A Cohesive Framework for Motor Stereotypy in Typical and Atypical Development: The Role of Sensorimotor Integration

Intergenerational choral singing to improve communication outcomes in Parkinson's disease: Development of a theoretical framework and an integrated measurement tool

Purpose: This study presented an initial step towards developing the evidence base for intergenerational choral singing as a communication-focussed rehabilitative approach for Parkinson's disease (PD).Method: A theoretical framework was established to conceptualise the rehabilitative effect of intergenerational choral singing on four domains of communication impairments - motor drive, timing mechanism, sensorimotor integration, higher-level cognitive and affective functions - as well as activity/participation, and quality of life. A computer-assisted multidimensional acoustic analysis was developed to objectively assess the targeted domains of communication impairments. Voice Handicap Index and the World Health Organization's Quality of Life assessment-abbreviated version were used to obtain patient-reported outcomes at the activity/participation and quality of life levels. As a proof of concept, a single subject with PD was recruited to participate in 9 weekly 1-h intergenerational choir rehearsals. The subject was assessed before, 1 week post, and 8 weeks post-choir.Result: Notable trends of improvement were observed in multiple domains of communication impairments at 1 week post-choir. Some improvements were maintained at 8 weeks post-choir. Patient-reported outcomes exhibited limited pre-post changes.Conclusion: This study provided the theoretical groundwork and an empirical measurement tool for future validation of intergenerational choral singing as a novel rehabilitation for PD.

[Motor impairments in children with autism spectrum disorders: causes and possibilities for correction]

Autism spectrum disorder (ASD) is characterized by triad of abnormalities in the form of developmental distortion with a lack of communicative abilities, behavioral and motor stereotypies. Etiology and pathogenesis of disease currently are unknown, but multifactorial causes of this pathology have been suggested. Although social disorders are considered a defining characteristic, motor disorders are a key feature of ASD. They are based on a postural control impairment, which is accompanied by delayed psychomotor development, reduced ability to motor synchronism in early childhood, modified arrangement of muscles, problems with balance and gait, postural instability, coordination deficiency, presence of motor dyspraxia and other abnormalities.

OBJECTIVE

To analyze current scientific data about motor disorders in ASD and their correction possibilities in children with this pathology.

MATERIAL AND METHODS

Analysis of publications, contained in PubMed and Google Scholar databases, which give consideration to motor disorders in children with ASD, was carried out. The search was done by keywords: motor disorders, children, autism spectrum disorder, causes, correction.

RESULTS AND CONCLUSION

Adaptive physical culture during individual training is one of the available and effective methods of physical rehabilitation in patients with ASD. Children with ASD need three levels of psychological support, each of which offers individual exercises, depending on the nature and severity of speech and cognitive impairment.

A Feasibility Study of Bilateral Wrist Sensors for Measuring Motor Traits in Children With Autism

Direct, quantitative measures of hyperactivity and motor coordination, two motor characteristics associated with impairment in autism, are limited. Wearable sensors can objectively index real-world movement variables that may relate to these behaviors. Here, we explored the feasibility of bilateral wrist accelerometers for measuring upper limb activity in 3-10-year-olds with autism (n = 22; 19 boys, 3 girls; M age = 5.64, SD = 2.73 years) and without autism (n = 26; 15 boys, 11 girls; M age = 6.26, SD = 2.47 years). We investigated the relationships between movement characteristics related to duration, intensity, complexity, and symmetry on the one hand and parent-reported hyperactivity and motor coordination on the other. Participants with and without autism wore the sensors for 12-hour periods. Sensor variables varied by age but not sex, with movement intensity and complexity moderately related to motor coordination. These findings lend preliminary support to wearable sensors as a means of providing ecologically-valid metrics of motor characteristics that impact adaptive function in children with autism.

