Synuclein pathology is related to postoperative delirium in patients undergoing gastrectomy

Objective: The clinical characteristics of postoperative delirium are similar to core features of α-Synuclein-related cognitive disorders, such as dementia with Lewy bodies or Parkinson disease dementia. We therefore investigated the α-Synuclein pathology in patients who experienced postoperative delirium after gastrectomy for stomach cancer. Method: Patients with and without postoperative delirium were selected among patients undergoing total gastrectomy for primary gastric cancer from 2007 to 2011 (each n 5 16) at the university hospital. Immunohistochemical staining for α-Synuclein of both normal and phosphorylated form was performed in the myenteric plexus. A logistic regression analysis was applied to identify independent predictors of postoperative delirium. Results: No significant differences were observed for age, sex, operation time, or onset of delirium after total gastrectomy between patients with and without postoperative delirium. Patients with postoperative delirium had a higher frequency of intensive care unit admissions (43.8 vs 6.3%, p 5 0.037) and α-Synuclein-positive pathologies of normal (56.3 vs 12.5%, p 5 0.023) and phosphorylated form (43.8 vs 6.3%, p 5 0.037) compared with those without postoperative delirium. A logistic regression analysis revealed that immunoreactivity for normal α-Synuclein (odds ratio [OR] 9.20) and intensive care unit admission (OR 11.97) were independently associated with postoperative delirium. Conclusion: These results suggest that underlying α-Synuclein pathologies in the stomach are associated with postoperative delirium, implying that postoperative delirium represents a preclinical stage of α-Synuclein related to cognitive disorders.