title: Reperfusion does not improve impaired rapid-onset cortical plasticity in patients with severe stenosis of the internal carotid artery.
abstract: BACKGROUND
  Severe stenosis of the internal carotid artery (ICA) has been associated with impaired cognition in patients, but its effect on rapid-onset cortical plasticity is not known. Carotid endarterectomy (CEA) in patients with severe ICA stenosis reduces stroke risk, but the impact on cognition or physiology of the respective hemisphere remains controversial.
  
  
  RESULTS
  16 patients with severe stenosis of the ICA and 16 age and sex matched controls were included. Rapid-onset cortical plasticity was assessed using the paired-associative stimulation (PAS) protocol. PAS models long-term synaptic potentiation in human motor cortex, combining repetitive stimulation of the peripheral ulnar nerve with transcranial magnetic stimulation of the contralateral motor cortex. Cognitive status was assessed with a neuropsychological test battery. In patients, verbal learning and rapid-onset cortical plasticity were significantly reduced as compared to controls. Identical follow-up tests in 9 of the 16 patients six months after CEA revealed no improvement of cognitive parameters or cortical plasticity.
  
  
  CONCLUSIONS
  Decreased rapid-onset cortical plasticity in patients with severe stenosis of the ICA was not improved by reperfusion. Thus, other strategies known to increase plasticity should be tested for their potential to improve cortical plasticity and subsequently cognition in these patients.
authors: Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors: Jonathan
authors: J
authors: List
authors: Johannes
authors: J
authors: Albers
authors: Julia
authors: J
authors: Kürten
authors: Arne
authors: A
authors: Schwindt
authors: Eike
authors: E
authors: Wilbers
authors: Agnes
authors: A
authors: Flöel
mesh_terms: D000368:Aged; D016893:Carotid Stenosis / Q000503:physiopathology* / Q000601:surgery* / Q000628:therapy; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000503:physiopathology*; D003071:Cognition; D004599:Electric Stimulation Therapy; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009473:Neuronal Plasticity; D015424:Reperfusion; D013997:Time Factors; D050781:Transcranial Magnetic Stimulation