In this issue of the ARCHIVES, Josephs et al1 describe the features of a cohort of 16 patients with Parkinson disease (PD) who developed moderate to severe rest tremor, but otherwise suffered less disability than is typical during a decade of observation. Most patients had a family history of tremor, and pharmacologic responsiveness of tremor appeared to be disappointing. Based on their observations, the authors propose recognizing benign tremulous parkinsonism as a subtype of PD, a term that has been previously suggested.2 Is this a valid categorization, and is it useful for understanding the etiology of PD or managing its symptoms?