Non-verbal IQ and change in restricted and repetitive behavior throughout childhood in autism: a longitudinal study using the Autism Diagnostic Interview-Revised

BACKGROUND

Restricted and repetitive behavior (RRB) is one of the characteristic features of Autism Spectrum Disorder. This domain of symptoms includes a broad range of behaviors. There is a need to study each behavior individually to better understand the role of each in the development of autistic children. Moreover, there are currently no longitudinal studies investigating change in these behaviors over development.

METHODS

The goal of the present study was to explore the association between age and non-verbal IQ (NVIQ) on 15 RRB symptoms included in the Autism Diagnostic Interview-Revised (ADI-R) over time. A total of 205 children with ASD were assessed using the ADI-R at time of diagnosis, at age 6 years, and at age 11 years, and with the Wechsler Intelligence Scales for Children-Fourth Edition (WISC-IV) at age 8 years.

RESULTS

The proportion of children showing each RRB tended to diminish with increasing age, except for sensitivity to noise and circumscribed interests, where the proportion increased over time. Although there was no significant main effect of NVIQ, there was a significant interaction between age and NVIQ. This was mainly driven by Difficulties with change in routine, for which higher NVIQ was associated with the behavior remaining relatively stable with age, while lower NVIQ was associated with the behavior becoming more prevalent with age.

LIMITATIONS

The study focused on the presence/absence of each RRB but did not account for potential changes in frequency or severity of the behaviors over development. Furthermore, some limitations are inherent to the measures used. The ADI-R relies on parent report and hence has some level of subjectivity, while the Wechsler intelligence scales can underestimate the intellectual abilities of some autistic children.

CONCLUSIONS

These results confirm that specific RRB are differentially linked to age and NVIQ. Studying RRB individually is a promising approach to better understanding how RRB change over the development of autistic children and are linked to other developmental domains.

The Role of the Cerebellum in Repetitive Behavior Across Species: Childhood Stereotypies and Deer Mice

Recent studies suggest that the cerebellum may have a significant role in repetitive behaviors. In primary complex motor stereotypies, typically developing children have repetitive movements usually involving rhythmic flapping/waving arm/hand movements. Similarly, the deer mouse animal model exhibits inherited repetitive behaviors, with increased frequencies of spontaneous jumping and rearing. In this study, data from both children with motor stereotypies and deer mice were used to investigate the role of the cerebellum in repetitive behaviors. The 3.0-T MRI volumetric imaging of the cerebellum was obtained in 20 children with primary complex motor stereotypies and 20 healthy controls. In deer mice, cerebellar volume (n = 7/group) and cell counts (n = 9/group) were compared between high- and low-activity animals. Levels of cerebellar neurotransmitters were also determined via HPLC (n = 10/group). In children with stereotypies, (a) there were a statistically significant reduction (compared to controls) in the white matter volume of the posterior cerebellar lobule VI-VII that negatively correlated with motor control and (b) an 8% increase in the anterior vermis gray matter that positively correlated with motor Stereotypy Severity Scores (SSS). In deer mice, (a) there was a significant increase in the volume of the anterior vermal granular cell layer that was associated with higher activity and (b) dentate nucleus cell counts were higher in high activity animals. Similar increases in volume were observed in anterior vermis in children with stereotypies and a deer mouse model of repetitive behaviors. These preliminary findings support the need for further investigation of the cerebellum in repetitive behaviors.

Atypical neural processing during the execution of complex sensorimotor behavior in autism

Stereotyped behavior is rhythmic, repetitive movement that is essentially invariant in form. Stereotypy is common in several clinical disorders, such as autism spectrum disorders (ASD), where it is considered maladaptive. However, it also occurs early in typical development (TD) where it is hypothesized to serve as the foundation on which complex, adaptive motor behavior develops. This transition from stereotyped to complex movement in TD is thought to be supported by sensorimotor integration. Stereotypy in clinical disorders may persist due to deficits in sensorimotor integration. The present study assessed whether differences in sensorimotor processing may limit the expression of complex motor behavior in individuals with ASD and contribute to the clinical stereotypy observed in this population. Adult participants with ASD and TD performed a computer-based stimulus-tracking task in the presence and absence of visual feedback. Electroencephalography was recorded during the task. Groups were compared on motor performance (root mean square error), motor complexity (sample entropy), and neural complexity (multiscale sample entropy of the electroencephalography signal) in the presence and absence of visual feedback. No group differences were found for motor performance or motor complexity. The ASD group demonstrated greater neural complexity and greater differences between feedback conditions than TD individuals, specifically in signals relevant to sensorimotor processing. Motor performance and motor complexity correlated with clinical stereotypy in the ASD group. These findings support the hypothesis that individuals with ASD have differences in sensorimotor processing when executing complex motor behavior and that stereotypy is associated with low motor complexity.

