Neuropsychological toxicology: identification and assessment of neurotoxic syndromes.

Neuropsychological toxicology, or, more commonly, "neurobehavioral toxicology" is the study of how naturally or industrially produced nervous system poisons effect neuropsychological functioning. Research of this sort has been widely disseminated in European and Scandinavian medical literature during the past two decades but is only just beginning to enter neuropsychological literature of the United States. Neuropsychological sequelae of several representative human neurotoxins are briefly reviewed, including metallic lead, the solvent toluene, organophosphate pesticides and antihypertensive medication. These substances represent exemplars from some of the major classes of potentially neurotoxic substances; metals, solvents, pesticides, and prescription drugs. They are also examples of neurotoxins that have been examined with neuropsychological methods and for which neuropsychological symptoms or syndromes have been discovered. Testing procedures sensitive to neurotoxic exposure are also summarized. The role of the neuropsychologist as neurobehavioral toxicologist is explored. It is suggested that the neuropsychologist is in a unique position to perform research and clinical evaluations relating to neurotoxic exposure, and that the sub-clinical effects of neurotoxic exposure may be most sensitively discovered with these methods. Further, neurotoxic effects may be subject to misdiagnosis without knowledge of how to examine for these substances. The future expansion of neuropsychology into "neuropsychological toxicology" is advocated.