A new approach to corpus callosum anomalies in idiopathic scoliosis using diffusion tensor magnetic resonance imaging

The effect of Schroth Best Practice exercises and Cheneau brace treatment on perceptual and cognitive asymmetry in adolescent idiopathic scoliosis with thoracic major curve

BACKGROUND

Adolescent idiopathic scoliosis (AIS) patients have been found to exhibit cortical asymmetry. Although asymmetries in cortical structures have been found in patients with AIS, there has been no research on how conservative treatments affect cerebellar functional organization.

AIMS

This study aimed to examine the impact of conservative treatments on perceptual and cognitive asymmetry in the auditory system assessed by dichotic listening in AIS patients with thoracic major curves.

METHOD

This study involved 30 AIS patients and 21 healthy subjects. The intervention group used a Cheneau brace and performed 18 Schroth Best Practice (SBP) exercise sessions. Auditory lateralization was assessed using the Dichotic Listening Paradigm (DLP) in both groups before and after the intervention.

RESULTS

The 6-week intervention resulted in a significant increase in left ear responses in the force-left condition in the AIS (p < 0.05). Left ear responses were lower in AIS at baseline (p < 0.05). The results at week 6 were similar in all conditions (p > 0.05).

CONCLUSION

The results of this study demonstrated that SBP exercises and Cheneau brace treatment can improve perceptual and cognitive asymmetry in the auditory system in AIS patients with thoracic major curve. Scoliosis-associated changes in the spine and postural control may affect auditory perception by causing adaptations in sensory and motor networks. Future studies are needed to examine the connectivity in brain regions related to motor control and auditory processing after conservative treatment.

TRIAL REGISTRATION

Clinical trials number: NCT06141759.

The hindbrain and cortico-reticular pathway in adolescent idiopathic scoliosis

AIM

To characterise the corticoreticular pathway (CRP) in a case-control cohort of adolescent idiopathic scoliosis (AIS) patients using high-resolution slice-accelerated readout-segmented echo-planar diffusion tensor imaging (DTI) to enhance the discrimination of small brainstem nuclei in comparison to automated whole-brain volumetry and tractography and their clinical correlates.

MATERIALS AND METHODS

Thirty-four participants (16 AIS patients, 18 healthy controls) underwent clinical and orthopaedic assessments and brain magnetic resonance imaging (MRI) on a 3 T MRI machine. Automated whole-brain volume-based morphometry, tract-based spatial statistics analysis, and manual CRP tractography by two independent raters were performed. Intra-rater and inter-rater agreement of DTI metrics from CRP tractography were assessed by intraclass correlation coefficient. Normalised structural brain volumes and DTI metrics were compared between groups using Student's t-tests. Linear correlation analysis between imaging parameters and clinical scores was also performed.

RESULTS

AIS patients demonstrated a significantly larger pons volume compared to controls (p=0.006). Significant inter-side CRP differences in mean (p=0.02) and axial diffusivity (p=0.01) were found in patients only. Asymmetry in CRP fractional anisotropy significantly correlated with the Cobb angle (p=0.03).

CONCLUSION

Relative pontine hypertrophy and asymmetry in CRP DTI metrics suggest central supranuclear inter-hemispheric imbalance in AIS, and support the role of the CRP in axial muscle tone. Longitudinal evaluation of CRP DTI metrics in the prediction of AIS progression may be clinically relevant.

Cerebral White Matter Connectivity in Adolescent Idiopathic Scoliosis: A Diffusion Magnetic Resonance Imaging Study

Adolescent idiopathic scoliosis (AIS) is characterized by the radiographic presence of a frontal plane curve, with a magnitude greater than 10° (Cobb technique). Diffusion MRI can be employed to assess the cerebral white matter. The aim of this study was to analyze, by means of MRI, the presence of any alteration in the connectivity of cerebral white matter in AIS patients. In this study, 22 patients with AIS participated. The imaging protocol consisted in T1 and diffusion-weighted acquisitions. Based on the information from one of the diffusion acquisitions, a whole brain tractography was performed with the MRtrix tool. Tractography is a method to deduce the trajectory of fiber bundles through the white matter based on the diffusion MRI data. By combining cortical segmentation with tractography, a connectivity matrix of size 84 × 84 was constructed using FA (fractional anisotropy), and the number of streamlines as connectomics metrics. The results obtained support the hypothesis that alterations in cerebral white matter connectivity in patients with adolescent idiopathic scoliosis (AIS) exist. We consider that the application of diffusion MRI, together with transcranial magnetic stimulation neurophysiologically, is useful to search the etiology of AIS.

