Atypical Miller Fisher syndrome associated with glutamate receptor antibodies.

The present study reports a young woman with acute ataxia, areflexia and ophthalmoplegia, accompanied by psychosis and involuntary movements (IVMs) from disease onset. Anti-GQ1b and anti-GT1a antibodies were detected allowing for a diagnosis of Miller Fisher syndrome (MFS). However, psychosis and IVMs are atypical MFS symptoms and often mimic symptoms of anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis. Interestingly, the autoantibodies against full-length glutamate receptor-ε2 (GluRε2) and glutamate NR2B- and NR2A-containing heteromers (NR1/NR2) of NMDAR were also detected in the patient serum and cerebrospinal fluid. It was concluded that psychosis and IVMs in this patient were associated with autoantibodies against various GluRs.