What syndrome includes ataxia, ophthalmoplegia, and areflexia?

Miller Fisher syndrome includes the characteristic triad of ataxia, ophthalmoplegia, and areflexia.

Ataxia means impaired coordination and balance, ophthalmoplegia means weakness or paralysis of the muscles that move the eyes, and areflexia means absent or greatly reduced tendon reflexes. The syndrome usually begins acutely, often after an infection, and may cause double vision, unsteady walking, and difficulty with coordinated movement.

Miller Fisher syndrome is generally regarded as a rare regional variant of Guillain–Barré syndrome, an immune-mediated disorder in which peripheral nerves are injured. Many patients have antibodies against the nerve ganglioside GQ1b; these antibodies are found in roughly 90% of cases and are especially associated with eye-movement problems. Respiratory failure is less common than in classic Guillain–Barré syndrome, although overlap can occur.

Canadian neurologist Charles Miller Fisher described the syndrome in 1956 after studying three patients. Bickerstaff brainstem encephalitis can resemble it and may also involve ophthalmoplegia and ataxia, but altered consciousness and central nervous system involvement help distinguish that condition. The classic three-part combination makes Miller Fisher syndrome the canonical answer.