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Talk; other LD

Friday stream 1 Session 14.00 - 15.40 Length 25 minutes

Dyslexia, Dyspraxia or Just Special Educational Needs: discreet diagnostic entities, or an overlapping spectrum of symptoms?

Andrew Newton

Medical Advisor to the Dyslexia Association (North Somerset) andrew.newton@waht.swest.nhs.uk

Abstract

The overlapping nature of Dyslexia, Dyspraxia and Attention Deficit Hyperactivity Disorder is something that has long been recognised. Recent medical research on causation of the syndromes has shed light on biological mechanisms, which may account for the overlapping symptomatology.

A questionnaire study of groups of children diagnosed with Dyslexia, Dyspraxia and Attention Deficit Hyperactivity Disorder revealed very marked overlap of common symptoms between the three groups of children.

Co-morbidity may be the rule rather than the exception when it comes to specific learning difficulties. The inherent difficulty experienced in classifying children with specific learning difficulty probably reflects the diffuse and overlapping nature of the spectrum of developmental disorders.

An individual child's specific needs must be made the focus of attention in any given case rather than being the means towards achieving a diagnostic label.

Hypothesis

There is considerable symptomatic overlap between the specific learning difficulties, Dyslexia, Dyspraxia and Attention Deficit Hyperactivity Disorder.

Potential Reasons for Overlapping Symptomatology

There are a number of plausible reasons why there may be significant overlap between the specific learning difficulty conditions. The first and most widely accepted reason is that there is significant co-morbidity. More recently neurological studies have identified similarities of neurological dysfunction and this is now becoming widely accepted as being the explanation for these symptomatic overlaps.

Aims

This study was designed to demonstrate the degree to which there is a symptomatic overlap with regard to behaviours exhibited by children formerly diagnosed with Dyslexia/Dyspraxia/Attention Deficit Hyperactivity Disorder.

Methods

Full ethical approval for this study was obtained from the Medical Ethics Committee of Weston General Hospital. The study was questionnaire-based and utilised the service of three nationally recognised diagnostic centres dealing with children with specific learning difficulties. Each of the three centres chosen to participate in the study had a specific interest in children with each of the three target conditions (namely Dyslexia, Dyspraxia and Attention Deficit Hyperactivity Disorder).

Children aged between 7 and 10 years of age were eligible for entry into the study. All children entered into the study had to be newly diagnosed with one of the three target conditions. (Diagnosis of the children was made using standard diagnostic tests as employed at the diagnostic centres).

Fifty children were recruited from each centre (i.e. 50 children with diagnosed Dyslexia, 50 children with diagnosed Dyspraxia and 50 children with diagnosed Attention Deficit Hyperactivity Disorder).

The questionnaire was distributed to families by the diagnostic centre staff to be completed by the family on completion of their appointment at the diagnostic centre concerned. The completed questionnaire was then returned directly to the researcher for analysis in a sealed stamped addressed envelope.

The questionnaire contained 20 health-related questions and 50 behaviour questions with 'yes/no' response tick boxes.

The behaviour questions list was derived from listed typical behaviours of children with Dyslexia, Dyspraxia and Attention Deficit Hyperactivity Disorder as described in recognised standard texts on the conditions concerned (1, 2, 3, 4, 5,). Cross-check questions to assess responder variability were included.

The questionnaires were analysed by performing a frequency count for each reported behaviour within each diagnostic group. Common behaviours were defined as being those reported to be exhibited by more than half of the children within each diagnostic group.

Results

Commonly reported behaviours for each of the three diagnostic groups (Dyslexia, Dyspraxia and attention deficit hyperactivity disorder) were identified. The number of common behaviours for each of the three diagnostic groups is presented below in tabular form (Table 1).

Table 1 - The number of common behaviours reported within each diagnostic group

Overlaps of the common behaviours between the three diagnostic groups were then calculated. The number of overlapping behaviours between the different diagnostic groups is presented in tabular form below (Table 2).

Table 2 - Overlapping behaviours between the different diagnostic categories.

Six behaviours were found to be common in all three diagnostics groups. These six behaviours common to all three conditions were;

1. Tends to fidget excessively.
2. Shows poor attention to detail when working.
3. Tends to frequently loose belongings.
4. Makes frequent careless mistakes.
5. Has difficulty organising tasks.
6. Has difficulty following a series of instructions.

