Morphological Asymmetry Research Articles

Neuroanatomical asymmetry in the canine brain.

The brains of humans and non-human primates exhibit left/right asymmetries in grey matter morphology, white matter connections, and functional responses. These asymmetries have been implicated in specialized behavioral adaptations such as language, tool use, and handedness. Left/right asymmetries are also observed in behavioral tendencies across the animal kingdom, suggesting a deep evolutionary origin for the neural mechanisms underlying lateralized behavior. However, it is still unclear to what extent brain asymmetries supporting lateralized behaviors are present in other large-brained animals outside the primate order. Canids and other carnivorans evolved large, complex brains independently and convergently with primates, and exhibit lateralized behaviors. Therefore, domestic dogs offer an opportunity to address this question. We examined T2-weighted MRI images of 62 dogs from 33 breeds, opportunistically collected from a veterinary MRI scanner from dogs who were referred for neurological examination but were not found to show any neuropathology. Volumetrically asymmetric regions of gray matter included portions of the temporal and frontal cortex, in addition to portions of the cerebellum, brainstem, and other subcortical regions. These results are consistent with the perspective that asymmetry may be a common feature underlying the evolution of complex brains and behavior across clades, and provide neuro-organizational information that is likely relevant to the growing field of canine behavioral neuroscience.

Ultrasound measures of muscle morphology in people with multiple sclerosis are associated with muscle performance and functional mobility.

Neurologically-based muscle weakness is a common symptom in people with multiple sclerosis MS (MS), who may also exhibit muscle morphology changes and intrinsic muscle dysfunction. Diagnostic ultrasound (sonography) is a non-invasive, inexpensive, and clinically feasible method to measure muscle morphology. The purpose of this study was to investigate possible asymmetries in lower limb muscle morphology and performance in people with MS, and to assess the relationships of muscle morphology measures with individual patient characteristics, muscle performance, and functional mobility. This cross-sectional study was conducted at the Washington, DC Veterans Affairs Medical Center. The study participants were 29 Veterans with MS (52% female, 79% African-American, 48.6 ± 11.2 years old, Mean Expanded Disability Status Scale: 3.6 ± 1.4) who completed seated knee extension isokinetic strength and power tests, functional assessments (Timed 25-Foot Walk - T25FW, 5-Times Sit-to-Stand - 5STS), and quantitative B-mode ultrasound image acquisition of the rectus femoris muscle to derive morphology measures (thickness and echogenicity). The limb with weaker knee extension strength was identified as the more-involved limb. Differences between the more and less-involved limb were quantified using a t-test for all muscle morphology and muscle performance measures. Relationships between muscle morphology and patient characteristics, muscle performance, and functional mobility were evaluated using bivariate and multivariate analyses. The rectus femoris thickness from the more-involved limb was lower (p<0.001) than that of the less-involved limb, whereas echogenicity was not different between the two limbs (p=0.147). Rectus femoris thickness of the more-involved limb was directly related to age (r=-0.63, p<0.001), muscle strength (r=0.53, p=0.003) and power (r=0.53, p=0.003), and gait speed (r=0.42, p=0.024); whereas its echogenicity was positively associated only with muscle strength (r=-0.46, p=0.013) and power (r=-0.50, p=0.006). Together rectus femoris thickness and echogenicity of the more involved limb explained 44% and 48% of the variance in muscle strength and power, respectively (p<0.001). This study supports the ability of sonography to measure muscle morphology in people with MS, identify asymmetries, and quantify associations with important clinical correlates. Compared with more invasive and costly alternatives, sonography is a clinically feasible, relatively low-cost tool that can be used to assess muscle morphology in people with MS. Further research is warranted to determine the potential clinical utility of sonographic measures of muscle morphology in evaluating changes due to disease progression or therapeutic interventions in this population.

