Marieke van Rosmalen

Chapter 7 112 ABSTRACT Objective: Chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN) respond to immunomodulatory treatment. Management of treatment may be challenging as treatment response varies between patients and predictive biomarkers for treatment response or disease course are lacking. Quantitative magnetic resonance imaging (MRI) techniques are potential biomarkers for disease course and treatment response. Therefore, we performed a longitudinal quantitative MRI study in patients with CIDP and MMN and evaluated their quantitative parameters over time. Methods: We enrolled patients with CIDP (n = 23) and MMN (n = 7). All patients underwent MRI of the brachial plexus twice with a one-year interval. We obtained diffusion parameters, T2 relaxation times and fat fraction. We compared MRI parameters between baseline and follow-up scans using a linear mixed model and studied correlations with clinical parameters (e.g. treatment status and treatment response). Results: In patients with CIDP, mean diffusivity, axial diffusivity and radial diffusivity decreased while fat fraction increased over time ( p = 0.012, 0.018, 0.015 and 0.045 respectively). In MMN we found no significant differences between timepoints. We found no significant correlations between clinical parameters and quantitative MRI parameters in both patient groups. Discussion: This study shows that quantitative MRI parameters change over time in patients with CIDP, but not with MMN. We found no significant correlations between the changes in quantitative MRI parameters and available clinical data. Quantitative MRI techniques evaluated in this study are unlikely to serve as a biomarker to predict prognosis or to monitor treatment response.