title: Objective assessment of visual pursuit in patients with disorders of consciousness: an exploratory study.
abstract: Visual pursuit is a key marker of residual consciousness in patients with disorders of consciousness (DOC). Currently, its assessment relies on subjective clinical decisions. In this study, we explore the variability of such clinical assessments, and present an easy-to-use device composed of cameras and video processing algorithms that could help the clinician to improve the detection of visual pursuit in a clinical context. Visual pursuit was assessed by an experienced research neuropsychologist on 31 patients with DOC and on 23 healthy subjects, while the device was used to simultaneously record videos of both one eye and the mirror. These videos were then scored by three researchers: the experienced research neuropsychologist who did the clinical assessment, another experienced research neuropsychologist, and a neurologist. For each video, a consensus was decided between the three persons, and used as the gold standard of the presence or absence of visual pursuit. Almost 10% of the patients were misclassified at the bedside according to their consensus. An automatic classifier analyzed eye and mirror trajectories, and was able to identify patients and healthy subjects with visual pursuit, in total agreement with the consensus on video. In conclusion, our device can be used easily in patients with DOC while respecting the current guidelines of visual pursuit assessment. Our results suggest that our material and our classification method can identify patients with visual pursuit, as well as the three researchers based on video recordings can.
authors.affiliation: Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium. coma@chu.ulg.ac.be.|Neurology Department, University Hospital of Liège, Liège, Belgium. coma@chu.ulg.ac.be.
authors.forename: Sarah
authors.identifier: http://orcid.org/0000-0001-5663-6444
authors.initials: S
authors.lastname: Wannez
authors.affiliation: Laboratory for Signal and Image Exploitation, Department of Electrical Engineering and Computer Science, University of Liège, Liège, Belgium.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hoyoux
authors.affiliation: Laboratory for Signal and Image Exploitation, Department of Electrical Engineering and Computer Science, University of Liège, Liège, Belgium.
authors.forename: Thomas
authors.initials: T
authors.lastname: Langohr
authors.affiliation: Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium.|Neurology Department, University Hospital of Liège, Liège, Belgium.
authors.forename: Olivier
authors.initials: O
authors.lastname: Bodart
authors.affiliation: Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium.|Neurology Department, University Hospital of Liège, Liège, Belgium.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Martial
authors.affiliation: Phasya S.A., Liège, Belgium.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Wertz
authors.affiliation: Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium.|Neurology Department, University Hospital of Liège, Liège, Belgium.|Laboratory for NeuroImaging of Coma and Consciousness, Massachusetts General Hospital, Boston, MA, USA.|Acute Neurorehabilitation Unit, Department of Clinical Neurosciences, University Hospital of Lausanne, Lausanne, Switzerland.
authors.forename: Camille
authors.initials: C
authors.lastname: Chatelle
authors.affiliation: Laboratory for Signal and Image Exploitation, Department of Electrical Engineering and Computer Science, University of Liège, Liège, Belgium.
authors.forename: Jacques G
authors.initials: JG
authors.lastname: Verly
authors.affiliation: Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium.|Neurology Department, University Hospital of Liège, Liège, Belgium.
authors.forename: Steven
authors.initials: S
authors.lastname: Laureys
mesh_terms: D000328:Adult; D000368:Aged; D003244:Consciousness Disorders / Q000175:diagnosis* / Q000503:physiopathology*; D004185:Disability Evaluation; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D007259:Infrared Rays; D008297:Male; D008875:Middle Aged; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation; D011237:Predictive Value of Tests; D013223:Statistics as Topic; D014786:Vision Disorders / Q000175:diagnosis* / Q000209:etiology
keywords: Automatic detection; Behavioral assessment; Disorders of consciousness; Minimally conscious state; Visual pursuit