Bangalore February 28th
Duchenne research at
Maastricht
INTELLIGENCE AND LEARNING
Jos Hendriksen Ph.D.
Ruben Hendriksen, student
Debby Schrans, MsC.
Kempenhaeghe Epilepsy centre
& Centre of neurological
learning disabilities
University Hospital
Maastricht
EVERY BOY IS UNIQUE
THE AVERAGE BOY
WITH DUCHENNE DOES
NOT EXIST!
Outline
1. Introduction
2. Intelligence and DMD
3. Specific cognitive deficits
4. Academic achievement
5. What can we do?
Intelligence and DMD
Duchenne de Boulogne
1868
Already noticed problems
in cognitive functioning;
“The intellect was dull and speech was
difficult. The Temporal regions were
extremely projecting as in hydrocephalics”
Intelligence and DMD
Review of the reviews
Intelligence and DMD
Review of all studies on
Intelligence
N=1224 boys:
Mean age 12 (range 2-27 years)
Full Scale IQ
=80 (range 14-134)
Verbal IQ
=80 (range 39-144)
Performance IQ =85 (range 42-136)
Conclusion: mild impairment;
scores around an average of 80
Intelligence and DMD
Intelligence and age
Intelligence and DMD
Association between IQ
and age
VIQ improves with age:
<9 years: Mean = 78
>20 years: Mean = 86
Intelligence and DMD
It is important to keep in
mind that the cognitive
deficits in DMD are stable,
and even may improve
somewhat over time
(especially verbal IQ).
Intelligence and DMD
In summary:
there is more than a global
deficit
Intellectual impairment is:
• specific to language IQ (VIQ);
• stable over time;
• independent of functional
impairments.
Outline
1. Introduction
2. Intelligence and DMD
3. Specific cognitive deficits
4. Academic achievement
5. What can we do?
Specific cognitive deficits
Specific Language Impairment
(SLI)
- late onsett of speaking;
- word finding problems;
- deficit in auditory working memory;
- influent speech: restarts, fillers, pauzes;
- speech understanding >> expression.
Specific cognitive deficits
Short term memory deficits
Wicksell et al (2004):
The short term memory deficits might
play a critical role in the cognitive
impairment and intellectual development.
Controls
DMD
Specific cognitive deficits
Attention problems: incidence
Hendriksen & Vles, N=351 (DMD boys)
18,7%
7,5%
Specific cognitive deficits
Cognitive profile: a summary
Weaknesses
expressive language
working memory
attentional processes
Strenghts
unique for every boy
Specific cognitive deficits
Conclusion
•  There is a relation between brain structure
and cognitive involvement in Duchenne;
•  Dystrophin is normally located in specific
areas of the brain;
–  Hippocampus (responsible for memory)
–  Cerbellum (responsible for automatisation)
–  Prefrontal cerebral cortex (responsible for
executive functions like planning)
Intelligence and DMD
DMD and the brain
Prefrontal cortex
cerebellum, hippocampus
and prefrontal cortex
areas of greatest
abundance of dystrophin
in the brain
areas that directly
subserve cognitive
processes
Outline
1. Introduction
2. Intelligence and DMD
3. Specific cognitive deficits
4. Academic achievements
5. What can we do?
Academic achievements
Dutch study on reading in
DMD
Academic achievements
The study itself:
• 25 boys;
• All boys had finished elementary
reading instruction (>20 months
reading instruction);
• mean age 10 years (8 to 12 years).
Academic achievements
Academic achievements
Conclusion
Academic achievement
1. boys with DMD are at a higher
risk of reading disabilities
(40% risk)
2. early detection and
prevention are important:
early screening for language
difficulties
Outline
1. Introduction
2. Intelligence and DMD
3. Specific cognitive deficits
4. Academic achievement
5. What can we do?
What can we do?
Early detection
Seek specialist support when:
- Your boy has problems with early speech and
language (SLI);
- Your boy is falling behind his peers with
reading and spelling.
Psychological assessment and speech therapy
assessment is important.
What can we do?
Maastricht protocol
• Screening at 4 years of age:
–  language skills
–  strenghts and weakenesses
• Screening at 7 years of age:
–  written language skills
What can we do?
Early Intervention:
Training phonemic awareness in a preschool
programm: rhyming, ditties and playing with
sentences and words (Adams, 1998)
Effect: risc of dyslexia was reduced in children
of dyslectic parents from 40% to 17%
What can we do?
Parents can also contribute!
The benefits of reading aloud to children:
•  More precise phonological representations;
•  developing richer vocabulary;
•  developing lasting interest in reading.
What can we do?
Most important:
Enhance pleasure in reading
What can we do?
Conclusions
• Cognitive deficits are related to reading;
• reading is important for later education,
especially in boys with DMD;
• higher risk of reading problems in boys with
DMD: 40%;
• early screening and early intervention is
important;
• enhance pleasure.
Thank You for your attention
hendriksenj@kempenhaeghe.nl
schransd@kempenhaeghe.nl
• Questions?
• Comments?