As part of World Alzheimer’s Month, we sat down with Dr. Steven DeKosky, internationally recognized neurologist, Alzheimer’s researcher, and member of the BRAIN Center Steering Committee, to discuss the connections between traumatic brain injury (TBI), dementia risk, and the latest advances in Alzheimer’s care.
Dr. DeKosky, who has spent decades advancing the science of neurodegeneration, shared his thoughts on three key questions:
How do brain injuries affect a person’s risk for dementia, including Alzheimer’s?
A good deal depends on the severity of the injury. A moderate to severe injury leaving the patient with residua increases the likelihood that the person may develop dementia; the brain damage sustained leaves the patient with less capability to fend off further injury including neurodegenerative disease. This is one reason why dementia may emerge earlier than it otherwise would have. Without the injury it may have manifested later, or not at all.
Mild TBI has the same possible sequelae; TBI we know produces pathological change in both the expression of tau tangles and the subcortical white matter, which would contribute to cognitive loss and also lowered resistance to degenerative change, further trauma, or strokes. All of these injuries decrease the ability to fend off decline in neural connectivity and cognition.
How do new approaches in Alzheimer’s research inform what we’re learning about brain injury and neuroresilience?
Much of the research into neurodegenerative mechanisms in AD has application both to acute and chronic head trauma. Both the regenerative efforts that occur in the Alzheimer’s brain and our efforts to facilitate such have potential application following head injury. Amyloid Precursor Protein (APP) and beta amyloid both increase following head trauma for as yet unknown reasons. Neurofibrillary tangles appear late in the longitudinal course of repetitive TBI.
Development of anti-amyloid medications for Alzheimer’s disease they have application for treatment of head injury. Although we do not know the role of APP or beta amyloid in the acute phase of head trauma, experimental studies in animals may show us whether suppressing it with medications developed for AD results in better outcome.
What gives you hope right now in Alzheimer’s research or care?
Although we focus on the success or failure of single medications or medications of similar mechanism (because that is the way they must be tested to be eligible for approval) we have known for many years that Alzheimer’s disease, like other complex diseases, such as heart disease and cancer, are seldom treated with just one medication. Similarly, we’ve known for decades that the high likelihood was that Alzheimer’s disease would also require multiple medications to treat it and perhaps to prevent it.
The success, albeit not perfect, of the anti-amyloid antibodies and the emergence of medications to interfere with tau proliferation, are a likely close next step in the search for treatments. Coupled with these advancements are medications complementary to the hallmark pathologies, to suppress inflammation and oxidative stress. Other medications directed at other discovered pathologies, such as synaptic toxicity, may also contribute to new treatments.
The other major advance has been in diagnostic tests; most notably the development of blood tests with a very high accuracy and perhaps the ability to detect pre symptomatic disease.
These advances give me hope.
Looking Ahead
Dr. DeKosky’s insights underscore the profound connections between brain injury and Alzheimer’s disease, as well as the exciting progress being made toward new treatments and early detection. During World Alzheimer’s Month, his reflections remind us why continued research, collaboration, and awareness are essential to improving outcomes for individuals and families affected by both TBI and Alzheimer’s.