DEVELOPMENTAL COORDINATION DISORDER (DCD) AND THE ROLE OF ICTS AND NEUROFEEDBACK (NF) FOR TRAINING AND INTERVENTION

DCD is a neurodevelopmental disorder that affects many levels of a person's functioning, displaying a multitude of features that persist throughout the person's life. Neurofeedback is a widely used form of non-invasive intervention that is implemented worldwide in non-DCD populations and is presented to be effective targeting a lot of difficulties and common features of DCD. The purpose of this literature review is to highlight the impact of NF showcasing several studies of its effectiveness to several populations with main key characteristics that are found to be presented also in DCD. In the introduction, the basic definitions concerning the concepts of DCD and neurofeedback are described and in the main part, an analysis of DCD is made to further investigate its key characteristics that aligns with other populations (especially ADHD) in which further investigation using neurofeedback is proposed due to its effectiveness


PALAVRAS-CHAVE:
Neurofeedback. NF. NFT. EEG. Biofeedback. DCD RESUMEN DCD es un trastorno del neurodesarrollo que afecta muchos niveles del funcionamiento de una persona, mostrando una multitud de características que persisten a lo largo de la vida de la persona. Neurofeedback es una forma de intervención no invasiva ampliamente utilizada que se implementa en todo el mundo en poblaciones sin DCD y se presenta como eficaz para abordar muchas dificultades y características comunes de DCD. El propósito de esta revisión de la literatura es resaltar el impacto de NF mostrando varios estudios de su efectividad en varias poblaciones con características clave principales que también se presentan en DCD. En la introducción, se describen las definiciones básicas sobre los conceptos de DCD y neurofeedback y, en la parte principal, se realiza un análisis de DCD

NEUROFEEDBACK AND CLINICAL APPLICATION
For many conditions, including brain-based disorders, neurofeedback (NF) is a non-invasive intervention technique. It is primarily employed in the management of attention deficit disorders and the enhancement of academic performance.
Despite the fact that it can be used in conjunction with medication, it does not contain any medication. Electroencephalographic (EEG) biofeedback and neurotherapy are other terms used to describe neurofeedback (NF). The neurofeedback apparatus consists of NF hardware, such as a Brain Computer Interface (BCI), an EEG cup, and peripheral devices, as well as NF software 34 .
By measuring brain waves and sending a feedback signal to the individual, neurofeedback is a type of biofeedback that teaches people how to control their own brain functions. Typically, audio and/or visual feedback is provided by neurofeedback. Brain activity that is desirable or undesirable is accompanied by positive or negative feedback, respectively 21 .
Neurofeedback has many clinical applications and has been used to reduce the symptoms caused by various diseases and conditions. Some of them concern neurodevelopmental disorders such as ADHD 25, 30, 32, 34 , ASD 16,23 and specific and non-specific learning difficulties 23 . It has also been reported to target mental and neurological disorders such as anxiety, depression, epilepsy, insomnia, drug addiction, schizophrenia 21 . Finally, it has been used in neurorehabilitation in various neurological and neurodegenerative diseases 19 . The above studies have proven the effectiveness of the use of neurofeedback in the aforementioned populations and conditions.

