A new review article summarises the latest research on the early symptoms of frontotemporal dementia, biomarkers that can facilitate future diagnostics, and imaging methods that are currently under development.
Frontotemporal dementia is the second most common memory disorder affecting the working age population, and it accounts for approximately ten per cent of all progressive memory disorder cases. Frontotemporal dementia is largely hereditary. In the Finnish population, it is frequently caused by a repeat expansion mutation in the C9orf72 gene, which also causes ALS.
Diagnosing frontotemporal dementia is challenging, since the early symptoms do not include actual memory symptoms, but rather changes in behaviour and personality. This is also why frontotemporal dementia is often confused with psychiatric disorders.
Getting an early diagnosis is important in order to avoid potentially harmful drug therapy. Furthermore, an early diagnosis makes it possible to provide the patient and his or her family members with timely support to alleviate unnecessary insecurity and human suffering. Early diagnostics is also crucial for the development of future treatments impacting on disease progression.
Early symptoms of frontotemporal dementia are easily mistaken for symptoms of other diseases
Early symptoms of frontotemporal dementia include functional decline and changes in attention and social abilities. Behavioural symptoms and apathy are also common. The most detailed neuropsychological tests are able to detect these changes years before the actual onset of the disease.
However, the neuropsychiatric symptoms of early frontotemporal dementia can resemble the symptoms of psychotic disorders and mood disorders. This is why many patients often get a first, and erroneous, diagnosis of a psychotic disorder. Problems with the law have also been reported in connection with patients experiencing early symptoms, especially behavioural ones.
On the other hand, recent studies have shown that sometimes the early symptoms include deficits in episodic memory, which can resemble the symptoms of Alzheimer’s disease. This is why neuropsychological tests need to be supplemented by other diagnostic tools to ensure as early diagnosis as possible.
Imaging methods may improve future diagnostics
To date, magnetic resonance imaging, MRI, is used as the primary imaging method in diagnostics. When necessary, MRI can be supplemented by a PET scan, which provides further insight into the activity of brain metabolism. However, the imaging data can vary significantly from one patient to the next, and it is possible that a patient has frontotemporal dementia even when nothing out of the ordinary shows up in the images. In the future, functional MRI may provide additional tools for diagnosing early frontotemporal dementia. In addition, AI-assisted interpretation of brain images can enhance diagnostic accuracy.
New biomarkers can lead to early diagnosis
New laboratory samples of blood and cerebrospinal fluid may lead to an increasingly early diagnosis of frontotemporal dementia, provided that the newly discovered biomarkers prove reliable also in further studies. Used in the diagnostics of Alzheimer's disease, determining the levels of beta-amyloid and tau proteins in the cerebrospinal fluid may also be useful in the diagnostics of frontotemporal dementia; however, the accuracy is not high enough to make a differential diagnosis between the two. Neurofilament, a protein released by the brain as a result of nerve cell damage, is a promising new biomarker. It could help tell apart patients who have a psychiatric disorder from patients who are healthy or have frontotemporal dementia already at the early stages. In addition, various inflammatory markers can help in diagnosing the disease as well as in assessing the efficacy of future treatments.
Authored by a research group led by Anne Remes and Eino Solje at the University of Eastern Finland Institute of Clinical Medicine, the review article was published in Frontiers of Neuroscience. The clinical picture, early symptoms and development of diagnostic methods for frontotemporal dementia stand at the core of the group’s research.
The topic will also be discussed in the FinFTD Symposium to be held in Kuopio on 13 September 2019. Organised for the second time now, the symposium has become increasingly diverse and international.
Review article (open access):
Kasper Katisko, Antti Cajanus, Titta Korhonen, Anne M. Remes, Annakaisa Haapasalo, Eino Solje. Prodromal and early bvFTD: evaluating clinical features and current biomarkers. Front. Neurosci., 21 June 2019 | https://doi.org/10.3389/fnins.2019.00658. Submitted on 26.02.2019, Accepted on 07.06.2019
For further information, please contact:
Eino Solje, University of Eastern Finland, eino.solje(at)uef.fi
Anne Remes, University of Oulu, anne.remes(at)oulu.fi