PT  - JOURNAL ARTICLE
AU  - SAMUEL D. KAPLAN
TI  - Age distribution of patients with Parkinson's disease in 1960 and I970 in 110 hospitals
AID  - 10.1212/WNL.24.10.972
DP  - 1974 Oct 01
TA  - Neurology
PG  - 972--972
VI  - 24
IP  - 10
4099  - http://n.neurology.org/content/24/10/972.short
4100  - http://n.neurology.org/content/24/10/972.full
SO  - Neurology1974 Oct 01; 24
AB  - The age distribution was compared for 1960 and 1970 for all patients with a diagnosis of parkinsonism discharged from 110 hospitals. The mean age of these patients was 67.34 in 1960 and 71.55 in 1970. The expected mean age in 1970 if aging of the population were the only factor affecting the age distribution was 67.97, while the mean age expected in 1970 for a cohort with the observed age distribution of the 1960 patients was 72.50. The results are compatible with at least 79 percent of parkinsonian cases resulting from a cohort exposed to encephalitis lethargica, but because of the considerable difference in the number of parkinsonian patients in those hospitals in both years (1,165 patients in 1960 and 2,948 in 1970), this interpretation can be made only with extreme caution.