Comparison of natural histories of progressive supranuclear palsy and multiple system atrophy.

In order to identify early clinical features and survival predictors of supranuclear palsy (PSP) and multiple system atrophy (MSA), we compared the disease course of patients consecutively referred between 1987 and 1999 and followed to December 1999. Thirty-nine PSP and 74 MSA patients were diagnosed according to commonly accepted clinical criteria. Length of survival was ascertained from death certificates or by contacting relatives. Ten-year survival after disease onset was 29% for both disorders. Median survival was 7.0 years (PSP) and 7.5 (MSA). Neither age, symptoms at onset, or disability at diagnosis predicted survival. At diagnosis, all PSP patients had oculomotor palsy, whereas 89% of MSA patients had dysautonomia; bradykinesia and falls were the most frequent common signs. Distinctive early signs were palilalia, cognitive impairment and hyperreflexia in PSP; hypophonia, anterocollis and dysautonomia in MSA. MSA patients responded better to levodopa. Attention to early distinctive features can improve differential diagnosis and inform subsequent management.