Neuropsychological study of ciguatera fish poisoning: a longitudinal case-control study.

PURPOSE: The purpose of the study was to evaluate the neuropsychological effects of ciguatera fish poisoning (CFP). METHOD: In a longitudinal matched cohort study, 12 CFP cases and 12 matched friend-controls received baseline neuropsychological evaluations within one month after intoxication and follow-up evaluations approximately six months after baseline. RESULTS: Only one case received intravenous mannitol treatment, which occurred 10 or more days after intoxication. At baseline and follow-up evaluations, there were no statistically significant differences between CFP cases and controls on cognitive measures. At baseline, however, CFP cases endorsed significantly greater subjective toxicity symptoms (e.g. fatigue, tingling sensations) and greater anxiety symptoms than controls. Follow-up evaluations suggested resolution of all symptoms after six months. Subsequent analyses, in which data from this study were pooled with data from an earlier pilot study, supported these results. CONCLUSION: Untreated ciguatera was associated acutely with significant subjective neurotoxicity symptoms and anxiety which were transient, but not with objectively measured cognitive changes. Future investigation with a larger sample size is warranted.