Ciguatera and peripheral neuropathy: a case report

Ciguatera is the most frequently observed form of tropical fish poisoning. It appears as a syndrome associating general signs, gastrointestinal, cardi ac and neurological problems. Peripheral and central nervous system signs m ay be observed. We report a case of a 60-year-old man who developed Ciguate ra poisoning with diarrhea, facial paresthesia, myalgia, cramps and weaknes s. Physical examination revealed a motor distal deficit of the four limbs, myokymia and ataxia. EMG testing was in favor of an axonal neuropathy. Neur ologic symptoms persisted for two months. This case illustrates a new patho phyiological mechanism of neuropathy: "axonal channelopathy". Abnormalities of peripheral nerve sodium and potassium channels result in clinical and e lectrophysiological manifestations unrelated to axonal degeneration or demy elinization. The ciguatoxin mainly acts on sodium channels. Prolonged sodiu m channel activation results in repetitive axon firing. Recently ciguatoxin was recently demonstrated to have a novel action, blocking the sodium chan nel leading to slowed nerve conduction and decreased motor and sensory acti on potential amplitudes.