Overview

Behavioral variant of frontotemporal dementia (bvFTD) is a neurodegenerative disorder characterized by prominent changes in personality and behavior. It is the more common type of frontotemporal dementia (FTD), which accounts for 70% of cases. The other type of FTD is called primary progressive aphasia, which affects language abilities. Initially, an individual with behavioral variant of frontotemporal dementia may be diagnosed with mild cognitive impairment when deficits have not significantly disrupted daily life. As the disease progresses, an individual with behavioral variant of frontotemporal dementia may increasingly require assistance with activities of daily living. There is currently no cure for behavioral variant of frontotemporal dementia. However, there are a number of pharmacological and non-pharmacological treatments to help improve quality of life. A behavioral management plan involving both the patient and caregivers is the most effective.

Symptoms

People with behavioral variant of frontotemporal dementia suffer from profound changes in their personality and behavior, which may include disinhibition, impulsiveness, compulsion, poor judgment, apathy, loss of empathy, and dietary changes. These changes often appear dramatically different from the individual’s former self, and the individual usually lacks insight into these symptoms. For example, an individual with behavioral variant of frontotemporal dementia may begin shoplifting, gambling, or making inappropriate comments. As the disease progresses, people with behavioral variant of frontotemporal dementia may experience cognitive dysfunction, especially with executive functions, which are higher-order cognitive abilities such as planning, organizing, and problem-solving (1).

Neuropathology

Behavioral variant of frontotemporal dementia is caused by frontotemporal lobar degeneration (FTLD), which is a group of pathologies associated with abnormal aggregations of proteins in the frontal and temporal regions of the brain. The two most common types of FTLD pathologies associated with behavioral variant of frontotemporal dementia involve accumulations of the proteins tau and TAR DNA-binding protein 43 (TDP-43). Neuroimaging techniques such as magnetic resonance imaging (MRI) and positron emission tomography (PET) may reveal atrophy (brain cell loss) and hypometabolism in the frontal and anterior temporal lobes (1).

Prevalence

Prevalence is estimated to be 3.3-3.5 per 100,000 individuals between the ages of 45 and 65 years. This may be an underestimate due to frequent misdiagnosis of behavioral variant of frontotemporal dementia as atypical Alzheimer’s disease or late-onset neuropsychiatric disturbance (1).

Course

Onset usually begins between the ages of 45-65, but it can range from 30s to 90s. An individual may be diagnosed with mild cognitive impairment (MCI) in the beginning stages of the illness when the deficits do not substantially interfere with daily life. MCI is a dynamic, transitional stage between normal cognitive status (compared to others of similar age and educational background) and dementia. People with MCI can either revert back to normal cognition (especially if the cause of the cognitive dysfunction is modifiable, such as sleep or mood disorders) or progress to dementia. The median disease duration of behavioral variant of frontotemporal dementia is 8 to 11 years (1).

Treatments

There is currently no cure for behavioral variant of frontotemporal dementia. Pharmacological treatments such as antidepressants and atypical antipsychotic medications can be used to address behavioral symptoms. Non-pharmacological treatments are also utilized to improve quality of life. Cognitive and behavioral training and stimulation can improve behavior, mood, and cognition. Safety is a serious concern due to impulsivity and impaired judgment. The individual with behavioral variant of frontotemporal dementia may need to stop driving or require supervision with daily activities. Interventions aimed at both the patient and caregivers are the most effective. Caregiver burden in behavioral variant of frontotemporal dementia appears to be greater than that in Alzheimer’s disease. Resources to reduce caregiver stress (e.g., psychoeducation and support groups) should be an integral part of the treatment plan (2).

By Michelle Chen

References

  1. LaMarre, A & Kramer, J (2013). Accurate assessment of behavioral variant of frontotemporal dsmentia. In L. D. Ravdin & H. L. Katzen (Eds.), Handbook on the Neuropsychology of Aging and Dementia (pp. 313-332). NY: Springer.
  2. Piguet, O, Hornberger, M, Mioshi, E, & Hodges, J (2011). Behavioural-variant frontotemporal dementia: diagnosis, clinical staging, and management. The Lancet Neurology10(2), 162-172.