The value of somatosensory evoked potentials in the pre-operative evaluation of congenital scoliosis complicated with no spinal cord malformation

English Keywords:Congenital scoliosis  Evoked potentials  Somatosensory  Preoperative evaluation

English Abstract:

  【Abstract】 Objective：To investigate the value of somatosensory evoked potentials（SEPs） in the pre-operative evaluation of congenital scoliosis complicated with no spinal cord malformation.Method：Posterior tibial nerve SEPs（PTN-SEPs） were performed on 152 CS patients treated surgically，and patients with myelodysplasia were excluded.Absence of SEPs waveforms，prolongation of peek latency or asymmetrical peek latency were defined as pathological abnormality.The incidence of pathological SEPs was determined in all CS patients.The association of abnormal SEPs and type of CS，severity of scoliosis and kyphosis were also assessed.Result：4 cases with lower limbs paresis showed abnormal waveforms.Abnormal SEPs were found in 60（40.5%） patients that were confirmed without neurological deficit.The incidence of abnormal SEPs for type Ⅰ，type Ⅱ and type Ⅲ was 50.5%，10.0% and 47.1% respectively（P<0.05）.Among 50 cases with single scoliosis，only 1（2%） patient with vertebra rotational subluxation showed prolongation of peek latency or asymmetrical latency.However，of 102 kyphoscoliosis patients，63 cases（61.8%） had pathological SEPs.The mean scoliosis Cobb angle showed no obvious difference between SEPs normal group（66.8°±27.1°） and abnormal group（65.2°±26.7°），while the mean kyphosis Cobb angle for SEPs abnormal group（69.7°±21.7°） was significantly larger than that in SEPs normal group（50.9°±23.1°）.The rate of abnormal SEPs was higher in anglular kyphosis（69%） than in round kyphosis（45.2%）.Conclusion：The risk factors of neurological damage secondary to congenital scoliosis include type Ⅰor Ⅲ CS，severe angular kyphosis and vertebra rotation subluxation.SEPs can detect early potential neurological damage in congenital patients，which contribute to clinical evaluation and intervention.