Early reperfusion improves the recovery of contralateral electrophysiological diaschisis following focal cerebral ischemia in rats.
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.
Hung
Yu-Chang
YC
Neurophysiology Laboratory, Neurosurgical Service, Department of Surgery, National Cheng Kung University Medical Center and Medical School, Tainan, Taiwan.
Chou
Ya-Shuan
YS
Chang
Chi-Han
CH
Lin
Hsiao-Wen
HW
Chen
Hung-Yi
HY
Chen
Tsung-Ying
TY
Tai
Shih-Huang
SH
Lee
E-Jian
EJ
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