OBJECTIVETo investigate the value of somatosensory evoked potential (SEP) in the diagnosis of congenital scoliosis (CS) with intraspinal malformation.

METHODSFrom September 2001 to September 2007 posterior tibial nerve SEP were performed on 187 operatively treated CS patients. There were 85 male and 102 female, and the average age was 13.8 years (range from 30 to 22 years). Patients with intraspinal malformations were diagnosed by MRI. Absence of SEP waveforms, prolongation of peek latency or asymmetrical peek latency were defined as pathological change. The incidence of pathological SEP and clinical characteristics were compared between patients with and without intraspinal malformations.

RESULTSOf 187 patients, intraspinal malformations were diagnosed in 32 patients (17.1%). The incidence of intraspinal malformations was higher in type III (30.8%) than in type I and II CS patients (P < 0.05). The mean Cobb angle of scoliosis in patients with intraspinal malformations was greater than without intraspinal malformations, but there was no difference in kyphosis between the two groups. The ratio of abnormal SEP in patients with intraspinal malformations was 75.0% (24/32), while it was 38.7% (60/155) in patients without intraspinal malformations, and it showed significant difference between the two groups (χ(2) = 4.70, P < 0.05).

CONCLUSIONSSEP is a reliable tool for assessment of spinal cord function in patients with congenital scoliosis. It could be helpful for the diagnosis of intraspinal malformations, and also might provide an important reference for assessment and treatment of intraspinal malformations in congenital scoliosis.