Morphological asymmetry in two marine fish species Acanthopagrusarabicus (Family: Sparidae) and Planiliza klunzingeri (Family: Mugilidae), collected from brackish and freshwater environments in southern Iraq

Morphological asymmetry was analysed in two marine fish species Acanthopagrus arabicus and Planiliza klunzingeri, in brackish and freshwater habitats in southern Iraq. For both species, specimens from the Shatt al-Arab River and Shatt al-Basrah Canal exhibited greater asymmetry values for snout length. In both locations examined, the levels of asymmetry of the physical traits increased as the fish grew. The high levels of asymmetry in the two fish species may be linked to heavy metal pollutants in the two aquatic environments studied.

Supporting Data for Direct Observation of Seeded Conformational Conversion of hIAPP Reveals the Mechanisms for Morphological Dependence and Asymmetry of Fibril Growth

Supporting Data for Direct Observation of Seeded Conformational Conversion of hIAPP Reveals the Mechanisms for Morphological Dependence and Asymmetry of Fibril Growth

Stock Discrimination of Gilthead Seabream (Sparus aurata Linnaeus, 1758) through the Examination of Otolith Morphology and Genetic Structure

Reliable stock identification constitutes an integral component of effective fishery management. Current methods for the identification of putative stock units comprise the analysis of both phenotypic and genetic variability. The present study examined the spatial variation in otolith morphology (shape and asymmetry) and genetic composition of 395 wild-caught Gilthead seabream (Sparus aurata) specimens, collected from the Aegean and Ionian Seas (eastern Mediterranean) between 2014–2018. The degree of scale regeneration (SRD, % of regenerated scales) was used as an indicator to assess the potential presence of aquaculture escapees in the wild-caught samples. Otolith shape and asymmetry analyses showed a phenotypic discrimination between northwestern Aegean and Ionian Gilthead seabream populations. Genetic analyses of nine microsatellite markers revealed higher levels of genetic variation in the wild compared with samples obtained from aquaculture farms. Despite the absence of genetic structure among the wild-caught seabream populations, a low but statistically significant genetic differentiation was found between reared fish and fish collected in the field. The SRD was considered effective in detecting the presence of aquaculture escapees that may have escaped in either early or late rearing phases.

Somatic characteristic, morphological asymmetry and postural stability of youth male canoeists compared to control. A cross-sectional study.

To determine the relationships between selected morphological characteristics and the level of body composition asymmetry with postural stability among canoeists and a control group. The sample consisted of 43 males (21 canoeists 21.8±3.29 years and 22 university students 21.7±1.32 years). Measurements included body height and weight. Segmental body composition analysis was assessed using the bioelectrical impedance by determining: fat mass (FM, kg, %), fat-free mass (FFM, kg) and predicted muscle mass (PMM, kg). Postural stability was tested using the BIODEX Balance System. Anterior-posterior stability index (APSI), medial-lateral stability index (MLSI) and overall stability index (OSI) were calculated. Our findings suggest that the canoeists had statistically lower level of fatty tissue compared to controls. There was a statistically important difference between groups in lower limb FM (% and kg). In both groups morphological asymmetry was observed, but in most cases-in athletes. Asymmetries between right and left arms appeared in all parameters, while asymmetries between right and left legs were noted in all parameters except FM (kg). There were relationships between stature and body weight with postural stability in canoeists. Canoeists demonstrated better balance than controls, particularly in the APSI. For all stability indices, significant differences were observed between right and left legs across all participants. Athletes, with larger asymmetries or poorer balance, require more attention to improve performance and reduce the risk of overload injury. Future studies needed to develop sport-specific level of morphofunctional asymmetry which would be optimal for sport results and health as well.

