LATE Dementia, a New Type of Dementia

LATE dementia is a disease that’s very similar to Alzheimer's disease. How does it develop? Who does it affect? In this article, we tell you all about it!
LATE Dementia, a New Type of Dementia

Last update: 18 November, 2020

Between 15 and 20% of people diagnosed with Alzheimer’s disease actually suffer from LATE dementia. It’s a type of dementia that, until now, had been misdiagnosed as Alzheimer’s disease, as its clinical manifestations are similar. Experts expect that its incidence will increase in the coming years.

This disorder mainly affects the elderly. Just like Alzheimer’s, LATE dementia causes memory loss and the inability to perform everyday activities. In this article, we’ll share their differences and most important characteristics.

What’s LATE dementia?

A woman hugging her grandfather.
The symptoms of LATE dementia are similar to those of Alzheimer’s disease. However, in this case, the altered brain protein is TDP-43.

LATE dementia is a proteinopathy, which means that it’s caused by the alteration of certain proteins. It causes a dementia that’s very similar to the one Alzheimer’s disease causes.

LATE stands for limbic-predominant age-related TDP-43 encephalopathy. One of the differences between it and Alzheimer’s is that the altered brain protein is TDP-43. In the case of Alzheimer’s, the proteins TAU and beta-amyloid don’t function properly.

The protein TDP-43 is responsible for gene expression in the brain. An accumulation of these “badly folded” proteins is the cause of this disease. “Badly folded” proteins are those with a different shape to normal ones.

An excess of altered proteins produces neurotoxicity and neurodegeneration. 25% of people over 85 suffer from sufficient alterations of this protein to cause symptoms.

Who does this disease affect?

Another difference worth mentioning is that the likelihood of suffering from Alzheimer’s doesn’t indefinitely increase with age. However, the risk of LATE dementia does, especially after the age of 80.

The acronym LATE was chosen because it also served to define this characteristic of the pathology. Women are at an increased risk of developing this disease because, nowadays, their life expectancy is higher than that of men.

Since the number of elderly people over 80 will rise in the coming years, so will the incidence of this disease. Thus, LATE dementia may become a public health problem in the coming years.

How is LATE dementia diagnosed?

In recent times, due to the advance of diagnostic techniques, the TDP-43 protein has been identified more precisely. Currently, the most precise techniques for diagnosing Alzheimer’s disease are based on the study of biomarkers in the cerebrospinal fluid.

Such markers are the proteins TAU and beta-amyloid, which we mentioned above. Another diagnostic technique is finding accumulations of these proteins in the brain by using imaging techniques, such as PET scans.

However, most of the time, the diagnosis of Alzheimer’s is based on the symptoms and clinical picture. Doctors rarely request these biochemical tests to confirm the disease. That’s why some of the people who are diagnosed with Alzheimer’s actually suffer from LATE dementia.

In the case of LATE dementia, the goal is to apply the same techniques as in the case of Alzheimer’s disease but to look for the TDP-43 protein instead. The presence of a sufficient amount of this protein in its altered form confirms the diagnosis.

The symptoms of this disease

An old woman who's suffering from memory loss.
The symptoms of LATE dementia develop more slowly than other types of dementia. In its last stage, it’s similar to advanced Alzheimer’s disease.

LATE produces symptoms that progress more slowly than in other types of dementias. Recent studies suggest that the disease progresses in three stages.

These stages are based on the affected brain area and produce increased discomfort. These stages are:

  • Stage 1. Tonsillar involvement. At this stage, the patient notices subtle mood changes. Mood swings may occur with agitation and even aggressive outbursts.
  • Stage 2. Involvement of the hippocampus. When this area is affected, the signs of memory loss start to manifest. Although this isn’t the first stage, it’s the main reason why patients begin to go to the doctor.
  • Stage 3. Involvement of the medial frontal gyrus. It manifests as behavior and conduct changes. Patients find it difficult to lead a normal life. It resembles Alzheimer’s disease at an advanced stage.

Importance and conclusions

At present, the discovery of this new disease won’t lead to changes in the diagnosis and treatment of the dementias known so far. However, it has opened new research areas.

Knowing the etiology of these diseases more accurately can lead to the future development of specific treatments for each.

Currently, there’s no effective treatment for such diseases. This will become increasingly important because, as we discussed in previous sections, experts expect that the incidence of this disease will increase in the coming years.

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