Volumetric changes in cerebellar regions in adolescent idiopathic scoliosis compared with healthy controls

Abstract

Background context: Adolescent idiopathic scoliosis (AIS) is a three-dimensional spinal deformation that affects adolescents, especially girls. The etiopathogenesis of this disease remains uncertain, and studies have been carried out to understand its cause and related organs. Previous studies suggest that AIS is probably related to the cerebellum dysfunction, which could also be related to the abnormality in morphology of the cerebellum.

Purpose: The purpose of the study is to investigate the relationship between AIS and the volume and morphology of cerebellum.

Study design/setting: The study design of the cerebellum segmentation and volume quantification involved the following four steps: whole-brain normalization, cerebellum isolation, mapping with the statistical cerebellum template, and cerebellum regional volume correction.

Patient sample: In particular, high-resolution T1-weighted magnetic resonance images of 50 AIS patients with the right-thoracic curves (ie, Cobb angle ≥20°) and 40 age-matched normal controls were acquired. The exclusion criteria included history of head injury, back injury, severe headache, weakness or numbness in any limbs, urinary incontinence, nocturnal enuresis, and any space-occupying lesion found on magnetic resonance (MR) images.

Outcome measures: The AIS subjects were all with moderate-to-severe curves (ie, Cobb angle ≥20°) (9 moderate and 41 severe; mean Cobb angle 48.7°, range 20°-90°).

Methods: The cerebellum was parcellated to 28 regions by mapping with a well-recognized probabilistic MR cerebellum atlas. Student t test of each cerebellar region and the correction for multiple comparisons were performed.

Results: The volumes of four regions, namely right VIIIa, right VIIIb, left X, and right X, were significantly increased by approximately 7.43% to 8.25% in the AIS compared with the control group. Statistically, the results suggested that the cerebellar volume in AIS patients was larger compared with normal controls in the cerebellum regions of prepyramidal-prebiventer and intrabiventer fissures, intrabiventer and secondary fissures, and floccular-nodular (X)-posterolateral fissure to the inferior hemispheric margin.

Conclusions: The functions of the affected regions involve motor control, somatosensory, working memory, language, and response to visual stimulation. We conclude that the volume difference could be compensatory consequences in the central nervous system because of the persistent effort in AIS patients to maintain the body balance given the asymmetric spine.

Keywords: Adolescent idiopathic scoliosis; Cerebellum; Vestibular system.