Preservation of Eye Movements in Parkinson's Disease Is Stimulus- and Task-Specific

• DOI: 10.1523/jneurosci.1690-21.2021
• Publication Date: 2021-11-30T18:55:57Z
• Authors: Jolande Fooken; Pooja Patel; Christina B. Jones; Martin J. McKeown; Miriam Spering
• Keywords: Superior colliculus; Cued speech; Stimulus (psychology); Smooth pursuit; Inhibition of return

Parkinson's disease (PD) is a neurodegenerative that includes motor impairments, such as tremor, bradykinesia, and postural instability. Although eye movement deficits are commonly found in saccade pursuit tasks, preservation of oculomotor function has also been reported. Here we investigate specific task stimulus conditions under which PD preserved. Sixteen patients 18 healthy, age-matched controls completed battery tasks included stationary or moving targets eliciting reactive deliberate movements: pro-saccades, anti-saccades, visually guided pursuit, rapid go/no-go manual interception. Compared with controls, demonstrated systematic impairments targets: pro-saccades were hypometric anti-saccades incorrectly initiated toward the cued target ∼35% trials compared 14% errors controls. In patients, linked to short latency saccades, indicating abnormalities inhibitory control. However, patients' movements response dynamic relatively able track predict disappearing make quick decisions accurately Patients' interceptive hand slower on average but earlier, adaptive processes compensate for slowing. We conclude demonstrate dependency propose separate functional pathway through superior colliculus-brainstem loop bypasses fronto-basal ganglia network. Our results studying can support diagnosis further our understanding progression dynamics. SIGNIFICANCE STATEMENT Eye promising clinical tool aid disorders monitor progression. show some abnormalities, it not clear whether previously described task-specific. assessed different visual (stationary vs targets) (reactive deliberate) conditions. objects inaccurate targets. The stimuli might enable act predicted motion path target. These inform development tools rehabilitation maintenance performance.