Blood levels neuropsychological tests

Subtle, often subclinical, neurological effects have been demonstrated in workers with relatively low blood lead levels, below 40-60 J,g/100ml blood. Performance of lead workers on various neuropsychological tests was mildly reduced, relative to a control group, at mean levels of 49 j,g/100ml blood and, in a prospective follow-up study, at levels between 30 and 45 pg/lOOml blood.In some of these studies, the lead-exposed workers reported significantly more complaints of nonspecific subjective symptoms, such as anxiety, depressed mood, poor concentration, and forgetfulness. However, a recent evaluation of 21 studies found inadequate evidence of decreased neu-robehavioral test performance in adults with cumulative low-level exposure to lead. In con-... 

Neuropsychological tests considered to be particularly sensitive to prefrontal cortical functioning - such as the tests of motor planning, visual search, and verbal fluency the Tower of Hanoi the Stroop Color World Test and the Wisconsin Card Sorting Test-havebeen used to test this hypothesis. Diamond etal. (1994) reported that early and continuously treated children (with blood phenylalanine levels... 

Not all studies, however, support the dopamine-prefrontal dysfunction hypothesis. Mazzocco et al. (1994), using the Tower of Hanoi and visual search tests, found that children aged 6-13 who were treated early and continuously showed no deficits on the neuropsychological tests, despite a range of blood phenylalanine levels. 

There is a growing body of evidence that suggests that the performance of young children in neuropsychological tests may be impaired by exposure to lead levels below those that produce obvious cliniced s3miptoms. The literature indicates that there is a relationship between such as3miptomatic or subclinical elevation of blood lead levels emd a number of CNS effects, including... 

What can sleep neurophysiology and the new neuropsychology tell us about lucid dreaming, and how can we use that information to increase our access to that state And what, beyond entertainment, can we learn about the brain-mind from a scientific exploration of lucid dreaming The last question has one ready answer by placing experienced lucid dreamers in a PET scanner (or preferably an fMRI), we could test the hypothesis that, when lucid, dreamers increase the blood flow to their dorsolateral prefrontal cortices as that cortex reactivates to a level consistent with wake state executive function. 

Hansen ON, Trillingsgaard A, Beese I, et al A neuropsychological study of children with elevated dentine lead level assessment of the effect of lead in different socio-economic groups. Neurotoxicol Teratol 11 205-213, 1989 Haritos NP Chronic lead intoxication a report of 21 treated cases at Children s Hospital. Clinical Proceedings of the Children s Hospital 17 110-115,1961 Harvey PC, Hamlin MW, Kumar R Blood lead, behaviour and intelligence test performance in preschool children. Sci Total Environ 40 45-60, 1984 Hawk BA, Schroeder SR, Robinson G, et al Relation of lead and social factors to IQ of low-SES children a partial replication. American Journal of Mental Deficiency 91 178-183, 1986... 

The present study was designed to evaluate the relationship between different biological indicators of body lead burden and some neuropsychological functions in 7-8-year-old children, living in an industrial area polluted by lead. The neuropsychological functions were estimated by a battery of 6 psychometric tests. Lead was measured in blood, hair and teeth, and mean levels of 11.45 jug dl 9.94 figg and 6.80 jUg g respectively, were obtained. 

Harvey, P.G., Hamlin, M.W., Kumar, R. and Delves, H.T. (1984) Blood lead, and intelligence test performance in preschool children. ScL Total Environ., 40, 45-60 Kotok, D., Kotok, R. and Heriot, J.T. (1977) Cognitive evaluation of children with elevated blood lead levels. Am. ]. Dis. Child., 131, 791-793 Landrigan, P.J., Whitworth, R.H. and Baloh, R.W. (1975) Neuropsychological dysfunction in children with chronic low-level lead absorption. Lancet, 1, 708-712 Lansdown, R.G., Shepherd, J., Clayton, B.E., Delves, H.T., Graham, P.J. and Turner, W.C. 

---