Abstract Details

Title Distinctive Brain Atrophy Progression Patterns Aid Classification of Frontotemporal Dementia Variants

Topic Aging, Dementia, and Behavioral Neurology

Presentation(s) P4 - Poster Session 4 (5:00 PM-6:00 PM)

Poster/Presentation
Number 3-011

Objective To describe longitudinal structural MRI correlates of clinically overlapping frontotemporal dementia (FTD) variants, describing their patterns of cortical and subcortical atrophy and assessing their utility for differential diagnosis and prognosis.

Background The FTD spectrum encompasses a wide range of clinical phenotypes, with predominant behavioral and/or language presentations. Recently, a variant with predominant right temporal atrophy and clinical features straddling behavioral variant of FTD (bvFTD) and semantic variant of primary progressive aphasia (svPPA) has been described as semantic behavioural variant FTD (sbvFTD).

Design/Methods Our cohort included 71 patients with a clinical diagnosis of bvFTD (n=45), sbvFTD (n=11), or svPPA (n=15) and 37 healthy controls. Participants were followed-up for up to 24 months. Regional cortical thickness and subcortical volumes were assessed using linear mixed-effect models. Support vector machine (SVM) algorithms were employed to classify subjects based on baseline and longitudinal patterns of atrophy.

Results At baseline, patients with sbvFTD had an intermediate brain atrophy pattern between bvFTD and svPPA, with right-predominant temporal pole involvement associated with significant right frontal atrophy. Longitudinally, bvFTD patients progressed widely in bilateral cortical regions and basal ganglia, while svPPA continued steady progression within the temporal lobes, and sbvFTD showed progression in the left temporal and frontal lobes with limited further volume loss in the right hemisphere. Baseline cortical thickness values of frontal regions were predictors of subsequent functional decline in bvFTD and sbvFTD. A multiclass SVM model provided a good diagnostic classification accuracy, with similar results when using baseline data only (82%) and adding longitudinal data (83%).

Conclusions Our results singled out sbvFTD as a relatively distinct entity, with early involvement of extra-temporal cortical and subcortical regions. Our findings could help in the definition of machine learning aided diagnostic and prognostic protocols based on neuroimaging biomarkers in FTD variants.

Authors/Disclosures
Edoardo G. Spinelli, MD PRESENTER	Dr. Spinelli has nothing to disclose.
Francesca Orlandi	No disclosure on file
Silvia Basaia	Silvia Basaia has nothing to disclose.
Francesco Costa, MD	Dr. Costa has nothing to disclose.
Stefano Pisano, MD	Dr. Pisano has nothing to disclose.
Alma Ghirelli	No disclosure on file
Elisa Canu (Ospedale San Raffaele)	The institution of Elisa Canu has received research support from Italian Ministry of Health .
Veronica Castelnovo, MSc (San Raffaele Scientific Institute, Vita-Salute San Raffaele University)	Dr. Castelnovo has nothing to disclose.
Elisa Sibilla	Elisa Sibilla has nothing to disclose.
Ilaria Bottale, MD	Dr. Bottale has nothing to disclose.
Giordano Cecchetti (San Raffaele Hospital)	Giordano Cecchetti has nothing to disclose.
Francesca Caso, MD (Universita' Vita Salute San Raffaele)	Dr. Caso has nothing to disclose.
Giuseppe Magnani	Giuseppe Magnani has nothing to disclose.
Paola Caroppo	Paola Caroppo has nothing to disclose.
Sara Prioni (Fondazione IRCCS Istituto Neurologico Carlo Besta)	Sara Prioni has nothing to disclose.
Cristina Villa	No disclosure on file
Lucio Tremolizzo (UNIMIB)	Lucio Tremolizzo has nothing to disclose.
Ildebrando H. Appollonio, MD (Neurology Section, Dept. of Medicine and Surgery, University of Milano Bicocca)	Dr. Appollonio has nothing to disclose.
Federico Verde	Federico Verde has nothing to disclose.
Nicola Ticozzi, MD (Istituto Auxologico Italiano)	The institution of Dr. Ticozzi has received research support from Italian Ministry of Health . The institution of Dr. Ticozzi has received research support from AriSLA.
Vincenzo Silani, MD, FAAN (University of Milan Medical School - IRCCS Istituto Auxologico Italiano)	Dr. Silani has nothing to disclose.
Massimo Filippi, MD, FAAN (Ospedale San Raffaele, Neuroimaging Research Unit)	Dr. Filippi has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Alexion, Almirall, Biogen, Merck, Novartis, Roche, Sanofi. Dr. Filippi has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Alexion, Biogen, Bristol-Myers Squibb, Merck, Novartis, Roche, Sanofi, Sanofi-Aventis, Sanofi-Genzyme, Takeda. Dr. Filippi has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Bayer, Biogen, Celgene, Chiesi Italia SpA, Eli Lilly, Genzyme, Janssen, Merck-Serono, Neopharmed Gentili, Novartis, Novo Nordisk, Roche, Sanofi, Takeda, and TEVA. Dr. Filippi has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Springer Nature. The institution of Dr. Filippi has received research support from Biogen Idec, Merck-Serono, Novartis, Roche, the Italian Ministry of Health, the Italian Ministry of University and Research, and Fondazione Italiana Sclerosi Multipla.
Federica Agosta (San Raffaele Scientific Institute)	Federica Agosta has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Philips. Federica Agosta has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Elsevier INC.

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