Prevalence and clinical significance of superficial abdominal reflex abnormalities in idiopathic scoliosis.

To determine prevalence and significance of abnormal superficial abdominal reflexes (SARs) in idiopathic scoliosis. Study of 73 patients with presumed idiopathic scoliosis referred for magnetic resonance imaging (MRI), either as a routine pre-operative assessment (n=42) or because of abnormal symptoms or neurological signs (n=31). All patients were examined prior to magnetic resonance imaging (MRI), and the presence of abnormal SARs was noted. All patients then underwent MRI of the whole spine from the foramen magnum to the sacrum. The presence of Chiari 1 malformation and syrinx was recorded. The study group consisted of 11 males and 62 females with a mean age at time of MRI of 18 years (range 5-51 years) and a mean Cobb angle of 48 degrees (range 10-104 degrees). Abnormality of the SARs was recorded in eight cases (prevalence 11%). An abnormal MRI study was recorded in nine cases (12.3%), all patients having a syrinx and four having in addition, a Chiari 1 malformation. Of the patients with abnormal SARs, only 2 (25%) had an abnormal MRI study; 1 had unilateral absence of the reflexes whereas the other had complete absence of SARs. Of patients referred for MRI as a routine pre-operative assessment, 5 (11.6%) had an abnormal MRI study. In patients with idiopathic scoliosis, abnormality of the SARs was recorded in 11% of cases. Unilateral absence was present in one case only and was associated with the presence of syrinx. Other patterns of abnormality were not a useful indicator of underlying cord abnormality.