Prognosis for Parkinson plus syndromes is poor. This systematic review seeks to summarise and synthesise studies that investigated the association between potential prognostic factors and survival in patients with progressive supranuclear palsy (PSP) and multiple system atrophy (MSA).
MEDLINE, Embase, CINAHL and the Cochrane library were searched from inception for prognostic studies published in English, German or French. Reports involving a minimum of 10 patients identified by authors as having a likely or confirmed diagnosis PSP or MSA were eligible for inclusion. Methodological quality was graded using the Quality in Prognostic Studies tool. Results were pooled in random-effects meta-analyses or synthesised narratively.
We screened 1734 titles, of which 37 studies, presenting findings on 6257 patients (1911 PSP, 4346 MSA) fulfilled the inclusion criteria. Median survival ranged from 5.3 to 10.2 years. The following variables were identified as unfavourable predictors of survival: PSP-Richardson's phenotype, early dysphagia and early cognitive symptoms in PSP; severe dysautonomia, early development of combined motor and autonomic symptoms and stridor in MSA; and early falls in PSP and MSA. Sex and MSA phenotype did not predict survival whilst the prognostic effect of age at disease onset remains unclear. Statistical heterogeneity was generally low.
PROSPERO registration number: CRD42016032968.