Recommendations for Abnormal Behaviour Ethograms in Monkey Research

Laboratory monkey ethograms currently include subcategories of abnormal behaviours that are based on superficial morphological similarity. Yet, such ethograms may be misclassifying behaviour, with potential welfare implications as different abnormal behaviours are likely to have distinct risk factors and treatments. We therefore investigated the convergent validity of four hypothesized subcategories of abnormal behaviours ('motor', e.g., pacing; 'self-stimulation', e.g., self-sucking; 'postural', e.g., hanging; and 'self-abuse', e.g., self-biting). This hypothesis predicts positive relationships between the behaviours within each subcategory. Rhesus macaque (Macaca mulatta) data on 19 abnormal behaviours were obtained from indoor-housed animals (n = 1183). Logistic regression models, controlling for sex, age, and the number of observations, revealed that only 1/6 'motor' behaviours positively predicted pacing, while 2/3 'self-abuse' behaviours positively predicted self-biting (one-tailed p-value < 0.05). Furthermore, 'self-stimulation' behaviours did not predict self-sucking, and none of the 'postural' behaviours predicted hanging. Thus, none of the subcategories fully met convergent validity. Subsequently, we created four new valid subcategories formed of comorbid behaviours. The first consisted of self-biting, self-hitting, self-injurious behaviour, floating limb, leg-lifting, and self-clasping. The second comprised twirling, bouncing, rocking, swinging, and hanging. The third comprised pacing and head-twisting, while the final subcategory consisted of flipping and eye-poking. Self-sucking, hair-plucking, threat-biting, and withdrawn remained as individual behaviours. We encourage laboratories to replicate the validation of these subcategories first, and for scientists working with other species to validate their ethograms before using them in welfare assessments.

Developmental Functional Modules in Infant Vocalizations

Purpose Developmental functional modules (DFMs) are biological modules that are defined by their structural (morphological), functional, or developmental elements, and, in some cases, all three of these. This review article considers the hypothesis that vocal development in the first year of life can be understood in large part with respect to DFMs that characterize the speech production system. Method Literature is reviewed on relevant embryology, orofacial reflexes, craniofacial muscle properties, stages of vocal development, and related topics to identity candidates for DFMs. Results The following DFMs are identified and described: laryngeal, pharyngo-laryngeal, mandibular, velopharyngeal, labial complex, and lingual complex. These DFMs and their submodules, considered along with phenomena such as rhythmic movements, account for several well-documented features of vocal development in the first year of life. The proposed DFMs, rooted in embryologic, histologic, and kinematic properties, serve as low-dimensional control variables for the developing vocal tract. Each DFM is semi-autonomous but interacts with other DFMs to produce patterns of vocal behavior. Discussion Considered in relation to contemporary profiles and models of vocal development in the first year of life, DFMs have interpretive and explanatory value. DFMs complement other approaches in the study of infant vocalizations and are grounded in biology.

The Role of Mental Imagery in Parkinson's Disease Rehabilitation

Parkinson’s disease (PD) is a disabling neurodegenerative disease whose manifestations span motor, sensorimotor, and sensory domains. While current therapies for PD include pharmacological, invasive, and physical interventions, there is a constant need for developing additional approaches for optimizing rehabilitation gains. Mental imagery is an emerging field in neurorehabilitation and has the potential to serve as an adjunct therapy to enhance patient function. Yet, the literature on this topic is sparse. The current paper reviews the motor, sensorimotor, and sensory domains impacted by PD using gait, balance, and pain as examples, respectively. Then, mental imagery and its potential for PD motor and non-motor rehabilitation is discussed, with an emphasis on its suitability for addressing gait, balance, and pain deficits in people with PD. Lastly, future research directions are suggested.

