BACKGROUND: Anti-GQ1b antibody has been found in Miller Fisher syndrome (MFS), 
Guillain-Barré syndrome (GBS) with ophthalmoplegia, Bickerstaff brainstem 
encephalitis (BBE), and acute ophthalmoplegia without ataxia (AO). The aim of 
this study was to determine the clinical features of AO associated with 
anti-GQ1b antibody.
METHODS: We retrospectively collected 34 patients with anti-GQ1b antibody 
syndrome. Of these patients, 31 patients had ophthalmoplegia. The patients with 
ophthalmoplegia were classified into MFS (n = 13), AO (n = 11), GBS with 
ophthalmoplegia (n = 6), and BBE (n = 1). We analyzed clinical features and 
patterns of external and internal ophthalmoplegia of AO, and 
neuro-ophthalmologic findings were compared with those of other anti-GQ1b 
syndromes with ophthalmoplegia.
RESULTS: AO was observed in 11 (32.4%) of the 34 patients with anti-GQ1b 
antibody. External ophthalmoparesis was present in all the patients and included 
mixed horizontal-vertical (n = 7), pure horizontal (n = 3), and pure vertical 
gaze palsy (n = 1). Binocular involvement was common, but unilateral 
ophthalmoparesis was also observed in 27.3%. Other findings included ptosis (n = 
5, 45.5%) and internal ophthalmoplegia (n = 6, 54.5%). Other anti-GQ1b antibody 
syndromes had prominent neurologic signs including ataxia, weakness, and facial 
palsy in addition to ophthalmoplegia. The patterns of neuro-ophthalmologic 
findings did not differ between AO and other anti-GQ1b antibody syndromes with 
ophthalmoplegia.
CONCLUSIONS: Acute ophthalmoplegia (AO) commonly occurs in anti-GQ1b antibody 
syndrome and manifests as various combinations of external and internal 
ophthalmoplegia. Internal ophthalmoplegia is fairly common and unilateral 
involvement may occur in AO.