title: Antisaccade errors reveal cognitive control deficits in Parkinson's disease with freezing of gait.
abstract: Freezing of gait is a poorly understood symptom of Parkinson's disease (PD) that is commonly accompanied by executive dysfunction. This study employed an antisaccade task to measure deficits in inhibitory control in patients with freezing, and to determine if these are associated with a specific pattern of grey matter loss using voxel-based morphometry. PD patients with (n = 15) and without (n = 11) freezing along with 10 age-matched controls were included. A simple prosaccade task was administered, followed by a second antisaccade task that required subjects to either look towards or away from a peripheral target. Behavioral results from the antisaccade task were entered as covariates in the voxel-based morphometry analysis. Patient and control groups performed equally well on the first task. However, patients with freezing were significantly worse on the second, which was driven by a specific impairment in suppressing their responses toward the target on the antisaccade trials. Impaired antisaccade performance was associated with grey matter loss across bilateral visual and fronto-parietal regions. These results suggest that patients with freezing have a significant deficit of inhibitory control that is associated with volume reductions in regions crucial for orchestrating both complex motor behaviors and cognitive control. These findings highlight the inter-relationship between freezing of gait and cognition and confirm that dysfunction along common neural pathways is likely to mediate the widespread cognitive dysfunction that emerges with this symptom.
authors.affiliation: Parkinson's Disease Research Clinic, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW, Australia.
authors.forename: Courtney C
authors.initials: CC
authors.lastname: Walton
authors.affiliation: Parkinson's Disease Research Clinic, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW, Australia.|Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK.
authors.forename: Claire
authors.initials: C
authors.lastname: O'Callaghan
authors.affiliation: Parkinson's Disease Research Clinic, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW, Australia.|School of Social Sciences and Psychology, Western Sydney University, Parramatta, NSW, Australia.
authors.forename: Julie M
authors.initials: JM
authors.lastname: Hall
authors.affiliation: Parkinson's Disease Research Clinic, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW, Australia.
authors.forename: Moran
authors.initials: M
authors.lastname: Gilat
authors.affiliation: Parkinson's Disease Research Clinic, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW, Australia.|Healthy Brain Ageing Program, School of Psychology; Brain and Mind Centre & The Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia.
authors.forename: Loren
authors.initials: L
authors.lastname: Mowszowski
authors.affiliation: Parkinson's Disease Research Clinic, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW, Australia.|Healthy Brain Ageing Program, School of Psychology; Brain and Mind Centre & The Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia.
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Naismith
authors.affiliation: Neuroscience Research Australia, University of New South Wales, Sydney, NSW, Australia.
authors.forename: James R
authors.initials: JR
authors.lastname: Burrell
authors.affiliation: Neuroscience Research Australia, University of New South Wales, Sydney, NSW, Australia.|School of Psychology, Stanford University, Stanford, CA, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Shine
authors.affiliation: Parkinson's Disease Research Clinic, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW, Australia. simonl@med.usyd.edu.au.
authors.forename: Simon J G
authors.initials: SJ
authors.lastname: Lewis
mesh_terms: D000368:Aged; D056344:Executive Function / Q000502:physiology*; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology / Q000503:physiopathology*; D066128:Gray Matter / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology*; D011597:Psychomotor Performance / Q000502:physiology*; D012438:Saccades / Q000502:physiology*
keywords: Antisaccades; Cognitive control; Freezing of gait; Parkinson’s disease