title: You never know where you are going until you know where you have been: Disorganized search after stroke.
abstract: Disorders in spatial exploration can be expressed in a disorganized fashion of target cancellation. There is debate regarding whether disorganized search is related to stroke in general, to right brain damage or to unilateral spatial neglect (USN) in particular. In this study, 280 stroke patients and 37 healthy control subjects performed a computerized shape cancellation test. We investigated the number of perseverations and several outcome measures regarding disorganized search: Consistency of search direction (best r), distance between consecutive cancelled targets and intersections with paths between previous cancelled targets. We compared performance between patients with left and right brain damage (L, R) and with and without USN (USN+, USN-), resulting in four subgroups: LUSN-, RUSN-, LUSN+, and RUSN+. Higher numbers of intersections were found for the left brain- and right brain-damaged patients with USN and for the right brain-damaged patients without USN, compared to healthy control subjects. Furthermore, right brain-damaged patients with USN showed a higher number of intersections compared to right brain-damaged patients without USN and compared to left brain-damaged patients with USN. To conclude, disorganized search was most strongly related to the neglect syndrome, and patients with more severe USN were even more impaired.
authors.affiliation: Brain Center Rudolf Magnus and Center of Excellence for Rehabilitation Medicine, University Medical Center Utrecht and De Hoogstraat Rehabilitation, The Netherlands.
authors.forename: Antonia F
authors.initials: AF
authors.lastname: Ten Brink
authors.affiliation: Department of Experimental Psychology, Helmholtz Institute, Utrecht University, The Netherlands.
authors.forename: Stefan
authors.initials: S
authors.lastname: Van der Stigchel
authors.affiliation: Brain Center Rudolf Magnus and Center of Excellence for Rehabilitation Medicine, University Medical Center Utrecht and De Hoogstraat Rehabilitation, The Netherlands.
authors.forename: Johanna M A
authors.initials: JM
authors.lastname: Visser-Meily
authors.affiliation: Brain Center Rudolf Magnus and Center of Excellence for Rehabilitation Medicine, University Medical Center Utrecht and De Hoogstraat Rehabilitation, The Netherlands.|Department of Experimental Psychology, Helmholtz Institute, Utrecht University, The Netherlands.
authors.forename: Tanja C W
authors.initials: TC
authors.lastname: Nijboer
mesh_terms: D000368:Aged; D003072:Cognition Disorders / Q000000981:diagnostic imaging / Q000209:etiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D017063:Outcome Assessment, Health Care; D010468:Perceptual Disorders / Q000000981:diagnostic imaging / Q000209:etiology*; D012189:Retrospective Studies; D013028:Space Perception / Q000502:physiology*; D020521:Stroke / Q000150:complications* / Q000000981:diagnostic imaging / Q000523:psychology*; D015898:Tomography Scanners, X-Ray Computed
keywords: cancellation; disorganized search; spatial remapping; stroke; unilateral spatial neglect