9 Differences Between Alzheimer's and Frontotemporal Dementia

25 April, 2021
What are the differences between Alzheimer's disease and frontotemporal dementia? Although these two conditions seem similar, there are some significant differences between them.

The term “dementia” can be vague and confusing. This is because there are different types of dementia, each with its own unique characteristics. Today, we’ll be comparing and contrasting Alzheimer’s disease and frontotemporal dementia.

We’ll share nine specific differences in terms of the patient’s age at onset, affected cognitive functions, personality changes, location of brain lesions, etc. In other words, we’ll focus on patient symptoms and also touch on a few other factors.

Differences between Alzheimer’s and frontotemporal dementia

According to Ramos et al. (2008), the differences between these two types of dementia are the following:

A woman with frontotemporal dementia staring at the floor.

Age of onset

The first difference is the average age people start to show signs of these conditions. Alzheimer’s tends to affect people older than 65 and the risk increases with age. Frontotemporal dementia, on the other hand, usually starts much earlier, between the ages of 40 and 70.

Unlike Alzheimer’s, the prevalence of frontotemporal dementia doesn’t increase with age.

Types and locations of lesions

With Alzheimer’s disease, brain lesions appear on the inner face of the temporal lobe, especially in the hippocampus. From there, they spread to the rest of the temporal, parietal, and frontal lobes. As the name suggests, in the case of frontotemporal dementia, lesions appear on the temporal and frontal lobes.

Alzheimer’s involves a loss of neurons and synapses. In the brains of patients with Alzheimer’s, scientists have also identified the presence of tau proteins (highly soluble protein isoforms) and amyloid proteins (neuritic plaque).

Frontotemporal dementia patients also experience a loss of neurons and synapses and an increase in the tau protein. However, some elements that aren’t part of Alzheimer’s disease, which are Pick cells and occasionally Pick bodies. Lastly, the amyloid proteins and neuritic plaque typical of Alzheimer’s disease are absent in frontotemporal dementia.

Symptoms

Another difference between Alzheimer’s and frontotemporal dementia are the symptoms they cause. We’ll start with the most common symptoms of Alzheimer’s:

  • The onset of Alzheimer’s usually involves memory loss and the inability to learn new information.
  • Patients start to become disoriented about time and place.
  • They often have difficulty with language.
  • Personality changes are common, as well as behavioral disorders.
  • Some patients have auditory hallucinations or delirious thoughts.

The symptoms of frontotemporal dementia vary somewhat from the typical Alzheimer’s symptoms. The most common are:

  • In the beginning, this type of dementia doesn’t affect the patient’s memory.
  • Personality disorders, as with Alzheimer’s.
  • Abnormal behavior.
  • The patient might seem apathetic or hyperactive, as well as engage in repetitive activities.
  • Loss of affection and love towards others.
  • Emotional decline and indifference towards the things and people around them.
  • Patients with frontotemporal dementia often have language impairments that are similar to patients with Alzheimer’s.

Early symptoms

With Alzheimer’s disease, the first symptoms are memory problems and disorientation. With frontotemporal dementia, on the other hand, the first symptoms are personality changes and uninhibited behavior.

Insight

Insight is a cognitive phenomenon that clinical therapists use to describe the patient’s ability to understand what’s happening to them. According to Segui (2015), therapists can use insight to carry out different interventions.

Alzheimer’s patients tend to have insight at the beginning, but it becomes poor or defective as their condition worsens. However, people with frontotemporal dementia usually lose their insight completely.

Memory

People with Alzheimer’s suffer from a kind of amnesia that doesn’t improve with clues or hints. Scientists have also observed that Alzheimer’s affects memory from the very beginning, as soon as a patient starts to have symptoms.

Frontotemporal dementia, on the other hand, doesn’t affect memory to the same degree. Usually, patients have some problems with this particular cognitive function that improves with hints or clues.

“Remembrance of things past isn’t necessarily the remembrance of things as they were.”

-Marcel Proust-

Visual-spatial function

Alzheimer’s disease has a significant impact on cognitive abilities, particularly visual-spatial function, which is what allows you to mentally represent, analyze, and manipulate objects. Frontotemporal dementia patients don’t usually have any visual-spatial problems.

An elderly man with frontotemporal dementia.

Language and motor function

Another difference between these two diseases is language. Alzheimer’s patients suffer from anomia, circumlocution, and aphasias. Frontotemporal dementia patients, on the other hand, experience stereotypical language, echolalias, and mutism. As you can see, these two diseases vary markedly in this area.

Both diseases affect motor function. Alzheimer’s patients suffer from apraxias (the inability to executive intentional, learned motor tasks), while patients with frontotemporal dementia retain this function.

Neurological signs

Lastly, in terms of the neurological elements of the illness, Alzheimer’s disease involves myoclonias (muscle spasms) and crises. Frontotemporal dementia, on the other hand, can cause urinary incontinence and involuntary reflexes. Those are primitive reflexes that newborns have but that disappear with age and sometimes return with dementia.

While these are the most obvious differences between Alzheimer’s and frontotemporal dementia, there could be more. We’ve chosen to share these with you because they’re the most relevant when it comes to making a proper differential diagnosis.

As you can see, although these two diseases have some things in common (personality changes, language changes, and cognitive function alterations, for example), they’re quite different.

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  • Seguí, V. (2015). El insight en Psicología. ISEP Formación: 1-33.