Atrophy and hypometabolism patterns in Niemann-Pick type C: A cross-sectional and longitudinal study

Abstract Purpose We present a cross-sectional study comparing hypometabolism and atrophy patterns in Niemann–Pick disease type C (NP-C). We also present a longitudinal analysis of NP-C [18F]FDG-PET data. Methods 22 patients NP-C patients underwent MRI and [18F]FDG-PET imaging at baseline, and a subset of 12 patients were able to complete at least one follow-up PET imaging acquisition. Visual assessment and group-level voxel- and region-based analyses of the baseline MRI and PET images were performed by comparing our NP-C cohort to PET and MRI healthy volunteer cohorts. Per cent changes in metabolism (%/year/region) were calculated for longitudinal analysis. Results Significant atrophy was present in the cerebellum (p < 0.0001), thalamus (p < 0.001), and frontal and hippocampal regions (p < 0.01). The most common hypometabolism pattern included severe cerebellum, thalamus and cingulate hypometabolism (p < 0.0001), together with mild involvement of cortical areas. [18F]FDG PET provided stronger effect sizes and was able to show significant hypometabolism even in areas without atrophy. [18F]FDG uptake annual changes (p < 0.01) were found mainly in the cerebellum (-11%/year) and different frontal and temporal cortical regions (<-2%/year). Conclusions Our results add evidence to support the addition of [18F]FDG PET as a tool for the assessment of cross-sectional and longitudinal neurodegeneration in NP-C.