Erica Sloan
If you’ve heard of frontotemporal dementia (FTD), it may be because of Bruce Willis or Wendy Williams – two celebrities whose diagnoses in recent years have shed light on this infrequently discussed neurodegenerative disease. Though FTD is relatively rare, accounting for less than 10 per cent of the estimated 450,000 Australians living with dementia, it’s a common form of early-onset dementia.
In fact, most people who are diagnosed with it are ages 50 to 60, decades younger than the average person diagnosed with Alzheimer’s disease (which causes most cases of dementia). And yet, experts believe this is a significant undercount because it’s “rare enough that most medical providers, even specialists, don’t have experience with it, and so they don’t know what it looks like,” said Brad Dickerson, neurologist at the Mass General Brigham Neuroscience Institute and director of the Frontotemporal Disorders Unit at Massachusetts General Hospital.
The initial symptoms of FTD also diverge sharply from those of the more common Alzheimer’s disease because of the parts of the brain it attacks. FTD often starts “in the front of the brain, which is very important for behaviour, regulation of social interactions, addiction, drive, organising and planning,” said Bruce Miller, a professor of neurology and director of the Edward and Pearl Fein Memory and Aging Center at the University of California at San Francisco.
So, FTD generally manifests first with behaviour or mood changes – rather than the memory loss and thinking problems of Alzheimer’s (which typically first affects the areas of the brain responsible for these tasks, including the hippocampus). It’s the reason FTD is often misread as a psychiatric issue, Miller said. On average, it takes about three to four years for people to get a diagnosis of FTD, according to the Association for Frontotemporal Degeneration.
Below, experts explain why FTD tends to hit earlier in life than other dementias, the often-overlooked signs to know and what care for people with the condition looks like.
Why FTD starts earlier than other forms of dementia
Unlike Alzheimer’s, most people with FTD are diagnosed before age 65. The question of why is still being studied – but experts think the answer has to do with the underlying cause.
Roughly 20 per cent of cases are thought to be caused by any one of several genetic mutations. Two of them produce abnormal proteins with toxic effects on brain cells, and one of them leads to a deficiency in a protein that neurons need, Dickerson explained. These are readily passed down: You only need one bad copy of any of these genes to almost certainly develop FTD, he said, meaning that a child of a person with a mutation has a 50 per cent chance of inheriting it.
Genetic mutations can “drive the biology” of FTD, starting early in life, Miller said. “By the time someone reaches the age of 40 or 50, there may have been many years [during which] that genetic cause has wreaked havoc in their brain.”
Experts also think yet-to-be-discovered genes could play a role in some of the remaining 80 per cent of cases. After all, as many as 40 per cent of people with FTD have a family history.
One area of research is focused on genetic variants that, individually, are not disease-causing abnormalities, Dickerson said, but that could increase risk when they occur together. It’s thought that if you inherit particular sets of these genes, you could be made more vulnerable by other risk factors, perhaps environmental ones, than someone without a similar genetic pattern. (It’s not clear what these environmental factors might be yet, but Dickerson made the comparison to the known association between air pollution and an increased likelihood of developing Alzheimer’s and the fact that not everyone who lives in a polluted area will develop the disease.)
Ultimately, Miller said, the “number of FTD cases that have a genetic basis is likely quite high,” which pushes down the age of onset. As for the cases where a genetic link isn’t apparent, experts are still figuring out the contributors, though lifestyle is thought to be important. Research suggests that even those with a genetic mutation tied to FTD could delay symptoms if they are cognitively active and exercise regularly, Miller said. He added that head trauma is a risk factor that researchers are investigating, too.
Key early signs of FTD that are easy to miss
The symptoms of FTD depend on where exactly in the brain the condition starts. If it initially hits the temporal lobe, particularly on the left side, it’ll affect language skills, including the ability to speak and comprehend – causing a condition known as primary progressive aphasia. With this kind of FTD, people tend to get referred to a neurologist and diagnosed quickly, Dickerson said.
But as noted above, FTD most often begins in the frontal lobe and its earliest symptoms typically include behaviour or personality changes – called behavioural-variant FTD. The most common ones are easily mistaken as signs of psychiatric conditions such as depression or bipolar disorder, or dismissed as the effects of stress, burnout or even a midlife crisis. They include:
- Apathy. “People lose interest in doing things, they move less and they are less interested in the stories of loved ones,” Miller said.
- Addictive behaviours. They might turn to compulsive drinking, drugs, sex or several of the above, Miller pointed out.
- Loss of empathy. People with FTD tend to become alienated from their partners, children, friends and co-workers – and a big reason for that is losing the ability to feel what others are feeling, Miller said.
- Difficulty with planning, organising and managing money. FTD often hinders executive function, which refers to high-level cognitive skills including problem-solving, abstract thinking, regulating sensory input and decision-making. One way this could manifest: Dickerson said he’s seen many patients who have fallen victim to scams that might have seemed obviously problematic to someone without FTD.
- Disinhibition. FTD can cause people to lose their filter or start acting in ways that are socially inappropriate, Dickerson said. He gave the example of someone urinating in a public bathroom without closing the door behind them.
Loved ones and friends often notice these changes first. A person with FTD will generally lack insight into their symptoms and might not think anything is wrong, Dickerson said. They might relay a different story to a doctor, which can further complicate diagnosis.
The stigma surrounding both dementia and psychiatric conditions can also lead people with FTD and their family members to avoid seeking care. If they do, they often wind up getting referred to a psychiatrist, Dickerson said, rather than a neurologist.
By the time a diagnosis arrives, the disease has often progressed. “FTD moves about twice as fast as the typical Alzheimer’s disease,” Miller said, with an average life expectancy around seven to 13 years. “As the disease progresses, the apathy becomes more profound, and people completely immobilise,” he said. Some people develop motor problems, such as tremors; as many as 30 per cent of those with FTD wind up with symptoms consistent with amyotrophic lateral sclerosis (ALS), a motor neuron disease that causes weakness, muscle wasting and difficulty swallowing.
It’s the reason Miller said it’s important to “think about the brain, and the frontal lobes in particular, in any case of dramatic change in behaviour or personality”.
A helpful point to remember: Dementia is often understood as a loss, for instance, of memory or reasoning skills, and there can certainly be a loss of organisation with FTD. But many early symptoms of FTD also reflect “a gain of personality traits that were not there before,” Dickerson said. Ones that register as inappropriate or out of character should especially prompt a visit to a neurologist. “We can help families manage it if we get in early,” Miller said.
What treatment looks like for frontotemporal dementia
There is currently no cure for FTD. Care involves working with a team of experts – physicians, nurses, psychologists – to manage symptoms and behaviours, Miller said. “That often means thinking about, ‘Which ones of these [symptoms] need to be managed, and which can we ignore?’” Some may be harmful to the person with FTD and those around them, while others may be minor enough to learn to accept and work around.
Some people with FTD may benefit from the antidepressants known as selective serotonin reuptake inhibitors (SSRIs), Miller noted. “They can decrease irritability and compulsive behaviours and improve mood.” Those who have language deficits may also find speech therapy to be helpful, at least in early stages.
Both experts are hopeful, however, about the momentum they’re seeing in treatment research, which has been supported by growing awareness. Dickerson pointed to clinical trials that aim to restore levels of the deficient protein in one form of FTD. Miller noted studies attempting to lower tau – one of the abnormal proteins that can drive FTD – and gene-editing efforts to “turn off or turn down the bad genes” in other types of dementia. These approaches are “not quite ready yet for frontotemporal dementia,” but when they are, “it’s going to be really exciting.”
The Washington Post
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