Limbic-predominant age-related TDP-43 encephalopathy (LATE)

Limbic-predominant age-related TDP-43 encephalopathy (LATE) is a type of dementia that affects memory, thinking and social skills.

When people think about memory problems, Alzheimer’s disease comes to mind. But LATE is a different disease and has its own characteristics. Sometimes, people may have signs and symptoms of both LATE and Alzheimer’s disease.

People with LATE have problems with memory but often have a slower rate of clinical change than people with Alzheimer’s disease. They may notice that over time it’s more difficult to remember facts, conversations and events. People with LATE may repeat themselves often, be forgetful and have trouble finding the right words during conversations. They may also have difficulty understanding words.

Individuals with LATE may:

• Wander or get lost
• Make poor decisions
• Misplace things
• Have trouble driving
• Have difficulty keeping up with personal hygiene

Eventually, someone with LATE has trouble with daily living activities such as dressing, cooking or paying bills. The mental decline in LATE is slower than in other forms of dementia. This causes a slow, rather than a rapid, worsening of symptoms.

Who is at risk of LATE?

LATE usually affects older individuals, particularly those over age 80. Although advancing age is a risk factor for LATE, dementia is not part of the typical aging process.

Genetics can also increase a person’s risk of developing LATE. At least five genes are associated with the risk of LATE. These same genes may also increase the likelihood of other forms of dementia.

How is LATE diagnosed?

Currently, LATE can only be definitively diagnosed after death through an autopsy. But for people with symptoms, a diagnosis of LATE can be suggested through:

• Clinical history
• MRI or fluorodeoxyglucose (FDG)-positron emission tomography (PET) findings
• Ruling out other causes

Your health care provider may look for changes in the brain that can be caused by LATE. These can include signs of brain shrinkage (atrophy) and thinning of the parts of the brain responsible for memory formation. These changes can be seen on MRI examination and on autopsies. Thinning seems to be a stronger indicator of how severe the disease is compared with atrophy.

A buildup of the protein transactive response DNA-binding protein 43(TDP-43) may be another sign of LATE. This naturally occurring protein helps with nerve development. This buildup of TDP-43 is usually found in the part of the brain that supports memory, emotion, behavior and mood (limbic system). Right now, there isn’t a simple test to see whether a person has an excessive amount of TDP-43. This would be discovered only with an autopsy.

Another sign that could suggest a diagnosis of LATE is hardening and thickening of the walls of the arteries (arteriolosclerosis), which is common in people with LATE.

If your health care provider suspects you might have LATE, they may suggest a mental status examination to find out how severe the cognitive impairment is.

Researchers are working to find a simpler way to diagnose LATE, and other forms of dementia, to quickly identify these diseases. Researchers are working to develop a simple blood screening test for dementia, including LATE, but that is still being studied.

Current treatments

There isn’t a definitive treatment or cure for LATE yet.

To help improve overall health and manage the symptoms of dementia, the World Health Organization (WHO) has made recommendations that include:

• Increasing physical activity
• Maintaining a healthy diet
• Decreasing alcoholic intake
• Avoiding smoking
• Treating chronic conditions such as hypertension, high cholesterol, depression, obesity and diabetes

The WHO also suggests increasing accessibility of health care and social workers to people with dementia and their caregivers.

More studies are underway to discover better ways to diagnose and possibly treat LATE.