Koscik, Timothy R.van der Plas, EllenLong, Jeffrey D.Cross, StephenGutmann, LaurieCumming, Sarah A.Monckton, Darren G.Shields, Richard K.Magnotta, VincentNopoulos, Peggy C.2024-10-112024-10-112023Koscik TR, van der Plas E, Long JD, et al. Longitudinal changes in white matter as measured with diffusion tensor imaging in adult-onset myotonic dystrophy type 1. Neuromuscul Disord. 2023;33(8):660-669. doi:10.1016/j.nmd.2023.05.010https://hdl.handle.net/1805/43897Myotonic dystrophy type 1 is characterized by neuromuscular degeneration. Our objective was to compare change in white matter microstructure (fractional anisotropy, radial and axial diffusivity), and functional/clinical measures. Participants underwent yearly neuroimaging and neurocognitive assessments over three-years. Assessments encompassed full-scale intelligence, memory, language, visuospatial skills, attention, processing speed, and executive function, as well as clinical symptoms of muscle/motor function, apathy, and hypersomnolence. Mixed effects models were used to examine differences. 69 healthy adults (66.2% women) and 41 DM1 patients (70.7% women) provided 156 and 90 observations, respectively. There was a group by elapsed time interaction for cerebral white matter, where DM1 patients exhibited declines in white matter (all p<0.05). Likewise, DM1 patients either declined (motor), improved more slowly (intelligence), or remained stable (executive function) for functional outcomes. White matter was associated with functional performance; intelligence was predicted by axial (r = 0.832; p<0.01) and radial diffusivity (r = 0.291, p<0.05), and executive function was associated with anisotropy (r = 0.416, p<0.001), and diffusivity (axial: r = 0.237, p = 0.05 and radial: r = 0.300, p<0.05). Indices of white matter health are sensitive to progression in DM1. These results are important for clinical trial design, which utilize short intervals to establish treatment efficacy.en-USPublisher PolicyCognitive functionDM1DTIDiffusion imagingDisease progressionWhite matterArticle