Frontotemporal Dementia: Everything you need to know

What is frontotemporal dementia? Are all dementias the same? This post explains everything you need to know about frontotemporal dementia. Understanding why people with this type of dementia act the way they do can be helpful in providing better care specific to their needs and improving their quality of life.

frontotemporal dementia
Frontotemporal dementia – Photo by Cristian Newman on Unsplash

Frontotemporal dementia and prevalence: Definition

Frontotemporal dementia is a type of dementia that is characterized by a series of behavioral, cognitive or language changes. This translates, among other things, in that a person with frontotemporal dementia changes their behaviors and preferences that used to characterize them throughout their life.

Arnold Pick in 1892 was the first to point out frontotemporal dementia. The cases Pick described were characterized by marked changes in personality and behavior, along with language alterations. When analyzing their brain, all of these patients had their temporal and frontal lobes atrophied, hence the name of dementia.

Is this type of dementia common? Frontotemporal dementia has an estimated prevalence of between 15 and 22 cases per 100,000 inhabitants. Unlike other dementias, it usually appears between the ages of 50 and 60, making it the most frequent type of dementia in adults under the age of 65.

Types of frontotemporal dementia and most common symptoms

Three types of frontotemporal dementia have been identified:

  1. Behavioral variant frontotemporal dementia
  2. Semantic variant primary progressive aphasia
  3. Primary Progressive Aphasia: Non-Fluent Variant

Each of these variants appears with a particular and specific symptom picture:

  1. Behavioral variant frontotemporal dementia

This dementia is fundamentally characterized by a change in the patient’s personality. The symptoms are:

  • Apathy or lack of interest and initiative to make decisions or get involved in some task. The person can remain seated all day in the same position, without expressing any desire to perform any activity.
  • Behavioral disinhibition: The person may make socially inappropriate comments or behaviors, such as hugging strangers on the street or making open criticism of someone’s physical appearance in their presence.
  • Impulsiveness: An example of this might be making unnecessary purchases that involve a large amount of money, or driving recklessly.
  • Loss of empathy: The person ceases to be able to understand the mental states of other people and/or put themselves in the situation of others, which can generate problems in their social environment.
    There is an alteration in the recognition of basic emotions through faces (joy, anger, fear, disgust, and sadness).
  • Low awareness of illness: The person is not aware of the changes that are happening and their implications.
  • Stereotyped behaviors or rituals, as well as repeating words over and over again.
  • Changes in eating habits: For example, overeating or wanting to eat only one type of food, usually sweets.

Semantic dementia

This type of dementia is characterized by a significant alteration of the person’s language. Although the person may speak fluently with a normal number of words, the content of what they say is meaningless. Verbal language is there though with excessive use of words that do not contribute to the message.

People with this dementia also show difficulties in understanding the meaning of words and lose their naming ability. They have problems naming certain objects, people or animals.

Non-fluent progressive aphasia

This variant of frontotemporal dementia also causes significant language alterations. However, unlike semantic dementia, in this case, the fluency is altered.

Speech appears with short and simple sentences, few words and frequent pauses. In addition, there can be changes in rhythm and intonation when pronouncing words or phrases, being able to speak without any intonation or with a particular accent.

Possible causes and risk factors

The causes of frontotemporal dementia are unclear.

In 40% of cases, having a family history of dementia is a risk factor that increases the likelihood of developing frontotemporal dementia. However, only 10-15% of cases have been associated with clear autosomal dominant genetic factors.

Frontotemporal
Frontotemporal dementia- Photo by Nathan Anderson on Unsplash

Difference between frontotemporal dementia and other types of dementia

Frontotemporal dementia has a progressive course where deterioration of the frontal and temporal lobes of the brain is observed. However, in more advanced stages it spreads to other brain areas, generating symptoms that may overlap with other forms of dementia.

This is why it is very important for specialists to make a good differential diagnosis.

Frontotemporal dementia versus Alzheimer’s disease

The main difference between Alzheimer dementia and frontotemporal dementia is memory impairment. In Alzheimer’s disease, memory impairment is the main issue. The opposite happens in frontotemporal dementia, in which case although there may be some memory failures, as some studies affirm, it is not the main symptom.

Behavioral alterations may appear in Alzheimer’s type dementia, but it is rare that they appear without the presence of memory failures and visuospatial alterations.

In addition to a failure in episodic memory, there are alterations in visuospatial functions, in language, and hallucinations in late phases.

Vascular dementia

Vascular dementia is related to many symptoms since it will depend on the cerebral areas affected by the vascular event, such as a stroke.

