Sympathetic and parasympathetic subtypes of body-first Lewy body disease observed in postmortem tissue from prediagnostic individuals

Recent studies suggest the existence of brain-first and body-first subtypes within the Lewy body disorder (LBD) spectrum, including Parkinson's disease. These studies primarily focused on α-synuclein propagation through the parasympathetic vagal and olfactory bulb routes, leaving the possibility of a sympathetic nervous system spreading route unexplored. In the present study, we analyzed two postmortem datasets, which included 173 and 129 cases positive for Lewy pathology. We observed a clear distinction between brain-first and body-first subtypes in early prediagnostic cases with mild Lewy pathology. Brain-first cases displayed minimal peripheral organ pathology in prediagnostic phases, contrasting with marked autonomic involvement in prediagnostic body-first cases. Utilizing the SuStaIn machine learning algorithm, we identified two distinct body-first subtypes, one with vagal predominance and another with sympathetic predominance, in equal proportions. Our study supports the existence of three prediagnostic LBD subtypes and highlights the sympathetic nervous system alongside the parasympathetic system in LBD onset and progression.