Effects of transcranial magnetic stimulation on motor cortical excitability and neurofunction after cerebral ischemia-reperfusion injury in rats.
OBJECTIVE
To clarify the effects of repetitive transcranial magnetic stimulation (rTMS) on rat motor cortical excitability and neurofunction after cerebral ischemia-reperfusion injury.


METHODS
After determined awake resting motor threshold (MT) and motor evoked potentials (MEPs) of right hindlimbs, 20 Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) reperfusion injury, then rTMS were applied to rTMS group (n=10) at different time, while control group (n=10) received no stimulation. A week later, MT and MEPs were evaluated again, as well as neurological deficits and infarct volume. The effects of rTMS and MCAO reperfusion injury on these parameters were analyzed.


RESULTS
After MCAO reperfusion, both MT level and neurological deficit scores increased, distinct focal infarction formed, and latency of MEP elongated. Compared with the control group, the increased extent of MT and neurological scores of rats receiving rTMS were significantly lower (P < 0.05), as well as the infarct volumes reduced significantly (P < 0.05). But MEP was not affected by rTMS obviously. There was a positive linear correlation between postinjury MT and infarct volume (r = 0.64, P < 0.05).


CONCLUSIONS
rTMS may facilitate neurofunction recovery after cerebral ischemia-reperfusion. Postinjury MT could provide prognostic information after MCAO reperfusion injury.
Feng
Hong-lin
HL
Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730.
Yan
Li
L
Guan
Yu-zhou
YZ
Cui
Li-ying
LY
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D001921:Brain / Q000473:pathology*; D019054:Evoked Potentials, Motor; D006614:Hindlimb / Q000503:physiopathology; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000473:pathology / Q000503:physiopathology*; D050781:Transcranial Magnetic Stimulation