Pro-Saccades Predict Cognitive Decline in Parkinson's Disease: ICICLE-PD

Samuel Stuart, Rachael A. Lawson, Alison J. Yarnall, Jeremy Nell, Lisa Alcock, Gordon W. Duncan, Tien K. Khoo, Roger A. Barker, Lynn Rochester, David J. Burn*, ICICLE-PD Study Grp

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

Background

Cumulative dementia incidence in Parkinson's disease (PD) is significant, with major personal and socioeconomic impacts on individuals with PD and their carers. Early identification of dementia risk is vital to ensuring optimal intervention. Saccadic deficits often distinguish neurodegenerative disorders and cognitive impairment, but their ability to predict cognitive decline in PD has yet to be determined. The aims of this study were to (1) evaluate baseline (6.4 ± 6.1 months since PD diagnosis) differences in pro‐saccadic metrics between those with early PD and healthy age‐matched adults; and (2) assess the ability of baseline pro‐saccades to predict subsequent cognitive decline over 4.5 years.

Methods

One hundred and forty‐one PD and 90 age‐matched participants recruited at diagnosis underwent saccadometric assessment of pro‐saccades at baseline and had cognition assessed at baseline, 18, 36, and 54 months. Pro‐saccadic characteristics included latency, duration, amplitude, peak, and average velocity. Cognitive assessment included executive function, attention, fluctuating attention, and memory. Linear mixed‐effects models examined pro‐saccadic metrics as predictors of cognitive decline over 54 months.

Results

Pro‐saccades were significantly impaired at baseline in PD compared with controls. Pro‐saccadic characteristics of latency, duration, peak, and average velocity predicted decline in global cognition, executive function, attention, and memory over 54 months in PD. In addition, only reduction in global cognition and attention were predicted by pro‐saccadic metrics in age‐matched adults, indicating that PD findings were not purely age related.

Conclusions

Saccadic characteristics are impaired in early PD and are predictive of cognitive decline in several domains. Assessment of saccades may provide a useful non‐invasive biomarker for long‐term PD cognitive decline in early disease. © 2019 International Parkinson and Movement Disorder Society

Original languageEnglish
Pages (from-to)1690-1698
Number of pages9
JournalMovement Disorders
Volume34
Issue number11
Early online date23 Aug 2019
DOIs
Publication statusPublished - 1 Nov 2019

Keywords

  • biomarker
  • cognition
  • dementia
  • Parkinson's disease
  • saccades
  • EYE-MOVEMENT
  • REFLEXIVE SACCADES
  • IMPAIRMENT
  • VOLUNTARY
  • ATTENTION
  • DEMENTIA
  • DEFICITS
  • MOTOR
  • ANTISACCADES
  • SACCADOMETRY

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