Manuel Cassinello Marco, a specialist psychiatrist in neuropsychiatry and psychologist, explains in this article how frontotemporal dementia affects us.

Although when we think of dementia, Alzheimer’s disease usually comes to mind, the truth is that there are many other types of neurodegenerative conditions. These conditions have in common a progressive atrophy in different parts of the brain. Among these, we can find frontotemporal dementia. It is important to recognize the symptoms in order to seek professionals who can start rehabilitative treatment as early as possible.

Degeneration and frontotemporal dementia

Frontotemporal dementia or Pick’s disease refers to a clinical syndrome in which the predominant clinical features consist of personality changes associated with behavioral alterations, language impairments, and cognitive decline. However, it is important to differentiate it from frontotemporal degeneration. The latter only refers to the existence of atrophy limited to the anterior prefrontal and temporal lobes. In other words, there can be atrophy without associated clinical dementia.

Frontotemporal dementia, also known as Pick’s disease, is named after its discoverer, Arnold Pick. It is characterized by the presence of Pick bodies, which are groups of damaged neurons due to the deposition and impossibility of elimination of the so-called tau protein. It is also associated with a related phenomenon known as gliosis, which results in a scar-like lesion.

Symptoms of frontotemporal dementia

When we refer to frontotemporal dementia, it is important to note that we are not referring to a single clinical picture, but rather to different entities that share common brain lesions but can vary in their clinical manifestation. Therefore, in this section, we need to differentiate between the three main clinical variants: behavioral variant of frontotemporal dementia, non-fluent progressive aphasia, and semantic dementia.

• Behavioral variant: This is the most common variant, and the typical symptoms include:
  • Behavioral changes,
  • personality changes,
  • apathy (caution should be exercised with this presentation, as it is often confused with depressive disorder),
  • disinhibition,
  • inappropriate behaviors,
  • lack of judgment,
  • eating abnormalities such as ingesting non-nutritive substances (e.g., spoiled food),
  • neglect of personal hygiene and care,
  • rigidity in behaviors,
  • irritability.
• Non-fluent progressive aphasia: The symptoms of this variant include:
  • Anomia or difficulty finding words or naming objects (this is the fundamental symptom),
  • inappropriate use of verb tenses,
  • word order alterations,
  • broader grammatical errors,
  • mutism (this is the final symptom in the progression of this variant).
• Semantic dementia: In this variant, common symptoms include:
  • Difficulty understanding both written and spoken language,
  • difficulty naming objects or even describing them,
  • better preservation of autobiographical and episodic memory, which is remarkable because despite having limited comprehension, individuals can engage in a normal conversation. However, upon analysis, this conversation “lacks content.”

Stages of frontotemporal dementia

Although the course of all variants is progressive, with occasional worsening due to the appearance of complications such as infections, there are two practical phases:

• Phase 1 or presymptomatic phase: In this phase, the typical symptoms of the different presentation forms would not be present. However, some symptoms such as apathy, disinterest, or attention problems may be observed. During this stage, the family may begin to notice unusual situations but may not give them much importance unless there are family history factors.

• Phase 2 or symptomatic phase: In this phase, the most common symptoms within each variant would begin to manifest. The duration in years, as well as the number and intensity of symptoms, vary greatly from person to person, depending on factors such as hospitalizations, urinary tract infections, decompensation of other diseases, changes in living arrangements, etc. It is common to observe an increasing dependency on caregivers and family members during this phase.

Causes of frontotemporal dementia

As previously mentioned, when we talk about dementia, Alzheimer’s disease often comes to mind. However, frontotemporal dementia represents approximately 5 to 10% of all dementias, increasing to over 20% when the condition begins before the age of 65. Like Alzheimer’s, it follows a chronic and progressive course.

Frontotemporal dementia has a strong genetic component, with up to 50% of cases having a family history of frontotemporal dementia, psychiatric disorders, or ALS. It occurs equally in both sexes and has been associated with various genes: PGRN (progranulin gene) and MAPT (microtubule-associated protein tau), both located on chromosome 17q21. This means that frontotemporal dementia is hereditary in a high percentage of cases.

Diagnosis of frontotemporal dementia

Like other dementias, the diagnosis is primarily clinical and requires conducting a series of tests, including:

• Blood analysis including vitamin B12, folic acid, thyroid hormones, and other parameters to differentiate it from reversible causes of dementia.

• Cerebrospinal fluid examination to analyze tau protein levels and differentiate this dementia from Alzheimer’s disease.

• Neuroimaging studies such as anatomical and functional brain magnetic resonance imaging, which reveal atrophy in both frontal lobes and reduced activity. Atrophy in the temporal lobes may also be observed on occasion. It is important to note that, as it is not a homogeneous condition with three different forms, neuroimaging findings may vary from person to person and from one clinical variant to another.

Treatment of frontotemporal dementia

Unfortunately, there is currently no curative treatment for frontotemporal dementia, and the available treatments focus on symptom management. In this regard, the treatments available are:

• Antidepressants: Preferably those known as first-line or serotonergic, as there is a greater serotonin deficit in the atrophy area that can benefit from these treatments.

• Trazodone: An atypical antidepressant used to manage behavioral alterations, generally well-tolerated.

• Antipsychotics: At low doses, they help improve irritability, behavioral changes, possible psychotic symptoms, and insomnia.

• Regarding acetylcholinesterase inhibitors or memantine, commonly used in Alzheimer’s disease, there is no clear evidence recommending their use in patients with frontotemporal dementia.

• Cognitive rehabilitation: Currently, there are numerous cognitive rehabilitation programs that, although they do not modify the course of the disease, can significantly improve the quality of life of these patients by providing training guided by professionals to address their deficits.

Regarding life expectancy, the range of years can vary greatly. Typically, it ranges from two to ten years following diagnosis.

Therefore, it is vital to carry out a comprehensive multidisciplinary approach involving neurologists, occupational therapists, speech therapists, neuropsychiatrists, and neuropsychologists. The combination of all these professionals aims to provide proper treatment, both pharmacological and rehabilitative, to improve not only the patient’s quality of life but also that of their caregivers.

References

• Neuropsychogeriatrics Textbook.

• Neuropsychology by Javier Tirapu Ustárroz, Marcos Ríos Lago, and Fernando Maestú Unturbe.

• Introduction to Psychopathology and Psychiatry by J. Vallejo.

• Alzheimer’s Disease and Other Dementias by R. Alberca and S. López-Pouda.

• Geriatric Psychiatry by Agüera, Martín, and Sánchez.

If you liked this post on frontotemporal dementia, you may be interested in these NeuronUP posts: