Association for Frontotemporal Dementias

Behavioral Variant FTD (bvFTD)

Behavioral variant FTD (bvFTD) is the form of frontotemporal degeneration (FTD) characterized by early and progressive changes in personality, emotional blunting and/or loss of empathy. Patients experience difficulty in modulating behavior, and this often results in socially inappropriate responses or activities. Impairment of language may also occur after behavioral changes have become notable.

Patients typically start to have symptoms sometime in their 50s, though it can occur as early as at age 20 or as late as age 80. As with all FTD, the course of bvFTD will vary from one person to another. Not every symptom will be experienced by every person, nor will these symptoms develop in a pre-ordained sequence.

Key Clinical Features

The hallmark of behavioral variant FTD is a progressive deterioration in a person’s ability to control or adjust his or her behavior in different social contexts that results in the embarrassing, inappropriate social situations that can be one of the most disturbing facets of FTD. People manifest a loss of empathy early in the disorder that is often seen as indifference toward others, including loved ones. Apathy or lack of motivation may also be present. The patient typically does not recognize the changes in his or her own behaviors, nor do they exhibit awareness or concern for the effect these behaviors have on the people around them.

Behavioral symptoms

Emotional Symptoms

Neurological Symptoms

Key Pathological Features

Patients with behavioral variant FTD may have one of three abnormal protein collections in their brain cells, which can be seen at autopsy: TDP-43, tau, or fused in sarcoma (FUS) protein. See Overview of FTD [1] for details. The bulk of these protein buildups is usually found in the brain areas that have lost the most volume, the frontal and temporal lobes.

Genetics

The majority of bvFTD cases have not been linked to genetic mutations.

Treatment

As with all forms of FTD, there is currently no cure for bvFTD, and in most cases its progression cannot be slowed. Although no medications have been proven effective specifically in FTD, many clinicians look to the medications and treatment approaches targeting behavioral disturbances as necessary.

For instance, some FTD patients benefit from selective serotonin reuptake inhibitors (SSRIs, used in treating obsessive-compulsive behaviors, such as hoarding or craving sweets). Clinicians may also recommend antioxidants, such as coenzyme Q10, which are known to slow the progression of damage to brain cells in general, but there is little evidence to support this in frontotemporal degeneration.