[Ciguatera: clinical relevance of a marine neurotoxin]

Abstract

History and clinical findings: A 45-year-old woman complained of gastrointestinal symptoms followed by paraesthesiae of the mouth, face, hands, feet, and trunk after she had eaten fish while she was on a journey to the red sea. Additionally, she suffered from headaches and muscle aches, weakness of the arms and legs, instability of gait as well as troubles of vision, taste, speech, and swallowing. Neurological examination revealed a cerebellar syndromE with mild dysarthria, multifocal dysaesthesiae, paresis of the arms and legs, generalized hyporeflexia, bilaterally reduced vision, and ataxic gait.

Investigations: Laboratory work-up provided no diagnostic clues. Cranial and spinal magnetic resonance imaging were normal. The cerebrospinal fluid showed a normal cell count and a moderately impaired barrier function. Electrophysiological evaluation suggested a sensory and motor axonal neuropathy.

Diagnosis, treatment and course: Based on the history and the characteristic clinical findings we made a diagnosis of ciguatera, a marine food poisoning caused by the ingestion of fish contaminated with ciguatoxin. Symptomatic treatment with mannitol, amitriptyline, carbamazepine, and corticosteroids started 3 weeks after the onset of symptoms proved inefficient, however, during the 21 months of follow-up there was a marked spontaneous clinical and electrophysiological reversal of symptoms.

Conclusions: In the age of growing foreign tourism marine food intoxications have to be considered in the differential diagnosis of the frequently occurring travellers-diarrhea. The diagnosis of ciguatera is based on the typical history of a fishmeal followed by characteristic clinical findings with predominant neurological symptoms, often including dysaesthesiae, besides gastrointestinal disturbances. In the early phase of the disease intravenous therapy with mannitol has emerged as an efficient treatment.