Benign food-borne type B botulism presenting as unilateral internal ophthalmoplegia: a case report

BACKGROUND: Food-borne botulism is a rare neuromuscular junction disorder due to the effect of toxins released from Clostridium botulinum ingested by eating improperly stored food. Its classic manifestation is a rapidly evolving descending symmetrical flaccid paralysis with dysautonomia. CASE PRESENTATION: We have described a case of type B food-borne botulism with a benign clinical course characterized by an initially unilateral tonic mydriatic pupil. An extensive neurophysiological evaluation inclusive of pilocarpine eye drop(s) test, facial and limbs nerve stimulation and sudomotor tests, was decisively leading the diagnostic process. CONCLUSIONS: The importance of what has been described here lies in underlining that it is always advisable to consider food-borne botulinum intoxication, even in the case of unilateral/asymmetrical internal ophthalmoplegia without generalized progressive involvement of the voluntary muscles.