Investigation of the perceptual and cognitive asymmetry in the auditory system in patients with adolescent idiopathic scoliosis

BACKGROUND

Studies have shown that perceptual and cognitive asymmetries are present in the auditory system in patients with adolescent idiopathic scoliosis (AIS). The Dichotic Listening (DL) paradigm was formerly performed in non-forced (NF) conditions only, and no study has examined the conditions of attention to one ear.

OBJECTIVE

To investigate the perceptual and cognitive asymmetry in the auditory system in patients with AIS as well as the asymmetry changes according to the curvature characteristics of patients with AIS.

METHOD

The DL paradigm was performed on 38 patients with AIS and 10 healthy individuals in all conditions (NF, Forced Right [FR], Forced Left [FL]).

RESULTS

In the NF and FL conditions, the mean number of correct responses for the left ear was significantly lower in patients with AIS than in healthy individuals (p < 0.05). The correct responses for the right ear in the NF condition, right and left ear in the FR condition, and right ear in the FL condition did not show a significant difference between the groups (p > 0.05). Also, there was no difference between patients with AIS with both functional 3-curve and 4-curve (p > 0.05).

CONCLUSION

Our study indicates perceptual and cognitive asymmetry or lateralisation in the auditory system in patients with AIS. The asymmetry might be caused by the inability to direct their attention to the left ear, which is not affected by their curvature type. Further studies are needed to investigate perceptual and cognitive asymmetry behaviour models in the auditory system in patients with AIS.

CLINICAL IMPLICATIONS

Determination of perceptual and cognitive asymmetry in the auditory system may offer a new perspective on conservative treatment protocols for AIS patients. Besides, the DL paradigm can be easily used in patients with AIS as a non-invasive evaluation method in clinics.

Relationship Between Electromyographic Frequency of the Erector Spinae and Location, Direction, and Number of Spinal Curvatures in Children with Scoliotic Changes

INTRODUCTION

The aim of the study was to assess the relationship between erector spinae electromyographic frequency (SEMG) and the location, direction and number of spinal curvatures in children with scoliotic changes.

METHODS

Analysis comprised 103 (42,21%) children with scoliosis and 141 (57.79%) with scoliotic posture. Body posture and the spine were examined using the Diers formetric III 4D optoelectronic method. Electromyographic analysis was performed using a 14-channel Noraxon TeleMyo DTS apparatus.

RESULTS

In girls, the highest mean SEMG frequency of the erector spinae, calculated from 16 measurements, occurred in the case of scoliotic posture (Mean = 73.69 Hz), while in boys, the greatest values were noted for scoliosis (Mean = 79.75 Hz). There was a significant correlation between erector spinae SEMG frequency and curvature location, both in the scoliosis group (p = 0.003) and in the group with scoliotic posture (p = 0.04). There was also a significant correlation between SEMG frequency of the erector spinae and direction of the curvature, both in the scoliosis (p = 0.01) and scoliotic posture groups (p = 0.04), as well as between the erector spinae SEMG frequency and the number of spinal curvatures (scoliosis group: p = 0.03; scoliotic posture group: p = 0.03).

CONCLUSION

The study is of applicative value and fills the gap in research on erector spinae SEMG frequency of in low-grade scoliosis among small children. Our research can also be used in research on the etiology and progression scoliosis. Visible disturbances in the erector spinae SEMG frequency (activity and tension) contribute to the development of curvature and testify to the fact that these changes are the primary cause of idiopathic scoliosis. Scoliosis is merely a symptom, an external expression of CNS dysfunction that is not fully recognised. It is also visible on the SEMG record of postural muscles. Our objective is to contribute to creating a future model record for SEMG of the postural muscles, characteristic for children with scoliosis. Then, based on electromyographic examination, it will be possible to identify initial symptoms of scoliosis and start preventive rehabilitation before irreversible bone changes occur.

Altered White Matter Microstructure in the Corpus Callosum and Its Cerebral Interhemispheric Tracts in Adolescent Idiopathic Scoliosis: Diffusion Tensor Imaging Analysis

BACKGROUND AND PURPOSE

Neural system was one of the important contributors to the etiopathogenesis of adolescent idiopathic scoliosis; additionally, the morphology of corpus callosum interconnecting both hemispheres of the brain was found to be altered morphologically. Our aim was to evaluate and compare the microstructural changes of the corpus callosum and its interhemispheric white matter fiber tracts interconnecting both cerebral hemispheres in patients with adolescent idiopathic scoliosis and matched controls using diffusion tensor imaging.

