Objective: To investigate whether an impairment in cognitive function exists in patients diagnosed with fluoride poisoning as well as its biological basis.
Methods: Individuals suffering from fluoride poisoning from a high fluorine region were selected for the study group, while healthy individuals from a nonendemic region were selected as the control group. Using specific psychological methods, the indices of blood oxidative stress were also tested with the following: Thiobarbituric acid reac.on (TBA) for serum lipid peroxide (LPO), Ellman’s for reduced glutathione (GSH) in serum, nitrite method for superoxide dismutase (SOD) in red blood cells, and the Dithiobisnitrobenzoic acid (DTNB) method for glutathione peroxidase (GSHPx) in serum. As to determining the amount of NO in the subjects, this was done through testing the nitrous and nitrate (NO2/NO3) in serum.
Results: Between the study group and the control group, significant differences were observed in the data gathered from the psychological tests. Big differences were found in the tests of language fluency, recognition, similarity, associative learning, and working memory (digit span test). The total failure numbers from the psychological tests and the concentration of NO demonstrated a significant positive correlation, while the similarity test showed a significant negative correlation. SOD activity showed a significant negative correlation with the similarity and digit span tests.
Conclusion: The results suggest that some cognitive function limitations exist in those suffering from chronic fluoride poisoning, and its biologic basis may be related to the levels of SOD and NO.