RESUMO
PURPOSE: To evaluate the clinical characteristics of infants and young children who had developmental delay without delayed myelination and dysmyelination. METHODS: We retrospectively reviewed 59 cases of developmental disability between July 1996 and June 2001 at Inha University Hospital. Twenty-eight patients showed normal myelination(Group I), while thirty-one patients showed delayed myelination(Group II) by brain MRI. The following clinical records and diagnostic procedures were performed; birth history, head size, neurological examination, developmental assortment test, brain stem auditory evoked potential, visual evoked potential, electroencephalogram, chromosomal study, metabolic screening tests, and clinical psychologic tests. RESULTS: There were no significant differences of sex, age, gestational period, birth weight, etiology, and seizures between group I and II. The incidences of cerebral palsy and abnormal background activity of EEG in group II were significantly higher than those in group I. In group I, mental retardations or speech disorders were higher than motor handicaps. In group II, motor handicaps were higher than mental retardations or speech disorders. In both groups, cases accompanied with seizures, have a tendency of intractability. CONCLUSION: Characteristics of developmentally delayed patients with normal myelination by brain MRI were not significantly different from characteristics of patients with delayed myelination. Even though infants and young children with the developmental delay showed normal findings by brain MRI, they are likely to be accompanied by severe development retardation.