Relationship between T2-weighted hyperintensities (unidentified bright objects) and lower IQs in children with neurofibromatosis-1.
To address the controversy regarding the relationship between cognitive impairment (lowering of IQ) and magnetic resonance imaging (MRI) characteristics (T2-weighted hyperintensities or unidentified bright objects [UBOs]) in children with neurofibromatosis-1 (NF-1), we used a pairwise NF-1/ sibling design; we set out to predict the lowering of IQ in each child with NF-1 as a discrepancy from the IQ of an unaffected sibling (D-SIQ). Our multiple regression model included the age of the child with NF-1, familial or sporadic nature of the NF-1, number of locations in the child's brain occupied by T2-weighted hyperintensities (UBOs), and the volumetric percentage of brain tissue occupied by T2-weighted hyperintensities (UBOs). Only the number of locations occupied by UBOs accounted for IQ lowering (D-SIQ) in children with NF-1 (42% of the variance in D-SIQ). This is the first report to confirm that a continuum of lowered IQs in NF-1-affected children exists in relation to the distribution of UBOs (range 0-7), not just presence (vs. absence) of any UBOs.
Denckla
M B
MB
Kennedy Krieger Institute, Baltimore, Maryland 21205, USA.
Hofman
K
K
Mazzocco
M M
MM
Melhem
E
E
Reiss
A L
AL
Bryan
R N
RN
Harris
E L
EL
Lee
J
J
Cox
C S
CS
Schuerholz
L J
LJ
D000293:Adolescent; D002648:Child; D006801:Humans; D008607:Intellectual Disability / Q000150:complications*; D007360:Intelligence; D008279:Magnetic Resonance Imaging; D009456:Neurofibromatosis 1 / Q000503:physiopathology* / Q000523:psychology; D012044:Regression Analysis