Perioperative neurocognitive disorders(PND) is common to see in elderly patients. Although PND increases patient mortality as well as hospitalization time, apparent inflammatory factors, and related mechanisms are still unknown. Metabolites could reveal chemical fingerprints left behind by cellular processes, which in turn provide a new aspect to understand the biological process behind. we aim to found the metabolomics can aid the development of diagnostic markers of PND screening, early detection, and further, provide a basis for disease prevention and treatment.

Inclusion Criteria:

• Parkinson's patients undergoing elective deep brain stimulation
• Age ≥55 years
• ASA physical statusⅠ-Ⅲ
• Elementary school or above

Exclusion Criteria:

• patients with ASA physical status>III
• patients with systemic immune diseases, hematological diseases (hematological tumors or leukemia), patients after transplantation, malignant tumors
• patients with metabolic diseases such as diabetes, ketoacidosis, hyperosmolar syndrome, long-term hypoglycemia,gout
• patients who refused to join the study and lost to follow-up

we select Parkinson's patients undergoing elective DBS and observe who occur PND or not.