Significations et usages de Developmental_dyspraxia

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Developmental dyspraxia is a chronic neurological disorder beginning in childhood that can affect planning of movements and co-ordination as a result of brain messages not being accurately transmitted to the body.^[1] It may be diagnosed in the absence of other motor or sensory impairments like cerebral palsy^[2], muscular dystrophy, multiple sclerosis or Parkinson's disease.

  Epidemiology

Developmental dyspraxia (referred to as developmental coordination disorder (DCD)^{[3][4][5][6][7]} in the US and Europe) is a life-long neurological condition that is more common in males than in females, with a ratio of approximately four males to every female. The exact proportion of people with the disorder is unknown since the disorder can be difficult to detect due to a lack of specific laboratory tests, thus making diagnosis of the condition one of elimination of all other possible causes/diseases. Current estimates range from 5% to 20% with 5–6% being the most frequently quoted percentage in the literature. Some estimates show that up to 1 in 30 children may have dyspraxia.^[8]

  Assessment and diagnosis

Assessments for dyspraxia typically require a developmental history, detailing ages at which significant developmental milestones, such as crawling and walking, occurred. Motor skills screening includes activities designed to indicate dyspraxia, including balancing, physical sequencing, touch sensitivity, and variations on walking activities. A baseline motor assessment establishes the starting point for developmental intervention programs. Comparing children to normal rates of development may help to establish areas of significant difficulty.

However, research in the British Journal of Special Education has shown that knowledge is severely limited in many who should be trained to recognise and respond to various difficulties, including developmental coordination disorder, dyslexia and Deficits in attention, motor control and perception (DAMP). The earlier that difficulties are noted and timely assessments occur, the quicker intervention can begin. A teacher or GP could miss a diagnosis if they are only applying a cursory knowledge.

"Teachers will not be able to recognise or accommodate the child with learning difficulties in class if their knowledge is limited. Similarly GPs will find it difficult to detect and appropriately refer children with learning difficulties."^[9]

  Developmental profiles

Various areas of development can be affected by developmental dyspraxia and these will persist into adulthood,^[6] as dyspraxia has no cure. Often various coping strategies are developed, and these can be enhanced through occupational therapy, physiotherapy, speech therapy, or psychological training.

  Speech and language

Developmental verbal dyspraxia (DVD) is a type of ideational dyspraxia, causing linguistic or phonological impairment. This is the favoured term in the UK; however it is also sometimes referred to as articulatory dyspraxia and in the United States the usual term is childhood apraxia of speech (CAS).^[10]

Key problems include:

• Difficulties controlling the speech organs.
• Difficulties making speech sounds
• Difficulty sequencing sounds
  • Within a word
  • Forming words into sentences
• Difficulty controlling breathing and phonation.
• Slow language development.
• Difficulty with feeding.

  Fine motor control

Difficulties with fine motor co-ordination lead to problems with handwriting, which may be due to either ideational or ideo-motor difficulties. Problems associated with this area may include:

• Learning basic movement patterns.^[11]
• Developing a desired writing speed.
• The acquisition of graphemes – e.g. the letters of the Latin alphabet, as well as numbers.
• Establishing the correct^{[dubious – discuss]} pencil grip
• Hand aching while writing.

Fine-motor problems can also cause difficulty with a wide variety of other tasks such as using a knife and fork, fastening buttons and shoelaces, cooking, brushing one's teeth, applying cosmetics, styling one's hair, opening jars and packets, locking and unlocking doors, shaving and doing housework.^[12]

  Whole body movement, coordination, and body image

Issues with gross motor coordination mean that major developmental targets including walking, running, climbing and jumping can be affected. The difficulties vary from child to child and can include the following:

• Poor timing.
• Poor balance (sometimes even falling over in mid-step). Tripping over one's own feet is also common.
• Difficulty combining movements into a controlled sequence.
• Difficulty remembering the next movement in a sequence.
• Problems with spatial awareness, or proprioception.
• Some people with dyspraxia have trouble picking up and holding onto simple objects such as picking pencils and things up, owing to poor muscle tone and or proprioception.
• This disorder can cause an individual to be clumsy to the point of knocking things over and bumping into people accidentally.
• Some people with dyspraxia have difficulty in determining left from right.
• Cross-laterality, ambidexterity, and a shift in the preferred hand are also common in people with dyspraxia.
• Problems with chewing foods
• People with dyspraxia may also have trouble determining the distance between them and other objects.^[13]

  General difficulties

In addition to the physical impairments, dyspraxia is associated with problems with memory, especially short-term memory.^{[12][14][15][16][17]} This typically results in difficulty remembering instructions, difficulty organizing one's time and remembering deadlines, increased propensity to lose things or problems carrying out tasks which require remembering several steps in sequence (such as cooking). Whilst most of the general population experience these problems to some extent, they have a much more significant impact on the lives of dyspraxic people.^[17] However, many dyspraxics have excellent long-term memories, despite poor short-term memory.^[17] Many dyspraxics benefit from working in a structured environment,^[18] as repeating the same routine minimises difficulty with time-management and allows them to commit procedures to long-term memory.