MATERIALS AND METHODS

Brain DTI was performed in 69 patients with adolescent idiopathic scoliosis (female, right thoracic/thoracolumbar curve) and 40 age-matched controls without adolescent idiopathic scoliosis (female). 2D and 3D segmentation of the corpus callosum were performed using a region-growing method, and the corpus callosum was further divided into 6 regions, including the rostrum, genu, anterior and posterior midbodies, isthmus, and splenium. The laterality index was calculated to quantify the asymmetry of the corpus callosum. Interhemispheric fiber tractography were performed using the Brodmann atlas.

RESULTS

2D ROI analysis revealed reduced fractional anisotropy in the genu and splenium (P = .075 and P = .024, respectively). Consistently reduced fractional anisotropy on the left sides of the genu and splenium was also found in 3D ROI analysis (P = .03 and P = .012, respectively). The laterality index analysis revealed a pseudo-right lateralization of the corpus callosum in adolescent idiopathic scoliosis. Interhemispheric fibers via the splenium interconnecting Brodmann 3, 1, and 2; Brodmann 17; and Brodmann 18 (corresponding to the primary somatosensory cortex and primary and secondary visual cortices) were also found to have reduced fractional anisotropy (P ≤ .05).

CONCLUSIONS

Reduced fractional anisotropy was found in the genu and splenium of the corpus callosum and corresponding interhemispheric fiber tracts interconnecting the somatosensory and visual cortices via the splenium. Our results are suggestive of altered white matter microstructure within the brain of those with adolescent idiopathic scoliosis, which could be related to abnormal brain maturation during adolescence in adolescent idiopathic scoliosis and could possibly explain the previously documented somatosensory function impairment and visuo-oculomotor dysfunction in this condition.

Diffusion Tensor Imaging Shows Corpus Callosum Differences between High-Grade Gliomas and Metastases

BACKGROUND AND PURPOSE

The corpus callosum (CC) has an important role in regulating interhemispheric transfer and is thought to be instrumental in contralateral brain reorganization in patients with brain tumors, as suggested by a previous study reporting callosal differences between language dominance groups through diffusion tensor imaging (DTI) characteristics. The purpose of this study was to explore the structural differences in the CC between high-grade gliomas (HGGs) and metastatic tumors (METs) using the DTI characteristics of fractional anisotropy (FA), mean diffusivity (MD), and axial diffusivity (AD).

METHODS

HGG (n = 30) and MET (n = 20) subjects with Magnetic Resonance Imaging (MRI) scans including DTI were retrospectively studied. The tumor and CC were segmented using the 3-dimensional T1-weighted scans to determine their volumes. The region of interest (ROI; mean volume of the ROI = 3,090 ± 464 mm³ ) of the body of the CC was overlaid onto the DTI parametric maps to obtain the averaged FA, MD, and AD values.

RESULTS

There were significant differences in the distributions of FA and MD values between the two patient groups (mean FA for HGG/MET = .691/.646, P < .05; mean MD for HGG/MET = .894×10-3 mm 2/ second /.992×10-3 mm² /second, P < .01), while there was no correlation between the DTI parameters and the anatomical volumes.

CONCLUSION

These results suggest that there is more contralateral brain reorganization in HGG patients than MET patients and that neither the tumor nor callosal volume impact the degree of contralateral brain reorganization.

Adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is the most common form of structural spinal deformities that have a radiological lateral Cobb angle - a measure of spinal curvature - of ≥10(°). AIS affects between 1% and 4% of adolescents in the early stages of puberty and is more common in young women than in young men. The condition occurs in otherwise healthy individuals and currently has no recognizable cause. In the past few decades, considerable progress has been made towards understanding the clinical patterns and the three-dimensional pathoanatomy of AIS. Advances in biomechanics and technology and their clinical application, supported by limited evidence-based research, have led to improvements in the safety and outcomes of surgical and non-surgical treatments. However, the definite aetiology and aetiopathogenetic mechanisms that underlie AIS are still unclear. Thus, at present, both the prevention of AIS and the treatment of its direct underlying cause are not possible.