Ultrasound Measures of Muscle Morphology in Multiple Sclerosis and its Relation to Patient Characteristics, Muscle Performance and Functional Mobility

Multiple sclerosis (MS) is an inflammatory disease impacting the central nervous system affecting approximately 2.5 million people worldwide. Morphological changes in muscle tissue, such as muscle size and quality, may result from weakness due to decreased mobility. This study aimed to investigate asymmetries in lower limb muscle morphology via sonography in people with MS and to quantify relationships of muscle morphology measures with individual patient characteristics, muscle performance, and functional mobility. Twenty-nine Veterans with MS (52% female, 79% African-American, 48.6 ± 11.2 years old, Expanded Disability Status Scale: 3.6 ± 1.4) underwent measurement of ultrasound-measured rectus femoris (RF) muscle morphology (thickness and echo intensity), muscle performance (knee extension strength and power), and functional mobility (Timed 25-Foot Walk, 5-Times Sit-to-Stand). The more-involved limb was identified with weaker knee extension strength. Differences between more and less-involved limb were quantified using a t-test for all muscle morphology and performance outcomes. Relationships between muscle morphology, patient characteristics, performance, and functional mobility were quantified using bivariate and multivariate analysis. The more-involved limb had significantly less RF thickness (p<0.001) than the less-involved limb, but echo intensity was not different between limbs (p=0.147). The more-involved RF thickness was significantly associated with age, muscle strength, power, and gait speed, while echo intensity was associated with only muscle strength and power. Normalized RF thickness has a positive association with knee extension torque at 60 deg/sec and 180 deg/sec (p=0.003,p=0.003) and gait speed (p=0.024), whereas the corrected echo intensity values had negative associations at 60 deg/sec and 180 deg/sec (p=0.013,p=0.006). Asymmetrical differences between RF thickness measured by ultrasound are consistent with muscle strength and power asymmetries. Deficiencies in the morphology of the RF were associated with patient characteristics, knee extension muscle performance, and functional mobility. Ultrasound is an important clinical assessment tool used to identify muscle morphology asymmetries in MS. Multiple sclerosis (MS) is an inflammatory disease impacting the central nervous system affecting approximately 2.5 million people worldwide. Morphological changes in muscle tissue, such as muscle size and quality, may result from weakness due to decreased mobility. This study aimed to investigate asymmetries in lower limb muscle morphology via sonography in people with MS and to quantify relationships of muscle morphology measures with individual patient characteristics, muscle performance, and functional mobility. Twenty-nine Veterans with MS (52% female, 79% African-American, 48.6 ± 11.2 years old, Expanded Disability Status Scale: 3.6 ± 1.4) underwent measurement of ultrasound-measured rectus femoris (RF) muscle morphology (thickness and echo intensity), muscle performance (knee extension strength and power), and functional mobility (Timed 25-Foot Walk, 5-Times Sit-to-Stand). The more-involved limb was identified with weaker knee extension strength. Differences between more and less-involved limb were quantified using a t-test for all muscle morphology and performance outcomes. Relationships between muscle morphology, patient characteristics, performance, and functional mobility were quantified using bivariate and multivariate analysis. The more-involved limb had significantly less RF thickness (p<0.001) than the less-involved limb, but echo intensity was not different between limbs (p=0.147). The more-involved RF thickness was significantly associated with age, muscle strength, power, and gait speed, while echo intensity was associated with only muscle strength and power. Normalized RF thickness has a positive association with knee extension torque at 60 deg/sec and 180 deg/sec (p=0.003,p=0.003) and gait speed (p=0.024), whereas the corrected echo intensity values had negative associations at 60 deg/sec and 180 deg/sec (p=0.013,p=0.006). Asymmetrical differences between RF thickness measured by ultrasound are consistent with muscle strength and power asymmetries. Deficiencies in the morphology of the RF were associated with patient characteristics, knee extension muscle performance, and functional mobility. Ultrasound is an important clinical assessment tool used to identify muscle morphology asymmetries in MS.