People with dyspraxia may have sensory processing disorder, including abnormal oversensitivity or undersensitivity to physical stimuli, such as touch, light, and sound.^[13] This may manifest itself as an inability to tolerate certain textures such as sandpaper or certain fabrics and including oral toleration of excessively textured food (commonly known as picky eating), or even being touched by another individual (in the case of touch oversensitivity) or may require the consistent use of sunglasses outdoors since sunlight may be intense enough to cause discomfort to a dyspraxic (in the case of light oversensitivity). An aversion to loud music and naturally loud environments (such as clubs and bars) is typical behavior of a dyspraxic individual who suffers from auditory oversensitivity, while only being comfortable in unusually warm or cold environments is typical of a dyspraxic with temperature oversensitivity. Undersensitivity to stimuli may also cause problems. Dyspraxics who are undersensitive to pain may injure themselves without realising.^[13] Some dyspraxics may be oversensitive to some stimuli and undersensitive to others.^[13] These are commonly associated with autism spectrum conditions.

People with dyspraxia sometimes have difficulty moderating the amount of sensory information that their body is constantly sending them, so as a result these people are prone to panic attacks.^[17] Having other autistic traits (which is common with dyspraxia and related conditions)^[16] may also contribute to sensory-induced panic attacks.

Dyspraxia can cause problems with perception of distance, and with the speed of moving objects and people^[13] This can cause problems moving in crowded places and crossing roads and can make learning to drive a car extremely difficult or impossible.

Many dyspraxics struggle to distinguish left from right, even as adults, and have extremely poor sense of direction generally.^[12]

Moderate to extreme difficulty doing physical tasks is experienced by some dyspraxics, and fatigue is common because so much extra energy is expended while trying to execute physical movements correctly. Some (but not all) dyspraxics suffer from hypotonia, which in this case is chronically low muscle tone caused by dyspraxia. People with this condition can have very low muscle strength and endurance (even in comparison with other dyspraxics) and even the simplest physical activities may quickly cause soreness and fatigue, depending on the severity of the hypotonia. Hypotonia may worsen a dyspraxic's already poor balance.^[19]

  Overlap with other conditions

Dyspraxics may have other difficulties that are not due to dyspraxia itself but often co-exist with it. This is sometimes referred to as comorbidity.^[20] Dyspraxics may have characteristics of dyslexia (difficulty with reading and spelling), dyscalculia (difficulty with mathematics), dysgraphia (an inability to write neatly and/or draw) expressive language disorder (difficulty with verbal expression), ADHD (poor attention span and impulsive behaviour), or Asperger syndrome (consisting variously of poor social cognition, a literal understanding of language [making it hard to understand idioms or sarcasm] and rigid, intense interests). However, they are unlikely to have problems in all of these areas. The pattern of difficulty varies widely from person to person, and it is important to understand that a major weakness for one dyspraxic can be a strength or gift for another. For example, while some dyspraxics have difficulty with reading and spelling due to an overlap with dyslexia, or numeracy due to an overlap with dyscalculia, others may have brilliant reading and spelling or mathematical abilities. Some estimates show that up to 50% of dyspraxics may have ADHD.

Students with dyspraxia struggle most in visual-spatial memory. When compared to their peers who don’t have motor difficulties, students with dyspraxia are seven times more likely than typically developing students to achieve very poor scores in visual-spatial memory.^[21] As a result of this working memory impairment, students with dyspraxia have learning deficits as well.^[22]

Some students with dyspraxia can also have comorbid Specific Language Impairment (SLI). Research has found that students with dyspraxia and normal language skills still experience learning difficulties despite relative strengths in language. This means that for students with dyspraxia their working memory abilities determine their learning difficulties. Any strength in language that they have is not able to sufficiently support their learning.^[23]

  Other names

Collier first described developmental dyspraxia as 'congenital maladroitness'. A. Jean Ayres referred to it as a disorder of sensory integration in 1972 while in 1975 Dr Sasson Gubbay called it the 'clumsy child syndrome'.^[7] It has also been called minimal brain dysfunction although the two latter names are no longer in use. Other names include:

• Clumsy Child Syndrome
• Developmental Apraxia
• Disorder of Attention and Motor Perception (DAMP)
• Dyspraxia
• Developmental Co-ordination Disorder (DCD) - a subtly different condition by definition, in practice, very similar.
• Motor Learning Difficulties
• Perceptuo-motor dysfunction
• Sensorimotor dysfunction^[3]

The World Health Organisation currently lists Developmental Dyspraxia as Specific Developmental Disorder of Motor Function.^[7]

  Notable dyspraxics

Living people who have publicly stated they have been diagnosed with dyspraxia include actor Daniel Radcliffe,^[24] photographer David Bailey, Florence Welch from Florence and the Machine and actress Hannah McDonnell.^[25]

Writers suspected to have had the condition include Emily Bronte, Charlotte Bronte, poet Samuel Taylor Coleridge, G.K. Chesterton, Ernest Hemingway, Jack Kerouac and George Orwell.

Helen Burns, a character from Charlotte Bronte's Jane Eyre, is alleged to have been based on the author's dyspraxic elder sister Maria Bronte

  See also

• Apraxia
• Deficits in Attention, Motor control and Perception
• Motor coordination
• Motor skills disorder
• Working memory

  References

  External links

• Childhood Apraxia of Speech: Technical Report 2007 AHSA
• Apraxia Research
• Dyspraxia Foundation, UK
• Dyspraxia Association of Ireland
• Dyspraxia Adults Action
• Developmental Adult Neuro-Diversity Association (DANDA)
• Dyspraxia Foundation USA
• An Online Spelling Correction Resource Assisting Dyspraxia & Dyslexia
• Dyspraxia Information