Variability of neuropsychological deficits associated with carbon monoxide poisoning: four case reports.

Carbon monoxide (CO) poisoning is associated with variable neuropsychological deficits, depending on levels of CO exposure and individual differences. Studies to date have reported variable findings, as their subjects have been exposed to different levels of CO from different poisoning sources. Four unique case studies are presented, all of whom experienced the same level of CO poisoning (17-29%) in the same accident. Two of the individuals were brothers with an identical genetic disorder (i.e. syndactylism) and the other two were brother/sister. The results indicated: (1) variable neuropsychological deficits despite similar levels of CO poisoning; (2) consistent estimated decline in intelligence; (3) similar memory decline for the two brothers, but not for the brother and sister; and (4) consistent late-onset emotional-behavioural difficulties. The results also suggested that the neuropsychological and emotional-behavioural deficits had an impact on the individual's ability to work.