Diagnoses and Treatment of Children with Developmental Coordination Disorder (DCD)

Developmental coordination disorder (DCD) affects approximately 5- (Wood et al., 2017)% of school children, the majority being boys. It has been described using different terms, e.g., developmental dyspraxia and sensory integration dysfunction. The term' developmental coordination disorder' was agreed upon to create consensus in terminology and facilitate standardization in published research.

Children suffering from DCD have poor motor performance and may have psychosocial skills and physical health problems. They experience significantly increased symptoms of depression and anxiety and are not motivated to participate in social and physical activities. They have higher body mass and waist circumference; both risk factors are associated with cardiovascular disease and type 2 diabetes (Barra-Cabello, 2019). Some DCD children may only have problems with refined coordination movements, while others might present a more serious problem coordinating global movements, or both refined and global movements, making it difficult to establish a fully standardized and comprehensive treatment protocol (Cavalcante et al., 2019). It has been reported that balance dysfunction is one of the most common sensorimotor disorders exhibited by 73%- (Wood et al., 2017) 7% of children with DCD (Fong et al., 201 (Blank & Barnett, 2019).

Children with DCD may improve specific skills such as writing legibility with instruction and practice but will likely continue experiencing problems at school in other areas of occupational performance. For example, children with DCD demonstrate significant difficulty with activities of daily living (e.g., dressing, using utensils, toileting); academic task performance (e.g., copying, organizing seatwork, gym/PE participation); leisure activities (e.g., sports, playground activities); or any combination of the above activities. Difficulties in these areas can negatively impact the child's social integration and developing self-concept (Missiuna et al., 200 (Wood et al., 2017).).

There may be considerable problems diagnosing DCD in children below five. This is because younger children with motor delays may be late bloomers and spontaneously catch up, may not be motivated or cooperative with testing, and vary considerably in ADL skill acquisition (Blank & Barnett, 2019). The role of the physician in diagnosing DCD is clear. DCD is a diagnosis by exclusion, so a physician needs to rule out other possible explanations for the child's coordination difficulties. The physician also requires supporting documentation to determine whether DSM-5 criteria have been met (Missiuna et al., 200 (Wood et al., 2017).).

Developmental coordination disorder (DCD) is described in the International Classification of Diseases and the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), both used by physicians as tools to diagnose clinical conditions or diseases (Barra-Cabello, 2019). According to the DSM-5, individuals with DCD present with motor performance substantially below expected levels considering their chronological age and previous opportunities for skill acquisition. Poor motor performance may present as coordination problems in the areas of balance, clumsiness, developmental delays (e.g., walking, crawling, sitting), or in the acquisition of basic motor skills (e.g., catching, throwing, kicking, running, jumping, hopping, cutting, coloring, writing). The coordination disturbance significantly and persistently interferes with activities of daily living or academic achievement. The onset of symptoms is in the early developmental period. Motor skill deficits are not better explained by intellectual disability (intellectual development disorder) or visual impairment and are not attributable to a neurological condition affecting movement (e.g., cerebral palsy, muscular dystrophy, degenerative disorder) (Pam, 2019).

An appropriate, valid, reliable, standardized assessment is indicated to meet the motor performance criteria. There are a variety of tests that measure motor functioning, but few have been designed to assess individuals for diagnosing DCD. Within the literature, the two most widely used evaluations designed to support DCD diagnosis are the Movement Assessment Battery for Children, first and second edition (MABC 1&2), and the Bruininks-Oseretsky Test of Motor Proficiency. The MABC-2 and its previous version, the MABC-1, are the most used and best studied standardized motor tests for assessing individuals with DCD. Studies on the MABC-2 show good to excellent inter-rater reliability, good to excellent–retest reliability, and fair to good validity (construct and concurrent validity with BOT-2). The specificity of the MABC-2 seems to be good, and the sensitivity is lower in general. The Bruininks-Oseretsky Test of Motor Proficiency and its revised version, the BOT-2, show good to excellent reliability, fairly good validity (construct and concurrent validity with MABC-2), and good specificity. The American version of the BOT-2 has lower sensitivity than the MABC-2. In the absence of generally accepted cut-offs for identifying DCD, and in addition to the other criteria being satisfied, it is recommended that when using standardized assessment, the 6th percentile (1standard deviation) for the total score (standard score of <7) should be used as a cut-off. The currently available motor tests have a sensitivity below 90%, which means at least 10% of children with relevant motor problems are missed by administering only one test. If there are clear clinical signs of DCD, it was recommended that a second assessment should take place using a different standardized test (Blank & Barnett, 2019).

