What Is Frontotemporal Dementia?

Frontotemporal disorders (FTD), sometimes called frontotemporal dementia, is a blanket term for a group of neurological disorders caused by damage to cells in the brain's frontal and temporal lobes. FTD disorders can cause a variety of neurological symptoms, including changes in behavior, loss of motor skills, loss of the ability to speak and understand language, and many others.

In FTD, neurons (also called brain cells or nerve cells) produce abnormal proteins that affect the way neurons function, resulting in neuronal death. The death of neurons causes areas of the brain to shrink and deteriorate, which leads to FTD symptoms. FTD disorders are progressive diseases, meaning the condition and its symptoms worsen over time. The cause of FTD disorders is not completely known, although research is identifying some genetic components. There is no cure.

FTD tends to affect adults at a younger age compared to other forms of dementia. Most people with FTD are 45 to 65 years old. FTDs are the third most common form of dementia after Alzheimer's disease and Lewy Body dementia. Research suggests that FTD disorders are genetic, although more research is needed. Mutations in various genes seem to play a role in causing FTD disorders.

Types of FTD

There are three main types of frontotemporal dementia. These types are defined by the symptoms that people with these disorders present.

Behavioral Variant Frontotemporal Dementia (BvFTD)

Behavioral variant frontotemporal dementia (BvFTD) causes severe changes in a person's behavior or personality. This type of FTD can affect your ability to think clearly. This is the most common type of FTD, accounting for about half of the cases diagnosed. Behavioral variant frontotemporal dementia tends to initially affect adults between the ages of 50 and 60.

People with BvFTD might demonstrate impulsive behavior, a lack of empathy, and poor judgment, and experience difficulty concentrating on a day-to-day basis.

While this type of FTD causes changes in a person's behavior, it does not affect memory until the later stages of the disease.

Primary Progressive Aphasia

Primary progressive aphasia is the second most common type of FTD. These disorders affect a person's ability to speak and makes it difficult for them to understand language and writing. There are three subtypes of primary progressive aphasia:

• Logopenic variant of PPA (lvPPA): In lvPPA, people struggle with recalling single words, repeating sentences/phrases, and making phonological errors. They also show atrophy in the left posterior perisylvian or parietal areas, which are typically associated with Alzheimer's disease.
• Semantic primary progressive aphasia: The person loses their ability to understand speech and has a hard time finding words during conversation. Their speech may be fluent but might not make sense.
• Non-fluent/agrammatical primary progressive aphasia: The person has very halted speech and often jumbles words during conversation.

As this type of FTD progresses, the ability to speak might diminish and be lost completely.

Movement Disorders

These FTD disorders affect the brain's ability to control muscles and limb movement, making it hard for a person to control their body.

Some examples of movement disorder FTDs include corticobasal syndrome, supranuclear palsy, and amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease.

In some cases, these FTD movement disorders can occur at the same time as primary progressive aphasia or behavioral variant FTDs.

Symptoms of FTD

Symptoms depend on the type of FTD a person has. Symptoms of FTD disorders worsen over time for all three subtypes.

The main symptoms of behavioral variant frontotemporal dementia include:

• Lack of empathy for others
• Sudden lack of interest in family or activities they used to care about
• Behaving impulsively
• Loss of inhibitions
• Apathy, or a loss of emotional reactivity
• Difficulty planning and prioritizing tasks
• Difficult reading social cues
• Compulsive eating

Symptoms of primary progressive aphasia affect a person's ability to communicate. Some of the main symptoms include:

• Slurred speech
• Losing the ability to understand single words or sentences
• Trouble finding words during conversation
• Speaking in difficult-to-understand sentences
• Difficulty naming objects
• Not being able to speak

Finally, symptoms of movement disorder FTD severely impact muscle function and motor skills. Some of the main symptoms include:

• Muscle weakness that does not allow you to control your limbs
• Decreased coordination when walking and loss of balance
• Difficulty walking
• Problems swallowing, chewing, and controlling bowels
• Unusual muscle stiffness and rigidity, particularly in the upper body
• Tremors
• Uncontrollable eye movements
• Slowed movements
  

Causes of Frontotemporal Dementia

FTD disorders are caused by damage to nerve cells in the frontal and temporal lobes of the brain. The frontal lobe is a part of the brain that helps control decision-making, thinking, and reasoning. The temporal lobes help control memory, language comprehension, emotions, and many other functions.

Damage to nerve cells is caused by the accumulation of abnormal proteins within neurons. Some examples of these abnormal proteins are TDP-43, tau proteins, and beta-amyloid plaques. The accumulation of these abnormal proteins in neurons causes damage to brain tissue, making the frontal and temporal lobes shrink, which results in FTD symptoms. The type of FTD that a person gets depends on where the nerve damage occurs in the frontal and temporal lobes.

