Oscar Wh Wong1, Anne Yy Chan2, Adrian Wong3, Claire Ky Lau4, Jonas Hm Yeung5, Vincent Ct Mok6, Linda Cw Lam7, Sandra Chan8. 1. Department of Psychiatry, Tai Po Hospital, Hong Kong SAR. Electronic address: wwh869@ha.org.hk. 2. Department of Medicine and Therapeutics, Prince of Wales Hospital, Hong Kong SAR. Electronic address: cyy912@ha.org.hk. 3. Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR. Electronic address: adrianwong@cuhk.edu.hk. 4. Department of Medicine and Therapeutics, Prince of Wales Hospital, Hong Kong SAR. Electronic address: yeekaclaire@surgery.cuhk.edu.hk. 5. Department of Medicine, Alice Ho Miu Ling Nethersole Hospital, Hong Kong SAR. Electronic address: yeunghmj@ha.org.hk. 6. Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR. Electronic address: vctmok@cuhk.edu.hk. 7. Department of Psychiatry, The Chinese University of Hong Kong, Tai Po Hospital, G/F, Multi-centre Building, 9 Chuen On Road, Tai Po, Hong Kong SAR. Electronic address: cwlam@cuhk.edu.hk. 8. Department of Psychiatry, The Chinese University of Hong Kong, Tai Po Hospital, G/F, Multi-centre Building, 9 Chuen On Road, Tai Po, Hong Kong SAR. Electronic address: schan@cuhk.edu.hk.
Abstract
BACKGROUND: Cognitive deficits and eye movement abnormalities have been demonstrated to be detectable early clinical manifestations of Parkinson's disease. Understanding the relationship between these phenotypes may yield insight into the underlying anatomical pathways, assisting in the search for simple non-invasive markers of early neurodegeneration. OBJECTIVE: To explore the correlations between eye movement parameters with multi-domain cognitive functions in patients suffering from Parkinson's disease without dementia. METHOD: This is a cross-sectional case-control study of Parkinson's disease patients without dementia. Participants underwent global and domain-specific cognitive tests and an eye-tracking visual search task to characterize eye movement parameters. RESULTS: 62 Chinese Parkinson's disease patients without dementia and 62 sex-, age- and education-matched controls were recruited. The disease group performed worse in multiple cognitive tasks and exhibited a smaller saccadic amplitude. Negative correlations between the eye fixation duration and performance in semantic verbal fluency, verbal and visual recognition memory tasks were observed, though there was no moderation effect on the correlations due to the presence of Parkinson's disease. A common cholinergic deficit in the temporal and parietal regions may account for the observed correlations. The lack of association with predominantly frontal-executive tasks may suggest specificity of these correlations. CONCLUSION: Prolonged visual fixation duration is correlated with poorer performance in semantic verbal fluency, verbal and visual recognition memory tasks in Parkinson's disease patients without dementia, although these correlations are not specific. The clinical utility of eye movement parameters as an early marker for cognitive decline in Parkinson's disease warrants further exploration in longitudinal studies.
BACKGROUND:Cognitive deficits and eye movement abnormalities have been demonstrated to be detectable early clinical manifestations of Parkinson's disease. Understanding the relationship between these phenotypes may yield insight into the underlying anatomical pathways, assisting in the search for simple non-invasive markers of early neurodegeneration. OBJECTIVE: To explore the correlations between eye movement parameters with multi-domain cognitive functions in patients suffering from Parkinson's disease without dementia. METHOD: This is a cross-sectional case-control study of Parkinson's diseasepatients without dementia. Participants underwent global and domain-specific cognitive tests and an eye-tracking visual search task to characterize eye movement parameters. RESULTS: 62 Chinese Parkinson's diseasepatients without dementia and 62 sex-, age- and education-matched controls were recruited. The disease group performed worse in multiple cognitive tasks and exhibited a smaller saccadic amplitude. Negative correlations between the eye fixation duration and performance in semantic verbal fluency, verbal and visual recognition memory tasks were observed, though there was no moderation effect on the correlations due to the presence of Parkinson's disease. A common cholinergic deficit in the temporal and parietal regions may account for the observed correlations. The lack of association with predominantly frontal-executive tasks may suggest specificity of these correlations. CONCLUSION: Prolonged visual fixation duration is correlated with poorer performance in semantic verbal fluency, verbal and visual recognition memory tasks in Parkinson's diseasepatients without dementia, although these correlations are not specific. The clinical utility of eye movement parameters as an early marker for cognitive decline in Parkinson's disease warrants further exploration in longitudinal studies.