Miller-Fisher syndrome, Guillain-Barre syndrome with ophthalmoplegia, Bickerstaff s brainstem encephalitis and acute ophthalmoplegia share some clinical features, and common anti-GQ1b IgG antibody and these are introduced as anti-GQ1b antibody syndrome. These syndromes mostly present with paralysis of extraocular muscles and internal ophthalmoplegia rarely occurs. We report a case of acute isolated bilateral internal ophthalmoplegia associated with anti-GQ1b IgG antibody.

Many neurologic signs are found in Miller Fisher syndrome (MFS) especially including pupillary abnormalities. But when internal ophthalmoparesis is first manifestation in MFS, diagnosis may be difficult in acute phase of illness. We report two cases of MFS presenting with internal ophthalmoplegia. Pupillary areflexia may be involved in acute phase of MFS. When acute bilateral internal ophthalmoparesis is encounted in clinical practice, initial manifestation of MFS should be included in differential diagnosis.