A Mathematical Model to Examine Issues Associated With Using Portable Force-Measurement Technologies to Collect Infant Postural Data

Portable force-measurement technologies are becoming increasingly popular tools to examine the maturation of postural motor milestones, such as sitting and standing, in infants. These convenient, low-cost devices provide numerous opportunities to characterize postural development outside of the laboratory. However, it is important to understand the unique challenges and technical limitations associated with collecting center of pressure (CoP) data using portable force-measurement technologies in infant populations. This study uses a mathematical model to examine issues that emerge when using portable force-measurement technologies to collect sitting and standing postural data in infants. The results of our mathematical simulations demonstrate that the CoP errors from portable force-measurement technologies depend on the posture examined (e.g., sitting vs. standing), the anthropometrics of the person (e.g., height and weight), the frequency of body sway, and the experimental setup (e.g., an additional support surface being placed on top of the device). Recommendations are provided for developmental researchers interested in adopting these technologies in infant populations.

Visual feedback during motor performance is associated with increased complexity and adaptability of motor and neural output

Complex motor behavior is believed to be dependent on sensorimotor integration - the neural process of using sensory input to plan, guide, and correct movements. Previous studies have shown that the complexity of motor output is low when sensory feedback is withheld during precision motor tasks. However, much of this research has focused on motor behavior rather than neural processing, and therefore, has not specifically assessed the role of sensorimotor neural functioning in the execution of complex motor behavior. The present study uses a stimulus-tracking task with simultaneous electroencephalography (EEG) recording to assess the effect of visual feedback on motor performance, motor complexity, and sensorimotor neural processing in healthy adults. The complexity of the EEG signal was analyzed to capture the information content in frequency bands (alpha and beta) and scalp regions (central, parietal, and occipital) that are associated with sensorimotor processing. Consistent with previous literature, motor performance and its complexity were higher when visual feedback was provided relative to when it was withheld. The complexity of the neural signal was also higher when visual feedback was provided. This was most robust at frequency bands (alpha and beta) and scalp regions (parietal and occipital) associated with sensorimotor processing. The findings show that visual feedback increases the information available to the brain when generating complex, adaptive motor output.

Pre-emptive Intervention for Autism Spectrum Disorder: Theoretical Foundations and Clinical Translation

Autism spectrum disorders (ASD) are an emergent public health problem, placing significant burden upon the individual, family and health system. ASD are polygenetic spectrum disorders of neural connectome development, in which one or more feedback loops amplify small genetic, structural, or functional variations in the very early development of motor and sensory-motor pathways. These perturbations trigger a 'butterfly effect' of unpredictable cascades of structural and functional imbalances in the global neuronal workspace, resulting in atypical behaviors, social communication, and cognition long-term. The first 100 days post-term are critically neuroplastic and comprise an injury-sensitive developmental window, characterized by a neural biomarker, the persistence of the cortical subplate, and a behavioral biomarker, the crying diathesis. By the time potential diagnostic signs are identified, from 6 months of age, ASD neuropathy is already entrenched. The International Society for Autism Research Special Interest Group has called for pre-emptive intervention, based upon rigorous theoretical frames, and real world translation and evaluation. This paper responds to that call. It synthesizes heterogenous evidence concerning ASD etiologies from both psychosocial and biological research literatures with complexity science and evolutionary biology, to propose a theoretical framework for pre-emptive intervention. This paper hypothesizes that environmental factors resulting from a mismatch between environment of evolutionary adaptedness and culture initiate or perpetuate early motor and sensory-motor lesions, triggering a butterfly effect of multi-directional cascades of atypical developmental in the complex adaptive system of the parent and ASD-susceptible infant. Chronic sympathetic nervous system/hypothalamic-pituitary-adrenal axis hyperarousal and disrupted parent-infant biobehavioral synchrony are the key biologic and behavioral mechanisms perpetuating these atypical developmental cascades. A clinical translation of this evidence is proposed, for application antenatally and in the first 6 months of life, as pre-emptive intervention for ASD.

