By now, most people are familiar with early-onset dementia and the fact that it is incurable with few or no treatment options available. If you’ve ever had a loved one who has had dementia, you know how devastating the disorder can be. If you haven’t, thank your lucky star.
Early-onset dementia It is undoubtedly a harsh disorder for the person affected and those around him. Researchers have been working feverishly to understand more about it in hopes of finding something to combat the disorder.
That’s why this discovery by researchers from Trinity College Dublin is very exciting: it is a major breakthrough that can lead to effective treatment. It’s important not to put the cart before the horse on this one, but the research is certainly a significant advance in scientists’ understanding of early-onset dementia.
What is early-onset dementia?
Early-onset dementia is, as the name describes it, dementia that occurs earlier in life than it should (not that it should occur at all). Many people exchange the terms dementia and Alzheimer’s disease. Although they are related, they are not the same.
Dementia is a General term describing a disorder that causes significant cognitive impairment. Alzheimer’s disease is a type of dementia, just as early-onset is a type of dementia.
Many people associate dementia with memory loss. While memory loss is part of dementia, it is simply a symptom. Dementia occurs when a person’s brain cells stop working, stop connecting with other cells, and die. This leads to many impaired functions in addition to memory. This includes problem solving, decision making, speech and language interpretation problems, emotional problems, and even personality changes.
While most people over the age of 80 have some mild form of dementia, contracting it at a younger age leads to severe suffering, as the brain takes more time to deteriorate than a person in their 80s. It is a disorder that can make a person you have known all your life unrecognizable.
Terms and information to know
Before diving into the research, there are some terms and information that you will need to be familiar with to understand. The first is the cerebrovascular pathologies. Refers to Cerebrovascular diseases, which is essentially a general term for conditions that block blood flow to the brain. The word pathology refers to the cause and effects of a disease. For research, think of the term cerebrovascular pathologies in the sense of the causes of limited blood flow to the brain.
The second thing to know is that cerebrovascular diseases cause strokes and strokes lead to dementia. According to the American Association of Neurological Surgeons (AANS), cerebrovascular disease is the most prevalent life-threatening neurologic occurrence in the United States, and stroke is the third leading cause of death.
Another term you will come across is blood brain barrier (BBB). This is exactly how it sounds. It is a protective barrier that is extremely selective in what passes from the blood to the brain. In fact, it is so protective that it has been difficult for scientists to create drugs that overcome this barrier. Neurological and cerebrovascular disorders cause a breakdown of the BBB, resulting in degeneration of the central nervous system (CNS) that can lead to conditions such as dementia.
Other terms you should be familiar with are:
- Gene – a short DNA section It contains instructions on how your body looks and works.
- Alleles: a variant form of a gene, located in the same position as the gene on a chromosome. In humans, genes have two alleles (one from each parent).
- White matter: a type of brain tissue that contains axons (nerve fibers).
- Tau: a protein found in abundance in the CNS. This protein is responsible for the stability of axons.
- ALSP: stands for adult-onset leukoencephalopathy with axonal spheroids and pigmented glia. This is a rare form of dementia characterized by a degradation of white matter.
- Macrophages: cells responsible for seeking out and destroying harmful bacteria, cells, and other organisms.
- Amyloid – β: a peptide (building blocks of amino acids) that normally helps with neural growth and repair.
So far, all of this information can make you feel like you’re in a college-level biology class. Don’t despair – being familiar with this information will make the rest of the article that much easier to understand. The next section dives into the Trinity College Dublin research.
Neurological diseases are almost impossible to treat due to the difficulty of creating pathologies for them. However, the team at Trinity College Dublin did not let this stop them, as they discovered a mutation that can cause a rare form of early-onset dementia, ALSP. Led by Dr. Connor Delaney and Professor Matthew Campbell, this discovery is one of the most important discoveries of this decade.
Mutations cause ALSP in the colony stimulating factor 1 receptor (CSF1R) gene. Mutation is what breaks down white matter in the brain. This collapse leads to severe cognitive decline as early as the third or fourth decade of life (rather than more common forms of dementia, which generally affect people in their 60s).
Scientists had theorized that the cause of ALSP was due to overactive microglia cells in the brain. However, the researchers used data obtained from patient samples and clinical trials to identify that dysfunctional white blood cells are responsible for the mutated CSF1R genes.
How the process works
The whole process is a bit complicated, but damaged white blood cells set off a chain reaction in the body that eventually leads to early-onset dementia. CSF1R is made up of alleles, like all human genes. These harmful white blood cells cause at least one of the alleles to mutate and cause cerebral amyloid angiopathy (CAA). CAA is a harmful increase in the production of amyloid protein.
The amyloid protein then damages macrophages in the body, leading to a reduced ability to fight harmful cells and substances. One of those substances, β-amyloid, is normally healthy for people, but it blocks blood flow to the brain in abundance. Without macrophages being able to clear access to amyloid-β, a person is at risk of stroke, leading to dementia.
Why is microglia justified
Remember earlier in the article where it was claimed that scientists originally theorized that a collapse in microglia was the culprit for early-onset dementia? Microglia is a type of microfagus. However, the team’s research revealed that only bone marrow-derived microfago CSF1R mutations are to blame. Microglia are found in the CNS (the brain).
How the research will impact the future
A big reason why there is no effective cure or treatment for dementia is that scientists did not understand the cause of the disorder. Sure, the scientists were familiar that β-amyloid was a big contributor, but that was common knowledge without much of an answer to why the disorder occurs and progresses the way it does.
Research over the decades has not been fruitless. Scientists continued to learn more and more, which allowed them to understand what dementia patients go through. Because of this, the stages of dementia have been established and caregivers know what to expect at each stage. This allows dementia patients to receive the best level of care they need for each stage.
This discovery changes the dark void that hung over the answer to why, at least for this rare version of dementia. Being able to pinpoint the exact source of the disorder means they can focus more on a plausible cure or even a way to prevent it altogether.
Of course, this single investigation will not be enough to eradicate ALSP, but it gives scientists a starting point. It also opens up a theory to the cause of other forms of dementia. The hope is that scientists can take this discovery and expand it exponentially to learn more about the disorder.
This disorder is devastating for a person and their family. It is unfair because it significantly reduces the number of major years in a person’s life.
It’s scary, and there will be many times when you will feel helpless, especially when you don’t know anything, that you can do to change things or make them better. Sometimes even the strongest people face the difficulties that illness brings.
Discoveries such as that made by scientists at Trinity College Dublin may not be enough to save people who currently have the disorder. Yet it offers a glimmer of hope for people in the future. Knowing that the world is one step closer to a solution is a breath of fresh air for anyone dealing with a loved one with dementia.