Neuro-ophthalmic findings in botulism type B.

In June 1989, the largest recorded outbreak of food-borne botulism occurred in the United Kingdom. Twenty-seven patients were affected during the outbreak with type B botulism. A case note review of 14 patients admitted with this condition was performed and the neuro-ophthalmic findings are presented. Patients with severe disease presented with a combination of ocular and bulbar symptoms; in mild cases dysphagia was noted first and visual disturbance followed within 24 hours. Clustering of cases and bilaterality of cranial nerve signs aided in the diagnosis. Accommodative paresis and sixth cranial nerve palsy were frequent early signs. When there was respiratory paralysis and ventilatory failure, it occurred within 12 hours of the onset of a third cranial nerve palsy.