Evaluation of the Braak staging scheme for Parkinson's disease: introduction to a panel presentation.

Braak and colleagues have proposed a staging scheme for Parkinson's disease (PD) based on patterns of abnormal immunostaining for alpha-synuclein. They have proposed a temporal sequence in which the appearance of Lewy bodies and neurites in brainstem structures represent the earliest manifestations of the disease, and that this involvement of non-dopaminergic structures long antedates involvement of the substantia nigra and the appearance of the cardinal motor signs that are now required for diagnosis. This proposed scheme has had a wide and profound impact on many aspects of current thinking about PD, and it has already received wide acceptance. Given the importance and growing acceptance of the Braak staging scheme, the Scientific Program Committee for this Educational Symposium to honor the 50th Anniversary of the Parkinson's Disease Foundation agreed that it would be highly worthwhile to devote an entire session of the Scientific Program to consideration of the Braak staging scheme. There was a consensus among members of the Committee that, given the importance of the Braak scheme, it would be of value to create a venue that would stimulate and encourage a thorough and incisive critical analysis.