ABSTRACT – Miller Fisher syndrome (MFS) may be considered as a rare variant of Guillain-Barré syndrome (GBS). Together with GBS, Bickerstaff ’s brainstem encephalitis and acute ophthalmoparesis without ataxia, MFS is in the group of anti-GQ1b syndrome disorders (anti-GQ1b Sy). Among all GBS variants, MFS is distinctive, presenting with acute symptoms of ophthalmoparesis, ataxia and arefl exia, but without progressive limb weakness as the most characteristic symptom of GBS. MFS is a clinical entity based on typical clinical presentation and defi ned symptoms, and the fi nding of specifi c anti-GQ1b antibodies is not suffi cient for MFS diagnosis. Th e objective of this case report is to demonstrate the diversity of anti-GQ1b Sy clinical presentation. Here we describe a case of a male patient with acute bilateral ophthalmoparesis, mydriasis and unilateral right infranuclear facial nerve palsy, in whom muscle tendon refl exes were preserved and no ataxia was present. Serum antiganglioside antibody test was positive for anti-GQ1b antibody, confi rming the presupposed diagnosis of MFS. Although MFS is rare, it should be considered in patients with acute development of ophthalmoplegia. In rare cases of MFS with uncommon presentation, as it was in our case, positive serum antiganglioside antibody test will lead to the right diagnosisSAŽETAK – Miller Fisherov sindrom (MFS) može se smatrati rijetkom varijantom Guillain-Barréova sindroma (GBS). MFS, zajedno s GBS, Bickerstaff ovim encefalitisom moždanog debla (BBE) i akutnom o ft almoparezom (AO) bez ataksije, pripada skupini poremećaja unutar anti-GQ1b sindroma (anti-GQ1b Sy). Između svih varijanta GBS, MFS se manifestira na specifi čan način akutnim razvojem oft almoplegije, ataksije i arefl eksije, no bez progresivne slabosti mišića ekstremiteta kao karakterističnog znaka GBS. MFS je klinički entitet temeljen na tipičnoj kliničkoj slici i određenim simptomima, no nalaz specifi čnih anti-GQ1b protutijela nije dovoljan za dijagnozu MFS. Cilj je ovoga članka prikazati različitosti kliničke prezentacije anti-GQ1b sindroma. Opisujemo slučaj bolesnika s naglim razvojem obostrane oft almoplegije, midrijaze i unilateralne desnostrane infranuklearne pareze ličnog živca, bez ataksije te urednih miotatskih refl eksa. S obzirom na kliničku sliku i razvoj simptoma postavljena je sumnja na MFS, što je potvrđeno i pozitivnim nalazom serumskih anti-GQ1b protutijela. U zaključku, premda se rijetko pojavljuje, na MFS treba pomis liti u diferencijalnoj dijagnozi kod bolesnika s naglim razvojem oftalmoplegije. U rijetkim slučajevima neuobičajene prezentacije MFS-a, kao u našem slučaju, pozitivan nalaz antigangliozidnih protutijela omogućava postavljanje točne dijagnoz
