Idiopathic adolescent scoliosis and obesity: prevalence study.

PURPOSE: Adolescent idiopathic scoliosis (AIS) is a three-dimensional spinal deformity that affects 5% of the population. This pathology has multiple known etiological factors such as family predisposition, female gender, low body mass index, decrease in lean and fat masses. However, recent studies suggest that ciliary dysfunction could be the origin of certain types of obesity and AIS. This study aims to verify the existence of a link between these two pathologies. METHODS: A retrospective, cross-sectional, descriptive and monocentric study, based on a cohort of adolescents with obesity treated in a paediatric rehabilitation centre for specific care between 1 January 2010 and 1 January 2019. The prevalence of AIS was calculated by radiographic measurements. The diagnosis of AIS was established if the Cobb angle was ≥ 10°, associated with intervertebral rotation. RESULTS: 196 adolescents with obesity were included in the study (mean age 13.2 years, mean BMI 36 kg/cm2, gender ratio 2.1 of female to male.) The prevalence of AIS in adolescents with obesity was 12.2%, twice the prevalence of AIS in the general population. The characteristics of AIS in adolescents with obesity are predominantly female, 58.3% left thoracolumbar or lumbar principal curvatures, mean Cobb angle 26° and progressive in 29% of cases. CONCLUSIONS: Our study established a correlation between AIS and obesity with a higher prevalence than in the general population. The morphology of these adolescents makes screening for AIS more difficult.

Is self-image, in reference to the gravitational vertical, altered in adolescent idiopathic scoliosis? A multicenter, single-blind, case-control study.

PURPOSE: Adolescent idiopathic scoliosis (AIS) is associated with perturbation of orthostatic postural control. In humans, orthostatic postural control is organized around the gravitational vertical (GV). Perception of the GV involves a bottom-up process (central integration of multisensorial information) and a top-down process that uses cognitive mechanisms relying on body image. This study hypothesized that AIS would be associated with an erroneous central representation of verticality. The objective was to demonstrate an altered top-down process of sense of verticality in AIS. METHODS: This multicenter, single-blind, case-control study evaluated 63 adolescent girls with AIS divided into two groups (major AIS (n = 31) and minor AIS (n = 32)) and 30 matched non-scoliotic adolescents. Participants scored their perception of trunk appearance in an upright position using a pictographic scale. The outcome measure was the difference between perception score and real trunk deformity. RESULTS: Participants with major AIS presented with misperception of their trunk appearance in an upright position when compared with those with minor AIS or controls. CONCLUSION: Adolescents with major AIS underestimate their trunk deformity in an upright position. This suggests an altered representation of body image, affecting top-down control of sense of verticality.

A perception bias of the gravitational vertical is confirmed in Adolescent Idiopathic Scoliosis.

PURPOSE: Adolescent Idiopathic Scoliosis (AIS) is the most frequent spine deformity in adolescence. The cause of AIS remains unknown. Several studies show that AIS can be associated with a perception bias of gravitational vertical. In particularly, AIS patients with a right thoracic convexity exhibit deviation of the Subjective Postural Vertical. The origin of this disturbance could be located in trunk proprioceptive graciveptors. We wanted to verify this result with a population of lumbar and thoracolumbar AIS with left convexity. METHODS: It was a multicenter, cross-sectional case-control study. Thirty adolescents with left lumbar or thoraco-lumbar AIS (age 14.3 ± 1.7 years; Cobb angle 27.6° ± 6.1°) and 30 controls matched for age (14.0 ± 1.5 years), were compared for Subjective Visual Vertical (SVV) measured in static and dynamic (optokinetic stimulation) conditions, and Subjective Postural Vertical (SPV). RESULTS: For SVV, there was no difference in the two groups, for static and dynamic conditions. The SPV was significantly different between the two groups (p < 0.0001). The SPV was shifted to the left for most of the AIS patients (med - 2.4°[- 3.6; - 1.7]) compared with controls (med 0°[- 0.5; 1.7]). Adolescents with AIS perceived verticality with significant greater uncertainty in postural modality than controls (p = 0.017). CONCLUSION: Our study confirms a significant directional bias in the orientation of SPV in left lumbar or thoraco-lumbar AIS. This confirmation paves the way to a new physiopathological model focused on trunk proprioception. LEVEL OF EVIDENCE: III.

Do Adolescents With Idiopathic Scoliosis Have an Erroneous Perception of the Gravitational Vertical?

