Epidemiological Study of Children with Development Coordination Disorders ( DCD )

The objectives of the study is to determine the epidemiology of dyspraxia among preschool children in Alexandria. Method of the study: a case control study was designed. The sample of the study was 33 children (26 ♂ and 7 ♀) with dyspraxia and 33 normal children as a control. Both groups were subjected to the followings a) screening phase, b) developmental assessment and, c) clinical assessment. The results: Males are significantly affected more than females (p= 0.037). Prematurity (p= 0.012), allergic disease (p= 0.004), and positive family history (p= 0.000) are significant factors for dyspraxia. Dyspraxic children have significantly behavior problems (p=0.008), speech disturbance (p=0.000), and lack of imaginative play (p= 000). Conclusion dyspraxia is more common in males than females. Behaviour problems, speech disturbance and lack of imaginative play are more common in dysproaxic.


INTRODUCTION
Developmental coordination disorder (DCD) is the term used to describe difficulties in the development of movement skills.It becomes apparent in early childhood as a difficulty in learning or carrying out skills that require motor coordination.This condition affects a child's performance of every day tasks in the home, play, and school environments.
Up till now the cause of DCD is unknown, However, it is known that the difficulty arises in the processing of the information between the brain and the body, which affects the child's ability to move effectively. (1)spraxia is a neurological disorder of motor coordination usually apparent in childhood that manifests as difficulty in thinking out, planning out, and executing planned movements or tasks. (2)er the years dyspraxia and DCD have been used interchangeably along with Bull High Inst Public Health Vol.38 No.1 [2008]   other names such as "clumsy child syndrome.Currently the term DCD is the most acceptable term to describe these difficulties (1) whilst "dyspraxia" is a specific difficulty in motor planning and is a subtype of DCD. (1)spraxia may affect any or all areas of development.
Physical, intellectual, emotional, social, language, and sensory and may impair the normal process of learning thus is a learning difficulty.It is not a unitary disorder and so affects each

PURPOSE OF THE WORK
The purpose of the present work is to study the epidemiology of developmental dsypraxia among preschool children in Alexandria.The evaluation of motor functions followed a 3 types procedure:

A
Step 1: Screening phase: Using parent complete questionnaire to detect children with difficulty in motor development, based on parental reports of quantity of motor performance.
Step 2: Developmental assessment: Children who are screened positive were assessed with a more detailed, developmental evaluation to as certain the accuracy of the screening assessment and to confirm the deficit areas and exclude other CNS diseases.
Step 3: Clinical assessment: The following assessment was done for positively screened children: • Test for sustaining positions against gravity.
• Test for motor screening.
• Crossing test.IV criteria for diagnosis. (7)oup II: 33 normal children from the initial sample as a control group.
Both groups were subjected to the following.
* Imagination skills (by using open ended stories and role play.

RESULTS
Table 1 shows the main demographic features of the sample.
The incidence of dyspraxia children was 6.9% of all the sample.The ratio between males to females was 3.7.

Table (4)
shows the comparison between the 2 groups as regard fine motor development (p=<0.001).and 8% of all school-aged children. (10)In the present study, the prevalence of dyspraxia among the studied samples was 6.9%.

