Evaluation and Comparison of MRI Findings in Children with Global Developmental Delay and Isolated Neurodevelopmental Delay: A Cross-sectional Study

Background and objectives: Neurodevelopmental delay (NDD) is a chronic neurologic problem that adversely affects the quality of life of affected individuals. The aim of this study was to evaluate diagnostic efficacy of MRI for children with NDD by comparing magnetic resonance imaging (MRI) findings of patients with global developmental delay (GDD) and isolated NDD. Methods: A cross-sectional study was designed to enroll all patients with static developmental delay who had been referred to outpatient neurology clinic at Bahrami hospital (Tehran, Iran) between February 2012 and February 2013. The Bayley Scales of Infant and Toddler Development 4th edition, Denver Developmental Screening test, and a self-made questionnaire were used to detect GDD, isolated NDD, and record all necessary information of neurologic examination. Brain MRI was performed based on the guidelines for the selected patients. All abnormal MRI findings were identified and confirmed by a neuro-radiologist. Results: Overall, 140 patients with developmental delay were enrolled in the study. The prevalence of both GDD and isolated NDD was 50%. In addition, abnormal associated neurological symptoms were present in 67.9% of patients. Abnormal MRI findings were significantly more common among patients with GDD compare to patients with isolated NDD (P<0.001). However, positive MRI findings were more common among patients with isolated motor NDD (P=0.007). Microcephaly was the most common abnormal neurologic finding in patients with GDD (P=0.04). Movement disorders were also more frequently seen in patients with GDD than in patietns with isolated NDD (P=0.03). Conclusion: Based on the findings, brain MRI can be considered as a suitable diagnostic modality for GDD but not isolated NDD.