Predictors of survival in a series of clinically diagnosed progressive supranuclear palsy patients

Abstract

BackgroundInvestigations into prognostic factors in progressive supranuclear palsy have shown conflicting results. We performed a retrospective study in order to identify clinical predictors of survival in clinically diagnosed progressive supranuclear palsy patients referred to our centre. MethodsData on medical history, survival and five clinical disability milestones (inability to walk unassisted, unintelligible speech, severe dysphagia, dementia and institutionalization) were collected from outpatients' medical records and by a telephone interview to caregivers. Patients were subdivided into Richardson's syndrome and PSP-Parkinsonism according to symptoms during the first 2 years of disease. Survival was analyzed by the Kaplan–Meier method and Cox regression analysis. ResultsForty-three consecutive patients were enrolled (86% Richardson's syndrome). Motor disturbances were the most frequent symptoms of onset. During the follow-up, 60.5% of patients died after a median survival of 7.1 years (2.2–18). Older age at onset (>63) (HR 2.8; 95% CI: 1.3–5.7; p = 0.007), early dysphagia (HR 2.3; 95% CI: 1–5.3; p = 0.05) and early cognitive deficits (HR 3.6; 95% CI: 1.6–8.2; p = 0.002) were predictors of shorter survival. Compared to PSP-Parkinsonism patients, Richardson's syndrome patients had shorter survival and higher mortality risk although not statistically significant (HR 3 95% CI: 0.9–9.9; p = 0.07). Seventy-seven percent of patients developed severe disability during follow-up: shorter time to the first clinical disability milestone predicted shorter survival (HR 7.8; 95% CI: 2.3–26; p = 0.0008). Conclusions: early dysphagia, cognitive impairment, older age at onset, and time to disability were predictors of shorter survival; Richardson's syndrome had a less favorable course than PSP-Parkinsonism. Clinical milestones should be considered as possible endpoints in future clinical trials.