The purpose of this study is to assess whether a large clinical trial testing the effect of RIPC on neurologic outcome in patients undergoing elective cervical decompression surge is warranted.

Spinal cord ischemia-reperfusion injury commonly contribute to perioperative morbidity and mortality after elective cervical decompression surgery.Remote ischemic preconditioning(RIPC)is a phenomenon whereby brief periods of ischemia followed by reperfusion in one organ provide system protection from prolonged ischemia.The hypothesis of this protocol is that limb ischemic preconditioning could reduces spinal cord ischemia-reperfusion injury induced by elective cervical decompression surgery.Serum s-100B and NSE concentration will be measured before and after induction ,and at 6 hours,1,3,5 and 7days after surgery.JOA scores in all the cases will be evaluated before operation and at 7days ,1,3,6 month after surgery.

Inclusion Criteria:

• Patients with clinical and radiological signs of cervical compression myelopathy(ccm)
• Age 30-75
• Stage 1-2

Exclusion Criteria:

• Age>75
• History of heart,hepatic,renal or pulmonary disease.
• History of peripheral vascular disease affecting the upper limbs.