Overview of Alzheimers Research Roberto Fernandez MD, MPH, PhD Medical Director The Pat Summitt Clinic Brain and Spine Institute University of Tennessee Medical Center 1 Overview
Normal brain structure and function Alzheimers pathology - What we know Alzheimers pathology - What we don't know The scope of research Clinical Trials in Alzheimers disease Clinical research at the Pat Summitt Clinic Brain Function Motor function Spoken language
Attention Planning Making Choices Suppression of unwanted behaviors Sensation Visuospatial function Integration of different Sensory systems Primary visual processing
Language comprehension Visual recognition Auditory processing Memory Behavior 3 Normal Brain Structure and Function Image: http://www.nia.nih.gov Image: www.martinos.org/neurorecovery/images/tracts.png 4
Alzheimers Pathology. What we know Not all brain regions are affected equally or at the same time Some areas are more vulnerable Hallmark changes are first seen in medial temporal lobes
Images: www.alz.org 5 Beta Amyloid Plaques Image: https://commons.wikimedia.org/ Image: wiki.brown.edu
Amyloid is a naturally occurring protein Formed from by cleavage of amyloid precursor protein Beta-amyloid has tendency to aggregate forming plaques Plaques formation is potentially toxic to neurons 6 Tau and Neurofibrillary Tangles Normal tau protein changes configuration and forms clumps, called neurofibrillary tangles, cause cell dysfunction and eventually cell death. 7 Loss of function and disease progression
X X X Loss of connections among brain cells and functional networks result in loss of function (memory, language, etc) and may contribute to spread of disease and cause further injury. 8 Disease Progression Progression of disease leads to
inflammation, cell injury, cell death and brain atrophy. Images: www.alz.org 9 Alzheimers Pathology: What We Don't Know What causes the changes in amyloid and tau Why individuals with amyloid burden may not develop AD Why are some parts of the brain more vulnerable than
others Why are there different variants of disease How does disease spread across brain regions What is the relationship with aging Whats the role of loss of connections between brain regions 10 The Scope of Biomedical Research Basic Research Molecular Animal Models Human subjects
Images: http: npr.org Images: http://www.lpzoo.org/ The Scope of Biomedical Research Symptomatic Drug Trials Clinical Research Disease Modifying Epidemiology
Preventive Genetics Imaging/EEG Diagnostics Labs Other Interventions
Cognitive 12 Clinical Trials Clinical Trials A clinical research study is a scientific investigation designed to answer important questions about a specific intervention: Is it safe?
Does it work? Which dose works best? What are the side effects? 13 Clinical Trials Progression of Clinical Trials Phase I: Tests new drug or treatment in a small group of people to assess safety, safe dose range, and identify side effects Phase II: Tests safety and/or efficacy Phase III: Studies conducted in large groups to confirm effectiveness, monitor side effects and compare to
standard treatments 14 Clinical Trials Study Design Most trials are double blinded placebo-control trials Some may be open label Some have open label extensions after completion of blinded portion of the study Most have strict inclusion criteria Duration, frequency of visits and procedures (e.g. tests) varies depending on protocol Close monitoring for possible side effects
15 Clinical Trials When considering a clinical trial: Know your rights Do not feel obligated to participate
You can decide to stop at any time Make sure you inform yourself about research evidence backing the study It is OK to ask for second opinion Make sure you review and understand the informed consent. Dont be afraid to ask questions Make sure trial is conducted by a reputable institution All research with human subjects must be conducted by entities who have an Institutional Review Board (IRB) Be aware that food supplements and natural products may not be regulated in the same manner as therapeutic drugs, but may still have risks and possible side effects 16
Current Therapeutic Research in Alzheimers There are currently no approved medications that can cure, slow down or revert Alzheimers Approved medications are intended to treat symptoms and may provide temporary improvement Experimental drugs target know mechanism of disease through different approaches: Beta-amyloid: Antibodies that help clear plaques, prevent aggregation or block enzymes involved in amyloid formation Neurofibrillary tangles: Vaccine that stimulates the bodys immune system to attack an abnormal form of tau protein that destabilizes the structure of neurons Inflammatory response: Drugs that can modulate inflammation
Neuronal network dysregulation: Anti-epileptic drugs to modulate possible hyperexcitability of brain cells Neurotransmitter function 17 Monoclonal Antibodies Selective for aggregated betaamyloid Bind to amyloid plaques Signal to immune cells that then recognize plaque and remove it Images: www.alz.org
18 Clinical research at the Pat Summitt Clinic ENGAGE Clinical Trial Study evaluating the efficacy and safety of an investigational drug in people experiencing symptoms of early Alzheimers disease. It is intended for preclinical Alzheimers, also known as mild cognitive impairment Study drug is aducanumab, a monoclonal antibody Prior studies showed statistically significant reduction in plaque and slowing of cognitive decline Aim to determine whether the investigational drug can remove the plaques and have an effect on the slowing of the progression of
the condition Infrequent but potentially serious adverse events have been associated with this medication. These include brain swelling and 19 brain bleeds. ENGAGE Clinical Trial Approximately 1350 people with symptoms of early Alzheimers disease will take part in this study around the world. Two phases: a placebo-controlled phase, and an optional long-term extension phase. Placebo-Control phase: two-in-three chance of receiving investigational drug. This phase lasts 2 years Long-Term phase: All participants will receive the drug for 2 years
Participants who meet eligible requirements will visit the clinic once or twice per month During placebo- controlled phase, participants will receive either the investigational drug or placebo every 4 weeks for approximately 18 months (1.5 years). 20 You may qualify for the study if: You are 5085 years of age You are experiencing symptoms that might be related to early Alzheimers disease, such as problems with memory or thinking clearly You have someone who can be your study partner (accompany you to certain appointments and provide
information about your health). 21 Clinical Research at the Pat Summitt Clinic Visuospatial Impairments in Alzheimers Disease (AD) Up to 1/3 of AD begins with visuospatial symptoms
Associated with posterior cortical atrophy Disabling because it undermines independent living 22 Brain Areas for Visuospatial Orientation and Alzheimers disease
Dorsal Where? Ventral What? 23 Optic Flow The visual motion seen during self movement Alzheimers can impair optic flow perception, leading to disorientation 24
Brain responses to it can be measured with EEG 25 Brainwaves evoked by optic flow can differentiate early stage Alzheimers from normal aging. 26 Optic flow responses are associated with poor driving performance and
atrophy of specific brain regions that are affected in Alzheimers 27 Current Research To establish the parameters of OF-ERP components that will reliably differentiate normal aging from Alzheimers for early diagnosis and monitoring of disease progression Elucidate mechanism of Alzheimers disease that are poorly understood
Evaluate optic flow brain responses as objective predictors of driving capacity 28 Thank You