DEVELOPMENTAL MOTOR COORDINATION DISORDER (DCD) DEFINITION AND HISTORICAL REVIEW
Developmental motor coordination disorder (DCD) is a common childhood disorder that presents a wide range of severity and can often be underestimated by healthcare professionals. It is characterized by basic motor learning difficulties, such as learning fine and/or gross motor skills and is a condition in which a person's autonomy and functionality in activities of daily living are significantly developmental dyspraxia, reduced brain function, physical clumsiness, cognitive-motor disorder, and as clumsy child syndrome 26 .
The concept of DCD has evolved over time and the diagnostic criteria for the disorder have been refined through successive editions of the Diagnostic and Statistical Manual of Mental Disorders (DSM). In DSM-III-R (1987), DCD was referred to as "developmental dyspraxia" and was included in the category of "perceptual motor disorder". In DSM-IV (1994), DCD was renamed "developmental coordination disorder" and included in the "movement disorders" category. In DSM-V (2013), DCD is still included in the category of "movement disorders," but the criteria for diagnosis have been revised to better reflect current understanding of the disorder. In DSM-V (2013), DCD is defined as a "persistent difficulty planning, executing, and coordinating skilled movements that is not due to a lack of intelligence, sensory problems, or other medical conditions" 3 . It is diagnosed based on the presence of specific symptoms and functional impairment in activities of daily living and academic or occupational performance.
According to the DSM V for the diagnosis of the person the following diagnostic criteria must be met for the person to be diagnosed with DCD which are as follows: A. Given the person's chronological age and opportunities for skill learning, the acquisition and application of coordinated motor skills is significantly below what is predicted.
B. From criterion A the deficit in motor skills presented must significantly affect and persist in performing activities of daily living that are appropriate for the child's age such as self-care and self-maintenance, academic and productive skills, leisure time and play.
C. Symptoms must begin in the early developmental period.
D. These deficits in motor skills must not be the result of an intellectual disability or neurological conditions that may affect movement 3 .

DEVELOPMENTAL MOTOR COORDINATION DISORDER (DCD) AND COMORBIDITY
According to the systematic review by Blank et al (2019) prevalence estimates range from 5% to 6% of children aged 5 to 11 years, most commonly reported in the literature and boys appear to be more affected, with reported analogies of boys and girls to be from 1.9:1 to 7.3:1 15 . In Greece the rate of occurrence seems to reach 8% of the population 33 .
DCD is a disorder with an increased rate of comorbidity. Many of the children who receive this diagnosis also receive at least one other different diagnosis.
Some of them are receive the diagnosis of ADHD in which the comorbidity rate in studies seems to reach 50% 9,35 . Learning disorders, including developmental dyslexia, specific language impairment, behavioral problems, and autism spectrum disorder are also common in children with DCD with cooccurrence of these disorders to be as high as 30 to 50% 15 . shoes and using utensils, with these issues persisting into adolescence and adulthood. Children with DCD may also experience secondary psychosocial issues, including issues arising in their social relationships, reduced sense of self-worth, depressive disorders, and emotional/behavioral disorders 11,14,22 . Compared to their peers, children with DCD may have a lower quality of life.

JOURNAL HEALTH AND TECHNOLOGY -JHT ISSN 2764-7625 DEVELOPMENTAL COORDINATION DISORDER (DCD) AND THE ROLE OF ICTS AND NEUROFEEDBACK (NF) FOR TRAINING AND INTERVENTION
According to Cousins and Smith (2003) in a survey of adults aged 18-65 years to further investigate DCD in adulthood, the participating sample consisted of 19 individuals who formed pairs with typical and gender-specific and age control samples. Individuals with DCD or suspected DCD were given tests that included tasks of fine motor skills, writing, construction, obstacle avoidance, dynamic and static balance, divided attention, ball skills, response time, movement time and succession. It appeared from the findings that the DCD group showed lower performance in all tasks. Some of the features they presented were problems related to delay and variety of movements with many of the participants showing considerable problems in sequencing and dividing attention. This is also confirmed in the systematic review by Wilson et al, 2017 to provide a synthesis of data and evidence that will include recent research processes to provide consistency in theory about DCD and direction for new research work. For the purpose of this research, the data collection was done through the PICO framework, the analysis of 106 final articles from 7 electronic databases for the years 2011-2016. The researchers concluded that the nature of the task underlies motor control deficits in DCD. Also, these deficits are evident and more pronounced when dual tasks are produced and tasks that require greater motor precision in both temporal and spatial demands, more developed planning and adaptation and compensation at the perceptual-motor level to maintain stability. practice-and context-dependent motor learning, internal modeling, more variable kinematics and kinetics, as well as greater safety margins when moving. These findings are enriched in recent related research that was done to investigate the cerebellar differences found in children with DCD compared to children with typical brain development.

