Intraoperative monitoring and supramaximal stimulation on ulnar nerve for the treatment of cubital tunnel syndrome

Objective To evaluate the therapeutic effect of decompression and anterior transposition of ulnar nerve combined with intraoperative supramaximal stimulation.Methods A total of 30 patients diagnosed as cubital tunnel syndrome with moderate to severe damage were performed decompression and anterior transposition of ulnar nerve.The amplitude and latency period of compound muscle action potential(CMAP) of abductor digiti minimi muscle after decompression were measured and recorded.Then the ulnar nerve was treated with intraoperative supramaximal stimulation(80 mA,2 Hz,10 min).The amplitude and latency period of CMAP of abductor digiti minimi muscle were also measured and recorded.The data before and after stimulation were analyzed by statistics.Results The amplitude of CMAP of abductor digiti minimi muscle after decompression and after supramaximal stimulation was(2.5±0.4) mV and(6.2±0.8) mV,respectively,while the latency period of CMAP was(12.0±0.6) ms and(10.3±0.3) ms,respectively.There was significant difference in amplitude and latency period before and after stimulation(P0.05).The latency period of the CMAP of abductor digiti minimi muscle was shortened by 15.7% and the amplitude was doubled in average.Conclusion The use of intraoperative monitoring and supramaximal stimulation has the auxiliary therapeutic effect on the recovery of ulnar nerve in cubital tunnel syndrome.