title: Ignoring floor and ceiling effects may underestimate the effect of carotid artery stenting on cognitive performance.
abstract: BACKGROUND
  Data on neuropsychological outcome after carotid artery stenting (CAS) remain inconsistent, furthermore cognitive outcome seems to be unpredictable in the individual case. Previous studies reporting improvement or decline might be due to ceiling and floor effects of the applied cognitive tests. We applied cognitive testing before and after CAS, avoiding the pitfall of ceiling and floor effects.
  
  
  METHODS
  In our prospective database, we identified 72 patients free of clinical stroke with ≥70% carotid artery stenosis, who were treated with CAS. They were administered a neurocognitive test battery before and 3 months after CAS to compare cognitive performance before and after CAS. To avoid ceiling and floor effects of test performances, we additionally analysed subgroups of patients without baseline floor and ceiling cognitive performance.
  
  
  RESULTS
  Pre-interventional to post-interventional cognitive performance improved significantly in the subtests measuring verbal episodic memory; deterioration was observed in spatial memory. The subgroups of patients without baseline floor and ceiling cognitive performance improved in measures of global cognition, verbal episodic memory (patients with left-sided CAS) and divided attention (patients with right-sided CAS); we observed no significant effects in the other domains.
  
  
  CONCLUSIONS
  Ignoring floor and ceiling effects may underestimate the impact of CAS on cognitive performance.
authors.affiliation: Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria Department of Psychiatry, Klinikum rechts der Isar, Technische Universität München, Munich, Germany TUM Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, Munich, Germany Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Scherr
authors.affiliation: Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kunz
authors.affiliation: TUM Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors.forename: Anselm
authors.initials: A
authors.lastname: Doll
authors.affiliation: Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria.
authors.forename: Johannes Sebastian
authors.initials: JS
authors.lastname: Mutzenbach
authors.affiliation: Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria Research Institute of Neurointervention, Paracelsus Medical University Salzburg, Salzburg, Austria Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria.
authors.forename: Erasmia
authors.initials: E
authors.lastname: Broussalis
authors.affiliation: Neuroscience Institute, Christian Doppler Klinik, Paracelsus Medical University Salzburg, Salzburg, Austria Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria.
authors.forename: Hans Jürgen
authors.initials: HJ
authors.lastname: Bergmann
authors.affiliation: Neuroscience Institute, Christian Doppler Klinik, Paracelsus Medical University Salzburg, Salzburg, Austria Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria.
authors.forename: Margarita
authors.initials: M
authors.lastname: Kirschner
authors.affiliation: Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria.
authors.forename: Eugen
authors.initials: E
authors.lastname: Trinka
authors.affiliation: Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria Research Institute of Neurointervention, Paracelsus Medical University Salzburg, Salzburg, Austria Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria.
authors.forename: Monika
authors.initials: M
authors.lastname: Killer-Oberpfalzer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016893:Carotid Stenosis / Q000175:diagnosis / Q000523:psychology* / Q000628:therapy*; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000175:diagnosis / Q000523:psychology*; D016894:Endarterectomy, Carotid / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000592:standards*; D011446:Prospective Studies; D015607:Stents / Q000009:adverse effects*; D013997:Time Factors; D016896:Treatment Outcome
keywords: Angiography; Atherosclerosis