Clinical observations made during the administration of standardized assessments are extremely important when assessing children with DCD and may contribute more valuable information than the quantitative scores (Missiuna et al., 200 (Wood et al., 2017).). This author's opinion is that many therapists do not add important clinical observations such as attention, extraneous movement, ocular motor skills, or need for breaks during testing. These observations are important for determining the validity of test scores and the possible need for further testing or referral to other professionals.

Therapists are extremely well-positioned to provide information about the impact of motor impairment on activities of daily living and school-based therapists can easily observe motor performance in relation to school participation (Missiuna et al., 200 (Wood et al., 2017).). An instrument that was reported to be frequently used to diagnose DCD is the Developmental Coordination Disorder Questionnaire (DCDQ), a questionnaire validated for assessing the signs of motor delays that interfere with children's school and leisure activities. The DCDQ meets the DSM-5 criterion, which states that the coordination disturbance significantly and persistently interferes with activities of daily living or academic achievement. Motor delays perceived by parents/caregivers are strong indicators for attesting to the diagnosis of DCD. The DCDQ would be an excellent instrument to include parent/caregiver feedback in the therapy assessment in conjunction with standardized motor testing (Cavalcante et al., 2019).

Although some studies have shown that any intervention with DCD children would be better than no intervention, more attractive and motivational alternatives to conventional exercises should be encouraged (Cavalcante et al., 2019). Group therapy is more time-efficient and cost-effective for the therapist. The parents of children with DCD emphasize the importance of their children participating in organized physical activity groups and value therapy that improves their child's perceptions of self-confidence and competence over those that focus only on improving motor abilities. These views have led to suggestions that therapeutic interventions should focus on enhancing the social and physical skills of children with DCD (Wood et al., 2017).

Two adequately powered studies demonstrated very large improvements with three interventions; one being the Neuromotor Task Training approach which consisted of practiced components of soccer, netball, variations of tagging games, and other popular games in workstations, under the guidance of therapists who manipulated aspects of the environment and tasks as needed. After nine weeks of training (two 45– (Blank & Barnett, 2019) 0-minute sessions per week), the Neuromotor Task Training group showed a very large, statistically significant improvement on the MABC-2. Another effective treatment approach, 'conventional' motor training interventions (such as those commonly used by occupational therapists and physiotherapists), and finally, motor imagery training combined with practicing motor tasks was deemed effective. All three of these motor intervention programs had features in common: A task-oriented approach was a key feature, and, although two were group-based, they were tailored to the children's individual needs and particular interests. The use of equipment, like hoops, ropes, ladders, and outdoor games, was also a core feature of the interventions.

Wii®, core stability training, self-concept training, Tai Kwon Do, table tennis, and aquatic therapy are not supported by the available evidence and are based on empirical evidence. Their usage is not recommended. Effect sizes for these interventions are negligible, small, or stronger evidence for more effective interventions (Preston et al., 2016).

Building on the task-oriented approach, researchers have developed a more promising treatment strategy: 'task-specific' intervention to improve balance in children with DCD. This treatment exposes the children repeatedly to a given (balance) task under the right constraints (e.g., the child's natural environment). Several studies have shown that task-specific intervention can improve the motor performance of children with DCD in hopping, skipping, and various balance activities (Fong et al., 201 (Blank & Barnett, 2019).

Some authors propose that the use of Virtual Reality (VR) has a strong motivational factor for use in treatment. They report that the tasks are similar to a naturalistic situation, and the feedback provided by the game is almost immediate. Additionally, a large amount of movement repetition elicited during VR practice, and the adequately high degree of adherence to the VR activities should be considered important factors enhancing the success of these protocols. Despite the benefits of VR sited by the primary studies, individually, the evidence synthesis has shown that VR was not more effective than control interventions in improving the motor performance of children with DCD (Cavalcante et al., 2019).

