Introduction: Abnormal somatosensory evoked potentials (SEPs) have been documented in adolescent idiopathic scoliosis (AIS) patients with a small curve. However, SEPs patterns in large curve AIS patients are seldom reported.
Objectives: This study was to investigate the abnormality of the cerebellar tonsil position and SEPs in AIS patients, and to explore its clinical significance.
Materials and Methods: Posterior tibial nerve SEPs were evaluated on 489 young operative treated AIS patients with a Cobb angle 40 and 45 age-matched healthy control individuals. Absence of SEPs waveforms, prolongation of peek latency or asymmetrical peek latency were defined as pathological change. Base on the control reference, the incidence of pathological SEPs was determined in AIS group. The association of abnormal SEPs and curve severity for AIS patients was also assessed.
Results: Peak latency corrected for body height was slightly longer in AIS patients than in controls, however, with no significant difference. Interside difference of latency was significantly larger in AIS patients. Abnormal SEPs were found in 166 of 489 (33.9%) AIS patients. Among these, 17(3.5%) showed absent waveforms, 50(10.2%) had unilateral latency prolongation, 38 (7.8%) had bilateral latency prolongation, and 120 (24.5%) showed significant interside difference. Statistical analysis failed to show a correlation between abnormal SEPs and the curve severity of spinal deformity.
Conclusion and Significance: Disorder of somatosensory pathways does exist in a subgroup of AIS patients, and it might be a primary factor. Further effort would be done to understand the role of abnormal in the etiopathogenesis of AIS.