The main difference is that the onset is acute, rather than progressive as it is in the case of frontotemporal dementia. Symptoms are generally associated with alterations in language, calculus, attention or memory. If several smaller strokes are the cause of dementia, symptoms may appear more gradually and are usually accompanied by gait and movement disorders.

Neuroimaging tests will show focal signs to distinguish injured brain regions.

Lewy body dementia

The alterations in attention and memory stand out, although to a lesser extent than in Alzheimer’s disease. An important difference with frontotemporal dementia is its fluctuating course, with episodes of confusion and agitation in periods of hours or even days.

Also, unlike frontotemporal dementia, disease awareness is relatively well preserved. That is, patients are aware that something is happening to them.

In Lewy body dementia, semantic memory alteration and the appearance of certain behavioral alterations are also frequent. However, intense and elaborate visual hallucinations as well as sleep disturbances also occur in these cases.

Tips for family members of people with frontotemporal dementia

As can be deduced from what we have seen so far, frontotemporal dementia has several characteristics in comparison to other types of dementia.

On the one hand, frontotemporal dementia involves a series of personality and behavioral changes that may not be pleasant for family members and caregivers, such as disinhibition, lack of empathy, or apathy.

It is an early-onset dementia (between the ages of 50 and 60) that implies that the person acquires a relatively early situation of dependency that can continue for a long period of time. This dependency for decades may overburden caregivers.

For these reasons, it is advisable to inform the family and/or caregivers extensively about this type of dementia. Caregivers should learn to understand the behavioral disturbances that their family member might have: lack of empathy, impulsiveness, etc.

These guidelines can help you take care of your family member with frontotemporal dementia:

  • Rely on the use of routines to generate help the person anticipate changes or predict what might happen.
  • Make their setting feel like a safe place. Avoid having obstacles to prevent falls or accidents.
  • Learn behavioral management techniques.
  • It is important to understand that the person may have problems communicating or expressing their wishes correctly and that they need extra help to have their rights respected.
  • Avoid tensions or arguments.
  • Promote communication. Although the person may lose communication skills, seeking different communication strategies may be helpful. An example of this may be using simple phrases, with clear instructions and simple words. But be careful, this does not mean speaking in a childish way.
  • Share the burden and express emotions. Caregiving can be difficult, remember to take care of yourself as well to prevent overburdening.

References

Bang, J., Spina, S. y Miller, B. (2015). Frontotemporal dementia. The Lancet, 386,(10004): 24-30. Artículo de revisión de las características de la demencia frontotemporal, etiología y avances en su caracterización clínica, molecular y de neuroimagen.
Lillo, P. y Leyton, C. (2016). Demencia frontotemporal, cómo ha resurgido su diagnóstico. Revista Médica Clínica Las Condes, 27,(3): 309-318. Artículo de revisión que resume el recorrido histórico de la demencia frontotemporal y los criterios actuales para su diagnóstico.
Tabernero, M.E., Rubinstein, W.Y., Cossini, F.C. y Politis, D.G. (2016). Reconocimiento facial de emociones básicas en demencia frontotemporal variante conductual y en enfermedad de Alzheimer. Neurología Argentina, 8,(1): 8-16. En este estudio se evalúan las habilidades de reconocimiento de emociones básicas en 26 pacientes de DFT, 24 pacientes de demencia tipo Alzheimer probable y 23 sujetos control, observándose que los pacientes de ambos tipos de demencia manifiestan diferencias significativas en el reconocimiento de emociones respecto a la población control.
Pávez, A., Delgado, C. y Martínez, M., (2018). Quejas de memoria en demencia frontotemporal variante conductual: a propósito de un caso. Revista chilena de neuro-psiquiatría, 56(1). Se analiza el caso de una paciente con posible demencia frontotemporal y con quejas de memoria, además de describir subtipos amnésicos de la DFT.
Pérez, M.C. y García, S. (2018). Demencia frontotemporal: fronteras diagnósticas. International Journal of Developmental and Educational Psychology, 4,(1). Revisión de las características principales de la DFT y claves de ayuda para el diagnóstico diferencial con otros tipos de demencia.
Muñoz, A., Pérez, J.R. y Contreras, A. (2015). Diagnóstico diferencial etiopatogénico de la demencia: otras demencias. Medicine, 11,(72): 4345-4349. En este artículo se proporcionan herramientas para diferenciar la enfermedad de Alzheimer, la demencia por cuerpos de Lewy, demencia frontotemporal y otras demencias.
González-Cosío, M. Manual para el cuidador de pacientes con demencia: Recomendaciones para un cuidado de calidad. Editorial Lundbeck: México. Manual con pautas y recomendaciones para el cuidado de pacientes con demencia.