STUDY DESIGN: Multicenter, case-control study. OBJECTIVES: Demonstrate altered perception of verticality in AIS compared with matched controls. SUMMARY OF BACKGROUND DATA: The cause of adolescent idiopathic scoliosis (AIS) remains to be found. AIS is associated with neurosensorial anomalies, in particular, altered control of orthostatic posture. During kinetic activity, the upright posture, in humans, is determined in reference to the gravitational vertical (GV). We hypothesized that in AIS, there is a discordance in the perception of the GV and the true GV. In AIS, the longitudinal axis of the body would thus be misoriented because of an erroneous perception of the GV. METHODS: Thirty adolescents with right thoracic AIS (age 14.23 ± 1.75 years; Cobb angle 31.97°± 12.83°) and 30 controls matched for age (13.93 ± 1.85 years), body mass index, Tanner stage, and handedness were compared for subjective visual vertical (SVV) measured in static and dynamic (optokinetic stimulation) conditions, and subjective postural vertical (SPV). RESULTS: There was no difference in the two groups, AIS and controls, for SVV. The SPV was significantly different between the two groups (p = .00023). The SPV was shifted to the right for most of the AIS patients (2.13°± 2.22°) compared with controls (-0.08°±1.40°). There was a significant correlation between SPV and clinical frontal tilt in the AIS patients. CONCLUSION: Our findings demonstrate that patients with right thoracic AIS have an erroneous perception of the GV. In most AIS patients, SPV was shifted to the right, with no alteration of the SVV. AIS might be the consequence of a reoriented longitudinal body axis aligned with an erroneous vertical reference. The underlying mechanism might involve dysfunction of trunk graviceptors. The primary or secondary nature of this dysfunction remains an open question.

Clinical balance tests, proprioceptive system and adolescent idiopathic scoliosis.

PURPOSE: Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spinal column of unknown etiology. Multiple factors could be involved, including neurosensory pathways and, potentially, an elective disorder of dynamic proprioception. The purpose of this study was to determine whether routine balance tests could be used to demonstrate an elective alteration of dynamic proprioception in AIS. METHODS: This was a multicentre case-control study based on prospectively collected clinical data, in three hospitals pediatric, with spine consultation, from January 2013 through April 2015. From an original population of 547 adolescents, inclusion and non-inclusion criteria indentified 114 adolescents with right thoracic AIS (mean age 14.5 ± 1.9 years, Cobb angle 35.7 ± 15.3°) and 81 matched adolescents without scoliosis (mean age 14.1 ± 1.9 years). Participants performed three routine clinical balance tests to assess the static and dynamic proprioception: the Fukuda-Utenberger stepping test (angle of rotation in degrees and distance of displacement in cm) to assess dynamic balance; the sharpened Romberg test and the unipedal stance test (eyes closed) to assess static balance. RESULTS: There was no significant difference between AIS subjects and controls for the static tests, but there was a significant difference for the dynamic test for both measures: distance of displacement (p < 0.01) and angle of rotation (p < 0.0001). This result confirms our initial these: the dynamic proprioception is altered electively in AIS. CONCLUSION: These findings confirm recent AIS studies. Our results might be related to immature central integration of dynamic proprioceptive input leading to a poorly adapted motor response, particularly for postural control of the, in AIS. These balance tests can be performed in routine practice. Their validity as a biomarker for screening and monitoring purposes should be assessed.

Cervicocephalic relocation test to evaluate cervical proprioception in adolescent idiopathic scoliosis.

PURPOSE: Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spine associated with disturbed postural control. Cervical proprioception participates in controlling orthostatic posture via its influence on head stabilization. We hypothesized that patients with AIS exhibit altered cervical proprioception. METHODS: We conducted a case-control study to evaluate cervical proprioception using the cervicocephalic relocation test (CRT) in 30 adolescents with AIS (15.5 ± 1.5 years; Cobb 24.8° ± 9.5°) versus 14 non-scoliotic controls (14.6 ± 2.0 years). CRT evaluates cervical proprioception by measuring the capacity to relocate the head on the trunk after active rotation of the head in the transversal plane without visual control. Each subject performed ten right and then ten left head rotations. RESULTS: The CRT results were pathological in 12 AIS patients (40 %). The CRT mean was significantly different between AIS patients with a pathological CRT (5° ± 1.4° for right rotation; 4.2° ± 0.9° for left rotation) compared with AIS patients with a normal CRT (2.7° ± 0.6° for right rotation; 2.9° ± 0.8° for left rotation) or with the control group (3.5° ± 2.1° for right rotation; 3.1° ± 1.2° for left rotation). CONCLUSION: Cervical proprioception is impaired in certain AIS patients. This anomaly may worsen the prognosis of AIS (headache; balance disorders; worsened spinal deformity; complication after spinal fusion). We recommend systematic screening for altered cervical proprioception in AIS patients.

