this case showed no intraoperative wave abnormality, but postoperative right lower limb weakness was noted, and JOA score decreased compared with preoperation. False positive was 4.8%(2/42), 1 case had waveform returned to normal after performing hypertension; and the cause for the other one was unidentified, after closing the wound, waveform returned to normal; there was no damage of neurological function after operation, the improvement rate of JOA score was 82%. Conclusions: CSEP can reflect the functional state and integrity of the spinal cord so as to prevent irreversible damage to the spinal cord during the surgery of old atlantoaxial dislocation.