Visual perceptual disorders in patients with Parkinson’s disease

Visual perceptual disorders in patients with Parkinson’s disease I. van der Lijna,b, G.A. de Haana,b, F.E. van der Feena,b, J. Heutinka,ba Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen, The Netherlandsb Royal Dutch Visio, Centre of expertise for blind and partially sighted people, Huizen, The NetherlandsObjectivesDespite increasing recognition of non-motor symptoms of Parkinson’s disease (PD), visual disorders are still less well documented than other symptoms of the disease. This is alarming since visual disorders are highly associated with a decline in quality of life and participation in society. The current study aims to explore the nature of visual perceptual disorders in patients with PD.MaterialsThe DiaNAH test battery for visual perception (De Vries, et al. 2017) consists of 11 tests: Bells test, Cake Thief, Trail Making Test (TMT), L-POST Figure-Ground Segmentation, L-POST Motion Detection, L-POST Shape Ratio Discrimination, Corsi Block Tapping Task, Taylor Complex Figure, Dot Counting, Visual Object Space Perception (VOSP) Silhouettes, and Crowding. These tests are completed in Metrisquare© using a 24” tablet. MethodThirty PD patients (mean age: 72.17, 60% male, 93% good visual acuity) referred to Royal Dutch Visio for visual care and rehabilitation were assessed by a neuropsychologist. A frequency analysis of the scores on the DiaNAH tests was performed to explore the nature of visual perceptual disorders. ResultsThe results suggest that the most frequently occurring disorder was limited visuomotor speed and visual search in a complex task (TMT part B), found in 62% of patients. Diminished figure-ground perception (L-POST Figure-Ground Segmentation; 45%), visuocognitive load (Crowding; 41%), and visuospatial functioning (Taylor Complex Figure; 34%) were also found in a considerable amount of patients. Least common were problems in visual shape recognition (L-POST Shape Ratio Discrimination; 14%), object perception (VOSP Silhouettes; 11%), and non-lateralized attention and spatial cognition (Cake Thief; 7%). Compared to normative data of healthy individuals, patients attained an abnormal score on an average of 3 out of 11 tests. DiscussionThe results show that a wide range of visual perceptual disorders commonly occur in patients with PD referred for visual care and rehabilitation. These disorders cannot be explained by low visual acuity, since 93% of patients had good visual acuity. ConclusionsFurther exploration regarding the nature, severity and prevalence of visual perceptual disorders in patients with PD is recommended, since this knowledge is essential to guide care and rehabilitation and to increase patients’ quality of life and participation in society. ReferencesDe Vries, S.M., J. Heutink, B. J. M. Melis-Dankers, A. C. L. Vrijling, F. W. Cornelissen & O. Tucha (2017). Screening of visual perceptual disorders following acquired brain injury: A Delphi study. Applied Neuropsychology: Adult; 25(3):197-209