The Effect of Propofol Versus Isoflurane Anesthesia on Human Cerebrospinal Fluid Markers of Alzheimer's Disease: Results of a Randomized Trial.

My research team focuses on 3 areas:

1) We are interested in the mechanisms of postoperative neurocognitive disorders such as delirium, and the relationship between these disorders and Alzheimer's Disease and Related Dementias (ADRD). Towards these ends, we use a combination of methods including pre and postoperative CSF and blood sampling, functional neuroimaging, EEG recordings, rigorous biochemical assays, and cognitive testing and delirium screening. In the long run, this work has the potential to help us improve long term neurocognitive outcomes for the more than 20 million Americans over age 60 who undergo anesthesia and surgery each year.

2) We are interested in the idea that altered anesthetic-induced brain EEG waveforms can serve as indicators of specific types of preclinical/prodromal neurodegenerative disease pathology, specific cognitive domain deficits, and postoperative delirium risk. We are studying this topic in the ALADDIN study, a 250 patient prospective cohort study in older surgical patients at Duke. Many people have viewed anesthesia and surgery as a "stress test" for the aging brain; we hope that this work will help us learn how to develop a real-time EEG readout of this "perioperative stress test" for the aging brain, just as ECG analysis can provide a real-time readout of cardiac treadmill stress tests. 

3) We are interested in how the APOE4 allele damages brain circuitry throughout the adult lifespan, and how this contributes to increased risk of late onset Alzheimer's disease as well as worse outcomes following other acute brain disorders such as stroke and traumatic brain injury (TBI). In particular, we are investigating the hypothesis that the APOE4 allele leads to increased CNS complement activation throughout adult life, which then contributes to increased synaptic phagocytosis and long term neurocognitive decline. We are also studying whether acutely modulating APOE signaling in older surgical patients with the APOE mimetic peptide CN-105 is sufficient to block postoperative CSF neuroinflammation and complement activation. 

Our work is transdisciplinary, and thus our team includes individuals with diverse scientific and clinical backgrounds, ranging from neuropsychology and neuroimaging to proteomics, flow cytometry and behavioral neuroscience in animal models. What unites us is the desire to better understand mechanisms of age-dependent brain dysfunction, both in the perioperative setting and in APOE4 carriers. 

At the present time, I am participating in collaborative research in the areas of primary malignant brain tumors, epilepsy and subarachnoid hemorrhage.

Primary malignant brain tumors are increasing in frequency. Patients harboring glioblastoma, the most malignant primary brain tumor, have a life expectancy of less than one year. In collaboration with the Division of Neurology and the Department of Pathology, clinical and laboratory trials have been initiated to identify better treatment for this condition. At present, trials of monoclonal antibodies and novel chemotherapeutic agents are being carried out.

Although physicians have been interested in seizures since the time of Hippocrates, the origin of seizures remains obscure. At Duke University we have treated approximately thirty seizure patients a year by removing abnormal portions of brain. Tissue from these resections is being analyzed for genetics and receptor abnormalities. Positron emission tomography and magnetic resonance imaging are being used to ferret out the origin of the patient's seizures.

Approximately 28,000 patients each year suffer a ruptured intracranial aneurysm. Approximately ten percent of these patients have a genetic predisposition to forming intracranial aneurysms. In conjunction with the Division of Neurology, we are screening candidate genes searching for the cause of intracranial aneurysms.

Our laboratory uses molecular biology, cell culture, and animal modeling techniques to examine the CNS response to acute injury. In particular, our laboratory examines the role of microglial activation and the endogenous CNS inflammatory response in exacerbating secondary injury following acute brain insult. Much of the in vitro work in this laboratory is dedicated to elucidating cellular responses to injury with the ultimate goal of exploring new therapeutic interventions in the clinical setting of stroke, intracranial hemorrhage, and closed head injury.

In conjunction with the Multidisciplinary Neuroprotection Laboratories, we also focus on clinically relevant small animal models of acute CNS injury. For example, we have recently characterized murine models of closed head injury, subarachnoid hemorrhage, intracranial hemorrhage and perinatal hypoxia-ischemia, in addition to the standard rodent models of focal stroke and transient forebrain ischemia. Recently we have adapted several of these models from the rat to the mouse to take advantage of murine transgenic technology. The objective of these studies are two-fold: to gain better insight into the cellular responses and pathophysiology of acute brain injury, and to test novel therapeutic strategies for clinical translation. In both cell culture systems and animal models, our primary focus is on examining the role of oxidative stress and inflammatory mechanism in mediating brain injury following acute brain insult, and examining the neuroprotective effects of endogenous apolipoprotein E in the injured mammalian central nervous system.

Our laboratory is committed to translational research, and has several active clinical research protocols, which are designed to bring the research performed in the Multidisciplinary Research Laboratories to the clinical arena. These protocols are centered around patients following stroke and acute brain injury, and are primarily based out of the Emergency Room and Neurocritical Care Unit. For example, we are currently examining the role of inflammatory mediators for use as a point-of-care diagnostic marker following stroke, intracranial hemorrhage, and closed head injury. We have recently translated a novel apoE mimetic from the preclinical setting to a multi center Phase 2 trial evaluating efficacy in intracranial hemorrhage. We are also examining the functional role of different polymorphisms of of inflammatory cytokines in the setting of acute brain injury and neurological dysfunction following cardiopulmonary bypass.

Best known for his work in assessing and improving clinical outcomes and quality of life following cardiac surgery, Dr. Mark Newman is President of the Duke Private Diagnostic Clinic (The Duke Faculty Practice Organization) and the Merel H. Harmel Professor of Anesthesiology at Duke University Medical Center. In addition, Dr. Newman developed the Multicenter Perioperative Outcomes Research Group of the Duke Clinical Research Institute established at Duke in 2001 to further the study of strategies to improve the outcomes of patients undergoing surgery and anesthesia. Dr. Newman has received funding from the National Institute on Aging, the American Heart Association, the National Heart, Lung and Blood Institute, the Anesthesia Patient Safety Foundation, and the International Anesthesia Research Society  to investigate the impact of perioperative outcomes (neurocognitive decline, stroke, myocardial infarction, renal injury) on quantity and quality of life following cardiac surgery and resulting in numerous seminal publications in the New England Journal of Medicine, JAMA and Lancet. Dr. Newman is a popular lecturer and speaker, having appeared on NBC Nightly News and The Today Show and having spoken at more than 200 national and international meetings.  Dr. Newman recently stepped down as the Chairman of the Duke University Department after 13 years to assume the role of PDC President.  During Dr. Newman’s tenure the department grew exponentially doubling its clinical and academic funding, and developing many outstanding individuals that have gone on to leadership roles at Duke and other key academic institutions across the country.

Current research interests include:
1. The relationship between white matter patency, functional connectivity (fMRI) and neurocognitive function following cardiac surgery.
2. The relationship between global and regional cortical beta-amyloid deposition and postoperative cognitive decline.
3. The effect of lidocaine infusion upon neurocognitive function following cardiac surgery.
4. The association between genotype and outcome after cardiac surgery.
5. Atrial fibrillation following cardiopulmonary bypass.

With a clinical background in neuroanesthesia and neurointensive care, I have a special interest in translational research in intracerebral hemorrhage and traumatic brain injury. I am fortunate to be part of a unique team of highly motivated and productive individuals who allow me to propel ideas from bench to bedside and the ability to reverse translate ideas from the bedside back to the bench.