Frontotemporal Dementia, also called Frontal Lobar Degeneration, is actually a group of diseases that can be grouped into four general types. These are behavioral variant FTD; progressive nonfluent aphasia; semantic aphasia; and corticobasal degeneration and progressive supranuclear palsy.
Behavior variant Frontotemporal Dementia (bvFTD) strips away many of a person’s social skills and emotions. You might notice that your parent or partner or friend no longer has much of the empathy they used to have. Your person might stop understanding when it is appropriate and not appropriate to do things, such as yelling out in movie theaters or undressing in public. Their personality might appear to shift radically from time to time, and you might wonder if you ever knew this person at all. Many patients with the behavior variant FTD often are sent through rounds of therapy and psychiatric care, none of which proves effective. Only later when a neurologist becomes involved is there a recognition of the possible diagnosis of Frontotemporal Dementia. People with the behavior variant often have no self-awareness that they are behaving oddly.
Another type of Frontotemporal Dementia is Progressive Nonfluent Aphasia (PFNA), also sometimes called Primary Progressive Aphasia. With this type of FTD, the patient understands the meaning of words but loses the ability to speak and write them. As the disease is developing, this person may grow quieter and quieter as they become more and more unwilling to speak, often because they are afraid or ashamed of their inability to get words out. This transition will be much more noticeable in people that were formerly quite talkative. These patients also often go through therapy and psychiatric care because stress and depression and myriad other causes are blamed for the stuttering related to the aphasia and the aphasia itself.
The third grouping of Frontotemporal Dementia types is semantic aphasia. With semantic aphasia, your partner or parent will continue to speak, but they will lose the meaning of words. So, for example, they might point to a desk and say the word “apple” and be completely convinced that they are saying the correct word for the object. A person with semantic aphasia will talk in sentences and paragraphs that have no understandable diagrammatic structure.
And finally, the last grouping of Frontotemporal types has two key pieces: corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP). These patients are generally diagnosed with Frontotemporal Dementia more quickly because of their physical symptoms. Your person might show signs of Parkinson’s Disease, or apraxia (lack of motor coordination and planning). They may fall backwards quite a bit and develop “alien hand syndrome” where they cannot seem to control the movements of their arms. Corticobasal degeneration also causes aphasia as well as psychiatric and cognitive disorders, such as dementia, depression and irritability. For this reason, people with CBD are often misdiagnosed with Alzheimer’s Disease. They are often are put into therapy or psychiatric care without the understanding that degeneration in the brain is directly involved.
People with Frontotemporal Dementia (FTD) can have a combination of each of these four types — there are no clear boundaries between the types. Some of these types have been shown to be genetically-related. So far, much of what we have to go on are these clinical criteria. But these explanations help to explain that Frontotemporal Dementia is not Alzheimer’s Disease.
My mother, age 69, was diagnosed with Frontotemporal Dementia in January 2011. She has Progressive Nonfluent Aphasia. She also shows the cognitive (but not motor) symptoms related to Corticobasal Syndrome, such as apraxia, acalculia, visual-spatial impairment and significant language issues. My father and I are her caregivers. Our story is at