Supplementary data on virus-like particles in the brainstem of Parkinson’s disease patients and controls [version 1; peer review: 2 approved with reservations]

In this study, we present 84 transmission electron microscopy (TEM) images of human brainstem tissue from 11 cases of late onset Parkinson’s disease (PD). The tissues were fixed, embedded, sectioned, and stained for TEM application. In addition, we present 14 images from autopsy specimens of 1 case of human poliomyelitis infection as positive controls and 14 images from 8 cases of autopsy specimens of other conditions as negative controls. In the TEM images of the PD cases there were cytoplasmic inclusion bodies consisting of virus-like particles (VLP) 30 nm in diameter that were associated with endoplasmic reticulum membranes. In the nuclei of the PD neurons there were VLP ranging from 40 nm to 50 nm in diameter. In the poliomyelitis cases, similar particles as were observed in PD which were interpreted to be poliomyelitis virus particles. In the negative controls one case was identified which showed similar VLP (Figure 1, controls). A Lewy body was found in this “control” case (Figure 10) suggesting that this was an undiagnosed case of PD.