DEVELOPMENTAL MOTOR COORDINATION DISORDER (DCD) AND NEUROLOGICAL BASIS
Voxel-based morphometry was used to measure cerebellar morphology and investigated using highresolution T1 images. The population included children aged 8 to 12 years and the sample consisted of 46 children of which 12 had typical development and 34 had DCD.
The research results showed reduced gray matter volume related to connections presented in the brainstem. In a measurement made using the motor assessment tool MABC, with tests that activate the specific affected areas of the brainstem, a significant positive correlation was shown in that the reduced volume of the gray matter is also associated with reduced motor skills that explain the motor learning difficulties that are presented 8 .
This confirms that a variety of DCD symptoms, including motor skills, attention, and executive function, are related to the processing of motor and cognitive functions provided by the cerebellum. The findings of the present research lend credence to this idea because fronto-parietal, sensorimotor, ventral attention, and default functioning networks, all of which have been found to be reduced in children with DCD, are linked to cerebellar regions associated with impaired motor performance 8 .

ADHD AND DEVELOPMENTAL COORDINATION DISORDER (DCD)
ADHD is characterized as a highly comorbid condition that can reach up to 80% of people who have already received the diagnosis. ADHD is dominated by a triplet of core symptoms characterized

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by inattention, impulsivity and hyperactivity. Something that is still observed are deficits concerning motor coordination as well as planning in movement.
In addition, ADHD is considered by research to be a neurodevelopmental disorder that exhibits the greatest and most common associations with DCD, as well as individuals with DCD exhibiting to a large extent problems related to inhibition and impulsivity. The scientific community has focused its attention on investigating the cause of these two phenomena to be able to provide answers through the study and identification of problems that arise in the development and maturation of the brain.
Recent studies using neuroimaging methods to examine the two populations revealed that there are significant differences in the way they manifest the motor deficit from a neurophysiological as well as a neurofunctional point of view 18 .
What is observed in the systematic review by Wilson et al, 2017 is that several of the studies conducted on DCD population did not include as exclusion criteria population with ADHD, which can cause confusion in the interpretation of the results and understanding of the core mechanism of DCD.
This need is also highlighted in the more recent reviews by Irie et al, 2021 and Zukic et al, 2022.

DEVELOPMENTAL MOTOR COORDINATION DISORDER (DCD) AND THE NEED FOR FUTURE RESEARCH USING NEUROFEEDBACK
Neurofeedback as a treatment method for children with DCD and its research presents a vast In some studies, it has been mentioned and investigation has been suggested, due to the complexity of this specific condition and the increased comorbidity it presents, especially with ADHD.
The research of Noroutzi et al, 2018 proved the effectiveness regarding the improvement of motor skills.
This particular study investigated whether using neurofeedback (NFT), compared to a control group, could improve bilateral coordination in children with ADHD.
The sample consisted of twenty children with ADHD (mean age: 7:9, SD, 2:11) who were divided into two groups: the group that received NFT and a control group. The two groups completed a bilateral coordination test at three different time points as well as after the 12-session intervention. Participants in the control group underwent sham NFT conditions while those in the NFT group received training to increase Sensory Motor Rate (SMR) in C3 and C4.
The results showed that the NFT group made fewer errors in both bilateral coordination patterns than the control group. A significant improvement in a bilateral coordination task was observed in

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children with ADHD after SMR neurofeedback training (NFT). Thus, it appears that SMR NFT has the potential to enhance and improve motor control in ADHD patients.
This research highlights the need for future investigation using the same protocol in a population with DCD, due to the increased comorbidity that occurs and the fact that the motor deficits in the particular sample obtained may be a consequence of DCD.
In an even more recent study by Seikh et al, 2022 to highlight the effectiveness of NFT on motor function, anxiety and sleep habits in children with ADHD, the authors take for granted the comorbidity of DCD with ADHD as a feature of the condition.
In the present research, a sample of 20 children aged 7 to 9 years was collected and divided into two groups, the group that received NFT and the control group. The experimental group received NFT and physical activity training for 24 sessions of 45 minutes, while the control group followed their normal daily schedule. The results showed that there was a big difference between the two groups regarding the motor functions, anxiety and sleeping habits of the children.
Also, one of the most presented problems associated with DCD is reported to be executive