Is Brain MRI Needed in Diagnostic Evaluation of Mild Intellectual Disability?

ABSTRACT

AIM: The purpose of our study was to suggest an imaging strategy and guidelines for the selection of the children with mild intellectual disability (ID) for magnetic resonance imaging (MRI), to avoid unnecessary imaging. METHODS: The brain MRIs and patient reports of 471 children were reviewed for the imaging findings and ID severity. The correlation between the clinical and brain MRI findings was analyzed in the 305 children with mild ID. RESULTS: Thirty-eight (12.5%) of the children with mild ID had significant abnormal brain MRI findings. Thirty-five of these had other neurological symptoms or diseases in addition to ID, which were an indication for brain MRI. In the logistic regression analysis, seizures (in patients without an epilepsy diagnosis), epilepsy, movement disorders, dysmorphia, encephalitis, traumatic brain injury, and abnormal head size were statistically significant symptoms or comorbidities associated with abnormal MRI findings. Only three children (1.0%) with mild ID had a significant MRI finding without any other clinical symptoms or disease. CONCLUSION: Routine MRI in children with mild ID without specific neurological symptoms, dysmorphic features, or related diseases is not suggested for revealing an etiology of mild ID. Since children with ID usually need to be sedated for MRI, routine imaging in the diagnostic evaluation of mild ID should be carefully considered. Clinical examination, other symptoms, and related diseases should be carefully assessed to decide the need for MRI.