What causes these proteins to accumulate in neurons is still unknown. Multiple studies have identified genes that, when mutated, may play a role in causing the accumulation of abnormal proteins. Some examples of these genes include the MAPT gene, GRN gene, and C9ORF72 gene.

People with a family history of FTD disorders are more likely to get FTD. Approximately 40% of people with FTD have a family history of FTD disorders.

Diagnosis

FTD conditions are hard to diagnose because symptoms are very similar to other dementias, like Alzheimer's disease. Your healthcare provider (likely a neurologist, which is a medical doctor who specializes in the brain and spinal cord) might use a combination of cognitive tests, an analysis of family history, and brain imaging tests to narrow down your symptoms and differentiate between FTDs and other types of dementia.

Family History

Your healthcare provider will assess your family history to help determine your risk. They might also order genetic testing to assess if you have mutations on any identified genes that may contribute to the development of FTD.

Neurocognitive Tests

These exams will assess different aspects of your cognitive skills. They will test your memory, thinking, and language skills using a series of questions. These tests might also evaluate if you have other psychiatric conditions that might be contributing to your FTD symptoms, like depression. Some of these tests include the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment, and the Functional Cognitive Assessment.

To test for progressive aphasia, your healthcare provider might perform some language fluency tests. Some of these tests involve asking you to say many words that start with a single letter in one minute or to spell words backward.

Radiographic/Brain Imaging Tests

Magnetic resonance imaging (MRI) and computerized tomography (CT) scans are imaging techniques that your healthcare provider can use to visualize your brain tissue and evaluate if areas of your frontal or temporal lobe are damaged.

Treatments for FTD

Currently, there are no FDA-approved treatments to slow down or prevent FTD disorders. However, various approaches can be used to help manage symptoms and improve quality of life. These include:

• Medications: While there's no medication specifically approved to treat FTD, some drugs may help manage symptoms like depression, agitation, or sleep disturbances.
• Environmental modifications: Changing your direct environment can help lower stress and agitation. This could mean creating routines, reducing distractions, taking safety precautions, and getting help with daily tasks.
• Speech and language therapy: Some people with FTD experience difficulties with language and communication. Speech and language therapy can help maintain communication abilities for as long as possible and provide alternative communication methods if needed.
• Lifestyle management: Eating a nutritional diet, getting regular exercise, and limiting tobacco and alcohol use can all help with maintaining physical and mental functioning.

Clinical Trials

More research is needed to advance FTD treatment. Clinical trials involve testing new treatments, interventions, or therapies to determine their safety and effectiveness in managing a condition. Some trials aim to advance our understanding of FTD and develop treatment options for affected individuals.

Participants in clinical trials may receive experimental medications, therapies, or procedures under close medical supervision. These trials are crucial for finding potential breakthroughs to treat FTD and improve the quality of life for affected individuals and their families.

Related Conditions

Some other neurological conditions are related and often occur alongside FTD disorders. Mainly different types of FTD disorders are related to each other; having one FTD disorder makes it more likely for a person to develop another type of FTD disorder.

Additionally, sleep disorders are very prevalent in people with FTD. Sleep disturbances have been reported in up to 70% of patients with FTD. These sleep disorders are more likely to happen in people with primary progressive aphasia and behavioral variant frontotemporal dementia.

Sleep disorders like insomnia, excessive daytime sleepiness, and restless legs syndrome have been reported in over 45% of all cases of FTD disorders.

Living With FTD

Linking with FTD disorders takes a significant toll on individuals with the disease and their families. The prognosis of FTD disorders varies from person to person. The average survival time after diagnosis is approximately 7.5 years.

While FTD disorders are progressive and challenging diseases, there are many ways to improve outcomes for people with FTD disorders. Collaboration between healthcare providers, family members, social workers, physical therapists, and mental health professionals contributes to the overall well-being of people with FTD which can lead to major improvements in quality of life.

Some strategies people with FTD and their family members can use to manage FTD disease progression and symptoms include:

• Maintaining a regular schedule to avoid distractions when experiencing behavioral variant frontotemporal dementia symptoms
• Discussing the possibility of taking some medications to manage behavioral changes
• Using a notebook to manage progressive aphasia language symptoms
• Speaking slowly with clear sentences, and working with a speech pathologist to regularly exercise language comprehension and speaking
• Physical and occupational therapy to help manage movement disorder symptoms
• Exercises to keep muscles active and the use of assistive devices to aid in movement like walkers and wheelchairs

Finally, non-profit organizations like the Association for Frontotemporal Degeneration, The Alzheimer's Association, and CurePSP are available to provide care and disease management resources and support for people with FTD and their family members.