What Is Frontotemporal Degeneration? A Guide for Families

If your loved one is acting in ways that feel unfamiliar or concerning, you’re not alone. This guide is here to help you understand what might be happening and what steps you can take.

Frontotemporal Degeneration, or FTD, is a type of brain disease that affects how a person thinks, behaves, speaks, and moves. It is different from Alzheimer’s disease, which mostly affects memory. 

This guide will help you understand what causes FTD, the different types of FTD, common symptoms, who gets it, what causes it, and what to do if you think someone you love may have FTD.

What Causes FTD?

FTD happens when brain cells in certain parts of the brain that control thinking, speaking, and movement (in the frontal and temporal lobes) start to die. Scientists believe it is caused by a mix of genetic and non-genetic factors.

• It is estimated that 40% (or 4 in every 10) of people with FTD have a family history.  However because the symptoms of FTD can be variable and there is a high rate of misdiagnosis, family history may not include FTD specifically, but rather diagnoses of dementia, psychiatric disease, or motor disorders like ALS.
  
• 15-20% of people with FTD have a genetic change that can be identified as the cause of their disease.  While these changes are identified most often in people with a family history, about 5% of people with FTD who have no known family history of FTD or a related condition have a disease-causing genetic change. 

There are more than 10 genes that have been found to cause FTD.  The three most common are GRN, C9orf72, and MAPT.

To learn more about your risk, or your loved one’s risk, for a genetic form of FTD, talk with a genetic counselor.  You can find a genetic counselor through the National Society of Genetic Counselors or find out if you are eligible for free genetic counseling and testing through the Progranulin Information Navigator. 

Types of FTD

FTD is not just one disease—there are several different types of FTD that affect people in different ways:

1. Behavioral Variant FTD (bvFTD)

This type mostly affects behavior and personality. People may act in ways that seem rude, inappropriate, or unkind. They may lose interest in things they used to enjoy (apathy) or stop caring about others' feelings.  These behaviors are often reported by friends and family as being very atypical for the affected individual.  In some cases, these behaviors prompt a psychiatric evaluation and may lead to a misdiagnosis of a psychiatric disease before the correct diagnosis is identified.

2. Primary Progressive Aphasia (PPA)

This type affects language. There are three main forms:

• Nonfluent/Agrammatic PPA: Speech becomes slow and hard to understand due to difficulty coordinating the movement of the mouth and tongue.
• Semantic PPA: People forget the meaning of words or objects, like calling a dog a “thing” or being unable to describe what an object in a picture is used for (e.g. not able to say that a fork is used for eating). 
• Logopenic Variant PPA: People have a hard time finding specific words they are looking for but can still speak clearly and know the meaning of words. They may describe the word if they can’t find the word. For example, a patient with lvPPA may describe a dog as,  “you know, a small animal that barks, that you keep as a pet”

PPA goes beyond speech. People with PPA will, over time, lose the ability to speak, read, write and understand others. 

3. FTD-ALS

About 10–15% of people with FTD also develop ALS, or Amyotrophic Lateral Sclerosis—also known as Lou Gehrig’s disease.  People with FTD-ALS typically have a combination of motor symptoms such as difficulty walking, swallowing, and/or using one’s hands, in addition to behavioral FTD symptoms. 

4. Corticobasal syndrome (CBS) 

Like FTD-ALS, corticobasal syndrome (CSB) affects movement.  In this condition, strength is maintained but it becomes difficult for individuals to perform actions they mean to do like moving their leg to take a step forward or reaching out their hand and opening a door. Other symptoms like limb stiffness and muscle rigidity may develop as well.  Symptoms of CBS may be confused for atypical Parkinson's disease.

5. Progressive Supranuclear Palsy (PSP)

PSP ​​affects movement, balance, eye control, and thinking. Due to issues with balance, unsteady walking and muscle rigidity, people with PSP are at risk for falling.  One of the early signs is trouble moving the eyes up and down, which can make it hard to read, eat, or go down stairs.  Like CBS, individuals with PSP may be misdiagnosed with Parkinson’s disease.

Common Signs and Symptoms

The symptoms of FTD depend on the type but often include:

• Changes in personality or behavior
  
• Trouble speaking or understanding words
  
• Poor judgment or decision-making
  
• Loss of empathy (not caring how others feel)
  
• Repeating words or actions
  
• Trouble walking or moving
  
• Eating unusual foods or overeating
  

When Does It Start?

FTD often begins between the ages of 45 and 65, but it can happen earlier or later. It is the most common cause of dementia in people under 60.

What Should You Do If You Suspect FTD?

If you notice changes in behavior, language, or movement that seem unusual or worrying:

1. Write down what you observe – when it started, how it has changed, and how it affects daily life.
   
2. See a doctor – preferably a neurologist or FTD specialist.
   
3. Ask for a full evaluation – this may include memory tests, brain scans, and talking with a genetic counselor.

YOU’RE NOT ALONE

Organizations like The Association for Frontotemporal Degeneration (AFTD) or the FTD Disorders Registry offer help, education, and community resources. The Progranulin Information Navigator also provides access to free genetic counseling and testing for eligible participants, a directory of research studies and clinical trials, and connections to trusted organizations.

Final Thoughts

FTD is a serious disease, but you’re not alone. Learning more, finding the right doctors, and building a support system can help you and your family take the next steps. Early diagnosis can also open the door to support, planning, and even research opportunities that may help others in the future.