A Venn diagram representation of the distribution of common behaviours is presented below. (Fig. 1)

Figure 1 : The overlap of common behaviours between Dyslexia, Dyspraxia and ADHD

Literature review

The overlap of symptomatology between the specific learning difficulties, Dyslexia, Dyspraxia and Attention Deficit Hyperactivity Disorder is becoming increasingly well recognised. Kaplan presented research at the Novatis Foundation Conference in 1998 (6) to support the hypothesis that co-morbidity is the rule rather than the exception in specific learning difficulties. (Professor Kaplan's work suggested that 52% of children with Dyslexia have features of Dyspraxia and 33% of children with attention deficit hyperactivity have features of Dyspraxia).

Even 20 years ago it was recognised that Dyslexic children had significant co-ordination difficulties (this was demonstrated experimentally by looking at dyslexics' ability to maintain a steady tapping rhythm with their fingers)(7). Recent neuro-imaging studies have identified an association between abnormal cerebellar activation and the presence of motor learning difficulties in Dyslexic adults (8).

Children diagnosed with Dyspraxia have long been recognised as having spelling and reading difficulties (9) however the true extent and implications of the symptomatic overlaps are only now being fully recognised and addressed at a practical level in schools (10, 11).

At a medical level the validity of Attention Deficit Hyperactivity Disorder as a singular entity is also being questioned with many eminent researchers suggesting that rather than being a definable disease entity it is a cluster of symptom complexes. (12).

Discussion

The findings of the questionnaire-based study of children with specific learning difficulties suggest that there is indeed a very large symptomatic overlap of common symptoms between the conditions, Dyslexia, Dyspraxia and Attention Deficit Hyperactivity Disorder.

The key points arising from this work are as follows:

1. Co-morbidity may be the rule rather than the exception.
2. The inherent difficulty in classifying children with specific learning difficulty probably reflects the very diffuse and overlapping nature of the spectrum of developmental disorders.
3. The current trend towards increasingly sensitive (and in some cases clinically invasive) diagnostic tests may be seen to be inappropriate in the light of the above two points.
4. Co-ordinated research is needed to help identify commonalities rather than differences in specific learning difficulty.
5. An agreed user-friendly (simple) terminology should be sought to help unite 'Health' and 'Education' and to help parents understand their child's needs.
6. An individual child's specific needs must be the focus in each case rather than representing the means towards achieving a diagnostic label for that child.

References

1. Demystifying Dyslexia. M Krupska, C Klein. London Language & Literacy Unit. 1995. ISBN 1 872972144
2. Specific Learning Difficulties. A Teacher's Guide. M Crombie. Ann Arbor Publications. 1997 ISBN 1 9005006025
3. Identifying and Supporting the Dyslexic Child. C Mellers. Desk Top Publications. 1993. ISBN 1 87240636X
4. Attention Deficit Hyperactivity Disorder. A Practical Guide for Teachers. P Cooper, K Ideus. David Fulton Publications. 1996. ISBN 1 8533464317
5. Developmental Dyspraxia. M Portwood. E P S Publications. 1996. ISBN 1 897585217
6. DCD How do you Define What it is and What it is Not? Proceedings of a Novartis Foundation Conference. October 1998.
7. Bi-Manual Coordination in Adolescent Boys with Reading Retardation. C Klicpera, P Wolff. Journal of Developmental Medicine and Child Neurology. 1981 (5) 617-625.
8. Association of Abnormal Cerebella Activation with Motor Learning Difficulties in Dyslexic Adults. R Nicolson, A Fawcett et al. The Lancet. 1999 (353) 1662-1667.
9. Spelling Performance of Children with Developmental Verbal Dyspraxia. M Smowling, J Stackhouse. Journal of Developmental Medicine and Child Neurology. 1983 (4) 430-437.
10. Identifying Assessing and Helping Dyspraxic Children. S Flory. Dyslexia (6) 202-214. 2000.
11. Interventions with Pupils with Dyspraxic Difficulties. P Payton M Winfield. Dyslexia (6) 202-214. 2000.
12. Attention Deficit Hyperactivity Disorder; A Disease or a Symptom Complex? W Weinberg et al. Journal of Paediatrics. 1997 (130) 665-668.