title: The functional anatomy of motor imagery after sub-acute stroke.
abstract: BACKGROUND
  The neural correlates of motor imagery (MI) are tightly coupled with the cortical motor control network. Therefore MI may have therapeutic potential for patients with motor deficits after an ischemic stroke.
  
  
  OBJECTIVE
  The aim of our study was to assess the hemispheric balance of the cortical motor network during motor imagery (MI) in patients recovering from stroke in the sub-acute stage.
  
  
  METHODS
  We studied 17 patients after cerebral ischemic stroke (sub-acute stage) and 12 healthy subjects using functional Magnetic Resonance Imaging (fMRI) during motor imagery and performance of isometric grip force movements (5 Newton). Laterality indices (LI) were calculated from regional activation analysis to assess hemispheric distribution of activity in pre-specified motor areas.
  
  
  RESULTS
  Laterality index (LI) revealed a more balanced cortical activity in MI for both controls (-0.03) and patients (-0.12) in the premotor cortex compared to movement execution (0.48 controls; 0.12 patients) and a trend towards a shift in contra-lesional activity in stroke patients.
  
  
  CONCLUSIONS
  Our results indicate a preserved interhemispheric balance of patients in the sub-acute stage when activating the cortical motor areas during MI. This could provide a reasonable physiologic baseline for using MI as an additional rehabilitative therapy for improving functional recovery in the sub-acute stage after stroke.
authors.affiliation: Department of Physical Medicine and Rehabilitation, University Hospital, Ludwig-Maximilian-University, Munich, Germany.
authors.forename: Eduard
authors.initials: E
authors.lastname: Kraft
authors.affiliation: Department of Pediatrics, University of Ulm, Germany.
authors.forename: Matthias C
authors.initials: MC
authors.lastname: Schaal
authors.affiliation: Department of Neurology, University of Ulm, Germany.
authors.forename: Dorothee
authors.initials: D
authors.lastname: Lule
authors.affiliation: Neurological Hospital, Bad Aibling, Germany.
authors.forename: Eberhard
authors.initials: E
authors.lastname: König
authors.affiliation: Department of Neurology, Hegau-Jugendhilfswerk, Gailingen, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Scheidtmann
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D019018:Imagery, Psychotherapy / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000033:anatomy & histology* / Q000502:physiology; D009068:Movement / Q000502:physiology; D009415:Nerve Net / Q000033:anatomy & histology* / Q000502:physiology; D020127:Recovery of Function / Q000502:physiology; D020521:Stroke / Q000175:diagnosis* / Q000523:psychology; D000071939:Stroke Rehabilitation
keywords: Motor imagery; fMRI; motor cortex; motor recovery; premotor cortex; stroke