Diagnosis and grading of the Parkinson's disease phenotype

Abstract

We examined criteria for the diagnosis and grading of the Parkinson's disease phenotype (PDP) using postmortem tissue and clinical features.We used cases of the PDP, incidental Lewy body disease (ILBD), other neurodegenerative diseases and control subjects. We stained paraffin slides and free‐floating tissue sections from different academic centers for H&E. StereoInvestigator (MBF, Williston VT) was used for counting. Features counted included: neuromelanin (NM) containing neurons, NM+ cells, NM– neurons, NM+ macrophages (MPs), NM+ clusters of MPs, free NM, LBs, pale bodies and other intraneuronal inclusions. Principle component analysis followed by linear discriminant analysis will be used with other clinical features to compare the levels of these morphological factors.Data presented will include cases not used, counts from paraffin and free‐floating sections, repeat counting, inter‐rater reliability, and statistical analysis.Disagreements were identified. Criteria, counts, morphology, and time required for counting varied between the two methods. Both methods have advantages and disadvantages. The use of additional cases to refine this approach may demonstrate which method is superior and how they relate to each other.