The functional significance of T2 hyperintense lesions (UBOs) and their role in learning disabilities associated with neurofibromatosis type 1 (NF-1) were studied by quantitative magnetic resonance spectroscopy (MRS) in 7 male patients, aged 6-19 years, and 7 controls, at Johns Hopkins University, Baltimore, MD. Choline metabolite concentrations within UBOs, globus pallidus, and thalami were elevated in younger NF-1 subjects (<10 years), and were normal in older patients. N-acetylaspartate (NAA) levels were preserved in younger subjects and reduced in older patients. NAA was also decreased in the periventricular white matter. The MRS metabolic abnormality in UBOs of NF-1 is representative of a more generalized abnormality in affected brain regions. Choline elevations, reflecting increased myelin turnover in edematous areas, is followed by axonal injury and reduced NAA. 
COMMENT. This work is an extension of previous reports from Johns Hopkins University concerning the relationship between UBOs and lower IQs in children with neurofibromatosis-1 . (see Progress in Pediatric Neurology III, PNB Publ, 1997;pp291-294, for a review of these and other reports, some showing conflicting results).
Ped Neur Briefs Nov 1997;11:84, reviews an article on learning disability subtypes in children with neurofibromatosis; academic underachievers fall into 3 groups: 40% have normal IQ test results, 50% have general learning disabilities, and 14% have visuospatial and motor coordination problems, without language deficits.