Usefulness of intra-articular botulinum toxin injections. A systematic review.

Botulinum toxin is a proven and widely used treatment for numerous conditions characterized by excessive muscular contractions. Recent studies have assessed the analgesic effect of botulinum toxin in joint pain and started to unravel its mechanisms. LITERATURE-SEARCH-METHODOLOGY: We searched the international literature via the Medline database using the term "intraarticular botulinum toxin injection" combined with any of the following terms: "knee", "ankle", "shoulder", "osteoarthritis", "adhesive capsulitis of the shoulder". RESULTS: Of 16 selected articles about intraarticular botulinum toxin injections, 7 were randomized controlled trials done in patients with osteoarthritis, adhesive capsulitis of the shoulder, or chronic pain after joint replacement surgery. Proof of anti-nociceptive effects was obtained in some of these indications and the safety and tolerance profile was satisfactory. The studies are heterogeneous. The comparator was usually a glucocorticoid or a placebo; a single study used hyaluronic acid. Pain intensity was the primary outcome measure. DISCUSSION-CONCLUSION: The number of randomized trials and sample sizes are too small to provide a satisfactory level of scientific evidence or statistical power. Unanswered issues include the effective dosage and the optimal dilution and injection modalities of botulinum toxin.

Evaluation of motion sickness susceptibility by motion sickness susceptibility questionnaire in adolescents with idiopathic scoliosis: a case-control study.

PURPOSE: Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spine, with unknown origin. Some studies have noted impaired postural balance in AIS, in particular, difficulty to manage situations with sensory conflict. The motion sickness susceptibility can be secondary to a sensory conflict, for example, between visual and vestibular information. Our hypothesis is: patients with AIS have difficulty in managing situations with sensory conflict and therefore have increased motion sickness susceptibility. The purpose of this study was to evaluate in AIS subjects by evaluating their susceptibility to motion sickness, as compared to a control group. METHODS: We conducted an analysis of data on motion sickness susceptibility collected prospectively from 2012, with the B score of motion sickness susceptibility questionnaire. This evaluation was completed for 65 adolescents (age 14.5 ± 1.6 year) with major right thoracic AIS (Cobb = 40.7° ± 13.1°) and 71 matched controls (14.6 ± 1.6 year). RESULTS: Adolescents with major right thoracic AIS were more susceptible to motion sickness (B score = 5.3 ± 5.8) than controls (B score = 3.4 ± 3.7) with significant difference (p = 0.025). CONCLUSIONS: We interpret our results suggesting there is difficulty for patients with AIS to manage situations with sensory conflict. Previous studies focusing on situations with sensory conflict in AIS have required sophisticated technology. They are not accessible for routine patient management. Our research shows the same result with simple, non invasive, low-cost and quick method: B score of motion sickness susceptibility questionnaire.

Eye-hand laterality and right thoracic idiopathic scoliosis.

PURPOSE: The adolescent idiopathic scoliosis (AIS) pathogenesis remains unknown. Certain studies have shown that there is a correlation between manual laterality and scoliotic deviation. A full study of manual laterality needs to be paired with one for visual dominance. With the aim of physiopathological research, we have evaluated the manual and visual laterality in AIS. METHODS: A retrospective study from prospective data collection is used to evaluate the distribution of eye-hand laterality (homogeneous or crossed) of 65 right thoracic AIS (mean age 14.8 ± 1.8 years; mean Cobb angle: 32.8°) and a control group of 65 sex and age-matched (mean age 14.6 ± 1.8 years). The manual laterality was defined by the modified Edinburgh Handedness Inventory. The evaluation of the visual laterality is done using three tests (kaleidoscope test, hole-in-the-card test, distance-hole-in-the-card test). RESULTS: The group of right thoracic AIS presents a significantly higher frequency of crossed eye-hand laterality (63 %) than the control group (63 vs. 29.2 %; p < 0.001). In the AIS group, the most frequent association, within crossed laterality is "right hand dominant-left eye dominant" (82.9 %). There is no relationship with the Cobb angle. CONCLUSIONS: Those with right thoracic AIS show a higher occurrence of crossed eye-hand laterality. This could point physiopathological research of AIS towards functional abnormality of the optic chiasma through underuse of cross visual pathways, and in particular accessory optic pathways. It would be useful to explore this by carrying out research on AISs through neuroimaging and neurofunctional exploration.