Supporting data for Direct Observation of Seeded Conformational Conversion of hIAPP Reveals the Mechanisms for Morphological Dependence and Asymmetry of Fibril Growth

Supporting data for Direct Observation of Seeded Conformational Conversion of hIAPP Reveals the Mechanisms for Morphological Dependence and Asymmetry of Fibril Growth

A large bubble around the AGB star R Dor detected in the UV

ABSTRACT Many asymptotic giant branch (AGB) and supergiant stars exhibit extended detached shells in the far-infrared, resembling rings or arcs. These structures have long been interpreted as the bow shock formed in the interface between the stellar wind and the interstellar medium (ISM), the astrosphere. To date, only a few AGB stars have been observed showing an extended shell in the ultraviolet (UV): the cometary tail drifting away from o Ceti, and a bubble around IRC+10216, CIT6, and U Hya. This paper describes a search of UV extended shells around AGB stars using archival Galaxy Evolution Explorer (GALEX) far-UV images. After inspecting visually 282 GALEX images, we identified the fourth discovery of a UV bubble around the AGB star R Dor. The bubble is seen as a 26 arcmin × 29 arcmin ring, corresponding to an actual diameter of 0.41 × 0.46 parsec2. The mass of the thin UV bubble is estimated to be ≃0.003 M⊙. The morphological asymmetry (less than ∼20 per cent) and brightness variations of this shell are uncorrelated with the stellar proper motion and thus they can rather be ascribed to inhomogeneities in the ISM. Archival Infrared Astronomical Satellite 60 and 100 μm images reveal that the bubble is filled with cold (i.e. ${\lesssim} 32$ K) dust. All UV bubbles known to date are limited to be within a distance ${\lesssim} 350$ pc and at high Galactic latitudes ($|b| \gtrsim 35^{\circ }$), which suggests that their detection is hampered in most cases by the strong UV interstellar extinction.

Architectural anatomy of the human tibialis anterior presents morphological asymmetries between superficial and deep unipennate regions.

The tibialis anterior muscle plays a critical role in human ambulation and contributes to maintaining the upright posture. However, little is known about its muscle architecture in males and females. One hundred and nine physically active males and females were recruited. Tibialis anterior muscle thickness, pennation angle, and fascicle length were measured at rest in both unipennate regions of both legs using real-time ultrasound imaging. A linear mixed model was used with muscle thickness, pennation angle, or fascicle length as the dependent variables. All models were carried out with and without total leg lean mass and shank length as covariates. Causal mediation analysis was computed to explore the effect of muscle thickness on the relationship between fascicle length and pennation angle. There were no significant differences between dominant and nondominant legs regarding muscle architecture. Muscle thickness and pennation angle were greater in the deep than the superficial unipennate region in males (1.9 mm and 1.1°, p < 0.001) and women (3.4 mm and 2.2°, p < 0.001). However, the fascicle length was similar in both regions for both sexes. The differences remained significant after accounting for differences in leg lean mass and shank length. In both regions, muscle thickness was 1-3 mm greater in males and superficial pennation angle 2° smaller in females (both, p < 0.001). After accounting for leg lean mass and shank length, sex differences remained for muscle thickness (1.6 mm, p < 0.05) and pennation angle (3.4°, p < 0.001) but only in the superficial region. In both regions, leg lean mass and shank-adjusted fascicle length were 1.4 mm longer in females than males (p < 0.05). The causal mediation analysis revealed that the estimation of fascicle length was positive, suggesting that a 10% increase in muscle thickness would augment the fascicle length, allowing a 0.38° pennation angle decrease. Moreover, the pennation angle increases in total by 0.54° due to the suppressive effect of the increase in fascicle length. The estimated mediation, direct, and total effects were all significantly different from zero (p < 0.001). Overall, our results indicate that the architectural anatomy of the tibialis anterior shows sexual dimorphism in humans. Tibialis anterior presents morphological asymmetries between superficial and deep unipennate regions in both sexes. Lastly, our causal mediation model identified a suppressive effect of fascicle length on the pennation angle, suggesting that increments in muscle thickness are not always aligned with increments in fascicle length or the pennation angle.

