Summary

A 25-year-old man presented with blurred vision, headache and dizziness. On questioning, there was also a history of a preceding diarrhoeal illness. Initial investigations were normal. However, after a week, he represented with a Parinaud's syndrome. In view of the preceding diarrhoea, the transient unsteadiness and the areflexia on examination, anti-GQ1b antibodies were requested. The resulting titre was positive confirming the suspected diagnosis of Miller Fisher syndrome. He responded to intravenous immunoglobulins with full resolution of his symptoms and signs. Although various unusual neuro-ophthalmological signs have been reported localising to the brainstem, to our knowledge, this is the first case report of Parinaud's syndrome being the presenting symptom of Miller Fisher syndrome.