Chronic neck pain and masticatory dysfunction.

Chronic nonspecific neck pain is a common problem in rheumatology and may resist conventional treatment. Pathophysiological links exist between the cervical spine and masticatory system. Occlusal disorders may cause neck pain and may respond to dental treatment. The estimated prevalence of occlusal disorders is about 45%, with half the cases being due to functional factors. Minor repeated masticatory dysfunction (MD) with craniocervical asymmetry is the most common clinical picture. The pain is usually located in the suboccipital region and refractory to conventional treatment. The time pattern may be suggestive, with nocturnal arousals or triggering by temporomandibular movements. MD should be strongly suspected in patients with at least two of the following: history of treated or untreated MD, unilateral temporomandibular joint pain and clicking, lateral deviation during mouth opening, and limitation of mouth opening (less than three fingerbreadths). Rheumatologists should consider MD among causes of neck pain, most notably in patients with abnormal craniocervical posture, signs linking the neck pain to mastication, and clinical manifestations of MD. Evidence suggesting that MD may cause neck pain has been published. However, studies are needed to determine whether treatment of MD can relieve neck pain.

The ability to change of three questionnaires for neck pain.

OBJECTIVE: To assess the sensitivity to change of three algofunctional scales for neck pain. METHODS: Observational, prospective study. Patients with neck disorders were included. Pain and patients' perceived handicap assessed on visual analogue scales (VAS Pain, VAS Handicap), and functional disability measures (Neck Disability Index, Neck Pain and Disability Scale, Northwick Park Neck Pain Questionnaire) were recorded twice, at baseline and at an 11-month follow-up assessment. Sensitivity to change was assessed using the effect size (ES) and the standardised response mean (SRM), and the non-parametric Spearman's rank correlation coefficient (r) was used to assess the correlation between quantitative variable changes and patients' overall opinion. Analysis of variance (ANOVA) followed by a Tukey-test was performed to determine if the scales distinguished improved, stable, and deteriorated patients. RESULTS: Seventy-one patients (43 women, mean age 49 years) were included and evaluated twice at an interval of 11 +/- 2 months. The three scales showed good sensitivity to change. The ANOVA showed a group effect, and individual changes in the scales scores were statistically different in two-by-two comparisons (improved, stable or deteriorated patients). Changes in NPDS scores had the highest correlation with patient's overall assessment (r = 0.592). CONCLUSION: The three scales can detect changes in patients with neck disorders. Changes in NPDS score had the best correlation with patients' overall opinion concerning their neck disorder and this questionnaire should be given preference in clinical trials.

French translation and validation of 3 functional disability scales for neck pain.

OBJECTIVE: To translate and assess the reliability and the construct validity of 3 functional disability scales for neck pain. DESIGN: Reliability and validity study. SETTING: Tertiary care teaching hospital and outpatient clinic. PARTICIPANTS: One hundred one patients (mean age, 49 y). INTERVENTION: French translations were obtained by using the "translation-backward translation" method. Adaptations were made after a pilot study. MAIN OUTCOME MEASURES: Impairment outcome measures (visual analog scale [VAS] pain, neck range of motion, morning stiffness, score of neck sensitivity, radiologic score of Kellgren) and patients' perceived handicap (VAS) were recorded at the baseline visit. Three functional disability scales (Neck Disability Index [NDI], Neck Pain and Disability Scale [NPDS], Northwick Park Neck Pain Questionnaire [NPQ]) were recorded twice, at baseline visit and 24 hours later. Reliability was assessed by using the intraclass correlation coefficient (ICC) and the Bland and Altman method. Construct (convergent and divergent) validity was investigated by using the Spearman rank correlation coefficient and a factor analysis was performed. RESULTS: Test-retest was excellent for the NPDS and NDI (ICC =.91,.93, respectively) and good for the NPQ (ICC =.84). The Bland and Altman method showed no systematic trend. Expected convergent and divergent validity were observed only for the NPDS; 3 main factors were extracted by factor analysis and explained 78% of the cumulative variance. CONCLUSION: The 3 translated scales are valid, but the NPDS seems to have the best construct validity.