Cognitive Benefit of Intensive Rehabilitation Using Rhythmic Music Training in Children With Complex Neurodevelopmental Disorder

Inclusion Criteria: * Diagnosis of neurodevelopmental disorder involving at least two impairments (ADHD + DCD, ADHD + Dyslexia, Dyslexia + DCD, ADHD + Dyslexia + DCD), according to DSM-5 criteria (2015), established at the Language and Learning Disorders Reference Center (CRTLA) of Toulouse University Hospital. * Aged between 8 years and 10 years 6 months. * Enrolled in elementary school. * Visual, auditory (with permitted aids), motor, oral and written expression and comprehension abilities sufficient, according to the investigator physician's assessment, to perform cognitive tests and follow the intervention. * Patient beneficiary/affiliate of the French Social Security system. * Signed informed consent from parent(s) / legal guardian(s) in accordance with French law and Good Clinical Practice, along with minor's assent. * Authorization for image and sound recording. Exclusion Criteria: * Practice of a musical instrument during the current year (in a music school or leisure activity). * Behavioral disorder making group practice difficult (e.g., oppositional defiant disorder) according to the investigator's opinion. * Patient diagnosed with autism spectrum disorder or intellectual developmental disorder (IQ \< 70). * Patient with epilepsy (with or without treatment). * Uncorrected hearing or visual impairment. * Current treatment with psychostimulants or psychotropic drugs (notably methylphenidate, antidepressants). * Patient lacking access to a stable internet connection required for teleconsultation assessments. * Any family or sociological condition preventing compliance with the procedures outlined in the study protocol, according to the investigator's opinion. * Patient participating in another human research study involving experimental treatment or behavioral therapy. * Ongoing rehabilitative care is not an exclusion criterion for the study.