A body of evidence has linked DCD to significant impairments in general visual-motor control and the processing of task-relevant, visual information; the ability to use predictive information to guide action; the pursuit tracking of objects; and the ability to maintain fixation on visual targets. Some of this research was laboratory-based. However, deficits in the control of vision have obvious implications on the production and control of coordinated movement in the 'real world.' Maintaining visual fixation on a target and tracking an object is fundamental for aiming and interception skills, which are the building blocks for activities in sports and with many playground games. Throwing and catching is a perfect example of a task where these visual abilities are critical, and it is not surprising that children with DCD struggle with this. Teaching participants to adopt the Quiet Eye strategy by observing video footage of their eye movements (QE training; QET) improved catching techniques in children with average motor skill ability and with DCD. DCD children who were given a brief QET intervention experienced significant improvements in their catching coordination and catching kinematics, and the benefits were maintained after a (Blank & Barnett, 2019)-week detraining period. Results from the gaze and performance data revealed some important implications;

All children improved on the interceptive motor task, stressing that DCD should be considered an impaired motor proficiency rather than a fundamental inability to learn motor skills.

DCD children were able to demonstrate more functional eye movements in order to compensate for oculomotor atypicality directly.

QET instructions resulted in more effective retention of interceptive skills than typical explicit instructions that focus on movement control (Wood et al., 2017).

Many populations, such as those with DCD, demonstrate a high incidence of difficulty processing and integrating sensation (Smits-Engelsman et al., 2012). One study found that most children (Wood et al., 2017) 17% with developmental coordination disorder presented with some difficulties in sensory processing and integration that impacted their participation in activities of daily living (Blank & Barnett, 2019). Jean Ayres articulated the importance of considering the sensory-motor factors that may be affecting participation in tasks such as activities of daily living. Studies indicate that sensory integration interventions may contribute to improved outcomes in the areas of reading and related skills, sensory-motor skills, motor planning, socialization, behavioral regulation, and attention, all skills that individuals with DCD need in order to be successful in school and life (Preston et al., 2016).

Craig, a school-based OT, worked with a third-grade student named Daniel, who had a medical diagnosis of dyslexia and DCD. Craig explained to Daniel's teacher that the occupational therapy evaluation revealed that Daniel had difficulty visually following a line of print. Craig used a colored index card to help Daniel keep his place while reading a book. Craig added that he had also highlighted spaces on worksheets to help Daniel adjust the size and spacing of his responses, which was another area of difficulty for Daniel. Craig stated that Daniel was independent using these strategies in occupational therapy and asked Daniel's teacher if Daniel was using the strategies in class, and she indicated that he was not. It was apparent that Daniel was not generalizing the skills acquired in the OT setting into his natural environment. So, Craig began working with Daniel in the classroom to help with skill generalization by addressing Daniel's challenges when they occurred within his natural environment. When Craig met with Daniel's teacher again, he reported that he had learned a lot about the pace of instruction and demands of the curriculum in the classroom. As a result, he decided to introduce text-to-speech and speech-to-text software for Daniel's use in the classroom. Daniel's teacher reported that due to the modifications, Daniel was more available for learning and liked using the technology. Daniel's teacher also stated that Craig offered solutions to help Daniel access the curriculum, but she was able to collaborate in "real-time" while the OT was in the classroom (Seruya & Garfindel, 2018).

Therapists are in a good position to assist physicians with diagnosing DCD through standardized assessment of motor skills and addressing possible delays in activities of daily living at home and school.

There is some evidence that supports specific interventions that improve individual skills in children with DCD diagnosis. There does not appear to be a one size fits all therapy intervention protocol, probably due to the variability of challenges that are unique to each individual with the diagnosis.

A comprehensive therapy evaluation should be conducted, which would include standard assessment and clinical observations in order to look at specific skills and underlying deficits such as balance, ocular motor control, and sensory processing/modulation abilities in order to get to the root cause of the functional performance challenges of these children and plan interventions and suggest modifications/adaptations as indicated.

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