Behavioral Variant FTD
Behavioral variant FTD (bvFTD), the most common form of FTD, is responsible for about half of all cases of this disease. BvFTD is also frequently referred to as frontotemporal dementia or Pick’s disease.
The hallmarks of bvFTD are personality changes, apathy, and a progressive decline in socially appropriate behavior, judgment, self-control, and empathy. Unlike in Alzheimer’s disease, memory is usually relatively spared in bvFTD. People with bvFTD typically do not recognize the changes in their own behavior, or exhibit awareness or concern for the effect their behavior has on the people around them.
Clinical symptoms of bvFTD can overlap with FTD disorders whose dominant symptoms are motor dysfunction, which include progressive supranuclear palsy (PSP), corticobasal syndrome (CBS) and Amyotrophic lateral sclerosis–FTD spectrum disorder (ALS-FTSD).
Know the Signs… Know the Symptoms
The following are possible symptoms of bvFTD:
A loss or lack of restraint based on social norms, leading to inappropriate behavior and impulsivity. Behaviors may include:
- Making uncharacteristic rude or offensive comments
- Ignoring other people’s personal space
- Shoplifting, reckless spending
- Touching strangers or inappropriate sexual behavior
- Aggressive outbursts
Indifference or lack of interest in previously meaningful activities. Behaviors may include:
- Loss of interest in work, hobbies, and personal relationships
- Neglect of personal hygiene
- Loss of initiative
Loss of warmth, empathy, or concern for others. Behaviors may include:
- Indifference to important events (e.g., death of a family member or friend);
- Failure to recognize that loved ones are upset or unhappy
Compulsive or Ritualistic Behaviors
Single behaviors or routines that are performed over and over. These may include:
- Repeating words or phrases
- Hand rubbing, clapping
- Re-reading the same book over and over again
- Walking to the same place at the same time every day
Changes in Eating Habits or Diet
Excessive, compulsive or inappropriate eating & drinking, or other pronounced changes in dietary preferences.
- Binge eating
- Carbohydrate craving
- Eating only specific foods
- Increased or first-time use of tobacco products
- Excessive water or alcohol consumption
- Attempting to consume inedible objects
Deficits in Executive Function
Poor decision-making, judgment, problem-solving, and organizational skills. Examples include:
- Difficulty planning the day’s activities
- Questionable financial decisions
- On-the-job mistakes
Agitation, emotional instability. These may be conveyed through:
- Frequent and abrupt mood changes
Lack of insight
As noted above, failure to recognize changes in behavior or exhibit awareness of effects of behavior on others. Behaviors may include:
- Blaming others for consequences of socially unacceptable behavior; e.g., job loss
- Anger at limitations on activities
Diagnosis is challenging in the early stages of bvFTD, and it is commonly misdiagnosed— for example as depression, other psychiatric disorders, Alzheimer’s disease, vascular dementia, Parkinson’s disease or even an alcohol or drug dependence. If you have concern that you or a loved one may have been misdiagnosed with another condition – or if you have concern about any of the signs and symptoms listed above – it is important to consult a doctor.
Treatment, Management, and What to Expect
The rate of progression of symptoms can vary, but eventually the behavioral and cognitive symptoms will become more pronounced. Significant impairment in daily activities of living may require additional support, such as residency in a full-time care facility outside the home.
As with all forms of FTD, there is currently no FDA-approved medicines for bvFTD, and in most cases its progression cannot be slowed. Behavioral and environmental interventions are currently considered to be the most effective way to manage symptoms. Challenging disruptive behaviors can cause more agitation, while reassuring and distracting tactics are considered to be more helpful.
Pharmacotherapy options are limited and the evidence for using medications developed for other conditions are based mainly on small open label studies or individual case reports. Some individuals with bvFTD may benefit from taking a selective serotonin reuptake inhibitor (SSRI) to address symptoms such as apathy, irritability and disinhibited behavior. Small, controlled clinical trials provide evidence for improvement with trazodone, an anti-depressant, showing improvement in eating behaviors and depression.
Atypical antipsychotics such as risperidone, olzanzapine, quetiapine have been used to treat agitation, but they can also bring increased risk from unwanted side effects and are not approved for use in FTD.
Is FTD inherited? In at least half of affected individuals, the answer is “no” – their FTD is said to be sporadic, meaning that none of their relatives are known to have FTD. However, approximately 40% of affected individuals with FTD do have a family history that includes at least one other relative diagnosed with a neurodegenerative disease. Their FTD is described as familial. In general, there is not a one-to-one correspondence between the familial type of a specific FTD disorder and a specific gene. However, 10-30% of bvFTD is genetic and is due to mutations in the MAPT, GRN, C9orf72 or rarer genes.
Possible or probable behavioral variant FTD is a clinical diagnosis made based on a group of signs and symptoms that are evaluated by a doctor. Brain imaging can be used to support the diagnosis, but at present there is no biomarker that can confirm a bvFTD diagnosis.
Only autopsy can provide a definitive diagnosis of the disease based on confirming the underlying pathology found in the brain. FTD is broadly classified into two major subtypes based on the accumulation of abnormal tau protein or accumulation of the transactive DNA binding protein 43 (TDP-43) in nerve cells in the frontotemporal lobes which leads to nerve cell death and atrophy of those brain regions. A smaller proportion of people will have accumulation of the FUS (fused in sarcoma) protein instead of tau or TDP-43.
The findings at autopsy may result in refinement post-mortem to the initial clinical diagnosis. In some cases, Alzheimer’s pathology may actually be found to be responsible for the signs and symptoms of bvFTD.