- The patient has a likely alternative diagnosis for Parkinsonism based on history, physical examination or laboratory testing. Atypical Parkinsonian variants (such as Shy-Drager, olivopontocerebellar atrophy, progressive supranuclear palsy and striatonigral degeneration) and secondary Parkinsonism (e.g., secondary to trauma or metabolic abnormalities; history of encephalitis, oculogyric crises or use of dopaminergic antagonists/depleting drugs) will be excluded.