Contribution of Subradiant Plasmon Resonance to Electromagnetic Enhancement in Resonant Raman with Fluorescence Examined by Single Silver Nanoparticle Dimers

The spectral relationships between surface enhanced resonant Raman scattering (SERRS) and plasmon resonance observed in far field scattering cross are investigated using single silver nanoparticle dimers with focusing on the lowest energy (superradiant) plasmon resonance. We find that these relationships can be classified into two types. The first is SERRS spectral envelopes with spectral shapes similar to those of plasmon resonance spectra. The second is SERRS envelopes exhibiting higher energy shifts from the plasmon resonance spectra. These results are examined as an effect of degree of morphological asymmetry in dimers based on an electromagnetic (EM) mechanism. The analysis of the first and second types reveals that dipole-dipole and dipole-quadrupole coupled plasmon resonance (subradiant Fano resonance) respectively determine the EM enhancement. This mechanism is commonly important for the development of plasmonic nanostructures for various surface enhanced spectroscopies.

MORPHOLOGICAL ASYMMETRY OF ANTENNAE AND BEHAVIORAL ASYMMETRIES DURING GROOMING IN THE COCKROACH &lt;i&gt;PERIPLANETA AMERICANA&lt;/i&gt; L.

Animal behaviors are often characterized by behavioral asymmetry, or lateralization, which is caused in part by the morphological asymmetry of the body and/or brain. To test the hypothesis that functional asymmetry of grooming is connected with morphological asymmetry of the antennae in American cockroach Periplaneta americana, we measured the length of the antennae, scapus diameter, pedicel diameter and length, and segment’s diameter and length. The data obtained indicate statistically significant differences: segment length is greater on the left antennae, and segment width is greater on the right antennae, except for a short region near the base. Correlation analysis revealed the following relationships: longer right antenna corresponds to more time spent cleaning it; scapus diameter larger on the right antenna correlates with antenna cleaning frequency; asymmetry of flagellum segments has no effect on cleaning asymmetry. Presenting sex pheromone at a suprathreshold dose increased asymmetry of antennal grooming, while asymmetry for leg grooming was generally unchanged. Thus, the asymmetry of antennal grooming, resulting at least in part from morphological asymmetry, significantly changes in the presence of a biologically important olfactory stimulus, the sex pheromone.

Morphological Asymmetry of Antennae and Behavioral Grooming Asymmetries in the Cockroach Periplaneta americana L.

Morphological Asymmetry of Antennae and Behavioral Grooming Asymmetries in the Cockroach Periplaneta americana L.

Predation history has no effect on lateralized behavior in Brachyrhaphis rhabdophora.

Evolutionary biologists have grown increasingly interested in laterality, a phenomenon where bilaterally symmetrical organisms show a side bias in some trait. Lateralized behavior is particularly interesting because it is not necessarily tied to morphological asymmetry. What causes lateralized behavior remains largely unknown, although previous research in fishes suggest that fish might favor one eye over another to view potential food sources, mates, and to assess predation risk. Here we test the hypothesis that a history of predation risk predicts lateralized behavior in the livebearing fish Brachyrhaphis rhabdophora. To do this, we used a detour assay to test for eye bias when a focal fish approached various stimuli (predator, potential mate, novel object, and empty tank control). Contrary to our predictions, we found no differences in lateralized behavior between fish from populations that co-occurred with fish predators relative to those that do not co-occur with predators. In fact, we found no evidence for behavioral lateralization at all in response to any of the stimuli. We explore several possible explanations for why lateralized behavior is absent in this species, especially considering a large body of work in other livebearing fishes that shows that lateralized behavior does occur.

