ALLFTD

ALLFTD is a North American natural history study of frontotemporal lobar degeneration (FTLD) that prepares for clinical trials in its sporadic and familial forms. It merges and continues two NIH-funded consortia: ARTFL (Advancing Research and Treatment for FTLD, 2014 to 2020), which focused on sporadic FTLD, and LEFFTDS (Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects, 2015 to 2020), which followed families with MAPT, GRN or C9orf72 mutations. ALLFTD started in March 2020 and is coordinated from Mayo Clinic Rochester and the UCSF Memory and Aging Center. Raw MR images have been shared since July 2023 through the "FTLD" project on the LONI Image and Data Archive, after the ALLFTD team approves a data request.

Composition

The consortium reports clinical data for more than 3000 participants across ALLFTD and its two predecessor studies. Participants have a clinical FTLD syndrome (behavioral variant FTD, semantic or nonfluent variant primary progressive aphasia, FTD with ALS, corticobasal syndrome or progressive supranuclear palsy) or belong to a family with a known FTLD gene mutation or a strong family history, which includes carriers who have no symptoms yet. A 2024 consortium report counted 1363 ALLFTD baseline visits since January 2020, and over 1000 participants across the three studies have more than one visit.

Acquisition

MRI was acquired in a subset of ARTFL and LEFFTDS participants and is part of every ALLFTD longitudinal visit. The neuroimaging core at Mayo Clinic runs a harmonized protocol with T1-weighted, T2-weighted, FLAIR, diffusion, arterial spin labeling and task-free functional MRI across the sites. A published ALLFTD diffusion study used 3T Siemens Prisma scanners at four sites with 1 mm T1-weighted MPRAGE and multi-shell diffusion imaging. The study runs at 26 to 28 sites in the United States and Canada. Shared images are refaced and carry minimal header information.

Annotations

Images come with clinical diagnoses, disease severity ratings (CDR plus NACC FTLD), neuropsychological scores and functional measures. Regional volumes based on the Desikan atlas are provided with approved clinical data requests. Plasma neurofilament light is available for part of the cohort.

Known limitations

The number of participants and sessions with MR images in the LONI release is not published. Imaging coverage of the predecessor studies is partial. The data repository is marked as under review, so access terms may change. Gene mutation status is handled separately from other data and must be deleted after analysis.