ObjectiveTo quantitatively assess oculomotor impairments in multiple system atrophy (MSA) and to explore their correlation with clinical characteristics. MethodsWe recruited 45 patients with MSA, including 21 with dominant ataxia (MSA-C), 24 with dominant parkinsonism (MSA-P), and 40 age-matched healthy controls. Detailed oculomotor performance in the horizontal direction was measured using videonystagmography (VNG). ResultsWe found that the proportion of abnormal eye movements in patients with MSA was 93.3% (37.7%, 51.1%, 73.3%, 71.1%, and 37.8% on fixation and gaze-holding, without fixation, saccade, smooth pursuit, and optokinetic nystagmus tests, respectively). Patients with MSA-C showed significantly lower gains in smooth pursuit test and optokinetic nystagmus test, and a higher incidence of hypermetria in the saccade test than patients with MSA-P (all P < 0.05). No oculomotor deficits were correlated with age, age of onset, sex, disease duration, or Unified Multiple System Atrophy Rating Scale (USMARS) (all r < 0.25, P > 0.1). ConclusionsAn extremely high incidence of oculomotor impairments could be observed using VNG in both the MSA-C and MSA-P subtypes, although there were some differences between them. SignificanceA comprehensive oculomotor examination could serve as a valuable tool in the diagnostic workup of patients with MSA.