Aim: To investigate whether there is any difference in regional brain volumes between AIS patients and age matched, sex matched control subjects.

Method and Materials: 20 adolescent idiopathic scoliosis (AIS) female patients (age ranged from 11 yrs to 18 yrs, mean age of 14.5 yrs) and 20 sex matched, age matched controls have undergone MRI brain examination performed with a 1.5T scanner (Sonata, Siemens Medical Solutions, Erlanger, Germany). A Magnetization Preparation Rapid Acquisition Gradient Echo (MPR) sequence was used. Volumes of neuroanatomical regions were quantitated automatically by using whole brain segmentation technique of atlas-based hybrid warping. The whole brain was classified into 100 fine anatomical regions.

The results were taken as significant when p value was less than 0.05.

Results: Significant unilateral regional differences were found in the following regions:

Left thalamus and left postcentral gyrus of AIS patients were significantly larger than the control subjects. Anterior and posterior limb of right internal capsule, right caudate nucleus, right cuneus and left middle occipital gyurs of AIS patients were significantly smaller than the control subjects. Some regions were bilaterally involved: Perirhinal and hippocampus regions were larger in AIS while inferior occipital gyrus and precuneus were smaller than the corresponding regions in the control subjects. In the midline, the volumes of corpus callosum and brainstem in AIS patients were significantly larger than the control subjects.

Conclusion: Our study found that significant differences in particular regional brain volumes exist between AIS patients and the controls. Most of these regions involved the brain unilaterally, indicating that there might be abnormal asymmetrical development of the brain in AIS. This is the first study of its kind to show the presence of L-R asymmetry of regional brain volume difference in AIS patients as compared to normal controls. The findings might also help to explain the reported poor performance in the combined visual and proprioceptive test, spatial orientation test, abnormal nystagmus response to calorie test, and impaired postural balance in AIS patients.

We undertook a comparative study of magnetic resonance imaging (MRI) vertebral morphometry of thoracic vertebrae of girls with adolescent idiopathic thoracic scoliosis (AIS) and age and gender-matched normal subjects, in order to investigate abnormal differential growth of the anterior and posterior elements of the thoracic vertebrae in patients with scoliosis. Previous studies have suggested that disproportionate growth of the anterior and posterior columns may contribute to the development of AIS. Whole spine MRI was undertaken on 83 girls with AIS between the age of 12 and 14 years, and Cobb’s angles of between 20° and 90°, and 22 age-matched controls. Multiple measurements of each thoracic vertebra were obtained from the best sagittal and axial MRI cuts. Compared with the controls, the scoliotic spines had longer vertebral bodies between T1 and T12 in the anterior column and shorter pedicles with a larger interpedicular distance in the posterior column. The differential growth between the anterior and the posterior elements of each thoracic vertebra in the patients with AIS was significantly different from that in the controls (p < 0.01). There was also a significant positive correlation between the scoliosis severity score and the ratio of differential growth between the anterior and posterior columns for each thoracic vertebra (p < 0.01). Compared with age-matched controls, the longitudinal growth of the vertebral bodies in patients with AIS is disproportionate and faster and mainly occurs by endochondral ossification. In contrast, the circumferential growth by membranous ossification is slower in both the vertebral bodies and pedicles.