Cohort Study of Risk Factors for Postoperative Cognitive Decline

Adults 65 years and older represent the fastest-growing age group in the United States, and account for one third of all surgical patients. These older adults are at the highest risk for deleterious postoperative neurocognitive outcomes. Postoperative cognitive dysfunction (POCD) occurs in up to 40% of older adults after major non-cardiac surgery. POCD is a syndrome characterized by a decrease in performance on neuropsychological test battery from before to after surgery. Neuropsychological testing for POCD typically spans cognitive domains including memory, attention, concentration, and/or executive function. There is an increasing body of literature suggesting that exposure to surgery and anesthesia increases the risk of Alzheimer's disease (AD). Surgery and anesthesia enhance neuropathologic changes known to underlie AD including amyloid beta accumulation and aggregation, neuroinflammation, increased levels of tau and tau phosphorylation, and memory decline. However, not everyone with a history of surgery and anesthesia develops POCD, suggesting biological risk factors are involved.

Inclusion criteria

• Scheduled for an in-patient, elective spine surgery where subject will receive general anesthesia
• Presenting to spine clinic and undergoing conservative, non-surgical management of spine disorder
• Subjects must have sufficient vision and hearing to complete neuropsychological testing
• Proficient in spoken and written English language

Exclusion criteria

• Diagnosed dementia or dementia-related treatment (i.e. donepezil prescription, or memory-care facility residence)
• Significant disease of the central nervous system (CNS) (i.e. Parkinson's disease)
• History of stroke or traumatic brain injury
• Major psychiatric disorder (i.e. schizophrenia)
• Alcohol or drug abuse according to DSM-V within the last 2 years
• Need for urgent/emergent surgery
• Surgery/anesthesia within prior 12 months
• Refusal of consent