Alzheimer’s Disease

Alzheimer’s Disease (AD) is a progressive neurodegenerative disorder. It is the main cause of dementia, a syndrome defined by loss of cognitive capacities and independence in daily life. Approximately two thirds of all dementia cases are caused by AD. Patients with AD dementia typically suffer from progressive memory loss. The societal and economic impact of dementia is enormous. Currently, 50 million people in the world are diagnosed with dementia.

As the world’s population ages, this number is expected to triple by 2050. At this moment, the costs associated with dementia are estimated at one trillion US dollars per year. These costs are expected to double by 20301.

Biologically, dementia is considered the end-stage of Alzheimer’s Disease. The cascade of pathological events in the brain starts up to 20 years prior to expression of clinical symptoms. The pathological hallmark of AD is abnormal accumulation of amyloid and tau proteins in the brain. This accumulation distorts signal transmission between brain regions, which eventually causes neuronal atrophy. The cause of this pathological cascade of events cannot be pinpointed to a single factor. A combination of genetic, environmental, and other external factors all contribute to triggering this cascade2.

Alzheimer’s Disease poses numerous clinical and scientific challenges, as well as several unmet medical needs. First and foremost, there is no cure for AD. Several medications are available that may alleviate symptoms of AD dementia. However, treatments to slow or stop disease progression have not been developed successfully to date. Second, diagnosing patients in an early disease stage is very difficult. Typically, patients consult a physician for the first time when they experience memory problems. However, at that point, the brain has already suffered a lot of neural damage. Major scientific efforts are focused on developing methods for earlier identification of Alzheimer’s Disease patients.


References

1  The World Alzheimer Report 2018. The state of the art of dementia research: New frontiers.
2 Jack CR et al. 2018. NIA-AA Research Framework: Toward a biological definition of Alzheimer's disease. Alzheimers Dement, 14(4), 535-562