Prevalence of movement disorders in elderly community residents

We studied movement disorders (MD) in community residents of Saskatchewan aged > or = 65 years. A representative sample of 70 individuals had detailed neurological evaluation. Those who had definite and possible MD at first examination had a second neurological assessment by a senior neurologist. The most prevalent MD was essential tremor (ET) (14%) followed by Parkinson's disease (PD) (3%). The marked difference in prevalence ratios for PD and ET are attributed to: (a) higher incidence of ET in the general population; (b) a greater possibility that most, if not all, ET cases would reside in the community whereas a sizable proportion of elderly PD cases may be institutionalized, and (c) shortened survival in PD but a normal life expectancy in ET.