Three-dimensional non-kinematic simulation of the post-emergence evolution of bipolar magnetic regions and the Babcock-Leighton dynamo of the Sun

Context. The Babcock-Leighton flux-transport model is a widely accepted dynamo model of the Sun that can explain many observational aspects of solar magnetic activity. This dynamo model has been extensively studied in a two-dimensional (2D) mean-field framework in both kinematic and non-kinematic regimes. Recent three-dimensional (3D) models have been restricted to the kinematic regime. In these models, the surface poloidal flux is produced by the emergence of bipolar magnetic regions (BMRs) that are tilted according to Joy’s law. Aims. We investigate the prescription for emergence of a BMR in 3D non-kinematic simulations. In particular, we examine the effect of the radial extent of the BMR. We also report our initial results based on a cyclic Babcock-Leighton dynamo simulation. Methods. We extended a conventional 2D mean-field model of the Babcock-Leighton flux-transport dynamo into 3D non-kinematic regime, in which a full set of magnetohydrodynamic (MHD) equations are solved in a spherical shell using a Yin-Yang grid. The large-scale mean flows, such as differential rotation and meridional circulation, are not driven by rotationally constrained convection, but rather by the parameterized Λ-effect in this model. For the induction equation, we used a Babcock-Leighton α-effect source term by which the surface BMRs are produced in response to the dynamo-generated toroidal field inside the convection zone. Results. We find that in the 3D non-kinematic regime, the tilt angle of a newly-emerged BMR is very sensitive to the prescription for the subsurface structure of the BMR (particularly, its radial extent). Anti-Joy tilt angles are found unless the BMR is deeply embedded in the convection zone. We also find that the leading spot tends to become stronger (higher field strengths) than the following spot. The anti-Joy’s law trend and the morphological asymmetry of the BMRs can be explained by the Coriolis force acting on the Lorentz-force-driven flows. Furthermore, we demonstrate that the solar-like magnetic cycles can be successfully obtained if Joy’s law is explicitly given in the Babcock-Leighton α-effect. In these cyclic dynamo simulations, a strong Lorentz force feedback leads to cycle modulations in the differential rotation (torsional oscillation) and meridional circulation. The simulations, however, do not include radiative effects (e.g., enhanced cooling by faculae) that are required to properly model the torsional oscillations. The non-axisymmetric components of the flows are found to exist as inertial modes such as the equatorial Rossby modes.

Exploring the emergence of morphological asymmetries around the brain's Sylvian fissure: a longitudinal study of shape variability in preterm infants.

Brain folding patterns vary within the human species, but some folding properties are common across individuals, including the Sylvian fissure's inter-hemispheric asymmetry. Contrarily to the other brain folds (sulci), the Sylvian fissure develops through the process of opercularization, with the frontal, parietal, and temporal lobes growing over the insular lobe. Its asymmetry may be related to the leftward functional lateralization for language processing, but the time course of these asymmetries' development is still poorly understood. In this study, we investigated refined shape features of the Sylvian fissure and their longitudinal development in 71 infants born extremely preterm (mean gestational age at birth: 26.5weeks) and imaged once before and once at term-equivalent age (TEA). We additionally assessed asymmetrical sulcal patterns at TEA in the perisylvian and inferior frontal regions, neighbor to the Sylvian fissure. While reproducing renowned strong asymmetries in the Sylvian fissure, we captured an early encoding of its main asymmetrical shape features, and we observed global asymmetrical shape features representative of a more pronounced opercularization in the left hemisphere, contrasting with the previously reported right hemisphere advance in sulcation around birth. This added novel insights about the processes governing early-life brain folding mechanisms, potentially linked to the development of language-related capacities.

Three-Dimensional Assessment of Temporomandibular Joint Morphology and Facial Asymmetry in Individuals with Different Vertical Skeletal Growth Patterns.

