Neuropsychological toxicology investigates the impact of chemical exposure on the structure and functioning of the nervous system and by implication the neuropsychological performance of affected individuals. As in mainstream neuropsychology, brain damage is assessed by measuring changes in the cognitive, psychomotor and emotional domains using diagnostic neuropsychological tests. The field of neuropsychological toxicology has undergone significant growth in the last 20 years, amongst growing concerns over people’s potential everyday exposure to approximately 70 000 chemicals. Growing awareness of the possible dangers associated with neurotoxic exposure has lead to the increased regulation of exposure levels especially in industrial settings. This in turn has lead to a gradual shift in neuropsychological toxicology from the assessment of severe neurotoxic damage to the evaluation of subclinical signs, which may develop into disabling damage over many years of exposure. The assessment of these subclinical signs has proven to be tricky as they cannot always be measured through diagnostic tests and may be mimicked or hidden by numerous confounding variables. The need for the effective assessment of these subclinical signs has created a need for more sensitive tests and improved research methodology. This paper uses evidence from cellular pathology and anatomical pathology (dynamic brain localisation theory) as a guide for the selection of neuropsychological tests. The purpose of the paper is to review the neuropsychological outcomes of toxic exposure, with an emphasis on test sensitivity (screening) and specificity (diagnostic) to carbon disulphide (solvent), manganese (metal) and organophosphate (pesticide) exposure. Findings from this review point to the possible advantages of the continued use of standardised neuropsychological batteries that enable the assessment of global functions in addition to tests that measure deficits associated with the toxicodynamics of the neurotoxin under investigation. Methodological recommendations include the use of simultaneous cross-sectional and longitudinal designs to control for numerous confounding variables and correlation designs to determine dose-response relationships. Future studies need to address the sensitivity and specificity criteria of various neuropsychological measures utilising the principle of neurotoxicodynamics.
Dissertation (MA (Research Psychology))--University of Pretoria, 2007.
Marais, A.A.S. (Adriaan Albertyn Scheepers)(University of Pretoria, 2009-12-09)
The metabolism of absorbed xenobiotic compounds in humans results in a mixture of target compounds applicable for analysis, trapped in complex biological matrices. Gas chromatography-mass spectrometry (GC-MS) is a powerful ...
Botha, C.J. (Christoffel Jacobus); Venter, Elna; University of Pretoria. Faculty of Veterinary Science. Dept. of Paraclinical Sciences. Section Pharmacology and Toxicology(2002)
Can grow under a variety of ecological conditions, though generally absent from shallow gravelly soils as well as wet watercourses.
Botanical description: General: It is a small to medium-sized deciduous ...