Utility of the Movement Disorders Society Criteria for Progressive Supranuclear Palsy in Clinical Practice

Objectives: When the 2017 Movement Disorders Society Criteria for progressive supranuclear palsy is applied, patients may appear to have multiple phenotypes. The maximum allocation extinction rules were developed to provide a consistent method for applying the criteria and reaching a single diagnostic label. In this study, we apply both to a neuropathologic cohort of progressive supranuclear palsy and other parkinsonian conditions. Methods: An autopsy cohort of 54 patients with progressive supranuclear palsy and 56 patients with other neuropathologic diseases was selected. Clinical data were retrospectively abstracted, and the diagnostic criteria for progressive supranuclear palsy were applied. All possible phenotypes applicable were listed and maximum allocation extinction rules were applied to assess reduction in the number of phenotypes ascribed per patient. Results: In the progressive supranuclear palsy group, 52 patients met the criteria for multiple phenotypes, with an average of 7 phenotypes per patient. In the nonprogressive supranuclear palsy group, all 56 patients had features of more than one phenotype, up to 3 per patient. After application of maximum allocation extinction rules, the majority of the patients in both groups had a single predominant phenotype. Freezing of gait, supranuclear gaze palsy, and frontal behavioral syndrome were more common in the progressive supranuclear palsy group. Conclusions: The diagnostic criteria for progressive supranuclear palsy identify many clinical features, thereby leading to assignment of multiple phenotypes per patient. We demonstrate that the maximum allocation extinction rules can effectively lead to a single consensus phenotype, maintaining a uniform diagnostic label for clinical and research applications.