Introduction |
Organophosphorus ester-induced chronic neurotoxicity (OPICN) --- also called chronic organophosphate-induced neuropsychiatric disorder (COPIND) --- is a set of long-term, persistent, chronic neuropsychiatric findings that some have attributed to cholinesterase inhibitor toxicity. |
Controversy |
There is a great deal of debate surrounding the subject of Organophosphorus ester-induced chronic neurotoxicity (OPICN). (Jamal 1997; Bateman 1999; Vale 1999; Colosio, Tiramani et al. 2003) It has been argued that the condition can follow either an acute, symptomatic exposure or repeated, asymptomatic exposures. (Abou-Donia 2003)
A number of the key studies supporting this argument, particularly those relating to asymptomatic exposures, have been criticized on methodological grounds. (Bateman 1999; Vale 1999; Colosio, Tiramani et al. 2003) In particular, determination of exposure in most studies has been based on recall rather than on objective measurements. This method of assessing exposure has not been shown to be very reliable. (Boyer, Templin et al. 1995) In addition, a number of the studies have been based on recall of exposures to pesticides in general, rather than specifically to cholinesterase inhibitors.
Some have pointed out that neuropsychiatric findings following severe acute exposures are consistent with damage from seizures and hypoxia, and may not represent a specific toxic effect. (Vale 1999) However, current evidence cannot rule out such a toxic effect, and better-designed studies are needed to resolve the debate. (Colosio, Tiramani et al. 2003) |
