An overview of FTD variants, symptomology and disease progression from neurologist Dr Ahmed
Dr Rebekah Ahmed, neurologist and director of the Memory and Cognition Clinic at Royal Prince Alfred Hospital in Sydney, Australia, shared with us her experience and advanced understanding of frontotemporal degeneration (FTD). Dr Ahmed has a special interest in FTD, having completed a PhD focussing on the metabolic abnormalities in FTD, and runs a referral clinic specifically for individuals with early-onset dementia.
FTD makes up for 15% of all cases, making it the second most common form of dementia.
FTD occurs when the nerve cells found in the frontal and temporal lobes of the brain are damaged, causing the lobes to shrink in size. According to Dr Ahmed, it is a type of dementia that usually affects people between the ages of 50–70 years, but it can affect people at a younger age. This means many individuals with FTD may still be working or have young children, which can have devastating effects on families.
We use the overall umbrella term of FTD, there are two types: there is a behavioural variant and primary progressive aphasia. Under the primary progressive aphasias there are two subtypes: progressive nonfluent aphasia and semantic dementia. Patients can also be classified as sporadic or genetic based on whether there is a family history and underlying genetic mutation.Dr Ahmed
Behavioural variant FTD (bvFTD) is the most common form of FTD, making up half of all cases of the disease. Individuals with bvFTD commonly present with changes in their behaviour and personality. These symptoms can often start very slowly and often get misdiagnosed as depression or a psychiatric illness. Over time the symptoms progress, and often individuals will develop:
• a lack of motivation and apathy
• inappropriate behaviour
• eating changes
• rigidness in their choices
Primary progressive aphasia (PPA) affects the ability to communicate. Two types make up PPA: semantic dementia (SD) and progressive non-fluent aphasia (PNFA). Individuals with SD present with degeneration in the knowledge and meaning of words and objects. As the disease progresses, SD individuals can become rigid in choices and therefore the symptomology can overlap with bvFTD. Individuals with PNFA develop non-fluent speech. Verbally this can sound like a stutter, and in written communication their grammar will often be incorrect.
Around 60–70 per cent of individuals with FTD have sporadic FTD, meaning none of their relatives are known to have FTD. However, around 30–40 per cent of people with FTD will have a family history of the disease.Dr Ahmed
“Although FTD and Alzheimer’s do have overlapping symptoms, there are some key differences that help us differentiate.”
According to Dr Ahmed, the main type of dementia FTD needs to be differentiated from is Alzheimer’s disease. The main differences between FTD and Alzheimer’s are:
- Usually individuals with Alzheimer’s are older, whereas it is not uncommon for FTD to occur in individuals in their 50s.
- People with Alzheimer’s tend to have short-term memory problems, visuospatial changes and can become lost going to places they normally know the way to; however, individuals with FTD experience a progressive decline in behaviour and changes in their personality.
- FTD is less common than Alzheimer’s and is still unheard of by much of the medical community. It is commonly misdiagnosed as Alzheimer’s, Parkinson’s disease or even as a psychiatric condition.
“Getting a diagnosis of FTD can be challenging and can take several years.”
According to Dr Ahmed, getting a diagnosis is often a combination of a clinical assessment and a neuropsychology assessment. Imaging using MRI scans to look for different patterns of brain shrinkage, and PET scans to see what areas of the brain are active with glucose and whether there is reduced activity in the front part of the brain, can help confirm a diagnosis.
“Life expectancy for individuals with FTD can vary. It is hard for families to live with the uncertainty.”
From symptom onset, the average life expectancy is around 10 –12 years, according to Dr Ahmed. With bvFTD, most individuals are late to be diagnosed as the behavioural changes may start subtly and are likely to be misdiagnosed; therefore, the life expectancy from diagnosis is around 3–5 years.
Treatments in the pipeline for FTD
“There are no treatment options for individuals with FTD. It is about managing the symptoms and supporting the families. There are, however, trials that are starting which are looking at FTD individuals with genetic mutations, but there is yet to be anything for individuals with sporadic FTD.”
For more information on current clinical trials visit the FTD Prevention Initiative website: https://www.thefpi.org
For more information about FTD research please read this article: Gene therapy research for frontotemporal dementia: understanding the science and clinical trial considerations.
“There needs to be far more support in place for individuals with FTD and their families.”
The fact there are no current treatment options available is a huge unmet need, according to Dr Ahmed. Dr Ahmed further explains that those who have early onset are likely to be raising young families and have work and financial responsibilities and are likely to need support when symptoms in FTD individuals progress, but there are currently no appropriate care facilities for them. “Placing individuals with FTD in their 40s or 50s in age care homes is not appropriate; there needs to be something put in place to meet their specific care needs.”
Some final words of advice from Dr Ahmed for anyone who believes they or a family member may have FTD…
Do not put it down to depression. If you think there has been a behaviour change, get yourself or your family member assessed by a neurologist. It will either put your mind at ease, or if you do receive a diagnosis of FTD, you can start putting support measures in place straight away.Dr Ahmed
Prevail Therapeutics, a wholly owned subsidiary of Eli Lilly and Company, is dedicated to developing gene therapy-based treatments with the potential to slow or stop the progression of neurodegenerative conditions such as frontotemporal dementia, Gaucher disease, and genetic forms of Parkinson’s disease. To learn more about Prevail, visit their website.