When people think of dementia, people often think of Alzheimer’s disease and the memory problems associated with it. However, there are many more types of dementia. A form that is less well known, and more commonly affects people under the age of 65, is Frontotemporal Dementia (FTD). In this case, the front of the brain is damaged, which initially leads to language or behavioral problems instead of memory problems.
For his PhD research, Roelant Ossewaarde has many conversations with patients in the Alzheimer Center of VUmc.
Roelant Osse value for NEMO Kennislink
Roelant Osse value for NEMO Kennislink
Roelant Ossewaarde conducts PhD research at the University of Groningen and the Hogeschool Utrecht into the use of software in the diagnosis of dementia. He trains the software to detect abnormalities in the language use of people with dementia. Ossewaarde experiences daily in his conversations with patients that these are difficult for a person to perceive. Sometimes he barely notices that they have language problems, but if they then have to write a piece, and he looks at it again afterwards, there is often a mismatch between the beginning and the end of a sentence. “But speakers all have compensatory mechanisms to disguise this.”
“When people have advanced dementia, you notice it immediately. You don’t need any specific knowledge for that. For example, they will use fewer words, or more words with less content. But we are looking for the features in language that appear first. To hear that subtlety, you need certain software. We are now developing this, because there is no speech analysis software for this specific group of people for Dutch yet.”
Late diagnose
People who get the prognosis of FTD are generally younger than people with Alzheimer’s: the disease usually develops when people are between the ages of 40 and 60. FTD affects the frontal parts of the brain: the frontal and temporal lobes. The frontal and temporal lobes play an important role in our behavior, but are also very important for language and speech. In FTD, the brain cells in these brain regions die.
Research is also being conducted into the way in which speech technology can be used in detecting Parkinson’s. We wrote about this before on NEMO Kennislink.
Roel Jonkers is professor of Neurolinguistics in Groningen and promoter of Ossewaarde. He explains that it can take a long time to diagnose FTD. “With someone who is 80 years old who becomes forgetful, you quickly think of dementia. It’s different with someone who is 50 and sometimes can’t think of a word. You are more likely to think of a burnout or stress. This form of dementia is not only characterized by memory problems, but also by behavioral and language problems.”
In order to arrive at an earlier diagnosis, he will work in the coming years with a multidisciplinary research team led by Professor Yolande Pijnenburg (Amsterdam UMC). They recently won a large NWO grant for this. “We do genetic research and use brain scans to find out what’s going on. And so we look at language.”
Nicest part
The linguistic research largely builds on Ossewaarde’s PhD research, who is currently collecting the latest data. To this end, he conducts low-threshold conversations with patients in the Alzheimer’s Center of the VU.
Ossewaarde: “People come to the neurologist’s consultation hours, and because it is an academic hospital, they are used to being asked: would you still like to participate in this study. And I’m literally in the next room. I will not say that people have little choice, but it is made very easy for them. They just have to sit in the next room. And I always like to say that: people often just like to participate. Even though these are people who have problems with speech and language, this is so easy for them, just to have a conversation, that they say, well this was actually the most fun part of the day.”
Featured by the editors
Climate Science
‘The living group gives me that family feeling’
Biology
Talk to NEMO Kennislink about fake embryos
Economy
Compensating for CO2 does not work as promised
Help from an algorithm
The people taking part in this study have all been diagnosed with Primary Progressive Aphasia, the variant of FTD that causes language problems. PPA roughly has three variants; Ossewaarde follows about twenty people for each variant. On average, he has a conversation of half an hour with these people three times; There is often half a year to a year between those conversations. In this way, he can also investigate how language and speech change during the disease.
The conversations are about different themes, the researcher explains, such as a memory of a Sinterklaas celebration or of the work people used to do. He then compares the audio recordings of those conversations with audio recordings of a healthy group of people, the so-called control group. He pays attention to all kinds of linguistic aspects: the use of voice, how fluent the language is, which words are used and how complex the sentences are. Where are the deviations?
“The question is, of course: when is the first moment that you can hear it and you do need the subtlety of the software for that. You only see the patterns when you listen to a very long recording. Only then do the statistical connections between all those linguistic aspects begin to be noticed. But that is very difficult to analyze, because transcribing half an hour of speech in detail is very time consuming. That is why we try to use speech analysis software for this, which we adapt especially for this, because it is actually not yet available for this group.”
Professor of Neurolinguistics Roel Jonkers: “We should not wait until there is a medicine against dementia and only then see how we are going to diagnose. We have to do that now.”
Roel Jonkers for NEMO Kennislink
Roel Jonkers for NEMO Kennislink
Combination of factors
The computer algorithm is specially trained to recognize all kinds of linguistic aspects that can have a predictive value, such as fluency (when and how many pauses are there in speech), word use (what kind of words are used: verbs, nouns), sentence complexity ( how long are the sentences, are there many subordinate clauses). It was striking that not one of these aspects appeared to be characteristic of people with FTD, but the combination.
“The algorithm can combine all those variables in all kinds of possible ways and then arrives at much stronger predictions. And because we ultimately know the diagnoses of these people, because they participate in a clinical process in a hospital, we can compare the results with what the neurologist says. And there we see that machine learning can predict quite well who should be in the control group and who should be in the patient group. My job as a scientist is now to investigate why the algorithm made that prediction.”
“Combining all these linguistic aspects is unique to this research,” says Jonkers. “The major research that we are now going to do will also include all kinds of aspects that have to do with behavior and vision. Because Frontotemporal Dementia not only affects language, it also affects other parts of cognition. In this way, our image of FTD becomes even sharper. It is great that we will soon be able to look at the same disorder in all kinds of ways and improve the diagnosis – because that is of course something that is very much needed.”
Customized therapy
The correct diagnosis is important in order to be able to offer patients a tailor-made therapy program. Jonkers: “With therapy you help people with dementia and their loved ones to deal with their problems. The problems are very personal: whether the brain damage is just a bit forward or backwards affects your language use. There is a flowing and a non-flowing variant. In the fluent variant, patients mainly have problems with language meaning, in the non-fluent variant they have more grammatical problems. The speech therapist can then offer tailor-made therapy.”
“Maybe there will come a time when there will be methods to treat dementia – that it will be limited or maybe even stopped. Even then you want to know as early as possible that it is there. So we don’t have to wait for that drug to come out and then see how we’re going to diagnose, we have to do that at the same time. That is why we are already working on it.”
Finally, it is also very important for the people themselves that they receive the correct diagnosis, Ossewaarde adds. “A lot of people I talk to say it took a long time for my neurologist to recognize that I have this instead of that. It makes their lot more bearable if they know what they have, if the label is right.” Or as someone writes on a platform for people with dementia: “The difficulty with me is that I am working on a sentence and suddenly the words disappear or that I no longer know what an object is. I recently had to get a stamp in a shop. ask, I didn’t think of it, and then you want to sink into the ground. These days I just say what’s wrong with me and that works well.”