Two teams evaluated the cognitive and behavioural problems of persons with Becker muscular dystrophy (BMD) in adults and in children aged 5 to 18 years.
The first natural history study, published in June 2022, was conducted over four years and involved 28 adults with BMD.
- The average IQ score was lower than in the general population, but highly variable (70 to 115). Only information processing speed and working memory were significantly affected.
- Other cognitive tests assessing reaction time to auditory and visual stimuli, executive functions and verbal memory show that only the latter is slightly affected.
- The most frequent problems were depressive symptoms (18.5%), social relational problems (29.6%), sleep disorders (33.3%), and affected working memory (48.8%). These were attributed to environmental factors, particularly bullying at school or stress at work.
- The cognitive and behavioral disorders observed did not seem to affect the participants’ academic career: 92.9% of them had an intermediate or higher level of education. 53.6% of them had a high level of education, despite the fact that they repeated almost twice as many years as the general population.
- All these elements and the variability observed do not allow us to draw up a behavioral profile specific to BMD. The observed disorders potentially constitute an obstacle during childhood and adolescence, but which patients learn to manage on a daily basis.
- Finally, no correlation could be demonstrated between the severity of motor impairment and the cognitive disorders observed.
Another study published in July 2022 provides more data on cognitive impairment in 22 young people aged between 5 and 18 years:
- The results are similar to those obtained in adults, with most participants (59.5%) having an IQ that is within or above the averages for the general population.
- Participants scored lowest on tasks involving working memory and information processing speed.
- The authors examined the correlation between the severity of cognitive impairment and the sites of mutations in the dystrophy gene (in front of or behind exons 31 and 44) and no differences were found.
