The impact of early childhood lead exposure on brain organization: a functional magnetic resonance imaging study of language function.
OBJECTIVE
The purpose of this work was to assess the long-term impact of childhood lead exposure on the neurosubstrate of language function and brain organization.


METHODS
Young adults from the Cincinnati Lead Study were recruited to undergo functional magnetic resonance image scanning while performing a verb generation task. These subjects have been followed from birth through early childhood with extensive documentation of lead exposure, neuropsychology, and behavior. Forty-two subjects provided useful imaging data. The locale, strength, and the correlation between brain language activation and childhood blood lead concentration were studied.


RESULTS
After adjusting for potential confounders, the activation in left frontal cortex, adjacent to Broca's area, and left middle temporal gyrus, including Wernicke's area, were found to be significantly associated with diminished activation in subjects with higher mean childhood blood lead levels, whereas the compensatory activation in the right hemisphere homolog of Wernicke's area was enhanced in subjects with higher blood lead levels.


CONCLUSIONS
This study indicates that childhood lead exposure has a significant and persistent impact on brain reorganization associated with language function.
Yuan
Weihong
W
Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
Holland
Scott K
SK
Cecil
Kim M
KM
Dietrich
Kim N
KN
Wessel
Stephanie D
SD
Altaye
Mekibib
M
Hornung
Richard W
RW
Ris
M Douglas
MD
Egelhoff
John C
JC
Lanphear
Bruce P
BP
D000328:Adult; D002648:Child; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D005625:Frontal Lobe / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism; D006801:Humans; D007804:Language Development; D007854:Lead / Q000009:adverse effects*; D008279:Magnetic Resonance Imaging; D008297:Male; D013702:Temporal Lobe / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism
D004785:Environmental Pollutants; D007854:Lead