Peri-Anesthetic Imaging of Cognitive Dysfunction (PAICOD)

• Comparison of preoperative vs postoperative Brain MRI changes [ Time Frame: 2 months ] [ Designated as safety issue: Yes ]
  Anesthetics can have prolonged effects on gene expression, protein synthesis and processing as well as cellular function, especially in the very young and the elderly. After anesthesia, some patients experience mild to very severe disorientation and even delirium without apparent cause. In the elderly, this Post-Operative Cognitive Dysfunction (POCD) - including changes in memory and executive function may persist and has been linked to an increased risk of death. Over the next 20-30 years, 40% of 65+ year-olds will undergo surgery; the cost of POCD in longer-term care, lost wages, and extended suffering of patients and families will remain high.
  
  

• Preoperative vs Postoperative Neurocognitive Testing [ Time Frame: 2 Months ] [ Designated as safety issue: Yes ]
  Pre- vs postoperative Neurocognitive Testing (NCT) is currently the primary method used to quantify changes in cognitive indices, including memory, processing speed, motor function, etc. This study will compare such pre- and post-op NCT with pre-and post-op MRI and fMRI to determine relationships between changes in each of these modalities.
  
  

For more than 160 years, "modern" anesthesia has provided immense benefit to patients of all ages. However, over the past several years, concern has been growing that for patients at the extremes of age, some anesthetic agents may harbor subtle, previously minimally examined, serious neurotoxic effects which can cause lasting decline in the function of the central nervous system (CNS). For the elderly, these effects may manifest in lasting post-operative deterioration of memory and the capacity for normal information processing that can result in the inability to perform the activities of daily living (ADLs) with eventual early demise. Unfortunately, even though our ability to evaluate anesthetic risk has grown asymptotically for virtually every organ system, the brain remains neglected. And even though we know a good deal about effect sites for general anesthetic agents, we still have an incomplete understanding of the potential toxic effects of anesthetics on the brain. Therefore, employing a human surgical model (endoscopic prostatectomy), we propose a pilot study of 15 otherwise neurologically intact, ASA I - III, males, 65+ year of age. After pre-enrollment screening (MMSE & BDI) and standard pre-op evaluation, subjects will undergo both anatomic and functional MRI studies plus a battery of neurocognitive tests (NCT) at two time points approximately 2-3 weeks apart prior to surgery. These pre-op studies will establish both a "non-surgical control" for the study as well as a baseline for post-op studies. 2-3 weeks after surgery, MRI and NCT will be repeated. The study aims to determine if MRI can demonstrate changes in the CNS pre-op vs post-op that relate to anesthesia and surgery and how those changes might correlate with NCT over the same interval.