Blei wie Quecksilber
schädigen das kindliche Gehirn
Decreased
brain volume in adults with childhood lead exposure
Cecil KM, Brubaker CJ,
Adler CM, Dietrich KN, Altaye M, Egelhoff JC, Wessel S, Elangovan I, Hornung R,
Jarvis K, Lanphear BP.
Cincinnati Children's
Environmental Health Center, Cincinnati Children's Hospital Medical Center,
Cincinnati, Ohio, United States of America. kim.cecil@cchmc.org
PLoS Med. 2008 May
27;5(5):e112.
BACKGROUND: Although environmental lead exposure is associated with significant
deficits in cognition, executive functions, social behaviors, and motor
abilities, the neuroanatomical basis for these impairments remains poorly
understood. In this study, we examined the relationship between childhood lead
exposure and adult brain volume using magnetic resonance imaging (MRI). We also
explored how volume changes correlate with historic neuropsychological
assessments.
METHODS AND FINDINGS:
Volumetric analyses of whole brain MRI data revealed significant decreases in
brain volume associated with childhood blood lead concentrations. Using
conservative, minimum contiguous cluster size and statistical criteria (700
voxels, unadjusted p < 0.001), approximately 1.2% of the total gray matter
was significantly and inversely associated with mean childhood blood lead
concentration. The most affected regions included frontal gray matter,
specifically the anterior cingulate cortex (ACC). Areas of lead-associated gray
matter volume loss were much larger and more significant in men than women. We
found that fine motor factor scores positively correlated with gray matter
volume in the cerebellar hemispheres; adding blood lead concentrations as a
variable to the model attenuated this correlation.
CONCLUSIONS: Childhood lead
exposure is associated with region-specific reductions in adult gray matter
volume. Affected regions include the portions of the prefrontal cortex and ACC
responsible for executive functions, mood regulation, and decision-making. These
neuroanatomical findings were more pronounced for males, suggesting that
lead-related atrophic changes have a disparate impact across sexes. This
analysis suggests that adverse cognitive and behavioral outcomes may be related
to lead's effect on brain development producing persistent alterations in
structure. Using a simple model, we found that blood lead concentration
mediates brain volume and fine motor function.
http://www.ncbi.nlm.nih.gov/pubmed/18507499?dopt=AbstractPlus