LEARNING DISABILITIES

About a third of boys with DMD have some degree of intellectual impairment. Boys with DMD have a higher incidence of learning disabilities than average, although few are seriously impaired or mentally retarded.

Studies since the 1960s have found the average IQ of Duchenne children to be in the 80s, compared with an average IQ for children in general of 100. IQs in the 80s are considered normal intelligence scores, but below average. IQs in the 70s are considered borderline between average and retarded. Only some of the Duchenne children studied had IQs in the retarded range, and many had very high IQs.

Some doctors once thought that the lower IQ scores only reflected emotional distress in the child and his family, disrupted education, impaired mobility and fewer life experiences. Perhaps there was a subtly transmitted attitude on the part of parents and teachers that learning wasn't important for a boy with DMD, since he probably wouldn't live to have a career.

Doctors now believe that dystrophin abnormalities in the brain may cause subtle and complex cognitive and behavioral deficits. Though not a form of mental retardation, these deficits can create problems with learning.

Inadequate dystrophin in three crucial brain areas can contribute to learning problems in children with DMD.

Exactly what role dystrophin plays in the brain isn't known for certain, although it's being studied. So far, we know that dystrophin is normally found in three crucial brain areas: the cortex, the cerebellum and the hippocampus. The cortex is an area where attention is regulated and signals coming from the rest of the brain are integrated. The cerebellum is where complex movement patterns are learned and fine-tuned. And the hippocampus is where short-term memories are prepared for storage as long-term memories (known as consolidation of memories). Logic dictates that if dystrophin is needed in these areas, then its lack could cause problems. The mental impairment found in DMD appears to be completely unrelated to the physical problems of DMD and isn't progressive.

The learning problems seen in some boys with DMD hamper their ability to receive information, store it in the brain and retrieve it. The problems occur in three general areas: attention focusing, verbal learning and memory, and emotional interaction.

The main problem is difficulty focusing attention. That alone could account for lower IQ scores in children with DMD. This type of attention deficit disorder leads to trouble focusing attention and letting go of attention. Children with this difficulty can't modulate, or regulate, their attention. Hyperactivity isn't part of this inattention problem.

In verbal learning, some boys with DMD have trouble with the phonological code, a system the brain uses to break down language into its smallest units of sound (known as phonemes). Normally, when people hear words, the brain processes and stores the words in a code of "sound bites," or phonemes, and probably later retrieves them the same way, before recoding them back into words. In DMD, the brain sometimes doesn't store information received verbally the way the normal brain does. This can lead to problems with reading, understanding spoken language and remembering what is read or heard.

Kids with deficits in the phonological code can benefit from special education that helps them use other pathways for learning, memory and language processing. This program can be spelled out in your child's IEP.

An IEP for a child with learning disabilities related to DMD should include goals and techniques to address auditory processing deficits; for example, it could say that teachers should give instructions in visual terms as well as spoken ones. Teachers can help with his short-term memory problems by having him keep a daily log of assignments and teaching him various ways of organizing information.

The effects of deficient brain dystrophin can also create difficulty with emotional interaction with other people that suggests a lack of "connectedness." Some observers say the child is immature, or "off" in some way that's hard to define.

Fortunately, these kinds of brain problems aren't unique to DMD, and special education teachers are quite familiar with them and with strategies to overcome them. The same kinds of programs offered to children with learning disabilities in the general population can make a big difference in the Duchenne child's capabilities and enrich his life. If your child is having trouble in school, talk to his teacher about special education in your school district. You may want to share with the school district materials from MDA, such as the article on learning disabilities from Quest magazine and this guide.

If you think your child with DMD may have a learning disability, you can have him evaluated by a developmental or pediatric neuropsychologist. You can arrange an evaluation through your school system's special education department, or request a referral to a neuropsychologist from the physician at your MDA clinic. If a learning disability is diagnosed, educational and psychological interventions can begin right away. The specialist may prescribe exercises and ways to interact with your child that can help improve these deficits.

The important thing is to maximize each child's capabilities and not to ignore learning disabilities if they exist.

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