title: Early reperfusion improves the recovery of contralateral electrophysiological diaschisis following focal cerebral ischemia in rats.
abstract: OBJECTIVE
  We evaluated electrophysiological benefits of reperfusion following ischemic stroke.
  
  
  METHODS
  Rats received either transient proximal occlusion of the right middle cerebral artery for 30 (Group I, n=8) or 90 minutes (Group II, n=8) or permanent  thermocoagulation of the distal right middle cerebral artery (Group III, n=6). Neurobehavioral outcome and somatosensory evoked potentials (SSEPs) were examined before and at 7 days after the onset of brain ischemia. Brain infarction was assessed after the rats were euthanized.
  
  
  RESULTS
  Before ischemia, stable SSEPs were consistently recorded. At 7 days post-insult, Group III (permanent occlusion) had the greatest reduction in the SSEPs recorded ipsilaterally and contralaterally. Groups I and II (transient ischemic groups) also had depressant SSEPs recorded from the ipsilateral  ischemic and the contralateral intact brain (electrophysiological diaschisis). However, prolonged ischemia resulted in greater brain infarction and increased neurological deficits in addition to greater reductions in the ipsilateral and the contralateral SSEPs.
  
  
  CONCLUSIONS
  Early  reperfusion facilitates the electrophysiological recovery in both ipsilateral lesional and the contralateral intact brain, which may be closely relevant to post-injury brain rewiring. We also demonstrated that contralateral electrophysiological diaschisis could be greatly reversed by early  reperfusion and is independent of the lesion size of striatum.
authors.affiliation: Neurophysiology Laboratory, Neurosurgical Service, Department of Surgery, National Cheng Kung University Medical Center and Medical School, Tainan, Taiwan.
authors.forename: Yu-Chang
authors.initials: YC
authors.lastname: Hung
authors.forename: Ya-Shuan
authors.initials: YS
authors.lastname: Chou
authors.forename: Chi-Han
authors.initials: CH
authors.lastname: Chang
authors.forename: Hsiao-Wen
authors.initials: HW
authors.lastname: Lin
authors.forename: Hung-Yi
authors.initials: HY
authors.lastname: Chen
authors.forename: Tsung-Ying
authors.initials: TY
authors.lastname: Chen
authors.forename: Shih-Huang
authors.initials: SH
authors.lastname: Tai
authors.forename: E-Jian
authors.initials: EJ
authors.lastname: Lee
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000503:physiopathology* / Q000628:therapy*; D002560:Cerebrovascular Circulation / Q000502:physiology; D055724:Electrophysiological Phenomena / Q000502:physiology; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000502:physiology*; D015424:Reperfusion / Q000379:methods*; D013997:Time Factors