Original Research ARTICLE
High-order visual processing, visual symptoms, and visual 1 hallucinations: A possible symptomatic progression of Parkinson’s 2 disease
- 1University of Utah Health Care, United States
- 2Mayo Clinic, United States
Objective: To determine whether Parkinson disease (PD) patients with visual hallucinations have different clinical characteristics and gray-matter volume than those with visual misperceptions or other visual symptoms.
Background: The spectrum of visual complaints in PD is broad and complex.
Methods: We conducted a retrospective chart review of 525 Parkinson disease patients to identify the frequency of visual symptoms and the association with clinical and radiological features. Brain volumetric MRI data was analyzed using multivariate logistic regression to differentiate cases with and without visual symptoms.
Results: Among 525 PD cases, visual complaints were documented in 177 (33.7%). Among these, 83 (46.9%) had visual hallucinations, 31 (17.5%) had visual misperceptions, and 63 (35.6%) had other visual symptoms (diplopia, blurry vision, photophobia, dry eyes and eye pain or soreness). When compared to other visual symptoms, patients with visual hallucinations had significantly higher age, duration of disease, rate of REM sleep behavior disorder, and cognitive impairment. Visual hallucinations patients had decreased age-adjusted volumetric averages in 28/30 gray-matter regions when compared to Parkinson disease without visual symptoms and 30/30 gray-matter regions when compared to visual misperceptions patients.
Conclusions: Visual symptoms in PD may represent a spectrum from other visual symptoms to visual misperceptions to visual hallucinations, with progression of the latter associated with older age, duration of disease, presence of REM sleep behavior disorder, cognitive impairment, and decreased gray-matter volume.
Keywords: Parkinson’s disease, Visual symptoms, Visual Hallucinations, Visual misperceptions, Gray-matter volume, REM sleep behavior disorder (RBD), cognitive impairment
Received: 20 Aug 2018;
Accepted: 05 Nov 2018.
Edited by:Tim Anderson, University of Otago, Christchurch, New Zealand
Reviewed by:Pedro Chana, Universidad de Santiago de Chile, Chile
Gennaro Pagano, King's College London, United Kingdom
Copyright: © 2018 Barrell, Bureau, Turcano, Phillips, Anderson, Malik, Shprecher, Zorn, Zamrini and Savica. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Rodolfo Savica, Mayo Clinic, Rochester, 55902, Minnesota, United States, Savica.Rodolfo@Mayo.edu