An Italian study carried out in 22 children with type I SMA, aged 3 to 11 years, without clear and understandable speech but able to communicate at least by yes and no, showed:
- a median IQ of 120 on the Raven Progressive Matrix Multiple Choice Intelligence Test;
- a normal level of morphosyntactic comprehension on a children’s grammar comprehension test;
- an average speech score of 5 on a scale of 1 (non-vocal) to 10 (normal speech process), lower in the most affected children.
Thus, despite a very severe motor and speech impairment, children with type I SMA without disease-modifying treatment present an overall cognitive level lying in a range slightly higher than that of the general population with a level of language comprehension. normal verbal.