Frequency distribution in intraoperative stimulation-evoked EMG responses during selective dorsal rhizotomy in children with cerebral palsy-part 2: gender differences and left-biased asymmetry.

INTRODUCTION: Spinal reflexes reorganize in cerebral palsy (CP), producing hyperreflexia and spasticity. CP is more common among male infants, and gender might also influence brain and spinal-cord reorganization. This retrospective study investigated the frequency of higher-graded EMG responses elicited by electrical nerve-root stimulation during selective dorsal rhizotomy (SDR), prior to partial nerve- root deafferentation, considering not only segmental level and body side, but also gender. METHODS: Intraoperative neuromonitoring (IOM) was used in SDR to pinpoint the rootlets most responsible for exacerbated stimulation-evoked EMG patterns recorded from lower-limb muscle groups. Responses were graded according to an objective response-classification system, ranging from no abnormalities (grade 0) to highly abnormal (grade 4+), based on ipsilateral spread and contralateral involvement. Non-parametric analysis of data with repeated measures was primarily used in investigating the frequency distribution of these various EMG response grades. Over 7000 rootlets were stimulated, and the results for 65 girls and 81 boys were evaluated, taking changes in the composition of patient groups into account when considering GMFCS levels. RESULTS: The distribution of graded EMG responses varied according to gender, laterality, and level. Higher-graded EMG responses were markedly more frequent in the boys and at lower segmental levels (L5, S1). Left-biased asymmetry in higher-graded rootlets was also more noticeable in the boys and in patients with GMFCS level I. A close link was observed between higher-grade assessments and left-biased asymmetry. CONCLUSIONS: Detailed insight into the patient's initial spinal-neurofunctional state prior to deafferentation suggests that differences in asymmetrical spinal reorganization might be attributable to a hemispheric imbalance.

The inhalation effects of by-products from chlorination of heated indoor swimming pools on spinal development in pup mice.

INTRODUCTION: It has been postulated that swimming in heated indoor swimming pools in the first year of life is associated with the development of spinal deformity in children. We explored in pup mice whether exposure to certain disinfection by-products resulting from chlorination of heated pools would affect the future development of the spinal column. METHODS: Mice, from birth and for 28 consecutive days, were exposed to chemicals known to be created by disinfection by-products of indoor heated swimming pools. The study made use of a body fluid analogue and a chlorine source to recreate the conditions found in municipal pools. A cohort of 51 wild-type C57B6 mice, male and female, were divided into two groups: experimental (n = 29) and controls (n = 22). 24 mice were observed for 8 months (32 weeks), with 27 culled at 4 months (16 weeks). Serial CT scanning was used to assess the spines. RESULTS: Exposure to disinfection by-products resulted in an increase in the normal thoracic kyphotic spinal angle of the mice when compared with their controls at 10 weeks; experimental mice kyphosis range 35-82° versus 29-38° in controls. At 14 weeks the kyphosis of the experimental mice had reduced in size but never to that of the control group. CONCLUSION: We have demonstrated the ability to influence spinal development in pup mice through environmental factors and shown that the developmental deformity became evident only after a significant latent period.

Fully Automated Measurement of Cobb Angles in Coronal Plane Spine Radiographs.

Background/Objectives: scoliosis is a three-dimensional structural deformity characterized by lateral and rotational curvature of the spine. The current gold-standard method to assess scoliosis is the measurement of lateral curvature of the spine using the Cobb angle in coronal plane radiographs. The interrater variability for Cobb angle measurements reaches up to 10°. The purpose of this study was to describe and assess the performance of a fully automated method for measuring Cobb angles using a commercially available artificial intelligence (AI) model trained on over 17,000 images, and investigate its interrater/intrarater agreement with a reference standard. Methods: in total, 196 AP/PA full-spine radiographs were included in this study. A reference standard was established by four radiologists, defined as the median of their Cobb angle measurements. Independently, an AI-based software, IB Lab SQUIRREL (version 1.0), also performed Cobb angle measurements on the same radiographs. Results: after comparing the readers' Cobb angle end vertebrae selection to the AI's outputs, 194 curvatures were considered valid for performance assessment, displaying an accuracy of 88.58% in end vertebrae selection. The AI's performance showed very low absolute bias, with a mean difference and standard deviation of differences from the reference standard of 0.16° ± 0.35° in the Cobb angle measurements. The ICC comparing the reference standard and the AI's measurements was 0.97. Conclusions: the AI model demonstrated good results in the determination of end vertebrae and excellent results in automated Cobb angle measurements compared to radiologists and could serve as a reliable tool in clinical practice and research.

The Influence of Bilateral and Unilateral Flat Foot on Coronal Spinopelvic Alignment in Asymptomatic Young Healthy Males.

BACKGROUND: This cross-sectional retrospective study aimed to present the influence of unilateral and bilateral flatfoot on coronal spinopelvic alignment in asymptomatic young healthy males. METHODS: It was carried out by examining the medical reports of individuals who apply to the National Health Board to work in positions requiring physical fitness between January 2018 and January 2019. Plain radiographies of the feet, pelvis, and spine were analyzed. Calcaneal pitch angle (CPA) for flatfoot, pelvic obliquity (PO), and Cobb angle (CA) for spinal asymmetry was measured. After all analyzes were completed, participants divided into 2 groups as unilateral (UniFF) or bilateral (BiFF) flatfoot, depending on the CPA measurements and compared. RESULTS: There was no statistically significant difference in age (p= .609). The UniFF group showed higher values in terms of BMI with a statistically significant difference (p= .01). The curve patterns identified as single thoracal, lumbal and double. Post hoc analyses suggests that males without spinal asymmetry were more likely to have unilateral flatfoot (p< .008). There were statistically significant differences between groups in PO and CA (p< .05). The effect size was found small to medium effect for PO and medium to large for CA. CONCLUSIONS: In conclusion, young males with bilaterally increased foot pronation demonstrate more increased pelvic obliquity and spinal curvature.

Idiopathic scoliosis: A pilot MR study of early vertebral morphological changes and spinal asymmetry.

Adolescent idiopathic scoliosis (AIS) a common spinal condition affecting adolescents. Though the etiology is still unknown, it is widely thought to have a multifactorial etiology and early diagnosis remains a significant challenge. The purpose of this study is to identify early vertebral morphological changes and patterns of spinal asymmetry in these at-risk individuals who later progress to adolescent idiopathic scoliosis. This was a retrospective study of patients treated for AIS between 1997 and 2017. We utilized two study groups, a group with immature onset of spinal asymmetry and a control group. Inclusion criteria for the immature onset group was defined by a Cobb angle between 10 and 40° diagnosed prior to the age of 12 with MRI scans and XRs available for review. Qualitative assessments observed for sagittal vertebral wedging, analysis of vertebral corner anatomy, spinal harmony, and sagittal balance. These findings were then qualitatively compared between groups. Twenty patients were included in this study, ten each in the immature onset and control groups. In the immature onset group, two patients had sagittal wedging, five had abnormal vertebral corners, nine did not have spinal harmony, and nine had negative sagittal balance, compared to none of the control patients having sagittal wedging, none having abnormal vertebral corners, all having spinal harmony, and nine having positive spinal balance. This pilot MRI study identifies qualitative vertebral morphological changes in patients who progress to AIS. Our findings suggest abnormal vertebral corner anatomy, sagittal wedging, and negative sagittal balance as potential early findings in patients who develop AIS.