Traumatic brain injury: A risk factor for Alzheimer's disease

Traumatic brain injury (TBI) constitutes a major global health and socio-economic problem with neurobehavioral sequelae contributing to long-term disability. It causes brain swelling, axonal injury and hypoxia, disrupts blood brain barrier function and increases inflammatory responses, oxidative stress, neurodegeneration and leads to cognitive impairment. Epidemiological studies show that 30% of patients, who die of TBI, have Aβ plaques which are pathological features of Alzheimer's disease (AD). Thus TBI acts as an important epigenetic risk factor for AD. This review focuses on AD related genes which are expressed during TBI and its relevance to progression of the disease. Such understanding will help to diagnose the risk of TBI patients to develop AD and design therapeutic interventions.

► Traumatic brain injury (TBI) is an important epigenetic risk factor for the development of Alzheimer's disease.
► Aβ plaques which are pathological features of Alzheimer's disease are seen in 30% patients who die of TBI.
► Although many patients survive the initial insult, TBI initiates a chronic disease process.
► As TBI affects many areas of the brain, a multiplicity of neurobehavioral symptoms is common after TBI.