Frontotemporal Lobe Dementia (FTD) dementia is progressive and relatively rare form of dementia that afflicts people who are typically younger than age 65 years. This disease affects the frontal and temporal lobes causing social disinhibition, loss of language, repetitive behaviors, apathy and distractibility. Lisa and Gary Radin, authors of "What If It's Not Alzheimers?" also describe less common visual-spatial-perceptual impairments such as difficulty comprehending seen objects.
Proteins that Cause FTD
According to Professor David Mann, professor of neuropathology at the University of Manchester, a gene on chromosome 17 is responsible for making the tau protein. In the cases where FTD is inherited, gene mutations change the structure of the protein making it unable to carry out its normal functioning. According to psychiatrist and author Daniel G. Amen, the tau protein blocks molecules from flowing from the cell body to the rest of the cell--eventually causing cell death. When the tau protein accumulates and clumps, it is called "tauopath." According to the Mayo Clinic, patients with FTD upon autopsy are shown to have abnormal protein-filled structures called Pick bodies; this type of dementia was once called Pick's disease. However, today Pick's disease is considered a specific pathological disease rather than a form of FTD.
The Genetics of FTD
According to the Mayo Clinic, more than half the people who develop FTD have no family history of dementia. Most cases occur by chance---or sporadically---rather than being inherited. According to The Association for Frontotemporal Dementias, in cases when a patient has no family history of the disease, there is no increased risk that family members will inherit it. However, about 5 to 10 percent of the patients with the disease have a family history of it and each child of an affected person has a 50 percent chance of inheriting it. In these cases, the age of onset is often younger---some patients develop the disease in their 20s or 30s.
Ruling Out Causes of FTD
According to Lisa and Gary Radin, authors of "What If It's Not Alzheimer's?" the disease does not appear to be associated with any geographical area or socioeconomic demographic and does not appear to be caused by brain injury. Unlike Alzheimer's and vascular forms of dementia, FTD is not associated with smoking, high blood pressure, high fat diets or a lack of physical exercise or mental stimulation.
References
- North West Dementia Center: Frontotemporal Dementia: Fact Sheet
- The Association for Frontotemporal Dementias:Frontotemporal Dementia
- "Preventing Alzheimer's"; William Rodman Shankle, M.S., M.D. &Daniel G. Amen, M.D.; 2004
- Mayo Clinic: Frontotemporal Dementia
- "What If It's Not Alzheimer's?"; Lisa Radin & Gary Radin, 2003.
