Dementia is a broad category encompassing various syndromes associated with the ongoing decline in brain functioning
You might have assumed that all brains are roughly the same size. But scientists suggest this isn’t always the case – in fact, the shape of our brain could potentially help detect early signs of dementia.
New research from the University of California explored this concept, analysing over 2,600 brain scans of adults aged 30 to 97. Remarkably, they observed that ‘uneven shaping’ was particularly prominent in older adults experiencing cognitive decline, which could indicate new markers for identifying dementia risk.
Senior author Niels Janssen explained: “Most studies of brain ageing focus on how much tissue is lost in different regions. What we found is that the overall shape of the brain shifts in systematic ways, and those shifts are closely tied to whether someone shows cognitive impairment.”
Dementia is a broad category encompassing various syndromes associated with the ongoing decline in brain functioning. Alzheimer’s disease is the most common form, accounting for about 60 to 70% of cases, according to the World Health Organisation.
In the fresh analyses, scientists observed that older adults experiencing cognitive decline showed greater expansion in the ‘inferior and anterior parts of the brain’, while the ‘superior and posterior regions’ contracted inward. Adults with ‘poorer reasoning’ skills were also frequently noted to have ‘more pronounced posterior compression’, referring to something pressing upon the back.
However, according to the team, one of the study’s most striking implications was understanding the ‘potential impact of shape changes with age on the entorhinal cortex’. This specifically describes a small but crucial memory base located in the brain.
The study indicates that these shape alterations might physically push this vulnerable area nearer to the rigid base of the skull. The entorhinal cortex is also among the initial regions where tau, a harmful protein associated with Alzheimer’s disease, starts to accumulate.
Co-author Dr Michael Yassa also explained: “This could help explain why the entorhinal cortex is ground zero of Alzheimer’s pathology. If the ageing brain is gradually shifting in a way that squeezes this fragile region against a rigid boundary, it may create the perfect storm for damage to take root.
“Understanding that process gives us a whole new way to think about the mechanisms of Alzheimer’s disease and the possibility of early detection.” Overall, scientists think that gaining a better understanding of how brain shape changes could assist in understanding the mechanisms of risks, even during the earliest stages of the disease.
Dr Yassa continued: “We’re just beginning to unlock how brain geometry shapes disease. But this research shows that the answers may be hiding in plain sight – in the shape of the brain itself.”
Key symptoms of dementia
While signs of dementia can vary depending on the type, common symptoms during its onset may include:
- Struggling to follow a conversation or find the right word
- Being confused about time and place
- Mood changes
- Difficulty concentrating
- Finding it hard to carry out familiar daily tasks, such as getting confused over the correct change when shopping
- Memory loss
The NHS encourages anyone experiencing these symptoms to seek medical advice. Its guidance reads: “Although there is no cure for dementia at the moment, an early diagnosis means its progress can be slowed down in some cases, so the person may be able to maintain their mental function for longer.
“A diagnosis helps people with dementia get the right treatment and support. It can also help them, and the people close to them, to prepare for the future.”
For more information, head to the NHS website.