title: Cortical reorganization due to impaired cerebral autoregulation in individuals with occlusive processes of the internal carotid artery.
abstract: OBJECTIVE
  To study the impact of impaired cerebral autoregulation on cortical neurophysiology, long term potentiation (LTP)-like plasticity, motor learning and brain structure.
  
  
  METHODS
  12 patients with unilateral occlusion or severe stenosis of the internal carotid artery were included. Impairment of cerebral autoregulation was determined by vasomotor reactivity in transcranial Doppler sonography. Corticomotor excitability, cortical silent period and LTP-like plasticity were assessed with transcranial magnetic stimulation, motor learning with a force production task, and brain structure with high-resolution MRI of the brain.
  
  
  RESULTS
  In the affected hemisphere, corticomotor excitability was significantly higher, cortical silent period and LTP-like plasticity significantly lower, compared to the contralateral side. No significant difference emerged for motor learning, cortical thickness and white matter integrity between the hemispheres.
  
  
  CONCLUSIONS
  Despite decreased LTP-like plasticity in the affected hemisphere, motor learning was comparable between hemispheres, possibly due to gamma-aminobutyric-acid (GABA)B-mediated corticomotor excitability changes within the affected hemisphere. Our results may help to develop interventions to beneficially modulate cortical physiology in the presence of cerebral hypoperfusion.
authors.affiliation: Department of Neurology, Charité-University Hospital, Berlin, Germany; Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Germany. Electronic address: Jonathan.List@charite.de.
authors.forename: Jonathan
authors.initials: J
authors.lastname: List
authors.affiliation: Department of Neurology, Charité-University Hospital, Berlin, Germany.
authors.forename: Susan
authors.initials: S
authors.lastname: Hertel-Zens
authors.affiliation: Department of Neurology, Charité-University Hospital, Berlin, Germany.
authors.forename: Jan Carl
authors.initials: JC
authors.lastname: Kübke
authors.affiliation: Department of Neurology, Charité-University Hospital, Berlin, Germany; Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Lesemann
authors.affiliation: Department of Neurology, Charité-University Hospital, Berlin, Germany.
authors.forename: Stephan J
authors.initials: SJ
authors.lastname: Schreiber
authors.affiliation: Department of Neurology, Charité-University Hospital, Berlin, Germany; Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Germany; NeuroCure Cluster of Excellence, Charité-Universitätsmedizin Berlin, Germany. Electronic address: Agnes.Floeel@charite.de.
authors.forename: Agnes
authors.initials: A
authors.lastname: Flöel
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000098:blood supply / Q000473:pathology*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000473:pathology*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006706:Homeostasis; D006801:Humans; D007858:Learning / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009048:Motor Skills; D009473:Neuronal Plasticity; D009483:Neuropsychological Tests; D010477:Perfusion; D010865:Pilot Projects; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*; D066127:White Matter / Q000473:pathology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D005680:gamma-Aminobutyric Acid
keywords: Carotid artery stenosis; GABA; LTP-like plasticity; Motor learning; Transcranial magnetic stimulation