Miller Fisher syndrome is classically described as an acute inflammatory polyneuropathy clinical variant, associating external ophthalmoplegia, ataxia and loss of tendon reflexes. Despite recent advances in the comprehension of this syndrome, with the description of anti-GQ1b anti-ganglioside antibodies associated with abnormal neuromuscular transmission in the serum of Miller Fisher syndrome patients, there is ongoing debate on the peripheral or central origin of the symptoms. Some authors argue that there is a brainstem and cerebellar involvement. Indeed, since description of the syndrome, numerous cases have been reported with electrophysiologic and imaging evidences of brainstem involvement in the syndrome. Described and discussed here is the case of a 4-year-old child with Miller Fisher syndrome and cerebral lesions evident on magnetic resonance imaging, suggesting a Fisher-Bickerstaff spectrum.