A study of motor unit number estimation by multiple point stimulation in evaluating outcome of surgical treatment of Hirayama disease / 中华骨科杂志

ABSTRACT

Objective　To investigate the relationship of motor unit number estimation(MUNE)by multiple point stimulation with the outcome of surgical treatment patients with Hirayama disease(HD).Methods　A total of 36 consecutive patients including unilateral in 26 cases and bilateral in 10 cases with Hirayama disease treated by anterior cervical discectomy decompression and fusion in Peking University Third Hospital from October 2007 to May 2015 were reviewed retrospectively.There were 35 males and 1 female,aged from 16-26 years(average,19.2 years).A total of 46 hands were enrolled.Odom criteria was used to evaluate the subjective outcome of surgical treatment.Multiple point stimulating technique was used to estimate the motor unit number of abductor pollicis brevis and abductor digitiminimi preoperatively and at the time of pre-operation and the latest follow-up.Hands were divided into two groups based on Odom criteria(Group A with excellent and good;Group B with fair and poor).The difference between the two groups were examined by t text.Results　A total of 46 hands with complete clinical and electrophysiology data were followed up for 12-96 months(average,28.2 months).The outcome at the final follow-up according to Odom criteria wasExcellent in 8 cases,Good in 18 cases,Fair in 20 cases and no Poor case.MUNE of abductor pollicis brevis increased significantly after surgery from 139.6±68.4 to 188.2±60.4(t=-5.86,P<0.001).MUNE of abductor digitiminimi increased significantly after surgery from 75.0±66.3 to 104.2±80.4 significantly(t=-3.86,P<0.001).For two groups in age,follow-up period,preoperative MUNE of abductor pollicis brevis,and preoperative abductor digitiminimi,there was no significant difference.The illness course of Group A was 24.0±11.3 months,which was significantly shorter than Group B 34.9±21.2 months(t=-4.452,P<0.01).Group A had more increased MUNE of abductor pollicis brevis 65.6±64.1 compared with Group B 26.7±34.7(t=2.446,P<0.05)and Group A had more increased MUNE of abductor digitiminimi 42.6±59.3 compared with Group B 11.8±32.4 after surgery(t=2.088,P<0.05).Conclusion　MUNE by multiple point stimulating technique could be used to evaluate the neurological function of Hirayama disease and the outcome of surgical treatment quantitatively.