Functional and structural asymmetry in primary motor cortex in Asperger syndrome: a navigated TMS and imaging study

Motor functions are frequently impaired in Asperger syndrome (AS). In this study, we examined the motor cortex structure and function using navigated transcranial magnetic stimulation (nTMS) and voxel-based morphometry (VBM) and correlated the results with the box and block test (BBT) of manual dexterity and physical activity in eight boys with AS, aged 8–11 years, and their matched controls. With nTMS, we found less focused cortical representation areas of distinct hand muscles in AS. There was hemispheric asymmetry in the motor maps, silent period duration and active MEP latency in the AS group, but not in controls. Exploratory VBM analysis revealed less gray matter in the left postcentral gyrus, especially in the face area, and less white matter in the precentral area in AS as compared to controls. On the contrary, in the right leg area, subjects with AS displayed an increased density of gray matter. The structural findings of the left hemisphere correlated negatively with BBT score in controls, whereas the structure of the right hemisphere in the AS group correlated positively with motor function as assessed by BBT. These preliminary functional (neurophysiological and behavioral) findings are indicative of asymmetry, and co-existing structural alterations may reflect the motor impairments causing the deteriorations in manual dexterity and other motor functions commonly encountered in children with AS.

Home-Based, Therapist-Assisted, Therapy for Young Children With Primary Complex Motor Stereotypies

BACKGROUND

Complex motor stereotypies (CMS) typically begin before age three years and include rhythmic, repetitive, fixed movements that last for seconds to minutes and can be interrupted with distraction.

OBJECTIVE

We evaluated the effectiveness of a home-based, parent-provided therapy accompanied by scheduled telephone calls with a therapist, in five- to seven-year old children with primary CMS.

METHODS

Eligible families received an instructional digital versatile disk (DVD) written instructions, and scheduled telephone contacts with a therapist at baseline (DVD receipt), one, three, and eight weeks later. At each call, parents completed outcome measures and received feedback. Outcome scales Stereotypy Severity Scale (SSS) Motor and Impairment scales and a Stereotypy Linear Analogue Scale (SLAS) were also completed via the Iinternet (REDCap)-at screening, one and two months post-baseline call. At study conclusion, participants were divided into an intent-to-treat (ITT; had at least one call) or a lost-to-follow-up (LTF) group.

RESULTS

Thirty-eight children (mean =  6 years ± 11 months) were enrolled. The LTF group (n = 14) had significantly higher scores than the ITT (n = 24) group on all attention-deficit/hyperactivity disorder ratings (P < 0.01), but not stereotypy severity. Primary outcome scores, acquired by telephone and REDCap, showed a significant reduction in SSS Motor and Impairment scores between the initial and the last completed evaluation (P ≤ 0.001). Calculated change ratios were SSS Motor -0.23/-0.30 (cal/REDCap); SSS Impairment -0.31/-0.32; and SLAS -0.54 (REDCap). Clinical improvement was further supported by results from a parent improvement scale and end of study questionnaires.

CONCLUSIONS

Home-based, parent-administered behavioral therapy supplemented by telephone contact with a therapist is effective in reducing complex motor stereotypies in children.

Tourette syndrome research highlights from 2017

This is the fourth yearly article in the Tourette Syndrome Research Highlights series, summarizing research from 2017 relevant to Tourette syndrome and other tic disorders. The authors briefly summarize reports they consider most important or interesting. The  highlights from 2018 article is being drafted on the Authorea online authoring platform, and readers are encouraged to add references or give feedback on our selections using the comments feature on that page. After the calendar year ends, the article is submitted as the annual update for the Tics collection on F1000Research.