Piecing together the dementia puzzle
Decades of research have brought us to the cusp of having treatments that could slow Alzheimer’s disease or even stop it in its tracks. In the past two years, studies have shown that three promising medications, aducanumab, lecanemab and donanemab, can tackle the toxic proteins that damage brain cells. However, a crucial commonality of these treatments is that they all require an early diagnosis to be effective.
Currently, many people with dementia only receive a diagnosis when they are in the later stages of the disease responsible. This is because the diseases that cause dementia can start to take hold and change the brain up to 20 years before a person has recognisable symptoms. By this time, even if breakthrough medications can help prevent further decline, the existing damage to the brain cannot be undone.
How to confirm a diagnosis before symptoms appear is a challenge that many scientists, medical professionals and charities are working tirelessly to address. Researchers are racing to understand the subtle changes that happen when the cascade of events in the brain first begins.
At the same time, momentum is gathering in improving diagnostics to make detecting these changes possible. In the majority of cases, a diagnosis will be made after a suite of cognitive tests and scans looking at both the structure and function of the brain. Some cases will also involve tests on the cerebrospinal fluid that bathes the brain and contains proteins that can indicate changes in its environment.
We are now edging closer to tests that are less invasive and more accurate. Blood tests are being developed that have enough sensitivity to detect levels of harmful proteins, although they do not yet have the specificity to be a stand-alone test. The use of digital technologies, such as smartwatches and headbands, is also helping researchers develop and understand the fingerprints of dementia.
Barriers to diagnosis beyond new advancements
The lack of symptoms in the early stages of dementia is not the only barrier to diagnosis. Societal and personal factors can prevent some people from seeking help.
The stigma around Alzheimer’s disease and other forms of dementia can make people hesitant to consult a doctor, as can a lack of understanding about what dementia is and how it differs from the normal ageing process. In some cultures, dementia is not officially recognised as an illness, so it can be a taboo subject.
There are also barriers at the clinician and system levels. Not all primary care practitioners are trained to recognise dementia symptoms, so people may be dismissed or misdiagnosed with conditions that have similar symptoms. At the system level, there need to be enough specialists to conduct the diagnostic tests, the right infrastructure to provide these tests, and sufficient funding from governments and other decision-makers.