Rapid Cognitive Deterioration in Progressive Supranuclear Palsy: A 1-Year Follow-Up Study

Background: Nowadays, cognitive impairment has been characterized as one of the most vital clinical symptoms in progressive supranuclear palsy (PSP).

Objectives: Based on a relatively large cohort, we aimed to show the cognitive deterioration in different PSP subtypes during 1-year follow-up and investigate potential contributors for disease prognosis.

Methods: One hundred seventeen patients from Progressive Supranuclear Palsy Neuroimage Initiative (PSPNI) cohort underwent neuropsychological tests and 1-year follow-up, with 73 diagnosed as PSP-Richardson syndrome (PSP-RS) and 44 as PSP-non-RS. Patients were divided into normal cognition (PSP-NC), mild cognitive impairment (PSP-MCI), and PSP-dementia. Cognitive impairment and progression rates were compared between PSP-RS and PSP-non-RS, and determinants for MCI conversion to dementia were calculated by multiple cox regression.

Results: At baseline, 30.8% of PSP patients were diagnosed as dementia, 53.0% as MCI, and only 16.2% as NC. Compared to PSP-non-RS, PSP-RS suffered more from motor symptoms and cognitive impairment. During follow-up, PSP-RS also exhibited faster disease progression in Mini-Mental State Examination and visuospatial function, with cognitive deterioration in attention and executive function, but retained in language and memory subdomains. Twenty-seven of 62 PSP-MCI patients converted to dementia during follow-up, with the diagnosis of RS subtype as the most significant contributor to conversion (hazard ration = 2.993, 95% confidence interval = 1.451, 5.232, P = 0.009).

Conclusions: Patients with PSP-RS showed more severe cognitive impairment and faster decline longitudinally than patients with PSP-non-RS. Additionally, the diagnosis of RS subtype appears to be the most contributed factor for MCI conversion to dementia within just 1-year follow-up period.