Table (5): shows comparison between the two groups as regard social relative in the class
In whole populations sex differences are not significant, though twice as many boys have difficulties as girls.Clinic-based studies show a ratio of 4:1 suggesting that boys react to their difficulties in a more conspicuous way, or that there are higher expectations in performance of boys than girls. (4)Chambers and Sugden reported a 2:1 ratio, but claimed that the difference may reflect higher referred rates for boys. (11)Portwood 2001 (4)  Regarding the risk factors of dyspraxia in the present study, statistical analysis showed significant difference as regards the duration of pregnancy, family history for allergic disorder, and family history of similar condition.Gubbay (1985) (13) suggested that in perhaps 50% of  (14) also maintains that many features associated with dyspraxia are consistent with HUFA deficiencies or imbalances.
These include the core difficulties with motor coordination, attention, and sensory processing, as well as the excess of males affected, proneness to allergic or autoimmune conditions, irregularities of mood.
One of the main risk factors is prematurity, this is because the more premature the baby, the more the migration and connections of neurons may be distributed leading to difficulties with attention span, self control, self inhibition and motor coordination problems. (15)netic influences may also contribute to As regards the motor delay and the behavior disturbances significantly seen in these studied samples, they might be explained on the basis of Jean Ayer (18,19) sensory integration theory, sensory integration refers to functioning of the brain the central concept of the theory is that children may struggle to integrate sensory input (e.g., visual, auditory, tactile and proprioceptive cues, and develop aversions) (i.e., to being touched, to being exposed to new sounds).Also children may become overstimulated in any of these sensory channels, and their behavior and motor performance deteriorate in circumstances of overstimulation.She concluded that children with motor difficulties often have problems in the integration of sensory input, which make them vulnerable to problems resulting from sensory stimulation. (18,19)fficulties with motor planning are often at the least of these children frustrations.As children grow, they move away from simply experiencing the world and are instead called upon to master it.
Toys, tolls and self-care activities become more complex, requiring more intricate and sequenced motor planning behavior.Motor planning problems make it difficult for these children to master the use of objects, which leads to an increasing sense of frustration. (13)Recent studies reveal the importance of the limb praxis system which is a neural system important in higher-level  (20) , a sex differences in the praxis system would be expected to affect not only prexis but also oral motor control, because both musculature are served by overlapping components of the praxis system.
In a disorder as complex as dyspaxia it may be disguided to search for one primary deficit capable of accounting for all the observed manifestation of the disorder and whether their manifestations are correlated or secondary consequences of a primary or multiple deficit. (20,21)cause the development of pretense, receptive and expressive language, and mental representation all begin at approximately the same age (usually between age 1 and 2) researches have hypothesized strong conceptual relationships between these processes.
Recent research suggests that Broca's area (Beordmann area 44) a brain region critical for language may have evolved from neurons active during observation and execution of manual movement. (22)cause while it is true that many are  (Rourke 1989). (24)The NVLD person in different ways at different ages and stages of development and to different degrees. (3)It is inconsistent in that it may affect the child one day but not the next.It is a hidden handicap as, under normal circumstances, children with dyspraxia may appear no different from their peers, until new skills are tried or known ones taken out of context when difficulties may become apparent.Dyspraxia people can be of average or above average intelligence but are often behaviourally immature. (4)Evidence suggests that children do not "grow out" of DCD and difficulties may extend into adolescence and sometimes into adult life.Consequently, early diagnosis and intervention is important for both child and family!With while early intervention is beneficial while the brain is changing dramatically during the first years of life and new connections and abilities are required.(5)There is no cure for dyspraxia but the earlier a child is treated then the greater the chance of improvement.The dyspraxia foundation believes that promoting awareness will help people dyspraxic as dyspraxia to be understood, which will in turn build by their self-esteem.(6)Early intervention during the preschool age offers a good opportunity for school failure prevention as the most significant educational effects of the condition involve fine skills such as those used in writing or drawing, or planning and self organization weakness may also be observed in the mechanisms of speech production such that articulation is impaired and expressive language is inhibited.There may be secondary effects in terms of poor self image and limited social acceptance by peers.
control study was carried out to determine the epidemiology of DCD among preschool children in Alexandria the initial studies sample was 473 children as 265 males and 208 females in the age range between 4-6 years attending kindergarten in Alexandria of middle socioeconomic level.
, explains this difference by the research evidences that female brains use both hemispheres to process language (predominantly a left hemispheric function) and spatial tasks (predominantly a right hemispheric function).Where there is evidence of immaturity in the left hemisphere the characteristic presenting symptoms are those of dyslexia where the immaturity is basal in the right hemisphere the symptoms are those of dyspraxia.Statistics say that the ratio of boys to girls with both conditions is somewhere in the region of 4 or 5 to 1. the incidence of girls identified as having either difficulty will be reduced because of the residual functioning in the opposing hemisphere.If there are difficulties with the left hemisphere in boys they do not have any additional backupsystems and so the problem persists.In females, where both sides of the brain have operative function, the difficulties will be reduced in many cases to a level where they are not significant.(12) motor coordination as revealed by Landgren et al., (1998)(16)  study which noted familial clumsiness in a study on 1134 children in Sweden.This is in accordance with our study that reveals significant increase in children with positive family history of dyspraxia.While dyspraxia describes physical coordination difficulties, the associated problems are not limited to this sphere because motor coordination is the product of a complex set of cognitive and physical processes that are often taken for granted in children who are developing normally smooth, targeted, and accurate movements, both gross and fine requiring the harmonious functioning of sensory input, central processing this information in the brain, and coordination with the high executive cerebral functions (e.g., volition, motivation, and motor planning of an activity).Also required is the performance of a certain motor pattern.These elements must work in a coordinated and rapid way to enable complex movements to involving different parts of the body.Motor planning consists of the ability of children to imagine a mental strategy to carry out a movement or an action.In this study, children found to lack imagination this is in accordance with Wilson's study (2000) (17) which revealed that children with DCD have an impairment in the ability to generate internal representation of optional movements.Also Wilson (2000) (17) maintains that children with DCD have difficulties in generating an accurate representation of an intended action which is shown by deficits in motor imagery.
syndrome has been described as a diagnostic entity only recently.This explains the fact that it has no entry DSMN or ICD10 classification.Rourke suggests a dynamic model speculating that primary neuropsychological deficits lead to secondary deficits in modality specific aspects of attention and more generally in the extent to which children activity explore their environment. (23)These primary neuropsychological deficits include tactile perception, visual perception and motor coordination.In turn, these secondary deficits lead to tertiary deficits, particularly in non-school memory, abstract reasoning, executive functions, and specific aspects of speech and language specific measurable impairments in academic performance, social functioning and emotional well being are direct byproducts of this constellation of primary, secondary or tertiary neuropsychological deficits the accuracy of the diagnosis being directly proportional to the number and magnitude of symptoms present that are consistent with the diagnosis.The Learning Disabilities Association of America stresses the importance of early intervention owing to the fact that the early years of life are a period of phenomenal growth and learning.Early intervention with the toddler at risk for learning disability, will improve the child's chances of future school success, reduce the need for special education services in later years, and minimize the loss of self esteem brought on by school failure.Motor skills, both gross and fine, and social interaction are fundamental for successful school performance.The present study reveals significant impairment of these skills in children with NVLD.It is, therefore, essential that early

Table 2 shows the main risk factors of dyspraxia in children
Table(2) shows the main predisposing factors of dyspraxia prematurity has a significant effect (p = 0.012).Also allergic disorder has a significant and rule (p = 0.004) family.