The differential diagnostic value of a battery of oculomotor evaluation in Parkinson's Disease and Multiple System Atrophy

Abstract

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A novel tablet-based software for the acquisition and analysis of gaze and eye movement parameters: a preliminary validation study in Parkinson’s disease

“…In contrast to latency and velocity parameters, the literature is quite rich with strong evidence of PD patients requiring multi-step saccades to reach the target (Shaikh et al, 2019, Blekher et al, 2009, Zhou et al, 2021Gorges et al 2013, which is in line with the present findings reported here, where the average number of saccades required to reach the pro-saccade targets was significantly greater in PD patients. In addition, our findings here indicate that the first saccade towards the target (for both short and large eccentricity targets) was closer to the target in HC.…”

“…Similarly, findings regarding peak velocity have been mixed, with a few studies finding faster velocities in PD (Lu et al, 2019;Grillini et al, 2020), whereas most other studies found no differences between PD and healthy control (Blekker et al, 2009;Stuart et al, 2013;Gorges et al 2013;Zhou et al, 2021;Gitchel et al, 2012). In the present study, we find peak and mean velocities to be significantly increased in PD patients (only uncorrected p-value for peak velocity) for short eccentricity targets only.…”

“…Pro-saccades have been more extensively studied in PD than measures of fixation instability. Findings regarding saccade latency have been mixed to date, with several studies finding either no differences between PD patients and controls (Gitchel et al, 2012;Blekher et al, 2009, Perkins et al, 2021Nagai et al, 2020), shorter latencies in PD (Zhou et al, 2021) and longer latencies in PD (Zhang et al, 2021;Wu et al 2020;Waldthaler et al, 2019). It's unclear why this discrepancy across studies exists, but it may have to do with the type of eye-tracking technology used; the majority of the studies cited above that found either no difference or shorter latencies in PD used infrared eye-trackers from manufacturers such as Eyelink and Tobii, whereas the majority of studies cited above finding increased latencies used devices from other manufacturers such as Micromedical Technologies and Interacoustics, and EyeBrain.…”

Clinical value of video oculomotor evaluation in the differential diagnosis of multiple system atrophy and Parkinson's disease

“…There are differences between the pathophysiology and progression of MSA and Parkinson's disease (PD). However, symptoms overlap between the two conditions in the early stages, making clinical diagnosis difficult (Zhou et al., 2021 ). Traditional anti‐PD medications have limited effectiveness against MSA.…”

Baseline Wander Removal Applied to Smooth Pursuit Eye Movements From Parkinsonian Patients

“…While the presence of saccadic movements during SPEM is considered normal, their frequency, extent, and type are different in patients with PD compared to normal subjects [9]. Several types of abnormal and involuntary saccadic movements have been reported in the literature [9], namely corrective saccades, which are elicited to eliminate existing delays when SPEM lags with respect to a moving target; anticipatory saccades, a type of ballistic movements that anticipate future target positions; and saccadic intrusions, which are involuntary movements taking the form of an initial fast movement away from the expected eye position followed by a return secondary saccade or a drift. The presence of these corrective movements leads to a detectable decrease in saccade amplitude and increased saccade latency, as well as a slightly impaired smooth pursuit with catch-up saccades [10].…”