J Clin Neurol.  2024 Jan;20(1):37-45. 10.3988/jcn.2023.0037.

Abnormal Ocular Movement in the Early Stage of Multiple-System Atrophy With Predominant Parkinsonism Distinct From Parkinson’s Disease

• Zhou H
• Wei L
• Jiang Y
• Wang X
• Sun Y
• Li F
• Chen J
• Sun W
• Zhang L
• Zhao G
• Wang Z

• KMID: 2550028
• DOI: http://doi.org/10.3988/jcn.2023.0037

Abstract

Background and Purpose
The eye-movement examination can be applied as a noninvasive method to identify multiple-system atrophy (MSA). Few studies have investigated eye movements during the early stage of MSA with predominant parkinsonism (MSA-P). We aimed to determine the characteristic oculomotor changes in the early stage of MSA-P.
Methods
We retrospectively selected 17 patients with MSA-P and 40 with Parkinson’s disease (PD) with disease durations of less than 2 years, and 40 age-matched healthy controls (HCs). Oculomotor performance in the horizontal direction was measured in detail using videonystagmography.
Results
We found that the proportions of patients with MSA-P and PD exhibiting abnormal eye movements were 82.4% and 77.5%, respectively, which were significantly higher than that in the HCs (47.5%, p<0.05). Compared with HCs, patients with MSA-P presented significantly higher abnormal proportions of fixation and gaze-holding (17.6% vs. 0%), without-fixation (47.1% vs. 0%), prolonged latency in reflexive saccades (29.4% vs. 5.0%), memory-guided saccades (93.3% vs. 10.0%), and catch-up saccades in smooth-pursuit movement (SPM, 41.2% vs. 0) (all p<0.05). Compared with those with PD, patients with MSA-P presented a significantly higher proportion of catch-up saccades in SPM (41.2% vs. 2.5%, p<0.001).
Conclusions
MSA-P presented the characteristic of catch-up saccades in SPM in the early stage, which may provide some value in differentiating MSA-P from PD.

Keyword

multiple-system atrophy; Parkinson’s disease; oculomotor deficits; smooth-pursuit movement; catch-up saccades