Objective To observe the effect of transcutaneous acupoint electrical stimulation(TAES) on serum superoxide dismutase(SOD) activity

malondialdehyde(MDA) and S100β contents in craniotomy patients for studying its cerebral protection mechanism.Methods Fifty patients scheduled for neurosurgery were randomly divided into TAES group(n=25) and control group(n=25) with randomized block method.For patients of TAES group

TAES was applied to bilateral Hegu(LI 4) and Quchi(LI 11)

Zusanli(ST 36) and Sanyinjiao(SP 6) from 30 minutes on before anesthesia to the end of operation.Patients of control group were anesthetized with sevoflurane inhalation and intermittent(i.v.) of sulfenany and vecurnium bromide.Blood samples were taken for assaying serum SOD activity

MDA and S100β contents with purinase oxydasis

biochemiluminescence and enzyme linked immunosorbent assay separately.Scores of cognitive ability were given by using Mini Mental State Examination(MMSE).Results In comparison with pre-anesthesia

serum SOD activity decreased significantly 1 h after craniotomy in control group

at the end of operation in both control and TAES groups(P<0.05

P<0.01)

and increased markedly 48 h after operation in control group(P<0.05).Serum MDA in control group increased significantly 48 h after operation

while that in TAES group reduced apparently 24 h after operation(P<0.01).Serum S100β content in TAES group decreased remarkably 48 h after operation(P<0.01).Serum SOD activity of TAES group was significantly higher than that of control group 24 h after operation(P<0.05).Compared with control group

serum MDA contents of 24 h and 48 h after operation and serum S100β levels at 1 h after craniotomy and 48 h after operation were markedly lower in TAES group(P<0.01

P<0.05).No significant differences were found between two groups in the cognitive function scores(P>0.05).Conclusion TAES can increase serum SOD activity and reduce MDA and S100β levels in patients undergoing craniotomy

which may contribute to its effect in reducing lipid peroxidation induced cerebral injury.But its impact on the patient's cognitive function needs study further.