Co-existence of Parkinson's disease and progressive supranuclear palsy: case report and a review of the literature.

Idiopathic Parkinson's disease (PD) and progressive supranuclear palsy (PSP) are distinct clinicopathological entities characterized by α-synuclein and tau pathology, respectively. They have occasionally been reported to co-exist in the same patient. We describe a rare case of a 73-year-old Caucasian woman diagnosed as idiopathic PD 5 years before her death yet at autopsy had not only PD, but also PSP. Although this patient fulfilled clinical criteria for idiopathic PD and did not have supranuclear ophthalmoplegia, she had several atypical features, including early postural instability with falls, early dysphagia, and a relatively rapid course. In conclusion, this case and a literature review highlight the co-existence of synuclein and tau pathology in the same patient and demonstrate that multiple diagnoses may exist in patients presenting with parkinsonism. The clinical heterogeneity seen in parkinsonism may reflect the occurrence of combined pathology.