The aim of the current study was to investigate, by means of Cone-Beam Computed Tomography (CBCT), condyle−fossa relationship, temporomandibular joint (TMJ) morphology and facial asymmetry in subjects with different vertical skeletal growth patterns. CBCT of 56 patients (112 TMJs) were categorized into three groups according to the mandibular plane angle (MP): Hypodivergent (MP ≤ 23°), Normodivergent (23° < MP < 30°), and Hyperdivergent (MP ≥ 30°). TMJ spaces, width and depth of the condyle and thickness of the fossa were measured. Horizontal and vertical measurements were used to assess facial asymmetry. One-way Analysis of Variance (ANOVA) and post-hoc Turkey tests were computed for the between-groups comparison. Statistical significance was set at p < 0.05. Larger anterior joint space and smaller condylar dimensions (medio-lateral diameter and medio-lateral thickness) were observed in the hyperdivergent group compared to the normodivergent and hypodivergent groups. Right condylar distances to midsagittal plane were significantly larger than left distances in all the three groups. A vertical pattern of growth in healthy individuals seems to be associated with condylar position and dimension, while facial asymmetry values do not differ among different vertical groups.

A Comparison of Morphological, Jump, and Sprint Kinematic Asymmetries in Division I Track and Field Athletes

A Comparison of Morphological, Jump, and Sprint Kinematic Asymmetries in Division I Track and Field Athletes

ОСОБЕННОСТИ АРХИТЕКТОНИКИ ДИСТАЛЬНОГО ОТДЕЛА НИЖНЕЙ КОНЕЧНОСТИ У ЮНОШЕЙ И ДЕВУШЕК СЕВЕРНОГО РЕГИОНА ПО РЕЗУЛЬТАТАМ КОМПЬЮТЕРНОЙ ПЛАНТОГРАФИИ

According to the results of computer plantography conducted in 53 boys and 51 girls, natives of the Khanty-Mansi Autonomous Okrug – Yugra, regional and sexual features of morphometric parameters of the distal parts of the lower limb, their correlation interactions with anthropometric indicators, as well as manifestations of morphological asymmetry were established. 94% of girls and 92% of boys of KhMAO-Yugra have various types of foot deformities, which in 22.5% are combined. Transverse flatfoot is registered in 83% of boys and 77% of girls, has a mild degree of severity and in three-quarters of cases is bilateral. Longitudinal flatfoot is registered in 31% of boys and 41% of girls in the northern region, in 18% of cases it has the second and third degrees of severity and in ½ and ¾ of cases, respectively, it is bilateral. Every third girl and every second boy has a deviation of the posterior part of the foot from the vertical.

Vestibular Morphological Alterations in Adolescent Idiopathic Scoliosis: A Systematic Review of Observational Studies.

Adolescent idiopathic scoliosis (AIS) is the most frequent pediatric spinal deformity. Its treatment still shows limited results due to the existent lack of knowledge regarding etiopathogenesis. Thus, the purpose of the study is to check the existence of vestibular morphological alterations among idiopathic scoliosis patients. To meet the objective, we performed this systematic review searching studies in PubMed Medline, SCOPUS, Web of Science, CINAHL Complete and SciELO until 15 September 2022. Articles that analyzed the morphology of the vestibular apparatus were selected, comparing subjects with AIS versus healthy subjects. Variables were selected that measured the orientation of the channels as well as the general conformation of the vestibular apparatus. One hundred and eighty-five records were retrieved in the preliminary searches, of which five studies were finally included, providing data from 154 participants (83 cases and 71 healthy controls) with a mean age 16.07 ± 2.48 years old. Two studies conclude that the superior and lateral semicircular canals are longer and thinner in patients with AIS. One study concluded that the measure between centers of superior and lateral canals and the angle whose vertex is placed the center of posterior canal were significantly shorter in subjects with AIS than in healthy controls in the left-side of vestibular apparatus. Two studies found an asymmetry in the verticality of the lateral canals on both sides in subjects with AIS, although it is not clear whether the left canal is in a more horizontal or vertical position. Patients with AIS seem to present morphological asymmetries of the vestibular apparatus, fundamentally on the left side. These anomalies seem to correlate with the location of the curve but not with its laterality or severity.