The ‘body-first’ versus the ‘brain-first’ aetiology of PD

Several lines of evidence now support the idea that there are different aetiological subtypes of PD – the body-first and the brain-first types, as outlined on the slide.^1,2 In other words, the α‑synuclein pathology that characterizes PD can arise in the olfactory bulb of the brain, or in the enteric nervous system of the gut, and then spread throughout the nervous system; both processes may exist within the PD population.²

References:
1.Horsager J, Andersen KB, Knudsen K, et al. Brain-first versus body-first Parkinson’s disease: a multimodal imaging case-control study. Brain 2020; 143 (10): 3077–3088.

2.Borghammer P, Just MK, Horsager J, et al. A postmortem study suggests a revision of the dual-hit hypothesis of Parkinson’s disease. NPJ Parkinsons Dis 2022; 8 (1): 166.