Fig. 5: Aggregated alpha-synuclein proteins associated with increased brain atrophy.

a We analyze the influence of asyn SAA measured in HC, sPD, and LRRK2 PD participants. b Matched groups of 23 asyn SAA negative and 23 asyn SAA positive participants were selected based on age, sex, disease duration, and site. c Greater atrophy in asyn SAA positive participants. Differences between measured and predicted morphometry reveal more pronounced degeneration in asyn SAA positive compared to negative individuals. d Differences between measured and predicted morphometry for asyn SAA positive participants are shown across the brain. Orange indicates regions with less atrophy than expected; purple shows greater thinning or volume loss. Our findings reveal pronounced cortical thinning specifically linked to asyn SAA positive status, with distinct cortical regions showing increased vulnerability.