The significance of abnormalities on MRI was evaluated in 40 children with NF-1, aged 8 to 16 years, at the Children’s Hospital, Sydney, Australia. The distribution of Full Scale IQ scores was bimodal, one group with and a second group without cognitive impairment. Children with areas of increased signal intensity on MRI (unidentified bright objects, UBO+), accounting for 62.5% of the study population, had lower IQs than those without these lesions. Language function, visuomotor integration, academic achievement, and coordination were also impaired in the UBO+ group. IQ and achievement in the UBO- group were similar to the general population. 
COMMENT. UBOs in children with neurofibromatosis-1, representing areas of developmental dysplasia and aberrant myelination, are associated with cognitive deficits. Patients identified with UBOs should be managed separately from the UBO- group in determining the need for special education services.
Similar findings have been reported from the Johns Hopkins Hospital, Baltimore, MA . In a study of 12 families, children with NF-1 compared to unaffected siblings had a lower Full Scale IQ, multifocal cognitive deficits, reading disability, and neuromotor deficit. Paired cognitive differences correlated with the number of brain lesions on MRI.